阅读说明：本技术 用于行李物件的双轴向取向型热塑性聚合物叠层膜及其制造方法 (Biaxially oriented thermoplastic polymer laminate film for luggage articles and method for producing the same ) 是由 保利娜·M·科斯洛夫斯基 里克·希尔阿尔特 于 2018-03-15 设计创作，主要内容包括：本发明提供了一种由聚丙烯膜(100)形成的叠层(110)、一种由叠层(110)构造的行李箱壳体(120)、一种制造叠层(110)的方法以及一种制造行李箱壳体(120)的方法。所述膜(100)包括芯(102)和至少一个外层(104)。所述叠层(110)包括多个膜(110)。可以通过在预定压力、温度和时间条件下对多个膜(100)进行层压而形成所述叠层(110)。可以通过对叠层(110)片材进行深拉、同时向叠层(110)施加热和张力而形成所述壳体(120)。(The invention provides a laminate (110) formed from a polypropylene film (100), a luggage shell (120) constructed from the laminate (110), a method of manufacturing the laminate (110), and a method of manufacturing the luggage shell (120). The film (100) includes a core (102) and at least one outer layer (104). The stack (110) comprises a plurality of films (110). The stack (110) may be formed by laminating a plurality of films (100) under predetermined pressure, temperature and time conditions. The housing (120) may be formed by deep drawing a laminate (110) sheet while applying heat and tension to the laminate (110).)

1. A luggage shell (120) comprising:

A casing formed from a stack (110) of a plurality of coextruded films (100), the films (100) comprising:

A core (102) formed from a biaxially oriented thermoplastic polymer, and

At least one outer layer (104) formed from a thermoplastic polymer, the outer layer (104) having a thickness of 0.5% to 25% of the thickness of the film (100).

2. The luggage shell of claim 1, wherein the thickness of the film (100) is 10 μ ι η ± 5% to 100 μ ι η ± 5%.

3. The luggage shell of claim 1 or 2, wherein the thickness of the core (102) is 10 μ ι η ± 5% to 100 μ ι η ± 5%.

4. The luggage shell according to any of claims 1-3, wherein the outer layer (104) has a thickness of 0.6 μm ± 5% to 2.5 μm ± 5%, or 2% to 7% of the thickness of the film (100).

5. The luggage shell of any of claims 1-4, wherein from at least two adjacent films (100) to all films (100) of the plurality of films (100) are oriented in the same direction.

6. The luggage shell of any of claims 1-5, wherein the biaxially oriented thermoplastic polymer is biaxially oriented polypropylene.

7. The luggage shell of any of claims 1-6, wherein the outer layer (104) comprises a copolymer of polypropylene and polyethylene, or a terpolymer of polypropylene, polyethylene, and polybutylene.

8. The luggage shell of any of claims 1-7, wherein the core (102) has a higher melting point than the outer layer (104).

9. The luggage shell of claim 8, wherein the melting point of the core (102) is at least 10 ℃ higher than the melting point of the outer layer (104).

10. The luggage shell of any of claims 1-9, wherein the film (100) is stretched and stretched to a greater extent in one of the transverse and longitudinal directions than in the other of the transverse and longitudinal directions.

11. The luggage shell of claim 10, wherein the film (100) has a tensile strength of 60 to 190MPa in the longitudinal direction or 150 to 300MPa in the transverse direction.

12. The luggage shell of claim 10 or 11, wherein the film (100) has a stiffness of 3.5 to 5GPa in the transverse direction, or 1.5 to 3GPa in the longitudinal direction.

13. The luggage shell of any of claims 1-12, wherein the laminate comprises 10 to 50 films, or 22 or 23 films.

14. The luggage shell of any of claims 1-13, wherein the laminate has a thickness of 0.25mm to 2.5mm, or 0.5mm to less than 1 mm.

15. The luggage shell of any of claims 1-14, wherein the laminate (110) comprises at least one secondary material (118) constructed from a thermoplastic polymer different from the thermoplastic polymer of the core (102).

16. The luggage shell of claim 15, wherein the secondary material (118) is a film (100).

17. The luggage shell of claim 15 or 16, wherein the secondary material (118) is located within the laminate (110) or adjacent to and external to the laminate (110).

18. The luggage shell of any of claims 1-17, further comprising a fabric backing or top layer on the top side (114) of the laminate (110).

19. The luggage shell of claim 18, comprising a fabric backing layer, wherein the fabric backing layer comprises a mesh textile sheet, or a top layer, wherein the top layer comprises biaxially oriented polyester.

20. The luggage shell of any of claims 1-19, wherein the laminate (110) is formed by heating the film (100) under pressure and compacting the film (100) together.

21. A method of manufacturing a luggage shell (120), comprising:

Providing a membrane (100) comprising:

A core (102) formed from a biaxially oriented thermoplastic polymer, and

An outer layer (104) on at least one of the top side (103) and the bottom side (105) of the core (102), the outer layer (104) being constructed from a thermoplastic polymer that is different from the thermoplastic polymer of the core (102);

Laminating a plurality of films (100) together at a temperature of about 130 ℃ or less and a pressure of less than about 10 bar or less than about 40kN/m to form a stack (110); and

The laminate (110) is molded to form a luggage shell (120).

22. An apparatus (240) for manufacturing a luggage shell (120), comprising:

A press (244), the press comprising:

a male die (254) for forming a male die,

A female die (258), said female die (258) being shaped complementary to said male die (254), an

A clamping frame (264), the clamping frame (264) being for clamping a stack (110) introduced into the device (240); and

A heater array (246), the heater array (246) for heating the mold (254, 258), or for heating the stack (110), or for heating the mold (254, 258) and stack (110).

Technical Field

The present disclosure relates generally to luggage articles, and more particularly to the use of laminated biaxially oriented thermoplastic polymer films in the construction of luggage case shell structures.

Background

Hardsided luggage provides durability and support by forming the exterior of the luggage using a relatively hard material that can be molded. One disadvantage of these materials is that they are difficult to manufacture and mold, exhibiting low tolerance for slight variations in the manufacturing and molding process. This non-forgiveness of the material is particularly evident when producing deep-drawn articles. Luggage shells or cases made from these materials may need to be relatively thick and/or heavy to achieve the required strength. These materials and manufacturing and molding processes can also be expensive, and these processes can be time consuming.

The following documents are relevant to the present disclosure for reasons including various methods for materials for luggage articles: EP1763430, GB1386953, US4061817, IN256542 and IN 257341. However, these proposals may be improved.

Accordingly, it is desirable to provide an improved material, particularly a lightweight durable material, for an item of luggage, such as a luggage shell, and methods of manufacturing the material and the item of luggage that are convenient, fast, tolerant, and low cost.

Disclosure of Invention

Thus, according to the present invention, there is provided a material for making a luggage shell, a luggage shell constructed from the material, a method of making the luggage shell, and a luggage case comprising at least one shell constructed from the material, as described below and/or as defined in the appended claims.

In particular, the present disclosure provides an improved lightweight and impact resistant plastic laminate material. The material is versatile and can be modified to be deep drawn into items such as luggage shell. The luggage shell constructed from the laminate is lightweight, thin, durable, resistant to deformation, and has excellent impact resistance during handling.

A method of manufacturing a plastic laminate is provided that requires relatively little heat and pressure, and is fast and inexpensive. A method of manufacturing a deep-drawn article such as a luggage shell is provided. The method is convenient, rapid and low in cost.

In one example, the luggage shell is formed from a laminate of a plurality of coextruded films. The film includes a core formed from a biaxially oriented thermoplastic polymer and at least one outer layer formed from a thermoplastic polymer. The outer layer has a thickness of 0.5% to 25% of the thickness of the film.

In some examples, the film has a thickness of about 10 μm ± 5% to about 100 μm ± 5%.

In some examples, the core has a thickness of about 10 μm ± 5% to about 100 μm ± 5%.

In some examples, the outer layer has a thickness of about 0.6 μm ± 5% to about 2.5 μm ± 5%.

In one example, the outer layer is about 2% to about 7% of the thickness of the film. The outer layer may be less than about 5% of the thickness of the film, or may be about 2.5% of the thickness of the film.

In another example, at least two adjacent films are oriented in the same direction.

In yet another example, all of the films are oriented in the same direction.

In one example, the biaxially oriented thermoplastic polymer of the core is biaxially oriented polypropylene.

In one example, the outer layer includes a copolymer of polypropylene and polyethylene.

In another example, the outer layer includes a terpolymer of polypropylene, polyethylene, and polybutylene.

In some examples, the core has a melting point higher than the melting point of the outer layer. The melting point may be at least about 10 ℃ higher than the melting point of the outer layer.

In some examples, the film is stretched to a greater degree in one of the transverse and longitudinal directions than in the other of the transverse and longitudinal directions.

In some examples, the film has a tensile strength in the machine direction of about 60 to about 190 MPa.

In some examples, the film has a tensile strength in the transverse direction of about 150 to about 300 MPa.

in some examples, the film has a stiffness in the transverse direction of about 3.5 to 5 GPa.

In some examples, the film has a stiffness in the machine direction of about 1.5 to 3 GPa.

In some examples, the stack includes 10 to 50 films. The number of membranes may be 22 or 23 membranes.

In one example, the thickness of the stack is about 0.25mm to about 2.5 mm. The thickness of the stack may be from about 0.5mm to less than or equal to about 1 mm.

In some examples, the laminate may include at least one film constructed from a thermoplastic polymer that is different from the thermoplastic polymer of the core.

In some examples, the stack includes a top layer. The top layer may comprise a biaxially oriented polyester.

In some examples, the luggage shell includes a fabric lining layer. The fabric backing layer may comprise a mesh textile sheet.

In one example, a method of manufacturing a luggage shell includes: a film is provided, a plurality of films are laminated together to form a laminate, and the laminate is molded to form a luggage shell. The film has a core formed of a thermoplastic polymer and an outer layer on each of a top side and a bottom side of the core. The film is laminated at a temperature of 130 ℃ or less and a pressure of 10 bar or less, or in some instances at a pressure of less than 10 bar.

In one example, the core and the outer layer are coextruded to form the film.

In some examples, the film has a thickness of 10 μm ± 5% to 100 μm ± 5%.

In some examples, the core has a thickness of 10 μm ± 5% to 100 μm ± 5%.

In some examples, the outer layer has a thickness of 0.6 μm ± 5% to 2.5 μm ± 5%.

In some examples, the outer layer has a thickness of 0.5% to 25% of the thickness of the film. The thickness of the outer layer may be 2% to 7% of the thickness of the film.

In another example, at least two adjacent films are oriented in the same direction.

In another example, all of the films are oriented in the same direction.

In one example, the biaxially oriented thermoplastic polymer of the core is biaxially oriented polypropylene.

In one example, the outer layer includes a copolymer of polypropylene and polyethylene.

In another example, the outer layer includes a terpolymer of polypropylene, polyethylene, and polybutylene.

In some examples, the core has a melting point higher than the melting point of the outer layer. The melting point may be at least 10 ℃ higher than the melting point of the outer layer.

In some examples, the film is stretched to a greater degree in one of the transverse and longitudinal directions than in the other of the transverse and longitudinal directions.

In some examples, the film has a tensile strength in the machine direction of 60 to 190 MPa.

In some examples, the film has a tensile strength in the transverse direction of 150 to 300 MPa.

In some examples, the film has a stiffness in the transverse direction of 3.5 to 5 GPa.

in some examples, the film has a stiffness in the machine direction of 1.5 to 3 GPa.

In some examples, the stack includes 10 to 50 films. The number of membranes may be 22 or 23 membranes.

In one example, the thickness of the laminate is 0.25mm to 2.5 mm. The thickness of the stack may be 0.5mm to less than 1 mm.

In some examples, the laminate may include at least one film constructed from a thermoplastic polymer that is different from the thermoplastic polymer forming the core.

In another example, the film is laminated at a temperature of 110 ℃ to 130 ℃.

In yet another example, the film is laminated at a pressure of 5kN/m to 35 kN/m.

In some examples, the film is laminated at a pressure of 10 to 30 kN/m.

In some examples, the film is laminated in one continuous process.

In one example, laminating the film is performed in an isochoric press. In another example, laminating the membrane is performed in an isostatic press.

In another example, the stack is cooled at atmospheric pressure.

In some examples, molding the luggage shell is performed at a temperature of 140 ℃ to 180 ℃.

In one example, a method of manufacturing a luggage shell includes: the method includes providing a film, laminating a plurality of films together to form a laminate, and molding the laminate to form a luggage shell. The film has a core formed of biaxially oriented polypropylene and an outer layer on each of the top and bottom sides of the core. The film is laminated at a temperature of 130 ℃ or less and a pressure of less than 10 bar.

In some examples, the lamination temperature is 110 ℃ to 130 ℃.

in some examples, the pressure is 1 bar to 9 bar. The pressure may be 1 bar to 5 bar. In other examples, the pressure is less than 10 bar, or equal to or less than 10 bar.

In one example, lamination is a continuous process.

In one example, the lamination is performed in an isochoric press. In another example, laminating the membrane is performed in an isostatic press.

in another example, at least two adjacent films are oriented in the same direction.

In yet another example, all of the films are oriented in the same direction.

In some examples, the molding is performed at a temperature of about 140 ℃ to about 165 ℃.

In one example, there is provided a luggage shell, the method of manufacturing comprising: the method includes providing a film, laminating a plurality of films together to form a laminate, and molding the laminate to form a luggage shell. The film has a core formed of a thermoplastic polymer and an outer layer on each of a top side and a bottom side of the core, and the film is laminated together. When the film is a polypropylene film, the film is laminated at a temperature of about 130 ℃ or less and a pressure of less than about 40kN/m, or in an alternative example, the film is laminated at a pressure of less than about 10 bar. In another example, the pressure is about 40kN/m or less. In yet another example, the pressure is about 10 bar or less.

In one example, a luggage case is provided that includes at least one luggage case shell as described above. The manufacturing method of the luggage shell comprises the following steps: the method includes providing a film, laminating a plurality of films together to form a laminate, and molding the laminate to form a luggage shell. The film has a core formed of a thermoplastic polymer and may include an outer layer on each or only one of the top and bottom sides of the core, and the film is laminated together. When the film is a polypropylene film, the film is laminated at a temperature of about 130 ℃ or less and a pressure of less than about 40kN/m, or in an alternative example, at a pressure of less than about 10 bar. In another example, the pressure is about 40kN/m or less. In yet another example, the pressure is about 10 bar or less. In yet another example, a luggage case includes a cover shell and a base shell, either or both of which are manufactured by the foregoing method.

The following description will set forth, in part, additional embodiments and features that will become apparent to those skilled in the art upon examination of the description or which may be learned by practicing the disclosed subject matter. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which form a part hereof. One skilled in the art will appreciate that each of the various aspects and features of the disclosure may be used to advantage in some instances alone or in combination with other aspects and features of the disclosure in other instances.

Drawings

The description will be more fully understood with reference to the following drawings. The drawings, in which various elements are not drawn to scale, are provided as embodiments of the disclosure and are not to be understood as a complete description of the scope of the disclosure, wherein:

FIG. 1 is a partial illustration of a biaxially oriented thermoplastic polymer film according to one example.

Fig. 2A is a diagram showing a stack of biaxially oriented thermoplastic polymer films, according to an example.

Fig. 2B is a diagram of the various film layers in the stack of fig. 2A.

Fig. 3A is a diagram illustrating a system for making a laminate of the biaxially oriented thermoplastic polymer film of fig. 2A and 2B, according to an example.

Fig. 3B is a graphical representation of the temperature and pressure changes of the membrane during the process of fig. 3A.

Fig. 4A is a diagram illustrating a system for making a laminate of the biaxially oriented thermoplastic polymer film of fig. 2A and 2B, according to another example.

Fig. 4B is a diagram illustrating a system for making a laminate of the biaxially oriented thermoplastic polymer film of fig. 2A and 2B, according to another example.

fig. 5 is a block diagram of steps of a method of making a laminate of the biaxially oriented thermoplastic polymer film of fig. 2A and 2B, according to an example.

Fig. 6A is a right front isometric view of a luggage shell formed by the process of fig. 3A or 3C.

Fig. 6B is a left rear isometric view of the luggage shell of fig. 6A.

Fig. 7A is a front isometric view of a luggage case including the luggage case housing of fig. 5A.

Figure 7B is a rear isometric view of the luggage case of figure 7A.

Fig. 8 is a molding apparatus according to an example.

FIG. 9 is a block diagram of steps in a method of fabricating an article from the laminate of FIGS. 2A and 2B, according to one example.

Detailed Description

The present disclosure provides an improved material for a luggage shell and an improved luggage shell constructed from the material. In particular, the present disclosure provides a material that is lightweight, impact resistant, versatile and can be modified for deep drawing. Generally, such materials are constructed from a plurality of plastic films laminated together. A luggage shell constructed from such materials is lightweight, thin, durable, and resistant to deformation. The nature of this material that can be altered to perform the deep drawing process helps produce a luggage shell that is substantially free of wrinkles, including substantially free of wrinkles in corner regions, and can help produce a high quality surface finish, either alone or in combination. The term "constructed" as used herein may mean "including" or "containing".

The present disclosure may also provide a method of manufacturing an improved material that requires relatively less heat and pressure. The method may also be relatively fast and/or low cost. In particular, multiple plastic films are laminated under moderate heat and low pressure conditions.

A method of making a luggage shell from improved materials is also provided that is convenient, quick and inexpensive. The material may be heated, strained and deep drawn to produce the luggage shell.

Polymer film

Referring to fig. 1, a polymer film 100 includes a core 102 and at least one outer layer 104. As used herein, a "film" is a structure comprising a nonwoven, planar, continuous sheet member. The outer layer 104 may be located on the top side 103, the bottom side 105, or both the top side 103 and the bottom side 105 of the core 102. The core 102 is constructed from a thermoplastic polymer. The thermoplastic polymer may be biaxially oriented. As used herein, a "biaxially oriented" film is a film that has been stretched in two different directions, including as a non-limiting example, a film that has been over-stretched in the transverse and machine directions, as described in more detail below. Examples of the biaxially oriented thermoplastic polymer include biaxially oriented polypropylene homopolymer (BOPP), polyamide (BOPA), polyester (BOPET), polyvinyl alcohol (BOPVA), polylactic acid (BOPLA), and polyethylene (BOPE). In one embodiment, the core 102 is constructed from BOPP.

The outer layer 104 is constructed of a heat sealable material that is oriented or unoriented. In one example, the outer layer 104 is constructed from a copolymer of polypropylene (PP) and Polyethylene (PE). The polyethylene may comprise up to about 5% of the copolymer. In another example, the outer layer 104 is constructed from a terpolymer of polypropylene, polyethylene, and Polybutylene (PB). Together, polyethylene and polybutylene can constitute up to about 5% of a terpolymer.

The core 102 and the outer layer 104 may be constructed of compatible polymers such that the core 102 and the outer layer 104 may be co-extruded. In some examples, the core 102 and the outer layer 104 are constructed from polymers in the same polymer family. In one example, the core 102 is constructed of oriented polypropylene homopolymer (OPP) and the outer layer 104 is constructed of a copolymer of polypropylene and polyethylene. In another example, the core 102 is constructed from an oriented polypropylene homopolymer and the outer layer 104 is constructed from a terpolymer of polypropylene, polyethylene, and polybutylene.

the thickness of the core 102 may be about 10 μm + -5% to about 100 μm + -5%, such as about 30 μm + -5% to about 50 μm + -5%, or, about 13 μm + -5% to about 40 μm + -5%, or, about 40 μm + -5%. The melting point of the core 102 may be about 150 ℃ to about 190 ℃. In one example, the core 102 has a melting point of about 170 ℃.

The thickness of the outer layer 104 may be about 0.6 μm 5% to about 2.5 μm 5%. In one example, outer layer 104 has a thickness of about 1 μm 5%. The outer layer 104 may have a melting point of about 110 ℃ to about 135 ℃. In one example, the melting point is about 130 ℃.

The outer layer 104 has a lower melting point than the core 102. The difference between the melting point of core 102 and the melting point of outer layer 104 may be about 10 ℃ to about 60 ℃, alternatively, about 10 ℃ to about 50 ℃, alternatively, about 10 ℃ to about 40 ℃, alternatively, about 10 ℃ to about 30 ℃, alternatively, about 10 ℃ to about 20 ℃. The large difference in melting point between the core 102 and the outer layer 104 (e.g., 60 ℃ rather than 5 ℃) may facilitate the fabrication of a laminate 110 having improved mechanical and/or physical properties when constructing and designing the film 100, as described below. Without being bound to any mechanism or mode of action, the difference in melting points is sufficiently large to allow the temperature at which lamination occurs to melt the outer layer 104 but not the core 102. When the processing temperature approaches the melting point of the core 102, the core 102 may begin to soften, and the molecules of the core 102 may lose their orientation, which in turn may deteriorate the physical and mechanical properties of the resulting laminate 110 as compared to a laminate 110 in which the core 102 has not melted or softened.

The difference in melting point between the core 102 and the outer layer 104 is at least about 10 c when the film 100 is constructed and designed, which makes the process of laminating multiple films 100 together easier. When the processing temperature is high enough to melt or partially melt the outer layer 104 but not the core 102, the layers of the film 100 may slip relative to each other, or adjacent films 100 may slip relative to each other when forming the laminate 110. While the mechanical properties of the laminate 110 are best maintained by not melting the core 102 during the manufacture of the laminate sheet, in an alternative example, if the core 102 softens or partially melts during the manufacture of the laminate 110, the mechanical properties may be degraded, but still sufficient for further use. The melting point differential may also make the process of molding the laminate 110 easier because the laminate 110 becomes malleable by the outer layer 104 melting or partially melting and the core 102 melting, partially melting, or softening.

In one example, the outer layer 104 defines an outer surface 106 and an inner surface 108 adjacent to the membrane 100 and joined to the membrane 100. The outer surface 106 may be corona treated, which may help provide sufficient wettability and adhesion to the film 100 for subsequent printing, lamination, or coating of the film 100. In one example, outer layer 104 may be corona treated on outer surface 106.

The core 102 and at least one outer layer 104 may be co-extruded to form the film 100. In contrast to woven fabrics, in which threads or tapes are woven in two directions (warp and weft) to form a plastic fabric, the coextruded film 100 is produced by simultaneous extrusion of multiple layers. The film 100 may have a thickness of about 10 μm 5% to about 100 μm 5%. In one example, the film 100 has a thickness of about 30 μm 5% to about 50 μm 5%. In another example, the film 100 has a thickness of about 40 μm 5%. The film 100 may have about 13g/m²5% to about 37g/m²Plus or minus 5% by weight squared. The film 100 may be transparent, translucent, or opaque.

The thickness of the outer layer 104 may be about 0.5 to 25% of the thickness of the film 100. In some examples, the outer layer is about 2% to 7% of the thickness of the film 100. In one example, the outer layer 104 is about 2.5% of the thickness of the film 100. In another example, the outer layer 104 is about 5% of the thickness of the film 100 or less than about 5% of the thickness of the film 100.

The film 100 may be stretched in one or both of the transverse and longitudinal directions. In one example, the cross direction T is defined as the width of the core 102 or outer layer 104 web of material, which in one example may be in the direction of the rollers 226a, 226b, or 226c in fig. 3A. The longitudinal direction L is defined as the length of the core 102 or outer layer 104 web of material extending in a direction perpendicular to the transverse direction, which in one example may be in the machine direction as shown in fig. 3A. Alternatively, the transverse direction T and the longitudinal direction L may be reversed from that described above and shown in fig. 3A. The film 100 may be stretched after coextrusion. The amount of stretching in one direction may be the same or different than the amount of stretching in the other direction. In some examples, the film 100 is stretched in the cross direction about 4 to 15 times (i.e., about 400% to 1500%), about 5 to 14 times, about 6 to 13 times, or about 7 to 12 times. In one example, the film 100 is stretched about 9 times in the transverse direction. In some examples, the film 100 is stretched in the machine direction about 3 to 10 times, about 4 to 8 times, or about 4 to 6 times. In one example, the film 100 is stretched about 5 times in the machine direction. Variable stretching can produce anisotropic film 100. As a general illustration, the transverse and longitudinal orientations referred to throughout may be interchangeable. Also, in general, the film 100 is stretched to a greater degree in one of the transverse and longitudinal directions than in the other of the transverse and longitudinal directions.

The anisotropic film 100 has tensile strength in each of the transverse and longitudinal directions. The tensile strength in one direction may be different from the tensile strength in the other direction. In some examples, the tensile strength of film 100 in the transverse direction is greater than the tensile strength in the longitudinal direction. In some examples, the tensile strength of film 100 in the machine direction is greater than the tensile strength in the cross direction. The film 100 may have a tensile strength of about 150 to 300MPa in the transverse direction. In one example, the tensile strength of film 100 in the transverse direction is about 250 MPa. In another example, the tensile strength of film 100 in the transverse direction is about 207 MPa. The film 100 may have a tensile strength in the machine direction of about 60 to 190 MPa. In one example, the tensile strength of film 100 in the machine direction is about 130 MPa. In another example, the tensile strength of film 100 in the machine direction is about 91 MPa.

The film 100 has a stiffness in each of the transverse and longitudinal directions. The stiffness may be a measure of bending stiffness, where the bending axis is generally orthogonal to the direction of stretching. The stiffness in one direction may be different from the stiffness in the other direction. In some examples, the film 100 has a stiffness in the transverse direction that is greater than the stiffness in the longitudinal direction. In some examples, the film 100 has a stiffness in the machine direction that is greater than the stiffness in the cross direction. The film 100 may have greater stiffness in the direction in which it is stretched more. For example, a film that is stretched more in the transverse direction than in the machine direction has a stiffness that is greater in the transverse direction than in the machine direction. Similarly, a film stretched more in the machine direction than in the cross direction has a stiffness greater in the machine direction than in the cross direction.

in one direction, the film 100 may have a stiffness of about 3.5 to 5.5GPa or about 4 to 4.8 GPa. In another direction, the film 100 may have a stiffness of about 1.5 to 3GPa or about 1.9 to 2.3 GPa. In one example, the film 100 is stretched more in the transverse direction, has a stiffness of about 3.5 to 5.5GPa in the transverse direction, and has a stiffness of about 1.5 to 3GPa in the longitudinal direction.

In some illustrative examples, film 100 is constructed from a co-extruded oriented polypropylene core 102 and an outer layer 104, the outer layer 104 being constructed from a terpolymer of polypropylene, polyethylene, and polybutylene, one on each side of the core 102. In some illustrative examples, film 100 is constructed from a co-extruded oriented polypropylene core 102 and an outer layer 104, the outer layer 104 being constructed from a copolymer of polypropylene and polyethylene, one on each side of the core 102. For convenience, but not by way of limitation, film 100 may be referred to herein as [ PP-BOPP-PP ]]. The core 102 may have a thickness of about 38 μm 5%, and each of the outer layers 104 may have a thickness of about 1 μm 5%. Film 100 may have a thickness of about 36.4g/m²Plus or minus 5% by weight squared. The film 100 may have a melting point of about 169.2 ± 0.4 ℃. The tensile strength of the film 100 in the transverse direction may be about 207.2 ± 5.4 MPa. The tensile strength of the film 100 in the machine direction may be about 91.2 ± 18.7 MPa. Film 100 may be Tatrafan(Splovack, Switt, Terichem, Inc.). TatrafanDesigned for packaging food, candy, meat products, textiles and other goods.

In another example, film 100 may be formed by coextrusionThe oriented polypropylene core 102 is constructed with an outer layer 104, the outer layer 104 being constructed from a copolymer of polypropylene and polyethylene, or from a terpolymer of polypropylene, polyethylene and polybutylene. For convenience, but not by way of limitation, film 100 may be referred to herein as [ PP-BOPP ]]Or [ BOPP-PP ]]. The film 100 may have a thickness of about 20 μm 5%, and may have a thickness of about 22.8g/m²Plus or minus 5% by weight squared. Film 100 may be Tatrafan(Splovack, Switt, Terichem, Inc.). TatrafanDesigned for packaging food, candy, meat products, textiles and other goods.

Referring to fig. 2A, a plurality of films 100 form a stack 110. The number of films 100 in the stack 110 may be about 3 to about 50 films 100, about 5 to about 50 films 100, about 10 to about 50 films 100, about 15 to about 50 films 100, about 20 to about 50 films 100, about 25 to about 50 films 100, about 30 to about 50 films 100, about 35 to about 50 films 100, about 3 to about 40 films 100, about 3 to about 35 films 100, about 3 to about 30 films 100, about 3 to about 25 films 100, about 3 to about 20 films 100, or about 3 to about 15 films 100. In one example, the stack 110 includes about 10 to about 50 films. In another example, the stack 110 includes about 22 to about 35 films 100. In another example, the stack 110 includes about 3 to about 23 films 100. In yet another example, the stack 110 includes about 24 to about 28 films 100. In another non-limiting example, the stack 110 may be formed of 22 to 26 Tatrafan kxe film layers, one on each outer side, for a total of 24 to 28 films 100. In yet another example, the stack 110 includes 22 or 23 films 100.

The stack 110 may include a central portion 112, a first side or portion 114, and a second side or portion 116. The stack 110 may include the same number of films 100 in each of the central portion 112, the first side 114, and the second side 116, or the number may be different. The number of membranes 100 in the first side 114 and the second side 116 may be the same or different. In one example, the first side 114 and the second side 116 have the same number of membranes 100 and the number is less than the number of membranes 100 of the central portion 112. In one example, each of the first side 114 and the second side 116 has one membrane 100 and the central portion has 10 to 50 membranes 100.

The films 100 of the stack 110 may be of the same type or of different types. In one example, the stack 110 includes a center portion 112 having one type of film 100, a first side 114 having a second type of film 100, and a second side 116 having a third type of film 100. In another example, the stack 110 includes a center portion 112 having one type of film 100, and a first side 114 and a second side 116 each having a second type of film 100.

In one example, the central portion 112 is constructed from a plurality of [ PP-BOPP-PP ] films 100. When multiple [ PP-BOPP-PP ] films 100 are laminated together, two PP layers (which may be PP/PE copolymers or PP/PE/PB terpolymers as described above) are disposed adjacent to each other.

In one example, each of the first side 114 and the second side 116 may be constructed from at least one [ PP-BOPP ] or [ BOPP-PP ] film 100. When the [ PP-BOPP ] or [ BOPP-PP ] film 100 is laminated with the [ PP-BOPP-PP ] film 100, two PP layers (which may be PP/PE copolymers or PP/PE/PB terpolymers as described above) may be disposed adjacent to each other.

In one example, one or both of the first side 114 and the second side 116 of the laminate 110 may be constructed from at least one BOPET-BOPP, BOPP-BOPET, or BOPET-BOPP-BOPET film 100. In one example, the BOPET portion of the film 100 may be disposed on the outermost surface of the first side 114 or the second side 116. Positioning the BOPET on the outermost surface of the first side 114 or the second side 116 may help to achieve improved scratch resistance of the laminate 110 or the article formed from the laminate 110.

In one example, and referring to FIG. 2B, the stack 110 has a structure consisting of [ BOPP-PP ]]-[PP-BOPP-PP]_n-[PP-BOPP]The arrangement of the membranes 100 is shown, where n is the number of membranes 100. [ PP-BOPP-PP]Film 100 may be Tatrafan[PP-BOPP]And [ BOPP-PP]Film 100 may be Tatrafan

As described above, the film 100 may be stretched in one or both of the transverse and longitudinal directions. In a stack, the film 100 may be oriented in the same direction as the directly adjacent film 100. For example, two films 100 stretched more in the cross direction than in the machine direction may be directly adjacent to each other. In other words, two directly adjacent films 100 may be rotated by 0 ° with respect to each other in terms of the degree of stretching. Alternatively, two directly adjacent membranes 100 may be rotated 90 ° with respect to each other. For example, one film 100 stretched more in the cross direction than in the machine direction may be directly adjacent to a film 100 stretched more in the machine direction than in the cross direction. At least two films 100 in the stack 110 may be oriented in the same direction. In one example, all of the films 100 in at least the central portion 112 of the stack 110 are oriented in the same direction. In another example, all of the films 100 in the stack 110 are oriented in the same direction.

The thickness of the stack 110 may be about 0.25 to about 2.5mm, about 0.3 to about 2.5mm, about 0.5 to about 2.5mm, about 0.75 to about 2.5mm, about 1.0 to about 2.5mm, about 1.25 to about 2.5mm, about 1.5 to about 2.5mm, about 0.25 to about 2.25mm, about 0.25 to about 2.0mm, about 0.25 to about 1.75mm, about 0.25 to about 1.5mm, about 0.25 to about 1.25mm, or about 0.25 to about 1.00 mm. In one example, the stack 110 has a thickness of about 0.5 to about 2 mm. In another example, the stack 110 has a thickness of about 0.9 to about 1.5 mm. In yet another example, the laminate 110 has a thickness of about 0.5mm to less than about 1.0 mm.

The first side 114 may have the same thickness as the second side 116, or may have a different thickness. The thickness of the central portion 112 may be greater than the thickness of the first side 114 or the second side 116 or each of the first side 114 and the second side 116. The thickness of the central portion 112 may be greater than the combined thickness of the first side 114 and the second side 116.

The anisotropy of the film 100 may be imparted to the stack 110 comprising the film 100. For example, the tensile strength of the laminate 110 in one direction is different than the tensile strength in the other direction. In some examples, the tensile strength of the laminate 110 in the transverse direction is greater than the tensile strength in the longitudinal direction. In some examples, the tensile strength of the laminate 110 in the longitudinal direction is greater than the tensile strength in the transverse direction. The tensile strength of the stack 110 in the transverse direction may be about 100 to 250MPa, or about 150 to 200 MPa. The tensile strength of the stack 110 in the machine direction may be about 50 to 150MPa, or about 70 to 100 MPa.

In one example, stack 110 is clear, colorless, transparent, translucent, or opaque. In another example, the core 102 with at least one film 100 is constructed of a colored film 100, such as a PP, BOPP, or other type of film 100, that introduces color into the laminate 110.

In addition to the film 100 of the central portion 112, the first side 114 and the second side 116, the stack 110 may also include one or more auxiliary materials 118. In constructing and designing the laminate 110, the secondary material 118 may introduce a color, print, pattern, or design into the laminate 110. In some examples, the auxiliary material 118 is constructed from a solid film, such as a cast polypropylene film, which may be constructed from the same polymer as the outer layer 104. In some examples, the secondary material 118 includes the core 102 and at least one outer layer 104. As described above, the outer layer 104 may have a lower melting temperature than the core 102. The secondary or outer layer 104, when present, may have a melting temperature of about 130 ℃ or less.

The auxiliary material 118 may be introduced into the plurality of membranes 100 of the central portion 112, the first side 114, or the second side 116. Alternatively, the secondary material 118 may be introduced between the central portion 112 and the first side 114, or between the central portion 112 and the second side 116. As another alternative, the auxiliary material 118 may be introduced outside the outer surface of the first side 114 or the second side 116 as the outermost layer (top film) of the stack 110. The auxiliary material 118 may be co-extruded with the film 100 of the stack 110. Examples of auxiliary materials 118 include thermoplastic olefin films, printed films, colored polypropylene and/or polyethylene films, white or colored BOPP films, metalized BOPP films, short or chopped polypropylene fibers, short or chopped bi-component (BICO) fibers, knitted fabrics, woven fabrics, non-woven fabrics, polypropylene and/or polyethylene powders, and combinations thereof.

The stack 110 may be formed by laminating a plurality of films 100 under predetermined pressure, temperature, and/or time conditions. The stack 110 can be formed in a laminator. The laminator may be an isochoric press or an isobaric press. The laminator may include at least one roller, which may be a fixed roller or an endless roller. In an isochoric press, a constant volume is maintained, for example, by maintaining a constant gap distance between pressure applicators, such as opposing rollers spaced apart by a fixed distance in one example. In isochoric presses, such as those using circulating roll pressure modules, a combination of constant volume and constant uniform pressure is maintained or attempted to be maintained. The rollers in the isochoric press may be fixed in position relative to the laminator, or may be movable relative to the laminator, for example in an endless roller pressure module. The pressure exerted by an isochoric press with fixed rollers is commonly referred to as "line pressure", measured in kN/m. For example, pressure is applied by at least one roller, and in at least another example, line pressure is applied to the forming material as it passes through the gap between the opposing stationary rollers. In an isochoric press using a circulating roller pressure module, pressure is applied between opposing rollers as the rollers circulate in the pressure module. Because the rollers typically used in a fixed roller press are larger (about 100mm in one example) than the rollers used in an endless roller pressure module (about 25 to 40mm in one example), there is less pressure drop between adjacent rollers. The pressure applied in the endless roller pressure module may be considered or estimated as the pressure applied over the entire area of the material being formed due to the smaller pressure drop between adjacent rollers. As a result, the pressure exerted by the circulating roller pressure module is typically measured as "bar".

In isostatic presses, a constant uniform pressure is maintained, such as by allowing the gap distance between the pressure applicators to be defined by the feed material. The pressure applied by the isostatic press is generally the surface pressure, in kN/m²Or a bar measurement, or a measurement of bar,For example by applying pressure through at least one oil pad. In other examples, the pressure applicators are opposing oil pads separated by a gap. As used herein, "bar" generally, but not exclusively, refers to the surface pressure generated by an isostatic press or an isochoric press including circulating rollers. "kN/m" is used herein to refer generally, but not exclusively, to the line pressure generated by an isochoric press having fixed rollers. An example of a lamination press apparatus that can be used for this type of forming process (whether isochoric or isobaric, or a combination of both processes implemented) can be manufactured by Sandvik, such as Sandvik ThermoPress CB (CombiPress) (see http:// processes systems.

In some examples, the laminator is an isostatic press. In other examples, referring to fig. 3A, the laminator may be a dual belt isostatic press 220 with fixed rollers. The press 220 includes an upper belt 222, a lower belt 224, a plurality of upper rollers 226, and a plurality of lower rollers 228. Some or all of the rollers 226, 228 are operatively connected to a spring 234, which helps to regulate the pressure that the rollers 226, 228 exert on the material passing between the rollers 226, 228. The press 220 may also include at least one integrated heating zone 230 and at least one integrated cooling zone 232.

The straps 222, 224 may be constructed of Teflon or steel. The belts 222, 224 may be conveyor belts. The upper belt 222 is operatively connected to at least two upper rollers 226, such as four upper rollers 226a, 226b, 226c, and 226 d. The lower belt 224 operably connects at least two lower rollers 228, such as five lower rollers 228a, 228b, 228c, 228d, and 228 e. The upper rollers 226a, 226b, 226c, 226d and the corresponding lower rollers 228a, 228b, 228c, 228d may be positioned opposite each other on either side of the film 100 being laminated, respectively.

The distance or gap height h between the upper roller 226 and the corresponding lower roller 228_gMay be adjustable. The gap height between each pair of rollers 226a, 228a, 226b, 228b, 226c, 228c, 226d, 228d may be the same or different. Adjusting the gap height may help adjust or maintain the pressure applied by the rollers 226, 228, may help maintain a uniform volume of material between the rollers 226, 228, and may help control the thickness of the stack 110. In one example, the gap height is about 0.7mm to about1.2 mm. In another example, the gap height is about 0.95mm to about 1.0 mm.

The belts 222, 224 and rollers 226, 228 may help advance the plurality of films 100 through the press 220. The plurality of membranes 100 may be moved through the press at a constant or variable rate. Adjusting the rate may allow for pressure or temperature to be applied to the membrane 100 for different amounts of time. The rate can be from about 1m/min to about 8m/min, from about 2m/min to about 8m/min, from about 3m/min to about 8m/min, from about 4m/min to about 8m/min, from about 5m/min to about 8m/min, from about 1m/min to about 7m/min, from about 1m/min to about 6m/min, from about 1m/min to about 5m/min, from about 1m/min to about 4m/min, from about 1m/min to about 3m/min, or from about 2m/min to about 6 m/min. In one example, the rate is about 2 m/min. In another example, the velocity is about 6 m/min.

In one example, the press 220 is a Flatbed Laminator System (Meyer, Roetz, Germany).

Fig. 4A shows another example of a laminator that is a double belt isochoric press 220 with fixed rollers. The press 220 includes an upper belt 222, a lower belt 224, a plurality of upper rollers 226, and a plurality of lower rollers 228. The press 220 may also include at least one integrated heating zone 230 and at least one integrated cooling zone 232.

The belts 222, 224 may be made of Teflon or steel. The belts 222, 224 may be conveyor belts. The upper band 222 is operably connected to at least two upper pressure modules 227, such as seven upper pressure modules 227a, 227b, 227c, 227d, 227e, 227f, and 227 g. The lower band 224 operably connects at least two lower pressure modules 229, such as seven lower pressure modules 229a, 229b, 229c, 229d, 229e, 229f, and 229 g. Upper pressure modules 227a, 227b, 227c, 227d, 227e, 227f, and 227g and corresponding lower pressure modules 229a, 229b, 229c, 229d, 229e, 229f, and 229g may be disposed opposite each other on both sides of the membrane 100 being laminated, respectively.

Each pressure module 227, 229 may have the same width or different widths. In one example, the width of each pressure module 227, 229 is approximately 1000 mm.

Each upper pressure module 227a-g may include one or more upper rollers 226. Similarly, each lower pressure module 229a-g may include one or more lower rollers 228. The number of upper rollers 226 may be the same or different for each upper pressure module 227. The number of lower rollers 228 may be the same or different for each lower pressure module 229. The number of upper rollers 226 may be the same as or different from the number of lower rollers 228. Referring to fig. 4A, the upper pressure module 227 may include 5 upper rollers 226 and the lower pressure module 229 may include 5 lower rollers 228. In the design and operation of the press 220, the rollers 226, 228 may create a line pressure on the material (such as the film 100 or the stack 110) located between the upper roller 226 and the lower roller 228.

The belts 222, 224 and pressure modules 227, 229 or rollers 226, 228 may help advance the plurality of films 100 through the press 220. The plurality of membranes 100 may be moved through the press at a constant or variable rate. Adjusting the rate may allow for pressure or temperature to be applied to the membrane 100 for different amounts of time. The velocity can be from about 1m/min to about 8m/min, from about 2m/min to about 8m/min, from about 3m/min to about 8m/min, from about 4m/min to about 8m/min, from about 5m/min to about 8m/min, from about 1m/min to about 7m/min, from about 1m/min to about 6m/min, from about 1m/min to about 5m/min, from about 1m/min to about 4m/min, from about 1m/min to about 3m/min, or from about 2m/min to about 6 m/min. In one example, the rate is about 2 m/min. In another example, the rate is about 6 m/min.

In one example, the press 220 is a double steel belt constant volume hot press (Sandvik Process Systems, Sandviken, sweden).

in some examples, referring to fig. 4B, the laminator may be a constant volume laminator having at least one module 235 including circulating rollers 236 and at least one module 237 including fixed rollers 238. In this example, the material being formed moves from left to right, first through the circulating rollers 236 and then through the fixed rollers 238. The circulating roller 236 of the isochoric press may apply a surface pressure measured in bar. The stationary roll 238 of the isochoric press may apply a line pressure measured in kN/m. In one example, the heating zone 239, such as in the integrated heating zone 230 (see fig. 3A), may include a plurality of circulating rollers 235. In one example, a cooling zone 241, such as in the integrated cooling zone 232 (see fig. 3A), may include a plurality of fixed rollers 238.

Referring to fig. 5, a method 200 of manufacturing a laminate 110 may include: the method includes the steps of introducing a plurality of films 100 into a laminator step 202, applying a first pressure to the films 100 step 204, applying a first temperature to the films 100 for a first length of time step 206, applying a second pressure to the films 100 step 212, applying a second temperature to the films 100 for a second length of time step 214, and releasing the stack 110 from the machine step 218. In some embodiments, the method comprises one or more of the following steps: a step 208 of applying a third pressure to the membrane 100, a step 210 of applying a third temperature to the membrane 100 for a third length of time, and a step 216 of applying a fourth pressure to the membrane 100. The method 200 may be a continuous process, as opposed to a batch process.

When a temperature is applied to the film 100 in any one or more of the steps 206, 210, 214, the temperature may be high enough to melt or partially melt the outer layer 104, but not high enough to melt the core 102.

In the method 200 of manufacturing the laminate 110, the outer layer 104 may be melted. Alternatively or in addition to melting the outer layer 104, the outer layer 104 and the core 102, or the film 100 within or between the outer layer 104 and the core 102, may be cross-linked to one another or otherwise bonded to one another, such as by chemical, physical, or adhesive bonding. Melting, crosslinking, and/or otherwise bonding the film 100 can help produce a laminate 110 with improved physical properties such as stiffness, tensile strength, and strain to failure.

In step 202, a plurality of films 100 are introduced into a laminator. The laminator may be any of the machines described above, such as an isochoric press or an isobaric press.

In step 204, a first pressure P is applied to the plurality of membranes 100₁. The application of pressure may assist in laminating the films 100 together and may assist in producing a laminate 110 with high bond strength. Referring to fig. 3A, pressure may be applied by a pair of rollers, such as an upper roller 226a located on an opposite side of the film 100 as viewed from the lower roller 228 a. As the film 100 moves through the rollers 226a, 228a at any rate described above (such as about 2m/min), pressure may be applied to the portion of the film 100 between the rollers 226a, 228 a. In other instances, for example using an isostatic press, the pressure (surface pressure) is at least equal toAn oil pad is applied. P₁May be less than about 10 bar, such as about 1 to about 9 bar, about 1 to about 8 bar, about 1 to about 7 bar, about 1 to about 6 bar, about 1 to about 5 bar, about 1 to about 4 bar, about 1 to about 3 bar, or about 1 to about 2 bar. When P is present₁Measured in kN/m (line pressure), P₁May be less than about 40kN/m, such as from about 5 to about 35kN/m, or from about 10 to about 30 kN/m.

Referring to FIG. 3B, P is transferred by the roller₁When applied to the membrane 100, the membrane 100 may experience a pressure spike. As shown in fig. 3B, in the gap between the opposing rollers, the pressure level in the film 100 decreases until the next pair of opposing rollers is encountered.

Referring again to fig. 5, in step 206, the plurality of films 100 are heated to a first temperature T₁For a first time t₁. When T is₁Above ambient temperature, the heat may help laminate the films 100 together and may help produce a laminate 110 with high bond strength. When T is₁at or near the melting point of the outer layer 104 of the film 100, the outer layer 104 may begin to melt or become tacky. When T is₁At or near the melting point of the core 102, the core 102 may begin to relax and/or shrink. Referring to fig. 3A, the temperature may be controlled in the heating zone 230. T is₁May be from about 90 ℃ to about 150 ℃, from about 100 ℃ to about 150 ℃, from about 110 ℃ to about 150 ℃, from about 120 ℃ to about 150 ℃, from about 130 ℃ to about 150 ℃, from about 90 ℃ to about 140 ℃, from about 90 ℃ to about 130 ℃, from about 90 ℃ to about 120 ℃, or from about 90 ℃ to about 110 ℃. In one example, T₁About 130 ℃ or less. In another example, T₁From about 110 ℃ to about 140 ℃. In another example, T₁From about 105 ℃ to about 135 ℃. In yet another example, T₁From about 110 ℃ to about 130 ℃. In yet another example, T₁From about 115 ℃ to about 120 ℃. In order to obtain the desired T₁The temperature of the heating element for heating the film 100 may be at a higher temperature.

A first time t₁May be about 15 to 120 seconds, about 30 to 120 seconds, about 45 to 120 seconds, about 60 to 120 seconds, about 75 to 120 seconds, about 90 to 120 seconds, about 15 to 90 seconds, about 15 to 75 seconds, about 15 to 60 seconds, about 15 to 45 secondsOr about 15 to 30 seconds, or about 30 to 90 seconds. In one example, t₁Is 45 to 55 seconds.

Referring to fig. 3B, when the plurality of films 100 are heated to T₁The temperature of the film 100 may be over time t₁And (4) increasing. At t₁During which the pressure to which the membrane 100 is subjected may remain constant and below P₁。

Although shown as sequential steps in fig. 5, in some embodiments, steps 204 and 206 may occur simultaneously. In general, steps 202, 204, 206, 208 (when present), 210 (when present), 212, 214, 216 (when present), and 218 may be performed in the order depicted in fig. 5 or in a different order.

In step 212, as shown in FIG. 5, the plurality of membranes 100 are subjected to a second pressure P₂. Applying pressure can help laminate the films 100 together and can help produce a laminate 110 with high bond strength. In some embodiments, at t₁During which the application of heat followed by the application of pressure may help to press the films together or may help to define the thickness of the stack 110. Referring to fig. 3A, the pressure may be applied by a pair of rollers, such as a corresponding upper roller 226c on the opposite side of the film 100 as viewed from the lower roller 228 c. As the film 100 moves through the rollers 226c, 228c at any of the rates described above (such as about 2m/min), pressure may be applied to the portion of the film 100 between the rollers 226c, 228 c. In other examples, pressure (surface pressure) is applied through an oil pad, such as using an isostatic press. P₂Can be reacted with P₁The same or different. P₂May be less than about 10 bar, such as about 1 to about 9 bar, about 1 to about 8 bar, about 1 to about 7 bar, about 1 to about 6 bar, about 1 to about 5 bar, about 1 to about 4 bar, about 1 to about 3 bar, or about 1 to about 2 bar. When measuring P in kN/m (line pressure)₂When is, P₂May be less than about 40kN/m, such as about 5 to 35kN/m or about 10 to 30 kN/m.

Referring to fig. 3B, when P is applied to the plurality of films 100₂The membrane 100 may experience pressure spikes. The pressure can be in accordance with P₁About the same.

In step 214, as shown in FIG. 5, the plurality of membranes 100 is subjected to a second stepTwo temperature T₂For a second time t₂. When T is₂At or below ambient temperature, cooler temperatures may help stabilize the stack 110. Referring to fig. 3A, the temperature may be controlled in the cooling zone 232. The temperature may be controlled by, for example, circulating water through tubes in the cooling zone 232, or by spraying water onto one or more of the belts 222, 224 in the cooling zone 232. T is₂may be from about 10 ℃ to about 30 ℃, from about 15 ℃ to about 30 ℃, from about 20 ℃ to about 30 ℃, from about 25 ℃ to about 30 ℃, from about 10 ℃ to about 25 ℃, from about 10 ℃ to about 20 ℃, or from about 10 ℃ to about 15 ℃. In one example, T₂From about 15 ℃ to about 25 ℃.

A second time t₂May be about 2 to 90 seconds, about 5 to 90 seconds, about 10 to 90 seconds, about 20 to 90 seconds, about 30 to 90 seconds, about 40 to 90 seconds, about 50 to 90 seconds, about 60 to 90 seconds, about 2 to 60 seconds, about 2 to 50 seconds, about 2 to 40 seconds, about 2 to 30 seconds, about 2 to 20 seconds, about 2 to 10 seconds, or about 10 to 60 seconds.

Referring to fig. 3B, when T is applied to the plurality of films 100₂The temperature of the film 100 may be over time t₂And decreases. The temperature of the film 100 may be at t₁Initially falling below the starting temperature. At t₂During which the pressure to which the membrane 100 is subjected may remain constant and below P₂. The pressure may be atmospheric pressure. In some embodiments, the plurality of films 100 are cooled without the application of pressure.

Although shown as sequential steps in fig. 5, in some embodiments, steps 212 and 214 may occur simultaneously.

The pressure and temperature applied during the course of the method 200 is effective to laminate the plurality of films 100 together to form the stack 110. In step 218, the stack 110 is released from the laminator, as shown in FIG. 5.

In some embodiments, the method 200 includes subjecting the plurality of membranes 100 to a third pressure P₃Step 208. Applying pressure can help laminate the films 100 together and can help produce a laminate 110 with high bond strength. In some embodiments, at t₁During which heat is appliedPost-application of pressure may help to press the films together or may help to define the thickness of the stack 110. Referring to fig. 3A, the pressure may be applied by a pair of rollers, such as a corresponding upper roller 226b located on an opposite side of the film 100 as viewed from the lower roller 228 b. As the film 100 moves through the rollers 226b, 228b at any of the rates described above (such as about 2m/min), pressure may be applied to the portion of the film 100 between the rollers 226b, 228 b. In other examples, such as using an isostatic press, the pressure (surface pressure) is applied by at least one oil pad. P₃Can be reacted with P₁Or P₂The same or different. P₃May be less than about 10 bar, such as about 1 to about 9 bar, about 1 to about 8 bar, about 1 to about 7 bar, about 1 to about 6 bar, about 1 to about 5 bar, about 1 to about 4 bar, about 1 to about 3 bar, or about 1 to about 2 bar. When P is present₃Measured in kN/m (line pressure), P₃May be less than about 40kN/m, such as about 5 to 35kN/m or about 10 to 30 kN/m.

As shown in fig. 3B, when P3 is applied to the plurality of membranes 100, the membranes 100 may experience a pressure spike. The pressure may be less than P₁And P₂Each of which.

In some embodiments, the method 200 includes subjecting the plurality of films 100 to a third temperature T₃For a third time t₃Step 210. When T is₃Above ambient temperature, the heat may help laminate the films 100 together and may help produce a laminate 110 with high bond strength. Referring to fig. 3A, the temperature may be controlled in the heating zone 230. T is₃May be from about 90 ℃ to about 150 ℃, from about 100 ℃ to about 150 ℃, from about 110 ℃ to about 150 ℃, from about 120 ℃ to about 150 ℃, from about 130 ℃ to about 150 ℃, from about 90 ℃ to about 140 ℃, from about 90 ℃ to about 130 ℃, from about 90 ℃ to about 120 ℃, or from about 90 ℃ to about 110 ℃. In one example, T₃About 130 ℃ or less. In another example, T₃From about 110 ℃ to about 140 ℃. In yet another example, T₃From about 110 ℃ to about 130 ℃.

Referring to fig. 3B, when T is applied to the plurality of films 100₃The temperature of the film 100 may be over time t₃And (4) increasing. Film 100 at t₃The temperature during can be greater than that of film 100t₁And t₂Temperature during each period. Film 100 at t₃The pressure experienced during the process can be kept constant and below P₁、P₂And P₃Each pressure of (a).

Referring again to fig. 5, in optional step 216, the plurality of membranes 100 are subjected to a fourth pressure P₄. Applying pressure can help laminate the films 100 together and can help produce a laminate 110 with high bond strength. Referring to fig. 3A, the pressure may be applied by a pair of rollers, such as a corresponding upper roller 226d located on an opposite side of the film 100 as viewed from the lower roller 228 d. As the film 100 moves through the rollers 226d, 228d at any of the rates described above (such as about 2m/min), pressure may be applied to the portion of the film 100 between the rollers 226d, 228 d. In other examples, pressure (surface pressure) is applied through an oil pad, such as using an isostatic press. P₄Can be reacted with P₁Any one of P2 or P3 is the same or different. P₄May be less than about 10 bar, such as about 1 to about 9 bar, about 1 to about 8 bar, about 1 to about 7 bar, about 1 to about 6 bar, about 1 to about 5 bar, about 1 to about 4 bar, about 1 to about 3 bar, or about 1 to about 2 bar. When P is present₄Measured in kN/m (line pressure), P₄May be less than about 40kN/m, such as about 5 to 35kN/m or about 10 to 30 kN/m. In some embodiments, no pressure is applied, and P₄At about 1 bar or atmosphere.

The laminate 110 produced by the method 200 may exhibit a reduced level of shrinkage, and in some instances, only minimal shrinkage of the laminate 110 may occur. For example, laminate 110 may exhibit a shrinkage of about 1% at 110 ℃.

Luggage article constructed from a laminate of biaxially oriented thermoplastic polymer films

A luggage shell 120, such as a suitcase shell, may be constructed from the laminate 110 disclosed herein. Referring to fig. 6A and 6B, the luggage shell 120 may be in the form of a lid shell 122 (fig. 6A) or a base shell 134 (fig. 6B). The cover housing 122 includes a rear face 124, a cover top face 126, a cover bottom face 128, a cover right face 130, a cover left face 132, and one or more corner portions 146. The base housing 134 includes a front face 136, a base top face 138, a base bottom face 140, a base right face 142, a base left face 144, and one or more corner portions 146. Each corner portion 146 may be a recess for receiving a wheel when the housing 120 is used with an article of luggage.

Any one or more of faces 124, 126, 128, 130, 132, 136, 138, 140, 142, 144 or corner portions 146 may include surface features 148. The features may be located along the length, along the width, or at an angle of the faces 124, 126, 128, 130, 132, 136, 138, 140, 142, 144 or corner portions 146. The features 148 may be recessed areas such as grooves 147 and raised areas such as ribs 149, which may alternate. The features 148 may be aesthetically pleasing. The features 148 may also help provide rigidity or resist bending or deforming forces exerted on the housing 120, such as forces exerted normal to the features 148.

One or both of the base housing 122 and the cover housing 134 may be formed from a laminate 110 having a plurality of films 100 as described above. Briefly, the film 100 may be coextruded and may include a core 102 formed of oriented polypropylene and at least one outer layer 104 positioned adjacent the core 102.

The outer layer 104 may be constructed and designed as described above. In one example, the outer layer 104 is constructed from a copolymer of polypropylene and polyethylene. In another example, the outer layer 104 is constructed from a terpolymer of polypropylene, polyethylene, and polybutylene. The thickness of the outer layer 104 may be less than about 5% of the thickness of the film 100. In one example, the outer layer 104 is about 2.5% of the thickness of the film 100.

The plurality of films 100 form a laminate 110 used to construct the luggage shell 120, and the plurality of films 100 may be any number of films 100 described above. The films forming the stack 110 can have about 10 to about 50 films, about 22 to about 35 films, 22 films, or 23 films. At least two adjacent films 100 are oriented in the same direction. In one example, all of the films 100 are oriented in the same direction.

The thickness of the laminate 110 used to construct the luggage shell 120 may be any of the thicknesses described above. For example, the thickness of the stack 110 may be about 0.5mm to about 2mm, or may be about 0.5mm to less than about 1 mm.

One or both of the base housing 122 and the cover housing 134 may be deep drawn such that the depth of the base housing 122 or the cover housing 134 is very large relative to its length or width. For example, the depth of cover top surface 126 and cover bottom surface 128 may be up to one-half the length or one-half the width of rear surface 124. As another example, the depth of the base top surface 138 or the base bottom surface 140 may be up to half the length or half the width of the front surface 136.

Any of the luggage shells 120 described above may be used to form the main body of the luggage case 150, such as a hard-sided luggage case. Referring to fig. 7A and 7B, hardside luggage 150 is defined by a lid shell 122 and a base shell 134 operably joined together to form an outer shell 152 having an outer layer 154. One or both of the cover housing 122 and the base housing 134 may be produced by any of the methods described above. The outer layer 154 may have a textured or shaped surface.

The luggage case 150 includes a front panel 156, a rear panel 158, a top panel 160, a bottom panel 162, a right panel 164, and a left panel 166. Corner regions 168 are defined by the intersection of any two or three adjacent panels 156, 158, 160, 162, 164, and 166. For example, luggage case 150 includes four upper corner regions and four lower corner regions, each formed by the intersection of three adjacent panels. In addition, the edge formed by the intersection of any two adjacent panels may also be considered a corner region. The panels 156, 158, 160, 162, 164, 166 described herein may also be referred to as "sides". Accordingly, the first, second, and/or third sides of the luggage piece 150 may each be any of the various panels 156, 158, 160, 162, 164, 166 described herein. The luggage case 150 may also include a closure mechanism, such as a zipper, that extends along the side panels 164, 166 and central portions of the top and bottom panels 160, 162 and defines a closure line 170, the closure line 170 dividing the luggage case 150 into the lid and base housings 122, 134. A hinge (not shown) for pivotally connecting the cover housing 122 and the base housing 134 together is provided along the closure line 170. The zipper can be unzipped to allow the lid housing 122 and base housing 134 to pivot about the hinge portions to allow access to the interior. Various types of closure mechanisms, such as latches and hinge structures, are acceptable. Luggage case 150 may also include four wheels 172 that rotate about a vertical axis as shown, or may include other wheels or support structures to allow a user to pull or pull luggage case 150 at an angle or to direct it forward in an upright position. The luggage case 150 may include a top carrying handle 174 on the top panel 160 and a side carrying handle 176 on the side panels 164, 166. Luggage case 150 may also include a retractable handle 178. The pull handle 178 may be aligned along the outside of the rear panel 158 of the luggage case 150. Alternatively, the pull handle 178 may be aligned along the rear panel 158, but located within the luggage case 150.

The laminate 110 may be molded into an article such as a luggage shell 120. Forming the laminate 110 in a process that precedes and is separate from the molded article as the article is constructed can help produce an improved article, such as by causing the article to be free or substantially free of air bubbles formed between the films 100 in one example.

The laminate 110 may be produced by the method 200 described above. The laminate 110 may be cut to a predetermined shape and size to form a piece or sheet of laminate 110. The luggage shell 120 may be formed by molding the laminate 110 in a molding apparatus 240 such as a molding press or an insert molding machine. In one non-limiting example, the laminate may be molded by or using a method similar to that described in European patent No. 1763430, PCT/EP2014/055514 or DE10259883 (also US 2004/0118504). With respect to the method described in european patent No. 1763430, it should be noted that clamping of the stack 110 during moulding of the stack is less important, which is an advantage, since the moulding temperature of the stack 110 may be lower, and it reduces or avoids problems caused by material shrinkage that may occur at high moulding temperatures. Furthermore, the temperature range of the molding stack 110 can be larger compared to the process described in european patent No. 1763430, which discloses deep drawing of a thin layer of self-reinforced thermoplastic composite material at about 170 ℃, which is an advantage as it allows for greater flexibility in molding conditions.

Referring to fig. 8, the molding apparatus 240 may include a liner dispenser 242, a press 244, and a heater array 246. In some embodiments, the liner dispenser 242 receives and dispenses a textile sheet material, such as a mesh fabric, a knit fabric, a woven fabric, or a nonwoven fabric cloth, for molding with the sheet material of the stack 110. The "mesh" may be a textile sheet having openings formed therethrough, such as a warp knit open sheet. The textile sheet may be used as a liner for the interior of the luggage shell 120 produced in the molding apparatus 240. The textile sheet may introduce texture, color, printing, patterns or designs to the laminate 110. The textile sheets may be received and stored in a tray 248 before being distributed to the sheets of the stack 110. Alternatively, the textile sheet material may be dispensed to the stack 110 before the stack 110 enters the molding device 240. For example, using a mesh as the textile sheet may impart textural properties to the surface of the laminate 110.

Press 244 includes an upper table 250 and a lower table 252. The upper table 250 may support an upper die of a deep drawing tool 256, which may be a male die 254. In fig. 8, a portion of the upper table 250 is removed to more clearly show the male mold 254. The lower table 252 may support a lower die of a deep drawing tool 256, which may be a female die 258. The tables 250, 252 may be moved relative to each other. For example, upper table 250 may descend along column frame 260 and be guided by column frame 260 toward female mold 258. The lower table 252 may be moved upward toward the male mold 254. The dies 254, 258 are complementary to each other such that one die (e.g., male die 254) fits at least partially within the other die (e.g., female die 258).

Press 244 also includes a sheet gripper 264. The frame 264 is configured to controllably hold each stack 110 of sheets in position between the male mold 254 and the female mold 258. The shelf 264 may also be configured to stretch the stack 110 sheet, or to apply tension to the stack 110 sheet.

Heater array 246 includes upper heaters 266 and lower heaters 268. Heaters 266, 268 may be configured to slide simultaneously from heater array 246 to a position between male mold 254 and female mold 258.

Referring to fig. 9, a method 280 of manufacturing a luggage shell 120 may include: a step 282 of preheating the stack 110, a step 284 of introducing the stack 110 into the molding apparatus 240, a step 286 of clamping and heating the stack 110, a step 288 of molding the stack 110 into an article, and a step 290 of releasing the article from the molding apparatus 240.

In step 282, the stack 110 is heated to a desired temperature. The temperature is high enough to melt or partially melt the outer layer 104 and to melt or partially melt the core 102. The temperature may be from about 120 ℃ to about 190 ℃, from about 125 ℃ to about 190 ℃, from about 130 ℃ to about 190 ℃, from about 135 ℃ to about 190 ℃, from about 140 ℃ to about 190 ℃, from about 145 ℃ to about 190 ℃, from about 150 ℃ to about 190 ℃, from about 120 ℃ to about 185 ℃, from about 120 ℃ to about 180 ℃, from about 120 ℃ to about 175 ℃, from about 120 ℃ to about 170 ℃, from about 120 ℃ to about 165 ℃, or from about 120 ℃ to about 160 ℃. In one example, the temperature is from about 145 ℃ to about 170 ℃. In yet another example, the temperature is about 140 ℃ to about 165 ℃.

Instead of, or in addition to, melting the outer layer 104 and the core 102, or the film 100 within or between the outer layer 104 and the core 102, may be cross-linked to each other, or otherwise bonded to each other, such as by chemical, physical, or adhesive bonding. Melting, crosslinking, and/or otherwise bonding the film 100 may help produce a luggage shell 120 with improved physical properties such as durability, deformation resistance, and impact resistance.

Referring again to fig. 9, in step 284, the stack 110 of sheets is introduced into the molding apparatus 240. The stack 110 of sheets may be introduced into the press 244 from a sheet supply behind the press 244 (shown in fig. 8). Referring to fig. 8, the stack 110 is held between the male mold 254 and the female mold 258 by a sheet holder 264.

In step 286, the stack 110 is clamped and heated. The stack 110 (such as an edge of a sheet) may be clamped by a sheet clamp 264. The shelf 264 may or may not stretch the laminate 110 or apply tension to the laminate 110. Application of tension or pressure may help further consolidate the films 100 of the stack 110 together when the article is constructed. The tension or pressure applied to the stack 110 may be less than about 5 bar, such as about 0.5 bar to about 4 bar, about 0.5 bar to about 3 bar, about 0.5 bar to about 3.5 bar, about 0.5 bar to about 3 bar, about 0.5 bar to about 2.5 bar, about 0.5 bar to about 2 bar, or about 1.5 bar to about 2 bar.

Referring to fig. 8, the heaters 266, 268 may heat the stack 110 while the stack 110 is held between the male mold 254 and the female mold 258. The top and/or bottom surfaces of the stack may be heated. The stack may be clamped by the sheet clamp 264 or clamped and stretched. The laminate 110 may be heated to a temperature high enough to melt or partially melt the outer layer 104 and to melt or partially melt the core 102. The stack 110 may be heated to a temperature of: about 120 ℃ to about 190 ℃, about 125 ℃ to about 190 ℃, about 130 ℃ to about 190 ℃, about 135 ℃ to about 190 ℃, about 140 ℃ to about 190 ℃, about 145 ℃ to about 190 ℃, about 150 ℃ to about 190 ℃, about 120 ℃ to about 185 ℃, about 120 ℃ to about 180 ℃, about 120 ℃ to about 175 ℃, about 120 ℃ to about 170 ℃, about 120 ℃ to about 165 ℃, or about 120 ℃ to about 160 ℃. In one example, the stack is heated to a temperature of about 145 ℃ to about 170 ℃. In another example, the temperature is about 140 ℃ to about 165 ℃.

In some embodiments, step 286 includes introducing a fabric sheet into the top or bottom surface of the stack 110. For example, the object sheet may be placed between the upper heater 266 and the male mold 254.

Referring again to fig. 9, in step 288, the sheets of the stack 110 are molded into an article, such as the luggage shell 120. The stack 110 of sheets may be heated while molding. The laminate 110 may be heated to a temperature high enough to melt or partially melt the outer layer 104 and to melt or partially melt the core 102. The stack 110 may be heated to the following temperatures: about 120 ℃ to about 190 ℃, about 125 ℃ to about 190 ℃, about 130 ℃ to about 190 ℃, about 135 ℃ to about 190 ℃, about 140 ℃ to about 190 ℃, about 145 ℃ to about 190 ℃, about 150 ℃ to about 190 ℃, about 120 ℃ to about 185 ℃, about 120 ℃ to about 180 ℃, about 120 ℃ to about 175 ℃, about 120 ℃ to about 170 ℃, about 120 ℃ to about 165 ℃, or about 120 ℃ to about 160 ℃. In one example, the stack 110 is heated to a temperature of about 140 ℃ to about 180 ℃. In another example, the stack 110 is heated to a temperature of about 145 ℃ to about 170 ℃. In yet another example, the temperature is about 140 ℃ to about 165 ℃.

The stack 110 may be heated for about 10 seconds to about 40 seconds, about 15 seconds to about 40 seconds, about 20 seconds to about 40 seconds, about 25 seconds to about 40 seconds, about 30 seconds to about 40 seconds, about 10 seconds to about 35 seconds, about 10 seconds to about 30 seconds, about 10 seconds to about 25 seconds, or about 10 seconds to about 20 seconds. In one embodiment, the stack 110 is heated for about 15 seconds to about 35 seconds.

In one molding example, a lower mold (such as female mold 258) is moved upward to contact the underside of the heated and stretched laminate 110 sheet. The upper mold (in this case the male mold 254) moves downward, which forces the stack 110 of sheets into contact with most or all of the surfaces of the molds 254, 258, thereby shaping the stack 110 of sheets. If present, the fabric sheet is simultaneously adhered to the stack 110 sheet.

The molds 254, 258 can be quickly advanced together or closed, which can help reduce the amount of wrinkling created in the corner portions 146 of deep-drawn articles, such as the luggage shell 120. The dies 254, 258 may be held in the closed position for about 15 to 45 seconds, about 15 to 40 seconds, about 15 to 35 seconds, about 15 to 30 seconds, about 20 to 45 seconds, about 25 to 45 seconds, or about 30 to 45 seconds. In one example, the dies 254, 258 remain in the closed position for about 30 seconds.

At step 290, the luggage shell 120 is released from the molding device 240. The laminate 110 is heated and formed into the luggage shell 120 in the following time: about 60 to 120 seconds, about 60 to 110 seconds, about 60 to 100 seconds, about 60 to 90 seconds, about 70 to 120 seconds, about 80 to 120 seconds, or about 90 to 120 seconds. In one example, the laminate 110 is heated and formed into the luggage shell 120 in about 90 seconds.

the luggage shell 120 manufactured by the method 280 described above may be used in the luggage case 150 shown in fig. 7 b.

It should be noted that all directional and/or dimensional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, front, back, rear, forward, rearward, interior, exterior, inward, outward, vertical, horizontal, clockwise, counterclockwise, length, width, height, depth, and relative orientation) are only used for identification purposes to aid the reader's understanding of the implementation of the disclosed invention, and do not create limitations, particularly as to the position, orientation, use, relative size, or geometry of the invention unless specifically set forth in the claims.

Joinder references (e.g., attached, coupled, connected, joined, and the like) are to be construed broadly and may include intermediate members between a connected element and relative movement between such elements. Thus, joinder references do not necessarily imply that two elements are directly connected and in fixed relation to each other.

In some cases, the assembly is described with reference to an "end" having a particular feature and/or being connected to another part. However, those skilled in the art will recognize that the disclosed invention is not limited to components that terminate immediately beyond their point of connection to other components. Thus, the term "end" should be interpreted broadly, to include areas near, behind, in front of, or otherwise adjacent to the ends of a particular element, link, component, part, member, or the like. In the methods set forth directly or indirectly herein, the various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that these steps and operations may be rearranged, substituted, or omitted without necessarily departing from the spirit and scope of the present invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made which are within the scope of the appended claims.