阅读说明：本技术 一种用于鞋类的直接注射制造的模制系统 (Molding system for direct injection manufacturing of footwear ) 是由 J·M·汉森 J·S·莫滕森 于 2020-03-12 设计创作，主要内容包括：本发明涉及一种用于鞋类的直接注射制造(DIP)的模制系统(10),所述模制系统包括用于容纳模制所述鞋类的鞋底部件的注射材料的模腔,所述模制系统(10)包括-多个基础直接注射模具(40；40’,40”,40”’,40””),其中的每个可附接到注射模制设备(11),以及-多套(50)直接注射模具嵌件(52、54、56),每套(50)直接注射模具嵌件配置为当嵌入到所述多个基础直接注射模具(40)中的一个时定义所述模腔(80)的内表面(53、55、56)的至少一部分,其中,所述多个基础直接注射模具(40)中的至少两个在尺寸上彼此不同,对应于鞋底部件尺寸的不同范围。(The present invention relates to a molding system (10) for direct injection manufacturing (DIP) of footwear, the molding system includes a mold cavity for receiving an injection material for molding a sole component of the footwear, the molding system (10) includes-a plurality of basic direct injection molds (40; 40 ', 40 ", 40"', 40 ""), each of which is attachable to an injection molding apparatus (11), and-a plurality of sets (50) of direct injection mold inserts (52, 54, 56), each set (50) of direct injection mold inserts being configured to define at least a portion of an inner surface (53, 55, 56) of the mold cavity (80) when inserted into one of the plurality of base direct injection molds (40), wherein at least two of the plurality of base direct injection molds (40) differ from each other in size, corresponding to different ranges of sole component sizes.)

1. A molding system (10) for direct injection production of footwear, the molding system including a mold cavity for receiving injection material for molding a sole component of the footwear, the molding system (10) comprising:

-a plurality of basic direct injection moulds (40; 40 ', 40 "', 40" "), each of which is attachable to an injection moulding apparatus (11), and

-a plurality of sets (50) of direct injection mold inserts (52, 54, 56), each set (50) of direct injection mold inserts configured to define at least a portion of an inner surface (53, 55, 56) of the mold cavity (80) when inserted into one of the plurality of base direct injection molds (40),

wherein at least two of the plurality of base direct injection molds (40) differ from each other in size, corresponding to different ranges of sole component sizes.

2. The molding system of claim 1, wherein the plurality of basic direct injection molds (40) are in the interval of 2-40, such as 2-30 or 2-20.

3. Moulding system according to claim 1 or 2, wherein the number of sets (50) of direct injection mould inserts is in the interval 2-40, such as 2-30 or e.g. 2-20.

4. The molding system of claim 1, 2 or 3, wherein one of the sets (50) of direct injection mold inserts includes a plurality of mold insert components (52, 54, 56), such as 2, 3, 4, 5 or more.

5. The molding system of any of claims 1-4, wherein the plurality of sets (50) of direct injection mold inserts (52, 54, 56) are provided with the plurality of base direct injection molds (40).

6. The molding system of any of claims 1-4, wherein the multiple sets (50) of direct injection mold inserts (52, 54, 56) are manufactured by an additive manufacturing process, such as by 3D printing.

7. The molding system of claim 6, wherein the sets of direct injection mold inserts are manufactured as, for example, local and/or on-demand.

8. The molding system of any of claims 1-7, wherein the plurality of sets (50) of direct injection mold inserts (52, 54, 56) includes one or more sets for use in association with each of a plurality of base direct injection molds (40), and wherein the two or more sets of direct injection mold inserts for use in association with the same base direct injection mold differ from each other at least in a sole component dimension defined by the at least a portion of the interior surface (53, 55, 56) of the mold cavity.

9. The molding system of any of claims 1-8, wherein each of the plurality of basic direct injection molds (40) is configured to at least partially direct injected material to the mold cavity (80).

10. The molding system of any of claims 1-9, wherein the base direct injection mold (40) is at least partially fabricated from a metal, such as aluminum.

11. The molding system of any of claims 1-10, wherein the direct injection mold inserts (52, 54, 56) of the set (50) are at least partially fabricated from a metal, such as aluminum.

12. The molding system of any of claims 1-10, wherein the direct injection mold inserts (52, 54, 56) of the set (50) are manufactured at least in part using an additive manufacturing material that includes one or more polymers, includes one or more photopolymers, and/or includes at least one selected from the list of polymers, resin photopolymers, ABS, PLA, ASA, nylon/nylon powder, PETG, metal/metal powder, gypsum powder, HIPS, PET, PEEK, PVA, ULTEM, polyjet resin, and/or ceramic, and any combination thereof.

13. The molding system of any one of the preceding claims, wherein the base direction mold comprises a mold set of a first base side mold (42), a second base side mold (44), and a base bottom mold (46).

14. Moulding system according to any of the preceding claims, wherein the thermal conductivity of the basic direct injection mould at room temperature is higher than 50W/(m x K), preferably higher than 100W/(m x K), most preferably higher than 150W/(m x K).

15. The molding system of any of the preceding claims, wherein the thermal conductivity of the direct injection mold insert at room temperature is below 5W/(m x K), such as below 2W/(m x K), such as below 1W/(m x K), such as below 0.5W/(m x K).

16. The molding system of any of the preceding claims, wherein the cavities of the plurality of base direct injection molds (40; 40 ', 40 "', 40" ") differ in length (MCL) when attached to the injection molding apparatus.

17. The molding system of any of the preceding claims, wherein the cavities of the plurality of base direct injection molds (40; 40 ', 40 "', 40" ") differ in width (MCW) when attached to the injection molding apparatus.

18. The molding system of any of the preceding claims, wherein the mold cavities of the plurality of base direct injection molds (40; 40 ', 40 "', 40" ") differ in length (MCL) and width (MCW) when attached to the injection molding apparatus.

19. The molding system of any of the preceding claims, wherein the direct injection mold insert includes side inserts (52, 54) having insert flanges (70), wherein the insert flanges include upper contact surfaces (112) for contacting an outer surface (32) of an upper (30) and connection ends (114) connected to the respective side inserts (52, 54).

20. The molding system of claim 19, wherein the upper contact surface (112) has a height h1 in the range of 2-6mm, and/or wherein the link end (114) has a height h2 in the range of 6-15 mm.

21. A method of injection production of footwear, the method comprising the steps of:

-for a given footwear design,

-defining at least two different predefined shoe sizes (FS) to produce,

-providing at least two basic direct injection moulds (40), each of which is attachable and operable with an injection moulding apparatus (11),

-for each of a plurality of basic direct injection molds (40), providing at least one set of corresponding direct injection mold inserts (52, 54, 56),

-wherein at least one set of corresponding direct injection mold inserts (52, 54, 56) for each of the at least two base direct injection molds (40) defines at least two different predefined shoe sizes.

22. The direct injection production method according to claim 21, wherein the thermal conductivity of the base direct injection mold at room temperature is higher than 50W/(m x K), preferably higher than 100W/(m x K), most preferably higher than 150W/(m x K).

23. The direct injection production method according to claim 21 or 22, wherein the thermal conductivity of the direct injection mold insert at room temperature is below 5W/(m x K), such as below 2W/(m x K), such as below 1W/(m x K), such as below 0.5W/(m x K).

24. The direct injection production method of any one of claims 21-23, wherein the cavities of the plurality of base direct injection molds (40; 40 ', 40 "', 40" ") differ in length (MCL) when attached to the injection molding apparatus.

25. The direct injection production method of any one of claims 21-24, wherein the cavities of the plurality of base direct injection molds (40; 40 ', 40 "', 40" ") differ in width (MCW) when attached to the injection molding apparatus.

26. The direct injection production method of any one of claims 21-25, wherein the cavities of the plurality of base direct injection molds (40; 40 ', 40 "', 40" ") differ in length (MCL) and width (MCW) when attached to the injection molding apparatus.

27. The direct injection production method of any one of claims 21-26, wherein the direct injection mold insert is adapted to fit respective base injection molds having different base Mold Cavity Widths (MCW).

28. The direct injection production method of any one of claims 21-27, wherein the direct injection mold insert is adapted to fit respective base injection molds having different base cavity lengths (MCLs).

29. Direct injection production method according to any one of claims 21-28, wherein for a predefined shoe size the base injection mould and the set of corresponding direct injection mould inserts (52, 54, 56) are provided in order to keep the volume or size of the direct injection mould inserts (52, 54, 56) as small as possible.

30. The direct injection production method of any one of claims 21-29, wherein the at least two base molds differ in thermal conductivity from the corresponding base injection mold.

31. Direct injection production method according to any one of claims 21 to 30, wherein each of the at least two basic direct injection moulds (40) is attached to the injection moulding apparatus (11) by means of a detachable fixing means.

32. The direct injection production method according to any one of claims 21-31, wherein the at least one set of direct injection mold inserts (52, 54, 56) for each of the plurality of base direct injection molds (40) defines different respective dimensions of the predefined shoe size.

33. The direct injection production method of any one of claims 21-32, wherein the base direct injection mold is usable for manufacturing involving one footwear design and is reusable for manufacturing involving another footwear design.

34. The direct injection production method of any one of claims 21-33 wherein the base injection mold is selected from a plurality of available base molds.

35. Direct injection production method according to any of claims 21-34 and carrying out a mould system according to any of claims 1-20.

36. The direct injection mold system according to any one of claims 1-20, wherein the mold insert material has a conductivity of less than 2 or 1W/(m x K).

37. Direct injection mold system according to any one of claims 1-20 or 36, wherein the maximum length of the direct heat transfer path HTPI should be below 12cm, preferably below 10 cm.

38. The direct injection mold system of any of claims 1-20, 36, or 37, wherein the maximum length of the direct heat transfer path HTPI is at least 0.5 cm.

Technical Field

The present invention relates to a molding system and a direct injection production method.

Background

It is well known to manufacture footwear by means of injection moulding a sole directly to an upper.

Direct Injection Processes (DIP) are advantageous in many respects because the resulting footwear may have both flexibility and strength.

One challenge with such direct injection processes is that the manufacturing method is relatively expensive and not suitable for small volume production.

Disclosure of Invention

The present invention relates to a moulding system for direct injection production of footwear, the moulding system comprising a mould cavity for receiving injection material for moulding a sole component of the footwear, the moulding system comprising:

-a plurality of basic direct injection moulds, each of which is attachable to an injection moulding apparatus, an

-a plurality of sets of direct injection mold inserts, each set of direct injection mold inserts configured to define at least a portion of an inner surface of the mold cavity when inserted into one of the plurality of base direct injection molds,

wherein at least two of the plurality of base direct injection molds differ in size from one another, corresponding to different ranges of sole component sizes.

Thus, the production of a range of footwear, for example different sizes, different types (e.g. male/female, left/right, etc.), wherein the sole is produced by a Direct Injection Process (DIP) process, may be performed with improved, consistent quality and thus may be performed in a cost-effective manner. In the direct injection production aspect, where the sole is molded directly onto the footwear, a mold made of, for example, an aluminum block may be used, and where the mold is made of a mold cavity corresponding to the particular size footwear in question. However, this requires the presence of a relatively large number of individual moulds and is therefore hampered by the relatively high costs associated with the production equipment. Accordingly, it has been devised that a basic direct injection mold can be used, wherein the direct injection mold inserts are mounted so as to define the desired shape and size of the mold cavity. To cover a range of sizes, such as shoe sizes, etc., direct injection mold inserts are made in different sizes, such as sets. According to the present invention, a plurality of basic direct injection molds are included in a molding system, wherein at least two of these differ from each other in size, e.g., in the size of the internal cavity, wherein a set of direct injection mold inserts may be installed. Thus, when, for example, soles of U.S. size 6 to 7.5 are to be produced, one of the basic direct injection molds may be used and a specific set of direct injection mold inserts may be installed, for example, for the production of U.S. size 7. When, for example, soles of us size 8 to 10 are to be produced, another of at least two different basic direct injection moulds can be used, wherein another specific set of direct injection mould inserts can be installed, for example, for producing soles of us size 9.5.

By means of the invention, a wide range of shoe sizes can be produced by the moulding system, whereby the disadvantages of using relatively thin or relatively thick mould inserts can be avoided. If an attempt were made to produce a relatively wide range of shoe sizes using a single basic direct injection mold, this would require that at one end of the range the mold insert would be relatively large, e.g., thick, while at the other end of the range the mold insert would be relatively small, e.g., thin and possibly fragile, brittle, etc. Both of these cases may cause problems when performing injection molding, as regards temperature and/or temperature control, since the injection molding apparatus heats the mold to a predetermined temperature, which temperature affects the curing of the injected material forming the sole. Too low a temperature may result in imperfections in the sole, while too high a temperature may increase production time, for example, as curing time may be extended and other problems may result. Depending on the material of the mold inserts, the thickness of these inserts can cause problems, for example, when attempting to achieve a desired mold temperature and temperature profile (e.g., the temperature of the inner surface of the mold cavity). For example, thick inserts (having a lower thermal conductivity than, for example, the base direct injection mold material) may result in reduced thermal conductivity, thereby reducing production speed, for example, in connection with starting with a new set of ("cold") inserts, extending cure times, sole imperfections, and the like. It should be kept in mind here that in changing the production from one size of footwear to another, the transition between such thin and thick inserts would require adjustment of the production equipment to counteract the changes in thermal conductivity and thermal capacity characteristics. Furthermore, thin inserts may be more difficult to mount in a satisfactory manner within the mould cavity, since, for example, they may bend and may slip out, for example, from the grip with the coupling device, etc. These and other problems and disadvantages are avoided when using a molding system according to the present invention.

The term "set of direct injection mold inserts" -includes as few as one insert. The different embodiments of the invention are mainly shown in this application with three mold inserts, which is preferred. It is also clear that other numbers, down to one, may be applied within the scope of the invention.

In an embodiment of the invention, the plurality of basic direct injection molds is in the interval 2-40, such as 2-30 or such as 2-20.

The number of base injection molds for a given footwear piece should match the desired size and, in some embodiments, ensure that the size/volume of the insert is small enough for the molding system to work properly with direct injection process equipment. One possible approach might be to determine the number of sizes of the design and then use the same number of base molds, of course multiplied by two to obtain a left and right article of footwear. For a shoe family, for example 3 to 16 (men's usa size), i.e. 2 x 14-28 different base molds, then the respective mold inserts are 3D printed to the base mold or base mold set of each application.

Another method is to use the same base mold for two different sizes, for example sizes 11 and 12, and then print corresponding different inserts, fitting the soles, which are in the same base mold but define sizes 11 and 12, respectively, in the inner cavity.

Therefore, the number of fundamental modes can be reduced, if necessary. It should be noted, however, that the base mold can only be reused with other inserts between different footwear families, so in many applications it makes sense to simply determine the optimal shape for each desired size (e.g., different shapes for left and right footwear products of the same size) and then reuse these in producing new designs, with only the inserts having to be modified.

In an alternative arrangement, a series would include 18 or 24 basic mold sets, one for the left foot and one for the right foot in each set.

In another alternative arrangement, a series would include 9 or 12 basic die sets, one for the left foot and one for the right foot, and then the complete manufacturing series would be obtained by providing two different inserts for each die-thereby reducing the total number of basic dies necessary by 50%. Other families and strategies may be applied within the scope of the invention.

In an embodiment of the invention, the number of sets of direct injection mold inserts is in the interval 2-40, such as 2-30 or such as 2-20.

In an embodiment of the invention, one of the sets of direct injection mold inserts comprises a plurality of mold insert parts, such as 2, 3, 4, 5 or more.

In an embodiment of the present invention, the plurality of sets (50) of direct injection mold inserts are provided with the plurality of base direct injection molds (40).

Thus, the set of direct injection mold inserts may be provided in an assembly together with a corresponding base direct injection mold, whereby the molding system may be provided in a relatively uncomplicated manner, e.g. when manufacturing shoe soles of e.g. U.S. size 11.5, the thus marked set of direct injection mold inserts may be selected and mounted in a specific base direct injection mold, e.g. a base direct injection mold destined for production related shoe soles in e.g. the U.S. size range 10.5 to 12. The mold insert may thus be configured to be optimized in connection with a particular basic direct injection mold with respect to, for example, materials, thermal conductivity properties, heat capacity properties, etc.

In an embodiment of the invention, the sets of direct injection mold inserts are manufactured by an additive manufacturing process, for example by 3D printing.

Thus, it is possible to provide for e.g. locally manufacturing a set of direct injection mold inserts at or near the production site and/or when a specific set of mold inserts or replacement of mold inserts is required. Thus, the molding system may not even be shipped to a production site with an actual, physical set of direct injection mold inserts, but may provide the necessary means of manufacturing the mold inserts, e.g., material data, input data, etc., for a 3D printing device or the like, in order to manufacture mold inserts of the desired specifications according to particular embodiments of the present invention. Accordingly, advantages may be realized in that the actual storage of sets of direct injection mold inserts may be minimized, and in that production equipment costs may be reduced since only the set of direct injection mold inserts actually used need be provided.

It should be noted in this regard that when using the term including multiple sets of direct injection mold inserts in the system, it should be understood that this may not necessarily require the physical presence of the mold inserts, but that this means that material data, specifications, input data, etc., for example for 3D printing devices, etc., may be used for the same purpose.

In an embodiment of the present invention, the sets of direct injection mold inserts are manufactured on-demand (e.g., locally and/or on-demand).

Thus, local manufacturing, e.g. at or near the production site and/or when a specific set of mold inserts or replacement mold inserts is required, may be an advantageous possibility. Thus, the storage of a relatively large number of actual, physical sets of direct injection mold inserts may be avoided. Rather, the system may provide the necessary means to manufacture mold inserts as needed and as required, for example, by material data, input data, etc. for a 3D printing device or the like, in order to manufacture mold inserts of the required specifications according to particular embodiments of the present invention. Furthermore, production equipment costs may be reduced, as only the set of direct injection mold inserts that will actually be used need to be provided.

In an embodiment of the invention, the plurality of sets (50) of direct injection mold inserts comprises one or more sets for use in association with each of a plurality of base direct injection molds, and wherein the two or more sets of direct injection inserts available in association with the same base direct injection mold differ from each other at least in a bottom portion dimension defined by the at least a portion of the inner surface of the mold cavity.

Thus, the production system may be optimized, i.e. a suitable number of basic direct injection molds may be configured, each of which may be paired with a correspondingly configured direct injection mold insert, such that these components together form a direct injection mold for the purpose of providing the desired characteristics, e.g. a suitable thermal conductivity, e.g. from the injection molding apparatus to the inner surface of the installed direct injection mold insert, e.g. the mold cavity and the actual injected material used for forming the sole. In this respect it should be noted that according to this embodiment, the individual mould inserts may be designed with suitable dimensions, such as thickness, ensuring that on the one hand the thermal conductivity is not too small and on the other hand the actual insert is not too thin at one or more locations and thus does not have a poor strength.

For example, a molding system may include:

a basic direct injection mould for soles of U.S. size 6 to 7.5,

a basic direct injection mould for soles of us sizes 8 to 10,

-a basic direct injection mould for soles of footwear of U.S. size 10.5 to 12, and

basic direct injection mould for soles of us sizes 13 to 15.

In this regard, each set of direct injection mold inserts may include:

4 soles for us sizes 6, 6.5, 7 and 7.5,

-5 soles for U.S. sizes 8, 8.5, 9, 9.5 and 10,

-4 soles for U.S. sizes 10.5, 11, 11.5 and 12, and

3 soles for us sizes 13, 14 and 15.

It should be noted that there is a possibility of overlapping ranges, for example the first of the direct injection mold insert ranges described above may also include U.S. size 8. This may increase flexibility because, for example, when the production of U.S. size 7.5 shoes is ongoing and a small batch production of U.S. size 8 shoes is required, there is no need to change from one base direct injection mold to the next mold, after which U.S. size 7.5 shoes will continue to be produced. In this case, only the direct injection mold insert needs to be replaced.

In an embodiment of the invention, the plurality of basic direct injection molds are configured to at least partially direct injection material to the mold cavity (80).

In an embodiment of the invention, the base direct injection mold is at least partially made of metal (e.g., aluminum).

In an embodiment of the invention, the set of direct injection mold inserts is at least partially made of metal (e.g., aluminum).

In an embodiment of the invention, the set of direct injection mold inserts is manufactured at least in part using an additive manufacturing material comprising one or more polymers, comprising one or more photopolymers and/or comprising at least one selected from the list of polymers, resin photopolymers, ABS, PLA, ASA, nylon/nylon powder, PETG, metal/metal powder, gypsum powder, HIPS, PET, PEEK, PVA, ULTEM, polyjet resin and/or ceramic and any combination thereof.

In an embodiment of the present invention, the base direction mold includes a mold set of a first base side mold, a second base side mold, and a base bottom mold.

In an embodiment of the invention, the thermal conductivity of the basic direct injection mold at room temperature is higher than 50W/(m × K), preferably higher than 100W/(m × K), most preferably higher than 150W/(m × K).

In an embodiment of the invention, the thermal conductivity of the direct injection mold insert at room temperature is below 5W/(m × K), such as below 2W/(m × K), such as below 1W/(m × K), such as below 0.5W/(m × K).

In an embodiment of the present invention, the cavities of the plurality of base direct injection molds differ in length (MCL) when attached to the injection molding apparatus.

In an embodiment of the present invention, the cavities of the plurality of base direct injection molds differ in width (MCW) when attached to the injection molding apparatus.

In an embodiment of the present invention, the cavities of the plurality of base direct injection molds differ in length (MCL) and width (MCW) when attached to the injection molding apparatus.

In an embodiment of the invention, the direct injection mold insert may include side inserts having insert flanges (lip), wherein the insert flanges include upper contact surfaces for contacting an outer surface of the upper and connecting ends that connect to the respective side inserts.

The insert flange may be integral with the respective side insert.

The height h2 of the flange at the connection end of the flange is greater than the height h1 at the upper contact surface of the flange relative to the normal a of the upper contact surface. The normal a of the upper contact surface is arranged to intersect the upper contact surface centre point as seen in the height direction.

The flange may have a length l1 defined by the distance from the upper contact surface to the connection end along the normal a of the upper contact surface.

In an exemplary embodiment, the length of the flange 11 may have a dimension at least greater than the height h2, i.e., the length ratio between the length of the flange and the height h2 is at least 1:1. In another embodiment, the length of the flange may have a dimension less than the height h2, i.e., l1 < h 2. Thus, the height h2 provides support for the length of the flange, where the height h2 of the flange may have to increase as the length 11 increases.

In an embodiment of the invention, the upper contact surface may have a height h1 in the range of 2-6mm, and/or wherein the connection end may have a height h2 in the range of 6-15 mm.

More specifically, the height h1 may be between 3 and 5mm, or even more specifically about 4 mm. Preferably, the height h1 may be above 2mm, as a lower thickness may cause the material to bend, deform or warp during injection. This may be particularly the case if the mould insert is 3D printed from e.g. a polymer material.

More specifically, the height h2 may be between 7 and 12mm, wherein the height may be more specifically between 5-8 and 10 mm. The increased height h2 provides support to the flange, especially when the material is 3D printed from, for example, a polymer material.

In one embodiment, the size ratio between height h1 and h2 may be about 1:2, where h2 may be twice height h 1. In one embodiment, the size ratio may be about 1:1.5, with height h2 being 50% greater than h 1.

The invention also relates to a direct injection production method of footwear, comprising the following steps:

-for a given footwear design,

-defining at least two different predefined shoe sizes (FS) to be produced,

providing at least two basic direct injection molds, each of which is attachable and operable with an injection molding apparatus,

-for each of a plurality of basic direct injection molds, providing at least one set of corresponding direct injection mold inserts,

-wherein at least one set of corresponding direct injection mold inserts for each of the at least two base direct injection molds defines at least two different predefined shoe sizes.

By providing two different injection moulds defining different internal volumes, an injection mould having a relatively small/as small internal volume as possible can be selected, thereby minimizing the volume and size of the basic injection mould. This is important because if the volume and/or size of the insert becomes too large, the method can become very difficult to implement in a viable manufacturing environment. This may occur because the injected sole material is difficult to maintain at the desired temperature by cooling/heating or even passively, since the insert mold typically has very low thermal conductivity and effectively acts as an insulator between the injected material and the surrounding base mold if, for example, an insert is applied in a typical 3D printed material. If this happens, it is difficult to control the temperature by the heating/cooling means of the direct injection production apparatus to which the base mold is operatively attached.

This may lead to cavities in the sole or even to complete failure of the system, since in some cases the injected material may harden before it is evenly distributed in the mould.

In an embodiment of the invention, the thermal conductivity of the basic direct injection mold at room temperature is higher than 50W/(m × K), preferably higher than 100W/(m × K), most preferably higher than 150W/(m × K).

In an embodiment of the invention, the thermal conductivity of the direct injection mold insert at room temperature is below 5W/(m × K), such as below 2W/(m × K), such as below 1W/(m × K), such as below 0.5W/(m × K).

In an embodiment of the present invention, the cavities of the plurality of base direct injection molds differ in length (MCL) when attached to the injection molding apparatus.

In an embodiment of the present invention, the cavities of the plurality of base direct injection molds differ in width (MCW) when attached to the injection molding apparatus.

In an embodiment of the present invention, the cavities of the plurality of base direct injection molds differ in length (MCL) and width (MCW) when attached to the injection molding apparatus.

In an embodiment of the invention, the direct injection mold insert is adapted to fit corresponding base injection molds having different base Mold Cavity Widths (MCW).

In an embodiment of the invention, the direct injection mold insert is adapted to fit corresponding base injection molds having different base cavity lengths (MCLs).

In an embodiment of the invention, for a predefined shoe size, the base injection mold and the set of corresponding direct injection mold inserts are provided in order to keep the volume or size of the direct injection mold inserts as small as possible.

In an embodiment of the invention, the at least two basic molds and the corresponding basic injection mold differ in thermal conductivity.

In an embodiment of the present invention, the at least two basic direct injection molds may each be attached to the injection molding apparatus by means of a detachable fixture.

In an embodiment of the invention, the at least one set of direct injection mold inserts for each of the plurality of base direct injection molds defines different respective sizes of the predefined shoe size.

In one embodiment of the invention, the basic direct injection mold may be used for manufacturing involving one footwear design, and may be reused for manufacturing involving another footwear design.

In an embodiment of the invention, the base injection mold is selected from a plurality of available base molds.

In an embodiment of the invention, footwear is manufactured according to the direct injection production method of any of claims 21-34, and the method is performed in a mould system according to any of claims 1-20.

In an embodiment of the invention, the die insert material has a conductivity of less than 2 or 1W/(m × K).

In an embodiment of the invention, the maximum length of the direct thermal transfer path HTPI should be below 12cm, preferably below 10 cm.

In one embodiment of the present invention, the maximum length of the direct thermal transfer path HTPI is at least 0.5 cm.

Drawings

The invention will be explained in more detail below with reference to the drawings.

FIG. 1 shows a schematically illustrated last and mold seen in a cross-sectional view for direct injection molding of footwear according to the prior art;

FIG. 2 illustrates a schematically-illustrated base injection mold that may be used in connection with direct injection molding of footwear according to the present application;

FIG. 3 shows a schematic cross-sectional view of a footwear injection mold according to the present application;

4-7 show schematic cross-sectional views of the footwear injection mold from its open position to its closed position;

FIG. 8 illustrates a system according to embodiments of the invention;

FIGS. 9A-C illustrate a set of base molds within the scope of the present invention;

FIG. 10 illustrates a method of setting up a direct injection process for footwear according to an embodiment of the present invention;

11A and 11B illustrate advantageous features of embodiments of the invention;

FIG. 12a illustrates another embodiment of a direct injection mold insert;

FIG. 12b illustrates an embodiment of a cross-sectional view of a footwear injection molding system; and

fig. 12c is an enlarged view of the cut-out portion of fig. 12b, involving the flange region of the direct injection mold insert.

Detailed Description

Referring to fig. 1, a prior art molding system will be explained. This figure schematically shows a mold 2 and a last 20, both seen in cross-section, the last 20 and the mold 2 being usable for direct injection molding of footwear according to the prior art. The mould 2 may as mentioned already be made of metal, for example aluminium manufactured by e.g. CNC machinery, and may as shown in fig. 1 comprise a first side mould 4, a second side mould 6 and a bottom mould 8, which are arranged in such a way that the mould 2 can be opened and closed, for example movable in a horizontal direction as indicated by arrow A, B by the first side mould 4 and the second side mould 6 and in a vertical direction as indicated by arrow C by the bottom mould 8. As shown in fig. 1, the first side mould 4 and the second side mould 6 may be provided with a first side surface 5 and a second side surface 7, respectively, which are made during, for example, CNC milling and which generally define the desired pattern of the side of the sole to be moulded. Furthermore, the bottom mold 8 may be correspondingly provided with a bottom inner surface 8, which bottom inner surface 8 has been made during e.g. 8CNC milling and typically has a shape corresponding to the desired pattern of the underside of the sole to be molded.

Further, it is shown in fig. 1 that upper 30 may be placed on last 20, and that last 20, along with upper 30, may be moved in various directions, including downward relative to mold 2, as indicated by arrow D. It will be appreciated that when performing such a step, it is necessary that the mould 2 is in an open state to allow the last 20 to be moved into the mould 2. Mold 2 may thereafter be closed, thereby forming mold cavity 80 between upper 30, first side mold 4, second side mold 6, and bottom mold 8. The mould 2 is attached to an injection moulding apparatus (not shown in the figures, but illustrated as injection apparatus 11 in, for example, fig. 8) by means of which the injection material is injected into the mould cavity, where it comes into contact with the first side 5, the second side 7, the bottom inner surface 9 and the bottom part of the upper 30. When the injected material has the shape of the mold cavity, it is solidified.

Further details of the mold and molding process will be understood from the following, wherein the mold and molding process will be elucidated in connection with the accompanying fig. 2-7, which fig. 2-7 illustrate a direct injection apparatus and a direct injection process used in connection with the present application.

Fig. 2 shows a schematically illustrated basic direct injection mold 40 seen in a cross-sectional side view, which may be used in connection with direct injection molding of footwear according to the present application. The base direct injection mold 40 may include a first base side mold 42, a second base side mold 44, and a base bottom mold 46. It should be noted that more than these three base components may be used to form the base direct injection mold 40, e.g., two or more base side molds at one or both sides, etc.

Generally, it should be noted that these base parts are movable relative to each other, e.g. by means of a first base side mold 42 and a second base side mold 44, e.g. movable in a horizontal direction as indicated by the arrow, and by means of a base bottom mold 46, e.g. movable in a vertical direction as indicated by the arrow, whereby the base direct injection mold 40 may be arranged to open and close around the shoe last.

Furthermore, it should be noted that the base part is arranged to be coupled with an insert part (not shown here), for example by means of a base side coupling element 62 constituted by the first base side mould 42 and the second base side mould 44, for example on or in an inner surface of these, for example. Correspondingly, the base bottom mold 46 comprises a base bottom coupling element 66, for example on or in an inner surface of the base bottom mold 46.

Still further, it should be noted that base direct injection mold 40 may be configured to attach to an injection molding apparatus (not shown).

Fig. 3 shows a cross-sectional side view of a footwear injection mold 10 according to the present application, wherein the cross-sectional plane may be a vertical plane considered perpendicular to the longitudinal axis of the footwear injection mold. The footwear injection mold includes a base direct injection mold 40 and an insert component as described above, examples of which will be described below.

Accordingly, footwear injection mold 10 includes a base direct injection mold 40 having a first base side mold 42, a second base side mold 44, and a base bottom mold 46. Footwear injection mold 10 in fig. 3 is in an open state, wherein first base side mold 42, second base side mold 44, and base bottom mold 46 are spaced apart from one another, allowing access to the interior space from one or more locations, for example, for installation of inserts. The first base side mold 42, the second base side mold 44 and the base bottom mold 46 are provided with attachment means (not shown) allowing the base direct injection mold 42, 44, 46 to be attached to an injection molding apparatus (not shown), and wherein the attachment of the injection molding apparatus may be adapted to transfer heat from the injection molding apparatus to the base direct injection mold 42, 44, 46, such that the footwear injection mold may be heated to a predetermined temperature to optimize the injection molding of the footwear part in the mold cavity 80 (see e.g. fig. 6).

The first, second, and base side dies 42, 44, 46 may be provided with first, second, and bottom side inserts 52, 54, 56, respectively, wherein the first, second, and bottom inserts 52, 54, 56 may be coupled to the first, second, and base side dies 42, 44, 46, respectively. The first and second base side dies 42 and 44 may be provided with base side coupling elements 62 adapted to cooperate with insert side coupling elements 64 to allow the first and second side inserts 52 and 54 to be coupled with the first and second base side dies 42 and 44, respectively. The coupling elements 62, 64 may be adapted to retain the first and second side inserts 52, 54 relative to the first and second base side dies 42, 44, respectively, during an injection molding process. In a similar manner, the base bottom mold 46 may be provided with a base bottom coupling element 66 adapted to cooperate with a bottom insert coupling element 68 to allow the bottom insert 56 to be coupled to the base bottom mold 46. Coupling elements 66, 68 may be adapted to retain bottom insert 56 relative to base mold 46 during an injection molding process. Thus, it is ensured that first side insert 52, second side insert 54, and bottom insert 56 remain in place while footwear injection mold 10 is moved from its open position as shown in FIG. 4 to its closed position as shown in FIG. 6, and during the injection molding process as shown in FIG. 7.

As further shown in fig. 3, first side insert 52, second side insert 54, and bottom insert 56 may be coupled to first base side mold 42, second base side mold 44, and base bottom mold 46, respectively, when base direct injection mold 40 is in an open state, such as by engaging respective coupling elements 62, 64, 66, 68 as indicated by the dashed arrows in fig. 3. These coupling elements can be designed in various ways, for example as latching devices, self-locking devices, pressure couplings (press couplings), mating couplings (mating couplings) and the like. It should be noted that the first base side die 42, the second base side die 44 and the base bottom die 46 are shown in fig. 3 in a position separated from each other for clarity, so that the coupling with the insert components (e.g., 52, 54 and 56) can be further clearly seen.

Fig. 4 shows a cross-sectional view of footwear injection mold 10 corresponding to fig. 3, where first side insert 52, second side insert 54, and bottom insert 56 have been coupled to first base side mold 42, second base side mold 44, and base bottom mold 46, respectively. Further, footwear injection mold 10 has been arranged in an open state with last 20 carrying upper 30, placed in a position proximate to the opening of footwear injection mold 10.

The first side insert 52, the second side insert 54, and the bottom insert 56 may be adapted to provide the cavity 80 by providing a first side insert surface 53, a second side insert surface 55, and a bottom insert surface 57, the first side insert surface 53, the second side insert surface 55, and the bottom insert surface 57 providing the outer surfaces of the elements to be molded within the cavity 80. The upper portion of mold cavity 80 may be defined by upper 30, and upper 30 may be mounted on a last 20, which secures upper 30 relative to mold cavity 80. In addition, first side insert 52 and second side insert 54 are provided with flanges 70, wherein the flanges have a pattern and shape adapted to follow exterior surface 32 of upper 60. When flange 70 is pushed into contact with outer surface 32 of upper 30, as shown, for example, in fig. 5, the flange may close the mold cavity with bottom 34 of upper 30 and help prevent injection molding material introduced into mold cavity 80 from exiting mold cavity 80 through the upper opening of mold cavity 80.

The first and second side inserts 52, 54 may be provided with first and second contact surfaces 72, 74, respectively, at the bottom of the first and second side inserts 52, 54, which may be adapted to abut an upper contact surface 76 of the bottom insert surface 57. These contact surfaces may be adapted to enclose a mold cavity 80 between the first side insert 52, the second side insert 54, and the bottom insert 56. The contact surfaces may extend from the front ends (toe ends) of the first side insert 52, the second side insert 54, and the bottom insert 56 toward the respective rear ends (heel ends).

Further, the first side insert 52 and the second side insert 54 may have third and/or fourth contact surfaces (not shown) between the molds, wherein these contact surfaces may be positioned in areas where the first side insert 52 and the second side insert 54 separate the two sides of the mold cavity therebetween. Fig. 4 shows last 20 as having been introduced into the mold cavity, allowing the bottom of upper 30 to be exposed to the upper portion of mold cavity 80. Last 20 may be movable in a vertical direction into and out of mold cavity 80 so that when a footwear component has been molded into a vamp, last 20, upper 30, and the footwear component may be moved away from the mold cavity for removal and the next last and upper may be introduced into the mold cavity.

Fig. 5 shows a medial state of the footwear injection mold, in which first base side mold 42, second base side mold 44, first side insert 52, and second side insert 54 have been moved inward toward upper 30 in direction E, F, with flange 70 moved into contact with upper 30, and first side insert 52 and second side insert 54 contact each other at their toe and heel ends (not shown) to close off an upper portion of upper mold cavity 80. The flange 70 and the contact surface are forced into contact such that the flow of injection material cannot flow out of the mold cavity via the contact surface and the flange 70.

Prior to this movement, injection material 82 may be introduced into the mold cavity, for example, by introducing it into upper surface 57 of bottom insert 56 prior to closing footwear injection mold 10, wherein mold 10 may be closed to allow the injection material to expand to fill mold cavity 80 and bond to lower portion 34 of upper 30.

Fig. 6 shows the base mold 46 and bottom insert 56 having moved upward in vertical direction G, where bottom insert 56 abuts first side insert 52 and second side insert 54, thereby closing mold cavity 80. When footwear injection mold 10 is closed, mold cavity 80 is closed from the surrounding environment to ensure that injected material 82 takes the shape of mold cavity 80.

Fig. 7 shows the situation where the injected material 82 has expanded to fill the entire volume of the mold cavity 80, where the injected material 82 contacts the inner surfaces of the first side insert 52, the second side insert 54, and the bottom insert 56, leaving the outer surface of the injected material 82 in the shape of the mold cavity, and the inner surfaces of the first side insert 52, the second side insert 54, and the bottom insert 56 form the sole 100.

When injected material 82 has solidified, first and second base side dies 42, 44, along with first and second side inserts 52, 54, respectively, may move in a horizontal movement opposite direction E, F shown in fig. 5, and base bottom die 46, along with bottom insert 56, may move in a direction opposite direction G shown in fig. 6, thereby opening the footwear injection mold. Movement of first base side mold 42, second base side mold 44, and base bottom mold 46 allows first side insert 52, second side insert 54, and bottom insert 56 to be removed from injection material 82, and last 20, upper 30, and sole 100 to be removed from mold 10.

If the injection molding apparatus is used with a different type of shoe or a different size of shoe, first side insert 52, second side insert 54, and bottom insert 56 may be separated from base direct injection mold 40, e.g., from first base side mold 42 and second base side mold 44 and from base bottom mold 46, and replaced with another set of first side insert 52, second side insert 54, and bottom insert 57 that define an alternative mold cavity, and the last and upper are exchanged to close the upper portion of the mold cavity, wherein the additional set of first side insert, second side insert, and bottom insert may be coupled to base direct injection mold 40, e.g., to first base side mold 42 and second base side mold 44, and base bottom mold 46, respectively. Thus, the base direct injection mold 40 may be used for multiple (more than one) inserts, e.g., a first side insert, a second side insert, and a bottom insert, and the injection molding apparatus may be quickly prepared for injection of different types of articles of footwear.

Fig. 8 illustrates the system and some basic principles of an embodiment within the scope of the invention.

A plurality of base injection molds 400 are provided. Advantageously, one or more of the total number of base molds may be reused in previous manufacture of another design of footwear. The dimensions of the base mold may vary, for example, in relation to the thickness of the sidewalls. Alternatively, the same size may be produced in one batch, and then another size or another design produced with other mold inserts in another batch.

A plurality of mold inserts 500 are provided. The mold inserts are provided such that they define the desired dimensions with the corresponding base mold for injection molding in the desired design.

One or more molds 400 with corresponding inserts 500 are then attached to direct injection apparatus 11 for the manufacture of a plurality of articles of footwear 1000, wherein a sole is provided and molded to upper 300.

According to a preferred embodiment of the invention, the manufacturing system should comprise at least two different base molds and corresponding mold inserts.

Generally, it is within the scope of the invention that in a preferred embodiment the base mold and/or the components forming the base mold may be provided, for example, in cast or milled metal.

Within the scope of the invention, the insert may be made by different techniques. An attractive technique may be, for example, 3D printing. In this way, the same base mold can be used for different designs or batches, and then simply 3D printed mold inserts and used in combination with a universal base mold.

It should be noted that the fact shows that even insert molds provided by 3D printing of polymers or resins can be easily used in production lines of, for example, 5000 or 10000 pieces of footwear (such as shoes). The mold insert may need to be reprinted as more footwear lines are manufactured, such as 100000 pieces. It should be noted, however, that the manufacture of such further mold inserts may be relatively fast to manufacture, for example by 3D printing. This also means that such printing can be postponed until a need is detected.

The method and system according to the invention are therefore very dynamic and it is possible to construct a smaller series of shoes at less cost, since conventional moulds are extremely expensive and require a large amount of set-up time.

Figure 9A illustrates one advantageous embodiment and feature of the present invention. The illustrated embodiment includes a plurality of base molds, namely base injection molds 40 ', 40 ", 40'", and 40 "". These dies are shown in their respective cross-sections.

In the illustrated embodiment, a base mold, such as base mold 40', includes a mold set comprised of a first base side mold 42, a second base side mold 44, and a base bottom mold 46. The base mold and corresponding insert design are used for the manufacture of footwear of different sizes and/or footwear designs. The illustrated embodiment shows four different sizes of the same design.

Each of these molds 40 ', 40 "' and 40" ", form a separate base mold set that may be installed and operated with the footwear injection mold apparatus (11). The machine may be, for example, a direct-injection machine of DESMA, such as DESMA D522/24. To optimize the process, minor modifications can be made as long as the mold insert is applied.

The base mold set may be interchangeably assembled to the injection mold apparatus, thereby facilitating the manufacture of footwear by direct injection molding of each set of molds after assembly to the apparatus, with little manual adjustment required.

The base mold may be provided generally in metal (e.g., aluminum) to provide desired temperature conditions in the mold during molding. Such materials are known in the art, and the characteristics and injection molding equipment to operate such molds are also known in the art. Adjustment of the injection mold apparatus, whether manual or automatic, may of course be necessary or practical to facilitate optimal operation of the injection mold apparatus. Preferably, however, the injection mould apparatus itself can be operated as in the case of conventional injection moulds in terms of processing parameters, material usage etc.

The illustrated molds 40 ', 40 "' and 40" ", in this embodiment, are each formed of three different components, which, due to the geometric layout, may be advantageously applied to manufacture, for example, different sizes of the same footwear design.

It should be noted that 40 ', 40 "' and 40" ", preferably, should be designed to have the same or nearly the same periphery so that the mold can be mounted to injection molding apparatus 11 without the use of adapters or adjustments to injection molding apparatus 11.

In some embodiments of the invention, of course, such modifications may be applied or adapters used.

Fig. 9B illustrates that the direct injection mold inserts (52, 54, 56) have been inserted into the respective base molds, i.e., molds 40 ', 40 "' and 40" ". The system is shown in cross-section.

The illustrated system includes four base molds, each having a different corresponding mold insert. The system can of course design and apply other numbers of basic moulds depending on the manufacturing setup.

In this context, four base molds are provided in four different base sizes, and each corresponding mold insert is designed to provide a different size of the same footwear design.

Fig. 9C illustrates the direct injection molds 40 ', 40 "' and 40" "" of fig. 9B with embedded mold inserts 52, 54, 56. These dies are shown from above and in cross-section. Mold insert 56 is therefore not visible, but can be seen in the corresponding fig. 9B.

Of course, such manufacturing arrangements may vary significantly within the scope of the present invention. The main feature herein is that the base mold can be used as a universal mold, while the inserts can define unique footwear designs, e.g., differing only in size in the same footwear design.

The mold inserts for each of the illustrated base molds are different to provide different mold cavities. According to the invention, as indicated above, it is thus possible to provide a mould with as thin a mould insert as possible, even within a range of footwear sizes for a given footwear design.

This is advantageous because the direct injection molding process requires some degree of heating of the mold. If the thickness of the insert is too high, such heating is practically difficult to sustain during manufacture. Thus, the present method and system enable the manufacture of footwear inserts of different sizes.

Fig. 9C illustrates the designation of the base mold internal width MCW and base mold internal length MCL in their closed position during molding, when installed in and functionally operating with associated direct injection processing equipment (not shown). It is apparent that the illustrated system includes different base molds adapted for different shoe sizes 91-94, and that the illustrated base molds have different base mold interior lengths MCL and different base mold interior widths MCW. This is done in this embodiment to keep the thickness of the die inserts 52 and 54 as small as possible.

Fig. 10 illustrates another advantageous feature of an embodiment of the present invention.

The illustrated system includes a set of available base molds 400. These moulds may of course be made for this purpose, but may advantageously comprise a plurality of base moulds that can be used for any footwear series to be produced. The original figure shows that a total of eight base molds 400 are available. It goes without saying that some basic moulds may have the same dimensions, but that at least two basic moulds should be available in respect of the available moulds. This will be explained from the following description.

In the illustrated embodiment, three base molds 400 of different sizes are selected from the total number of available base molds. Also, the number of molds selected and the number of differently sized molds may be any suitable number so long as both are at least two and the number of base molds selected is at least the number of differently sized molds selected to meet the provisions of the present invention.

A 3D printing apparatus 700 is also provided and applied to 3D printing of a mold insert 500 cooperating with a selected base mold 400 one exemplary use of a combined base mold is illustrated in different aspects in fig. 2-6.

It should be emphasized that in the present industrial context, the basic mould is generally a mould having three parts, one bottom support and two sides. This is also illustrated in fig. 2-6. Of course, other numbers may be provided within the scope of the invention, so long as the sole can be molded to the upper and the molded footwear removed from the mold again. The same thing applies to the mold insert 500 and the description herein illustrates the use of three cooperating insert mold parts to create an effective working mold. Given the limitations given above, other numbers of sub-components forming the insert mold may be used within the scope of the present invention.

The three selected base molds 400 and the three correspondingly produced different insert molds 500 are then assembled to each other and to a direct injection manufacturing apparatus for manufacturing a plurality of articles of footwear 1000 and a base of direct injection material, such as polyurethane and a pre-formed upper 300, fed into apparatus 11. In the illustrative embodiment, three different series are provided, such as three different sizes or three different designs.

One of the many advantages associated with the illustrated method and system is that multiple base molds (of different sizes) may be applied to right/left shoes, shoes of different sizes, and/or different footwear/sole designs without the need for expensive milling of conventional molds. Such systems require the production of separate metal molds for each size and design, and the process of manufacturing such molds is very time consuming and expensive.

By applying different sized molds it may further be ensured that the insert may be applied with a minimum thickness/volume of 3D printed material. This is important because it is generally understood that direct injection molding requires reasonably high heat transfer capability of the mold in order to be able to maintain the mold at a desired temperature throughout the manufacturing process. The process includes cooling during manufacturing and heating during initial start-up.

While typical insert mold materials may be polymers or resins, natural or synthetic, the system of the present invention enables manufacturing. In this context it should be noted that such polymers generally have a relatively low heat transport compared to metals such as aluminium.

Thus, despite the differences in heat transfer characteristics of the applied insert mold material and the base mold material, many different sized base molds may have relatively "thin" insert molds and thereby produce footwear.

Fig. 11A and 11B illustrate considerations when applying methods and systems in accordance with embodiments of the present invention. This illustration is of course simplified, but helps to define and explain key design features according to advantageous embodiments of the present invention.

Fig. 11A and 1IB correspond to fig. 9B and 9C, but some explanation of the thermal conductivity of the base direct injection mold and mold insert is now made.

As previously described, a base mold, such as base mold 40', includes a mold set comprised of a first base side mold 42, a second base side mold 44, and a base counter mold 46.

The base mould and the base mould part are made of a material, such as aluminium, preferably a material having a high thermal conductivity, such as higher than 150W/(m × K).

The base mold is also fitted with mold inserts 52, 54, 56. The mold inserts are adapted to mate with corresponding differently sized cavities of the base molds 40 ', 40 "' and 40" ".

One typical challenge with mold inserts is that mold inserts having high thermal conductivity, which can be expensive, are manufactured using, for example, conventional milled aluminum blocks.

According to a preferred embodiment of the invention, an alternative way of manufacturing the inlay is by means of 3D printing. The most popular 3D printing materials are relatively cheap, but the thermal conductivity is typically below 1.0W/(m × K).

The illustrated embodiment will now be explained with reference to thermal characteristics. For each of the sizes 91 to 94 to be produced, an exemplary heat transfer path HTPI of the inserts 52, 54, 56 is illustrated, highlighting that the design of a set of base molds 40 ', 40 "', and 40" ", facilitates substantially the same heat transfer performance of the inserts, even if the heat transfer path of the base mold HTPBM is varied when producing footwear of different sizes. At least, and surprisingly, the applied system and method can advantageously provide a system and method that can both provide high quality DIP footwear, as well as be part of a system and method that can easily switch between different footwear designs and/or sizes, and that can also reduce manufacturing costs, by using a set of basic molds of different internal dimensions with high thermal conductivity, and mold inserts designed to be as small as possible with relatively low thermal conductivity, because the mold inserts provided by conventional 3D materials such as photopolymers can be manufactured relatively inexpensively and quickly compared to any method and system known in the art.

To improve the thermal conductivity between the mold insert and the base mold, a thermally conductive paste may be applied to the surface between the base mold component and the mold insert.

It is difficult to provide specific guidelines as to how precise size/volume limits should be designed to optimize, as these values depend on the mold insert material being used. For mold insert materials with an electrical conductivity of less than 2 or 1W/(m × K), the maximum length of direct thermal transfer path HTPI should be less than 12cm, preferably less than 10 cm. It should be noted, however, that the minimum length is, for example, about 1 centimeter.

Fig. 12a-12c illustrate another embodiment of direct injection mold inserts, particularly a first side insert 52 and a second side insert 54. Thus, fig. 12a shows an embodiment of a cross-sectional view of a pair of first and second side inserts 52, 54, corresponding to the example shown in fig. 3-7, for example. However, the insert flanges 70 of the side inserts shown in FIGS. 12a-12c are configured in a particular manner as will be explained below.

Fig. 12b corresponds to fig. 7 and thus shows an embodiment of a cross-sectional view of footwear injection molding system 10 in which the footwear component is molded and the side insert as shown in fig. 12a is applied. Thus, the injected material is shown having expanded to fill the mold cavity to form the sole 100, as explained in connection with, for example, fig. 3-7.

Fig. 12b shows that the injected material has expanded to fill the entire volume of the injection chamber and thus has been in contact with the inner surfaces 53, 55, 57 of the first side insert 52, the second side insert 54 and the bottom insert, respectively, and the outer surface 32 of the upper 30, thereby causing the injected material to assume a corresponding shape to form the sole 100.

When the injected material has solidified, first and second base side molds 42, 44, along with first and second side inserts 52, 54, respectively, may be moved in, for example, a horizontal motion, and base bottom mold 46, along with bottom insert 56, may be moved, for example, as follows, to open the footwear injection mold, whereby last 20, upper 30, and sole 100 may be removed from mold 10.

In fig. 12b, flange 70 is pushed into contact with exterior surface 32 of upper 30. Flange 70 thereby closes (seals) the injection chamber with the bottom of upper 30 and assists in preventing injection material introduced into the injection chamber from exiting the injection chamber through the upper portion of the injection chamber. Flange 70 may have a shape adapted to follow exterior surface 32 of upper 30.

The features of the first side insert 52 and the second side insert 54, and in particular the flange 70, will be explained in further detail below with reference to fig. 12c, which is an enlarged view of the cut-out portion 110 shown in fig. 12b, wherein the circular cut-out portion 110 is associated with the flange region of the first side insert 52. However, it will be understood that the following explanations apply equally to the second side insert 54, the flange 70 thereof, and the like.

In fig. 12c, cut-out portion 110 shows flange 70 in contact with exterior surface 32 of upper 30, where flange 70 may have a shape adapted to follow exterior surface 32 of upper 30. The flange 70 may be in the form of a ridge.

The shape of the flange 70 and the outer surface 32 is shown as being flat and extending in a plane (e.g., a vertical plane). It is apparent that the flange 70 and the outer surface 32 may have various other shapes, such as rough, curved, curvilinear.

Flange 70 may include an upper contact surface 112 for contacting outer surface 32 of upper 30, a connecting end 114 connected to first side insert 52, an upper surface 116 facing away from the injection chamber, and a lower surface 118 facing the injection chamber, as shown in FIG. 12 c.

The flange 70 may have a height h2 at the connection end 114 of the flange 70, with the height h2 being greater than the height h1 at the upper contact surface 112 of the flange 70 relative to the normal a to the upper contact surface 112. The normal a of the upper contact surface 112 is arranged to intersect the center point of the upper contact surface 112 as seen in the height direction, as shown in fig. 12 c. A flange plane is defined along a width of the flange 70 by a normal a to the upper contact surface 112, the flange plane configured to define a boundary between an upper half 120 and a lower half 122 of the flange 70, the upper half 120 disposed between the flange plane and the upper surface 116, the lower half 122 disposed between the flange plane and the lower surface 118.

The flange 70 has a length 11 (shown in fig. 12 c) defined by the distance from the upper contact surface 112 to the connection end 114 along the normal a to the upper contact surface 112.

In one example, the height h1 may be in the region between 2 and 6mm, where the height h1 may be more specifically between 3 and 5mm, or even more specifically about 4 mm. The height h1 of the upper contact surface 112 has been shown to be greater than 2mm because the lower thickness may cause the material to bend, deform or warp during injection. This may be particularly the case if the mold insert is 3D printed from, for example, a polymer material.

In contrast, a conventional mold made of aluminum or other metal substance may have an upper contact surface height h1 of approximately 1.5 millimeters.

In one example, the height h2 may be between 6 and 15mm, wherein the height h2 may be more specifically between 7 and 12mm, wherein the height may be more specifically between 5-8 and 10 mm. The increased height h2 provides support for the flange, especially when the material is 3D printed from, for example, a polymer material. In contrast, a conventional mold made of aluminum or other metallic material may have a height h2 of approximately 2-3 millimeters.

In one embodiment, the size ratio between height h1 and h2 may be about 1:2, where h2 may be twice height h 1. In one embodiment, the size ratio may be about 1:1.5, with height h2 being 50% greater than h 1.

In an exemplary embodiment, the length of the flange 11 may have a dimension at least greater than the height h2, i.e., the length ratio between the length of the flange and the height h2 is at least 1:1. In another embodiment, the length of the flange may have a dimension less than the height h2, i.e., l1 < h 2. Thus, the height h2 provides support for the length of the flange, where the height h2 of the flange may have to increase as the length 11 increases.

List of reference numerals

2 mould

4 first side form

5 first side surface

6 second side die

7 second side

8 bottom die

9 bottom inner surface

10 moulding system

11 injection moulding apparatus

20 shoe tree

30 shoe upper

32 outer surface of shoe upper

34 bottom of shoe upper

40 basic direct injection mould

42 first base side form

44 second base side form

45 second side insert surface

46 base bottom die

50 set direct injection mold insert

52 first side insert

53 first side insert surface

54 second side insert

55 second side insert surface

56 bottom insert

57 bottom insert surface

62 base-side coupling element

64 insert-side coupling element

66 base bottom coupling element

68 bottom insert coupling element

70 insert flange

72 first contact surface

74 second contact surface

76 upper contact surface

80 die cavity

82 injection material

91-93 for different moulds, e.g. of different sizes

100 sole

110 cut-out part

112 upper contact surface

114 connecting end

116 upper surface

118 lower surface

120 upper half part

122 lower half

300 shoe upper

400 basic mould

500 insert die

7003D printing equipment

1000 article of footwear

FS shoe size

Heat transfer path for HTPI injection mold

Heat transfer path of HTPBM basic mold

Width of MCW basic die cavity

MCL base cavity length

A is perpendicular to the upper contact surface 112 (at the center point)

h1 height of flange at contact surface

height of flange at connection end of h2

l1 Length of Flange