阅读说明：本技术 包含一个或多个浸渍非织造织物层的传送机带芯 (Conveyor belt core comprising one or more impregnated nonwoven fabric layers ) 是由 布伦特·怀特海德 米歇尔·泰勒 马歇尔·莱特 于 2019-10-10 设计创作，主要内容包括：本发明提供了一种带芯(1),其包括一个、两个或多于两个的浸渍层(21、22、23、24、25)；其特征在于,i)每个浸渍层(21,22,23,24,25)包括或基本上由非织造织物(3,301,302,303,304,305,306,307,308)和浸渍材料(4,401,402,403,404,405,406,407,408)组成,该浸渍材料包括或基本上由第一热塑性塑料、第一热塑性弹性体、第一弹性体或第一热固性塑料和可选的添加剂组成；由此,如果有两个或多个这样的浸渍层(21,22,23,24,25),这些浸渍层彼此相邻,ii)如果带芯(1)包括一个或多个这样的浸渍层(21,22,23,24,25),则至少部分地在一个给定方向上延伸并且呈一个细丝层(51)形式的增强细丝嵌入所述浸渍层(21)中的恰好一个的非织造织物(3)中；或者如果带芯(1)包括两个或更多个这样的浸渍层(21,22,23,24,25),那么至少部分地在一个给定方向上延伸并且呈恰好一个细丝层(52,53)的形式的增强细丝被夹在两个相邻的这样的浸渍层(21/22,24/25)之间,并且iii)该带芯没有织造织物。这种带芯可以被切割成纵向带或切割成圆盘或转角带。(The invention provides a tape core (1) comprising one, two or more than two impregnation layers (21, 22, 23, 24, 25); characterized in that i) each impregnation layer (21, 22, 23, 24, 25) comprises or essentially consists of a nonwoven fabric (3, 301, 302, 303, 304, 305, 306, 307, 308) and an impregnation material (4, 401, 402, 403, 404, 405, 406, 407, 408) comprising or essentially consisting of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives; whereby, if there are two or more such impregnated layers (21, 22, 23, 24, 25), which are adjacent to each other, ii) if the belt core (1) comprises one or more such impregnated layers (21, 22, 23, 24, 25), reinforcing filaments extending at least partially in a given direction and in the form of one filament layer (51) are embedded in the nonwoven fabric (3) of exactly one of said impregnated layers (21); or if the belt core (1) comprises two or more such impregnated layers (21, 22, 23, 24, 25), reinforcing filaments extending at least partially in one given direction and in the form of exactly one filament layer (52, 53) are sandwiched between two adjacent such impregnated layers (21/22, 24/25), and iii) the belt core is free of woven fabric. Such tape cores may be cut into longitudinal tapes or into circular discs or corner tapes.)

1. A tape core (1) comprising one, two or more than two impregnation layers (21, 22, 23, 24, 25); the method is characterized in that:

i. each impregnation layer (21, 22, 23, 24, 25) comprises or essentially consists of a nonwoven fabric (3, 301, 302, 303, 304, 305, 306, 307, 308) and an impregnation material (4, 401, 402, 403, 404, 405, 406, 407, 408), the impregnation material comprising or essentially consisting of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives, whereby, in the case of a laminate having two or more impregnation layers (21, 22, 23, 24, 25) in the case of (2), the impregnation layers are adjacent to each other,

in case the belt core (1) comprises one or more of the impregnation layers (21, 22, 23, 24, 25), reinforcing filaments extending at least partially in one given direction and in the form of one filament layer (51) are embedded in the nonwoven fabric (3) of exactly one of the impregnation layers (21); or

In the case that the tape core (1) comprises two or more of the impregnation layers (21, 22, 23, 24, 25), reinforcing filaments extending at least partially in one given direction and in the form of exactly one filament layer (52, 53) are sandwiched between two adjacent impregnation layers (21/22, 24/25), and

the belt core is free of woven fabric.

2. Belt core (1) according to claim 1, wherein each nonwoven is completely filled with an impregnation.

3. Belt core (1) according to claim 1 or 2, characterized in that the filament layer (51) is embedded in one or more of the non-woven fabrics of exactly one of the impregnation layers (21) and that the belt core (1) comprises 1 to 8 impregnation layers (21, 22, 23, 24, 25).

4. Belt core (1) according to claim 1 or 2, characterized in that the filament layer (52, 53) is sandwiched between two adjacent impregnation layers (21/22, 24/25) and that the belt core (1) comprises 2 to 8 impregnation layers (21, 22, 23, 24, 25).

5. Tape core (1) according to any one of claims 1 to 4, wherein the filament layer (51, 52, 53) comprises reinforcing filaments in the form of a first array of parallel reinforcing filaments.

6. A tape core according to claim 5 wherein the layer of filaments (51, 52, 53) further comprises a second array of parallel reinforcing filaments extending perpendicular to the filaments of the first array.

7. Tape core (1) according to any one of claims 1 to 4, wherein the filament layer (51, 52, 53) is in the form of a grid of reinforcing filaments having a square or rectangular grid.

8. Belt core (1) according to any one of claims 1 to 4, wherein the filament layers (51, 52, 53) are in the form of a grid with diamond shaped meshes.

9. Conveyor core (1) according to one of claims 1 to 8, characterized in that all impregnation layers (7, 21, 22, 23, 24, 25) comprise the same impregnation material or in that the impregnation layers (7, 21, 22, 23, 24, 25) comprise different impregnation materials.

10. Linear belt, obtainable from a belt core according to any one of claims 1 to 9 by cutting a linear belt of the desired width and length from the belt core such that the one given direction is in the length direction of the cut linear belt, wherein the reinforcing filaments extend at least partially in the one given direction, wherein the linear belt is in particular a conveyor belt, a machine belt, a power conveyor belt or a spindle belt.

11. Corner tape obtainable by cutting a circular section from a tape core according to claim 7, wherein the filament layer (51, 52, 53) is in the form of a grid of reinforcing filaments having a square mesh.

12. A method for manufacturing a tape core according to claim 1, said tape core comprising one or more impregnation layers (21, 22, 23, 24, 25), said method comprising the steps of:

i-1) providing a first non-woven sub-layer (31), a second non-woven sub-layer (32) and reinforcing filaments in the form of a filament layer (51), wherein the reinforcing filaments extend at least partially in one given direction;

i-2) arranging the filament layer (51) at the top of the second nonwoven sublayer (32) and the first nonwoven sublayer (31) at the top of the filament layer (51);

i-3) joining together the first and second nonwoven sub-layers (31, 32) to form a first nonwoven fabric (3) in which reinforcing filaments (51) are embedded, wherein the reinforcing filaments (51) extend at least partially in the given filament direction;

i-4) impregnating the first nonwoven fabric (3) with a first impregnating material (4) comprising or essentially consisting of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives to form a first impregnated layer (21) embedded with a filament layer (51);

i-5) optionally and independently of steps i-1) to i-4), or

i-5-a) providing one or more further nonwoven fabrics (303, 304, 305) and one or more further sheets (403, 404, 405) of a further impregnating material comprising or consisting essentially of a further thermoplastic, a further elastomer or a further thermoset and optional additives;

i-5-b) arranging said one or more further nonwoven fabrics (303, 304, 305) and said one or more further sheets (403, 404, 405) adjacent to and adjacent to said first impregnation layer (21) and to each other such that there is at least one further sheet immediately adjacent to any nonwoven fabric and at least one further nonwoven fabric immediately adjacent to any further sheet;

i-5-c) impregnating any further nonwoven fabric with impregnating material from the at least one further sheet immediately adjacent to the nonwoven fabric by means of heat and pressure simultaneously to form respective impregnated layers (21, 22, 23, 24, 25), and bonding any of the impregnated layers (21, 22, 23, 24, 25) and the first impregnated layer (21) together; or

i-5-d) providing one or more further impregnation layers (22, 23, 24, 25), each further impregnation layer comprising or consisting of a further nonwoven fabric impregnated with a further impregnation material comprising or consisting essentially of a further thermoplastic, a further elastomer or a further thermoset and optional additives, and each further impregnation layer being free of reinforcing filaments;

i-5-e) arranging said one or more further impregnation layers (22, 23, 24, 25) adjacent to said first impregnation layer (21) and to each other; and bonding any of said further impregnation layers (21, 22, 23, 24, 25) and said first impregnation layer (21) together using heat and pressure.

13. A method for manufacturing a tape core according to claim 1, said tape core comprising two or more impregnation layers (21, 22, 23, 24, 25), said method comprising the steps of:

ii-1) providing a first nonwoven (301), a second nonwoven (302), a first sheet of a first impregnated material (401), a second sheet of a second impregnated material (402) and reinforcing filaments, the first impregnated material comprising or consisting essentially of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives, the second impregnated material comprising or consisting essentially of a second thermoplastic, a second thermoplastic elastomer, a second elastomer or a second thermoset and optional additives, and the reinforcing filaments are in the form of a filament layer (52), wherein the reinforcing filaments extend at least partially in one given direction;

ii-2) arranging the filament layer (52), the first non-woven fabric (301), the second non-woven fabric (302), the first sheet (401) and the second sheet (402) adjacent to each other such that the first non-woven fabric (301) and the first sheet (401) are present on one side of the filament layer (52) and the second non-woven fabric (302) and the second sheet (402) are present on the other side of the filament layer (52), thereby sandwiching the filament layer (52) between the first non-woven fabric (301) and the first sheet (401) on the one hand and the second non-woven fabric (302) and the second sheet (402) on the other hand to form a layered composite (6);

ii-3) optionally and independently of steps ii-1) to ii-2), or

ii-3-a) providing one or more further nonwoven fabrics (303, 304, 305) and one or more further sheets (403, 404, 405) of a further impregnating material comprising or consisting essentially of a further thermoplastic, a further elastomer or a further thermoset and optional additives;

ii-3-b) arranging the one or more further nonwoven fabrics (303, 304, 305) and the one or more further sheets (403, 404, 405) adjacent to the layered composite (6) and to each other such that there is at least one further sheet in close proximity to any nonwoven fabric and at least one further nonwoven fabric in close proximity to any further sheet;

ii-3-c) impregnating any nonwoven (301 or 302 or 303 or 304 or 305) with an impregnating material from the at least one further sheet (401 or 402 or 403 or 404 or 405, respectively) immediately adjacent to the nonwoven by means of heat and pressure simultaneously to form a respective impregnated layer (21 or 22 or 23 or 24 or 25, respectively); and bonding all of said impregnated layers (21, 22, 23, 24, 25) and said laminar composite (6) together; or

ii-3-d) providing one or more further impregnation layers (22, 23, 24, 25), each further impregnation layer comprising or consisting of a further nonwoven fabric impregnated with a further impregnation material comprising or consisting essentially of a further thermoplastic, a further elastomer or a further thermoset and optional additives, and each further impregnation layer being free of reinforcing filaments;

ii-3-e) arranging said one or more further impregnation layers (22, 23, 24, 25) adjacent to said layered composite (6) and to each other;

ii-3-f) bonding any of said further impregnation layers (21, 22, 23, 24, 25) and said layered composite (6) together using heat and pressure,

wherein the filament direction will form the direction of travel of the belt.

14. A method for manufacturing a tape core according to claim 1, said tape core comprising two or more impregnation layers (21, 22, 23, 24, 25), said method comprising the steps of:

iii-1) providing reinforcing filaments in the form of a filament layer (53), and a first impregnation layer (21), wherein the reinforcing filaments extend at least partially in one given direction, the first impregnation layer comprising or consisting of a first nonwoven fabric, which is impregnated with a first impregnation material comprising or consisting essentially of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optionally additives, but the first nonwoven fabric is free of reinforcing filaments;

iii-2) or

iii-2-a) providing one or more further nonwoven fabrics (306, 307, 308) and one or more further sheets (406, 407, 408) of a further impregnating material comprising or consisting of a further thermoplastic material, a further thermoplastic elastomer, a further elastomer or a further thermosetting material and optional additives, the number of further nonwoven fabrics (306, 307, 308) being equal to the number of further sheets (406, 407, 408), and the number of further nonwoven fabrics (306, 307, 308) being designated as K;

iii-2-b) arranging a further nonwoven fabric (306), a further sheet (406) and optionally the filament layer (53) on one side of the first impregnation layer (21) and adjacent to the first impregnation layer (21) such that, with the provision of the optional filament layer (53), the filament layer (53) is sandwiched on the one hand between the first impregnation layers (21) and on the other hand between the further nonwoven fabric (306) and the further sheet (406);

iii-2-c) impregnating the further non-woven fabric (306) with impregnating material from the further sheet (406) using heat and pressure simultaneously to form a further impregnated layer (22), and bonding together the first impregnated layer (21), the optional sandwiched filament layer (53) and the further impregnated layer (22) to form a bonded laminar composite (7);

iii-2-d) using a further pair (307/407, 308, 408) of a further nonwoven fabric and a further sheet material being a sheet material of a further thermoplastic, a further thermoplastic elastomer, a further elastomer or a further thermoset plastic and optional additives, repeating steps iii-2-b) and iii-2-c) K-1 times on the combined layered composite (7), but in total the filament layer (53) is used exactly once in steps iii-2-b) and iii-2-c) and in the repeating steps of steps iii-2-b) and iii-2-c); or

iii-2-e) providing one or more further impregnation layers (22, 23, 24, 25), each comprising or consisting of a further nonwoven fabric, which further nonwoven fabric is impregnated with a further impregnation material, which further impregnation material comprises or consists essentially of a further thermoplastic, a further thermoplastic elastomer, a further elastomer or a further thermoset and optional additives, the number of further impregnation layers (22, 23, 24, 25) being designated as K;

iii-2-f) arranging a further impregnation layer (22) on one side of the first impregnation layer (21) and adjacent to the first impregnation layer (21) such that, with the provision of the optional filament layer (53), the filament layer (53) is sandwiched between the first impregnation layer (21) on the one hand and the second impregnation layer (22) on the other hand;

iii-2-g) bonding together the first impregnated layer (21), the optional sandwiched filament layer (53) and the further impregnated layer (21) using heat and pressure to form a bonded laminar composite (7);

iii-2-h) repeating steps iii-2-f) and iii-2-g) K-1 times on the bonded layered composite (7), using one of the further impregnation layers (23, 24, 25) in each repetition, but in the steps iii-2-f) and iii-2-g) and in the repetition of steps iii-2-f) and iii-2-g), the filament layer (53) is used exactly once in total.

Technical Field

The invention relates to a belt core, in particular for a conveyor belt, a machine belt, a power transmission belt or a spindle belt, comprising an impregnation layer and reinforcing filaments.

Background

Woven fabric-based belts are widely used as, for example, conveyor belts, machine belts, or power transmission belts. The woven fabric serves as a traction layer. The fabric is also flexible. Belt flexibility is required to allow the belt to bend over small radius wheels. However, since woven fabrics always have some elasticity in the longitudinal (belt running) direction, the belts so produced may not have sufficient tenacity in the longitudinal direction. To counteract this, it has also been proposed to additionally include high tenacity reinforcing filaments extending in the longitudinal direction of the belt into the belt, as an alternative to or in addition to the woven fabric.

In many cases, the woven fabric is covered with a polymeric material. The coating seals the fabric from the environment. This prevents contamination of the conveyed articles with fabric fibers, which would require edge sealing of the woven fabric as an additional manufacturing step if the belt started to wear and was uncoated, in order to prevent such fiber contamination or further degradation of the woven material. The coating may also act as a support for the subsequent cover layer(s) that the strip may have in order to adapt its intended application, and also give the cover layer(s) the same geometrically well-defined surface(s) due to its said geometrically well-defined surface(s).

In order to best adhere the coating(s) to the woven fabric, at least partially hairy natural fibers may be included (these fibers help adhere to the coated material through their hairy mechanical attachment points); alternatively, the adhesion promoter is used in combination with synthetic fibers substantially free of such hairy attachment points. However, the effectiveness of adhesion promoters is reduced due to the subsequent manufacturing and manufacturing processes of synthetic fabric-based tapes and demanding product applications (especially extreme heating/cooling and repeated high stress applications), leading to poor product integrity and separation along the interface, which leads to various undesirable (delamination/separation) product performance (durability, lifetime) problems.

Both the coating and the reinforcing longitudinal fibers in the strip may cause the following problems: i.e., during belt use and bending on a wheel, these longitudinal fibers begin to cut longitudinally through the coated material, which can lead to premature belt failure. It has therefore been proposed to embed and wrap such reinforcing fibers in a woven fabric. Here, the transverse (filling) fibers of the fabric prevent, at least to some extent, said longitudinal cutting. GB 1390603 discloses a conveyor belt in which a woven fabric is embedded with longitudinal reinforcing filaments.

Us patent 2008/078657 a1 discloses a conveyor belt having at least two nonwoven layers, which may be needle felt, and are preferably needle punched together. One of the two nonwoven layers is in contact with the elastomer 12, and preferably both nonwoven layers are impregnated with the elastomer 12. Such a conveyor belt has no reinforcing filaments.

Us patent 2008/0164127 a1 discloses a conveyor belt having a nonwoven layer, a woven layer and optionally a second nonwoven layer such that the nonwoven layers are on opposite sides of the woven layer, the nonwoven layers being needled together. An elastomer is used to join the woven and nonwoven layers. The elastomer may optionally be impregnated into the belt core to the extent desired and adjustable. In one embodiment, one side of the resulting belt core is saturated with elastomer 12 while the other side remains bare. Example 1 discloses a conveyor belt having two layers of nonwoven and a core woven scrim with an overlay layer of a synthetic rubber compound. The nonwoven layer itself is free of reinforcing filaments.

JP 2007/137993 a discloses a heat-resistant conveyor belt comprising a nonwoven fabric layer 2 laminated to a base fabric 3 consisting of several layers of warp yarns 11 and weft yarns 12. The nonwoven textile layer 2 and the base fabric 3 are needled together. Optionally, there may be another layer of non-woven textile 5 on the other side of the base fabric 3. The base fabric 3 is impregnated with a resin material. There are no other reinforcing filaments than the warp yarns 11 which are said to have "high strength".

GB 1354689 discloses an elastomeric article which may be a conveyor belt having a reinforcement comprising an assembly of longitudinally extending continuous parallel filaments. This elastomeric article preferably further comprises a woven fabric reinforcement layer. In example 3, a reinforcing tape is disclosed in which a carded web of PET staple fibers is saturated with an aqueous latex dispersion and "laid on top of and in contact with an assembly of parallel filaments".

WO 2017/102768 a1 describes a sheet material consisting of a mixture consisting essentially of randomly oriented fibres and a thermoplastic or thermoplastic elastomer and its use as a support in punching applications or as a top layer in punching belts. The sheet itself may be made of N geometrically well-defined polymer sheets and K types of fibers, wherein each K-th type of fiber may be in the form of a respective pre-assembled sheet, such as a nonwoven fabric.

The present invention seeks to provide an improved belt core which takes into account all of the aforementioned facts and problems, and which is suitable for use in the manufacture of different belt types therefrom.

Disclosure of Invention

Accordingly, the present invention provides:

a tape core comprising one, two or more impregnated layers; it is characterized in that

Each impregnated layer comprises or consists essentially of a nonwoven fabric and an impregnating material comprising or consisting essentially of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives; thus, if there are two or more such impregnated layers, they are adjacent to each other, and

if the belt core comprises one or more such impregnated layers, reinforcing filaments extending at least partially in one given direction and in the form of one filament layer are embedded in the nonwoven of exactly one of said impregnated layers; or

If the tape core comprises two or more such impregnated layers, the reinforcing filaments, which extend at least partially in one given direction and are in the form of exactly one filament layer, are sandwiched between two adjacent such impregnated layers.

Preferred embodiments of the tape core, methods for its manufacture and embodiments of the tape produced therefrom are in accordance with the claims.

Drawings

Fig. 1 shows a transparent top view of a tape comprising different embodiments of embedding of a filament layer of reinforcing filaments.

Fig. 2 shows a schematic process for making a nonwoven fabric comprising an embedded filament layer of reinforcing filaments.

Fig. 3 shows different process embodiments for producing tape cores of the present invention.

Detailed Description

It has been surprisingly found that by constructing a belt core from one or more layers of impregnated nonwoven fabric (wherein either exactly one of the impregnated layers also comprises exactly one embedded filament layer comprising reinforcing filaments running at least partially in a given filament direction, or wherein exactly one filament layer comprising reinforcing filaments running at least partially in a given filament direction is sandwiched between two such impregnated layers), belts cut from such a belt core in such a way (i.e. in the direction of travel of the filaments that will form the belt) have considerable flexibility relative to belts comprising woven fabric and other identical constructions. It is observed that said exactly one layer of filaments will tend to form one possible neutral plane of a linearly running belt cut out of such a belt core. It has also been found that leaving the remaining impregnated layers free of any embedded reinforcing filaments and without sandwiching any additional reinforcing filaments between them will provide maximum compressibility on the concave side of the belt and maximum stretchability on the convex side of the belt, thereby providing maximum flexibility to allow easy bending around small wheels. It has further been found that by embedding such reinforcing filaments in the nonwoven fabric of the impregnation layer or by sandwiching such reinforcing filaments between two adjacent impregnation layers each comprising a nonwoven fabric, the above-mentioned longitudinal cutting through of the impregnation material of the impregnation layer can be prevented. It has also been found that belts made from the belt cores of the present invention without the use of any woven fabric traction layer(s) in common provide comparable toughness to belts having woven fabric traction layer(s). It was also observed that the tape of the invention has a reduced noise level during operation, while maintaining tenacity and resistance to impregnation delamination, which may be attributed to the complete absence of interlacing nodes, which in turn is attributed to the absence of woven fabric (no "washboard" effect as mentioned in US 2008/0164127 a 1).

The term "belt core" as used herein refers to a laminar, layered composite comprising all the required layers, that is, one filament layer comprising reinforcing filaments and one, two or more impregnated layers each comprising a nonwoven fabric, but the laminar, layered composite does not necessarily have the spatial shape of a conveyor belt. As used herein, a "tape core" may be cut into one or more tapes of the invention of suitable size and width, provided that in the case of a tape intended for a linear direction of travel (hereinafter also referred to as a "linear tape"), the cutting of the tape(s) is carried out in such a way that the orientation of the filaments in one single filament layer will form the final intended direction of travel of the linear tape(s) so produced.

In the belt core of the invention, the reinforcing filaments form a single filament layer which is either embedded in the nonwoven fabric of a single impregnation layer or sandwiched between the nonwoven fabrics of two adjacent impregnation layers.

The reinforcing filaments form a layer of filaments in a plane parallel to the length (y) and width (x) of the tape core of the present invention (i.e., the thickness z of the tape core is perpendicular to this plane). If the filament layer is embedded in the nonwoven fabric, the vertical position of the filament layer is preferably in the thickness D of the nonwoven fabric contained therein_mpIn the range of 20% to 80%, more preferably in the range of 40% to 60% thereof, wherein D_mpThe definitions and measurements are made as explained herein below. By appropriate selection of the thickness D of the first and second nonwoven sub-layers_mpSuch vertical position can be easily controlled and the first and second nonwoven sub-layers can be joined together by chemical, thermal bonding or mechanical needling or by hydroentanglement to form a nonwoven fabric with embedded reinforcing filaments, as will also be explained below.

One filament layer contains "reinforcing filaments" which are intended to increase the toughness of the belt at least in the direction of travel of the belt. It is envisaged that the reinforcing filaments are preferably neither interlaced nor interwoven and each have one or more subsections which are each substantially straight and run without bends and which extend at least partially in a given direction which, in a linear strip cut from the strip core, will be the direction of travel of the strip.

For the purposes of the present invention, the term "extending at least partially in one given direction" shall mean that the quotient r calculated from all the reinforcing filaments contained in the entire tape is of the formula:

is at least 0.5. In equation (1):

-L_ik(in m) is the length of the kth straight subsection of the ith filament (e.g., the length of a single edge of a single lattice, i.e., the lattice dimension);

-ρ_ik(in g/m)³In units) is the material density of the kth straight subsection of the ith filament;

-cos(α_ik) Is the cosine of the angle that said k-th straight subsection of the ith filament has with respect to said one given direction;

-T_ik(in g/m) is the linear density of the kth straight subsection of the ith filament;

-the sum is performed over all K straight subsections of the ith filament; and is

-all I reinforcing filaments contained in the strip and carried out as per I.

For a layer of reinforcing filaments in the form of one or two arrays of parallel reinforcing filaments (that is, each ith filament has only a single straight sub-section of length L_iCorresponding to the total length of the ith filament), equation (1) is simplified to

Wherein

-L_i(in m) is the entire length of the ith filament;

-cos(α_i) Is the cosine of the angle said ith filament has with respect to said one given direction;

-ρ_i(in g/m)³In units) is the material density of the ith filament;

-T_i(in g/m isUnit) is the linear density of the ith filament;

-the sum of I is performed for all I reinforcing filaments.

In fig. 1a), 1b) and 1c) (which show a transparent top view of an embodiment of a linear tape cut from a tape core, the "given direction over which the reinforcing filaments extend at least partially" and correspondingly also the direction of travel of the linear tape are indicated by thick arrows.

With specific reference to fig. 1 a): the linear belt comprises a layer of filaments 51 or 52 or 53 in the form of one single array of parallel reinforcing filaments running exactly the entire length of the parallel reinforcing filaments in the direction of travel of the belt. In the definition of equation (2) above, all cosines are therefore 1 (zero angle to the direction of belt travel) and accordingly r from equation (2) becomes 1 regardless of filament linear density, filament material density and filament length. In addition, I defined for equation (2) divided by the width of the linear band may be considered herein as the number of reinforcing filaments in the width direction.

Preferably, in the embodiment of fig. 1a), all the reinforcing filaments are identical.

With specific reference to fig. 1 b): the linear belt comprises a filament layer 51 or 52 or 53 in the form of two arrays of parallel reinforcing filaments, the first array running exactly in the direction of travel of the belt and the second array running exactly perpendicular to the direction of travel of the belt. In the definition of equation (2) above, all cosines of the first array are 1 (the angle to the direction of belt travel is zero) and all cosines of the second array are 0 (the angle to the direction of belt travel is 90). Thus, the formula (2) becomes

Wherein

-L_i(in m) is the length of the ith filament running in the direction of belt travel, and ρ_i(in g/m)³In units) is the density of its material;

-L_i(in m is singlyBit) is the length of the j-th filament running perpendicular to the direction of belt travel, p_j(in g/m)³In units) is the density of its material;

-T_iand T_j(in g/m) are the linear densities of the ith filament running in the direction of belt travel and the jth filament running perpendicular to the direction of belt travel, respectively;

-all I reinforcing filaments running in the direction of belt travel are performed as a sum;

-proceeding according to J and for all J reinforcing filaments running perpendicular to the direction of belt travel; and

L_i、L_j、T_i、T_ji and J are chosen such that r from equation (3) is at least 0.5.

Here, J divided by the length of the linear tape may be considered as the number of reinforcing filaments of the tape in the length direction, and I divided by the width of the linear tape may be considered as the number of reinforcing filaments in the width direction.

Alternatively, also referring to fig. 1 b): the linear tape may also contain a layer of filaments 51 or 52 or 53 in the form of a square or rectangular grid. Wherein two of the opposing edges of each square or rectangular grid extend exactly in the direction of belt travel; all cosine values of these edges are 1 (they are at zero angle to the direction of travel of the belt). The other two opposite edges of each wire run exactly perpendicular to the direction of travel of the belt; all cosines of these other edges are zero (they are at an angle of 90 deg. to the direction of travel of the belt). Thus, equation (1) becomes:

wherein

-L_ik(in m) is the length of the kth straight subsection of the ith filament running in the direction of travel of the belt (e.g., the length of a single edge of a single grid, i.e., the grid dimension), and ρ_ik(in g/m)³In units) is the density of its material;

-L_ik(in m) is the length of the m-th straight subsection of the j-th filament running perpendicular to the direction of belt travel (e.g., the length of a single edge of a single grid, i.e., the grid dimension), and ρ_ik(in g/m)³In units) is the density of its material;

-T_ik(in g/m) is the linear density of the kth straight subsection of the ith filament;

-T_jm(in g/m) is the linear density of the m-th straight sub-segment of the j-th filament;

-all K straight sections of the ith filament running in the direction of the belt and contained completely in the belt are summed up according to K;

-proceeding according to M and for all M straight subsections of the j-th filament running perpendicular to the direction of the belt and fully contained in the belt;

-all I reinforcing filaments comprised in the whole belt, running in the direction of travel of the belt, are carried out as per I; and

-proceeding according to J and for all J reinforcing filaments in the width comprised in the whole belt running perpendicularly to the direction of the belt.

L_ik、L_jm、T_ik、T_jmI, J, K is selected such that r from equation (4) is at least 0.5.

Here, in addition, J divided by the length of the tape may be regarded as the number of filaments of the tape in the length direction, and I divided by the width of the tape may be regarded as the number of filaments in the width direction.

In the embodiment of fig. 1b), preferably, all the reinforcing filaments running in the direction of travel of the belt are identical and all the reinforcing filaments running perpendicular to the direction of travel of the belt are identical.

With specific reference to fig. 1 c): the linear belt comprises a layer of filaments 51 or 52 or 53 in the form of a grid with diamond shaped cells, all the cell edges running in a direction inclined with respect to the direction of travel of the belt, at a fixed angle α to the direction of travel of the belt. Thus, equation (1) becomes:

it is independent of the linear density, the material density and the edge length and it must also be at least 0.5.

Preferably, in this embodiment, each diamond-shaped cell has a longer diagonal and a shorter diagonal, wherein the longer diagonal runs in the direction of belt travel and the shorter diagonal runs perpendicular to the direction of belt travel.

With specific reference to fig. 1 d): in such corner tapes that are cut out circularly from the tape core of the invention, the filament layer must contain "reinforcing filaments" which increase the tenacity in any direction, since the direction of travel is not a fixed line but circular, as indicated by the circular arrows in fig. 1 d). The local direction of travel at each (x, y) point of the disk or corner band is a tangent to the circular direction of travel, which is indicated with three thick arrows for three exemplary (x, y) positions. A filament layer in the form of a grid with a square grid is here a preferred embodiment, in fig. 1d the filament layers are aligned in the x (horizontal) and y (vertical) directions. For any (i, k) square grid of this grid, one pair of opposing edges along the x-direction will have a fixed angle α relative to the local belt travel direction, while the other pair of opposing edges will have a corresponding fixed angle of 90 ° - α relative to the local belt travel direction. Since any (i, k) square grid is always anything from completely parallel to the local belt travel direction (α ═ 0 °) to completely perpendicular to the local belt travel direction (α ═ 90 °), the angle α of any (i, k) square grid to the local belt travel direction should be measured such that it is always in the range of 0 ° to 90 °. In addition, in a square grid, the linear density of all filament edges is equal, and therefore their material density T is equal, and therefore their length ρ, and therefore L, is equal. For each square grid, to avoid repeating the calculation of the number of edges, only one edge of each pair may be considered in the summation. Still further, the product I J, where I and J can be considered as very close to the number of square grids that are completely contained in a circular band segment, as defined in equation (1). Thus, the dual summation of i and k in equation (1) would be equal to summing all the square grids that are fully contained in the circular band segment, where only one edge of each edge pair is considered, as desired.

From equation (1) we can obtain

It is not less than 1.0 for any alpha in said range from 0 to 90 deg., and is therefore greater than 0.5, irrespective of T, L and p.

For the first exemplary position of FIG. 3d), the vertically (Y-direction) opposing edges of each grid make an angle α of about 35 with the corresponding local belt travel direction₁And in a second exemplary position, the edges are at an angle α of about 30 ° to the corresponding local belt travel direction₂. In a third exemplary position, if α is measured₃Measured so that it is in the range of 0 ° to 90 °, then these edges make an angle α of about 40 ° with the corresponding local belt travel direction₃. Thus, the corresponding angles of the corresponding horizontal (x-direction) grid edges for the three exemplary positions are 55 °, 60 °, and 50 °, respectively.

Each impregnated layer in the belt of the invention preferably consists essentially of only the nonwoven fabric and of the impregnating material, and as the case may be of reinforcing filaments. By "substantially consist" is meant in the context of the present invention that the sum of the weight contents of the nonwoven fabric, the impregnating material and, if present, the reinforcing filaments preferably represents at least 97% by weight of the impregnated layer. More preferably, each impregnated layer consists of a nonwoven fabric and an impregnating material and reinforcing filaments (if present). .

The impregnating material itself preferably consists essentially of a thermoplastic, thermoplastic elastomer, elastomer or thermoset and optionally additives. Additives may be added to the impregnating material, for example to impart some colour (dye or pigment), to act as a filler to improve abrasion resistance; increase or decrease CoF (coefficient of friction); providing flame retardancy; and/or provide visual (luminescent) and/or metal detectability, or may be added to the function of the plasticizer. The amount of these named additives with a given function may be up to 75% by weight based on the impregnating material, but is typically in the range of 1 to 25% by weight based on the impregnating material, provided that the type and amount of the additive(s) is such that the impregnating material can be softened or melted or otherwise liquefied (e.g. by dissolving or dispersing in a solvent) at some elevated temperature for at least the time required to impregnate the nonwoven fabric with the softened, melted or otherwise liquefied impregnating material.

The impregnating material "consists essentially of" the thermoplastic, thermoplastic elastomer, elastomer or thermoset and optional additives preferably means here that the sum of the weight contents of the thermoplastic, thermoplastic elastomer, elastomer or thermoset and optional additives discussed above preferably represents at least 95% by weight of the impregnating material, whereby the remainder is other unnamed components, such as impurities. More preferably, the impregnating material consists of a thermoplastic, thermoplastic elastomer, elastomer or thermoset and optionally the above-mentioned additives.

The nonwoven fabric(s) used in the belt core of the present invention are so conventional. They can in particular be made first of inorganic fibers, such as glass fibers, basalt fibers, carbon fibers or aramid fibers. Secondly, they may be made of synthetic organic fibres, such as polyester (such as PET or PBT), polyolefin fibres (such as polypropylene or polyethylene), polyamide (such as nylon-6, 6), viscose, polyphenylsulfone, or bicomponent fibres with a high-melting-point type fibre and a low-melting-point type fibre, or core-sheath fibres with a high-melting-point core and a low-melting-point sheath. The use or co-use of bicomponent fibers, such as in an amount of 50 to 100% by weight based on the total weight of the nonwoven fibers, can improve the tear and elongation resistance (toughness) of the nonwoven fibers, and thus the tear and elongation resistance (toughness) of the inventive tape comprising the nonwoven fibers. Third, the nonwoven fabric(s) may be made of natural organic fibers such as wool, cotton, hemp, ramie, jute, sisal, or flax. If there are multiple nonwoven fabrics in the belt core, it is preferred that the fiber orientation in all of the nonwoven fabrics be primarily in the same direction. This can be readily accomplished by carding the nonwoven fabric before it is impregnated and incorporated into the belt core.

The weight per unit area of any of these nonwoven fabrics is preferably 50 to 1500g/m²More preferably in the range of 50 to 400g/m²Within the range of (1).

The fibers of the nonwoven fabric preferably have a linear density of 3 to 50 dtex (dtex), more preferably 5 to 30 dtex, and the density of the fibrous material is preferably in the range of 0.9 to 1.3g/cm³Within the range of (1). The presence or coexistence of fibers (such as in an amount of 50 to 100% by weight based on the total weight of the nonwoven fibers) and having titers in lower portions of these ranges (such as in a range of 3 to 20 dtex) can improve the flexibility and resistance to elongation (tenacity) of the nonwoven fabric, and thus the flexibility and resistance to elongation (tenacity) of the inventive tapes comprising the nonwoven fabric. On the other hand, the presence or co-presence of fibers (such as in an amount of 50 to 100% by weight based on the total weight of the nonwoven fibers) and having titers in higher portions of these ranges (such as in the range of 30 to 50 dtex) can improve the tear resistance of the nonwoven fabric, and thus the tear resistance of the inventive tape comprising the nonwoven fabric. The length of the individual fibres in the nonwoven or in a sub-layer thereof is preferably in the range of 15 to 150mm, more preferably in the range of 30 to 100 mm. This refers to the individual length of each fiber, not the average length of all fibers. Thus, substantially all, i.e., at least 95%, of the fiber samples are intended to have such lengths. The weight ratio of nonwoven to impregnate in the impregnated layer(s) is preferably in the range of 30: 70 to 80: 20.

In the context of the present invention, any geometrically well-defined layer or sheet (which includes any spacers)The thickness D of the separate impregnated layer(s) and the entire tape core of the invention) is measured directly on the layer or sheet, and is then designated as D_m. Thickness D of tape core of the invention_mPreferably in the range of 0.3 to 5mm, more preferably in the range of 0.4 to 2 mm.

The thickness of any nonwoven fabric or nonwoven sublayer is determined at a certain overpressure (i.e., above atmospheric pressure) applied perpendicular to the surface of the nonwoven fabric. Such an overpressure can be applied, for example, by the measuring instrument itself or by an additional die compressing the sheet-like layer or the nonwoven fabric. For measuring the thickness of the nonwoven or of the sub-layer itself, the overpressure can be selected to be 0.2 bar. However, in order to define the correct amount of impregnating material to be used, the overpressure applied in the thickness measurement will be the same as the overpressure used in the corresponding impregnation step using heat and pressure (see below). The thickness measured under a certain applied pressure is designated hereinafter as D_mp。

Preferably, the amount of impregnating material is such that only void spaces in the nonwoven fabric are evacuated, so that the nonwoven fabric is completely filled with the impregnating material, but, on the other hand, no excess impregnating material is used that would form in the core region or layer of the finished belt without the nonwoven fabric. This requires consideration of the overpressure applied in any impregnation step, since the thickness D of the nonwoven fabric before impregnation or when impregnated with a molten or otherwise liquefied impregnating material_mpThis pressure is strongly dependent.

In order to correctly select the desired volume of impregnating material, the following formula (7) is indicated:

wherein:

-A (in m)²In units) is the geometric surface of the impregnation layer(s) to be prepared;

-_wD_mp(in m) is the thickness of the w-th nonwoven measured at the same overpressure applied during impregnation. If heat and pressure are usedLine dipping, then used for measurement_wD_mpThe overpressure of (c) should be the same as the overpressure used during the hot and pressure impregnation. Alternatively, if impregnation is carried out using an aqueous dispersion of the impregnating material, for the measurement_wD_mpShould be only 0.2 bar;

-_ww (in g/m)²In units) is the weight per unit area of the w-th nonwoven fabric;

-_wrho (in g/m)³In units) is the density of the fibrous material of the w nonwoven fabric at the temperature used in impregnation;

-the sum of w is taken over all the non-woven fabrics to be used;

-_sv (in m)³In units) is the volume of the s impregnating material to be used at the temperature used in impregnation; and

-all the impregnating materials used are carried out as the sum of the S.

Thus, if one-step impregnation/bonding of several nonwoven fabrics is selected to form the belt core of the present invention in a single step, then a above will also be the geometric surface of the belt core to be formed.

Alternatively, if sequential stacking is chosen, the above equation (7) applies only to one nonwoven fabric and one impregnated material to be used in one sequential impregnation/stacking step. W and S are equal to 1.

Exemplary thermoplastics or thermoplastic elastomers for the impregnating material may be selected from one of the commonly known subgroups: i) styrene block copolymers (TPE-s), ii) thermoplastic (co) polyolefins and blends Thereof (TPO), iii) elastomeric alloys (TPE-v or TPV), iv) Thermoplastic Polyurethanes (TPU), v) thermoplastic copolyesters and vi) thermoplastic polyamides.

Exemplary elastomers for the impregnating material are natural rubber, polyisoprene, polybutadiene, Styrene Butadiene Rubber (SBR), Nitrile Butadiene Rubber (NBR), ethylene propylene diene monomer rubber (EPDMP), polyurethane and acrylate rubber. Preferably, the elastomer is not yet vulcanized or crosslinked when used as an impregnating material, but may be vulcanized or crosslinked during the impregnation step, in particular when heat and pressure are used. To this end, the elastomer may contain an appropriate amount of a pre-mixed curative. For the purpose of calculating the amount by weight in the impregnation layer, such vulcanizing agents will be considered as optional additives with a given function.

Exemplary thermosets for the impregnating material are polymers or resins that crosslink and cure upon heating, rather than the elastomers described above. Examples are adducts of phenol/cresol formaldehyde (novolac) with epoxy resins such as epichlorohydrin, urea/formaldehyde resins, melamine resins, silicone resins, polyimides, bismaleimides and benzoxazines. These resins are preferably used in the uncured a-stage or partially cured B-stage, noting that no C-stage cure occurs during impregnation. The molecular weight of the starting resin and the extent of curing should preferably be controlled such that the cured resin is still sufficiently flexible.

On the one hand, preference is given to TPU's (such as from 1) by reacting an aromatic diisocyanate (such as the isomeric 2, 2' -, 2, 4 'or 4, 4' -diphenylmethane diisocyanate) with an aliphatic chain extender (e.g. C)₂-C₆Diols, such as ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 2-propanediol, 2-methylpropanediol, 1, 3-butanediol, 2, 3-butanediol, 1, 3-pentanediol, 1, 2-hexanediol and 3-methylpentane-1, 5-diol; or glycol ethers such as diethylene glycol, dipropylene glycol, and tripropylene glycol; and aminoalcohols such as ethanolamine, N-methyldiethanolamine) and 2) aliphatic polyester polyols or polyether polyols as soft segments) or TPO (such as those selected from: ii-1) has the structure XHC ═ CH₂Wherein X is selected from the group consisting of chlorine, acetoxy, phenyl, and cyano, and the comonomer (for copolymers) is ethylene and/or propylene; and ii-2) an ethylene-alpha-olefin copolymer, wherein the alpha-olefin is preferably selected from the group consisting of propylene, 1-butene, 1-hexene, 1-heptene, and 1-octene).

In one embodiment, all the impregnation layers of the tape core of the invention comprise the same impregnation material, which impregnation material preferably also comprises a thermoplastic or thermoplastic elastomer, in particular TPU.

The preparation of the tape core of the present invention can be carried out in several ways, three preferred ways being illustrated below with reference to fig. 1, 2 and 3. These figures illustrate a preferred manner of impregnating a nonwoven fabric with a preformed sheet of impregnating material. However, in the following description, other impregnation methods will be mentioned as alternatives thereof whenever possible.

In general, for all variations of fig. 3, any lower left to upper right hatching indicates a cross-section through the sheet of impregnated material, any upper left to lower right hatching indicates a cross-section through the nonwoven fabric, and any double hatching indicates areas or layers of the nonwoven fabric that have been or are being impregnated by the impregnated material. Any thick vertical arrows indicate the use of heat and pressure bonding.

The first variant i) of fig. 3 (claim 12) illustrates a method in which exactly one filament layer 51 embedded in one impregnation layer 21 is used. This variant comprises the following steps:

step i-1): first, a first nonwoven sublayer 31, a second nonwoven sublayer 32 and a filament layer 51 comprising reinforcing filaments extending at least partially in one given direction are provided. The two sub-layers 31, 32 comprise the above described fibres suitable for use in nonwoven fabrics and are therefore conventional. They may optionally be carded to impart a more uniform fiber orientation, preferably so that the fiber orientation is the same in both sublayers 31, 32. The reinforcing filaments are pre-oriented such that they are at least partially oriented in a given direction, or are directly provided with such an orientation.

Steps i-2), i-3), referring also to fig. 2, the filament layer 51 is arranged, in particular laid on top of the second nonwoven sublayer 32, and the first nonwoven sublayer 31 is arranged on top of the filament layer 51. The first nonwoven sublayer 31, the filament layer 51 and the second nonwoven sublayer 32 are pressed together, for example, using two compression rollers 91, 92. They can then be joined together, for example and preferably by needling, as shown in fig. 2 by needling apparatus 10. Alternatively, they may be joined together by chemical means (thermosetting adhesive), thermal bonding (hot melt adhesive) or mechanical means (stitched or otherwise mechanically joined together), or by so-called hydroentanglement. Needling or hydroentanglement also randomizes the nonwoven fibers in the z-direction (orthogonal to the length (y) and width (x) of the nonwoven).

In step i-4) the first nonwoven 3 is impregnated with a first impregnating material 4, which first impregnating material 4 comprises or essentially consists of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives as outlined above, to form a first impregnated layer 21 with an embedded filament layer 51. This impregnation step may be accomplished using a calender or extruder using a preformed sheet of the first impregnating material (as shown in fig. 3). It may also be done using an aqueous dispersion of the first impregnating material. Several successive applications of the aqueous dispersion can be applied here, for example, by doctor blade, kiss coating, spraying or dipping, with intermediate drying after each application before the first impregnating material is softened, optionally by heat and pressure and/or vacuum, to completely penetrate the nonwoven. As a still further alternative, the impregnating material may be applied to the non-woven fabric 3 as a powder or by flocculation, and then the deposited particles of the impregnating material are sintered together and impregnated into the non-woven fabric 3 using heat and optionally pressure.

In step i-5), there are two sub-variations: a first sub-variant comprising steps i-5-a) to i-5-c) (not shown in fig. 3, but similar to embodiment ii shown in fig. 3), and a second sub-variant comprising steps i-5-d) to i-5-e).

In a first sub-variant, step i-5-a) is to provide one or more further sheets of one or more further nonwoven fabrics and a further impregnating material, each comprising or consisting essentially of a further thermoplastic, a further elastomer or a further thermoset and optional additives, as exemplified above. Since there is only one layer of reinforcing filaments in the entire tape core and these reinforcing filaments have been introduced in steps i-2) and i-3), any such additional nonwoven fabricThere are no reinforcing filaments. Total volume of impregnating material provided by additional sheets, weight per unit area and thickness D of each nonwoven_mpAnd the material density is preferably selected such that the total void volume of all further nonwovens can be filled with the impregnating material, but no areas or layers without nonwovens are formed (see calculation using equation (7) above). In one embodiment, this may mean that the number of additional nonwoven fabrics is equal to the number of additional sheets, but this need not be the case.

Step i-5-b) is arranging said one or more further nonwoven fabrics and said one or more further sheets adjacent to said first impregnation layer 21 and to each other such that there is at least one further sheet next to any nonwoven fabric and at least one further nonwoven fabric next to any further sheet. This facilitates uniform and complete impregnation of the nonwoven fabric by the impregnating material from at least one adjacent sheet. The total number of additional sheets, the total volume of impregnating material they provide, and the weight per unit area and thickness D of all additional nonwovens_mpAnd the material density is preferably chosen such that the total void volume of all further nonwoven fabrics on one side of the first impregnation layer 21 can be filled with the impregnation material (see calculation with equation (7) above). Likewise, the total number of additional sheets, the total volume of impregnating material they provide, and the weight per unit area and thickness D of all additional nonwovens_mpAnd the material density is preferably selected such that the total void volume of all further nonwoven fabrics on the other side of the first impregnation layer 21 can be filled with the impregnation material. Here again, this means that on each of the two sides of the first impregnation layer 21, the number of sheets and nonwoven fabrics is equal.

In step i-5-c), any further nonwoven fabric is impregnated with the impregnating material from at least one further sheet immediately adjacent to the nonwoven fabric, using heat and pressure. This usually means the use of calenders, hot presses or drum presses. The applied overpressure is preferably at D_mpThe overpressure used in the above-described assay. Simultaneous impregnation and bonding together by heat and pressure is also carried out at a sufficiently high temperature that the thermoplastic, thermoplastic elastomer or B-staged resin melts, rather than simply softens. Only if the impregnating material is substantially molten, it has a viscosity low enough to penetrate all the voids in the adjacent nonwoven fabric(s) to form an impregnated layer. "substantially molten" in the context of the present invention may preferably mean that the melt has an MFI of at least 20g/10min, preferably at least 30g/10min, and most preferably from 30 to 60g/10min at 8.7kg at the chosen impregnation temperature. In each case, the conditions are such that the temperature is kept low enough to avoid decomposition of the impregnating material, and, if a thermosetting plastic is used in the impregnating material, the impregnation is substantially complete with the thermosetting plastic not curing beyond the B stage, but not the C stage.

In step i-5-d) of the second sub-variant, one or more further preformed impregnated layers 22, 23, 24, 25 are directly provided, each comprising or consisting of a further nonwoven fabric impregnated with a further impregnating material comprising or essentially consisting of a further thermoplastic, a further thermoplastic elastomer, a further elastomer or a further thermoset and optional additives, as outlined above. These may be preformed from the respective nonwoven fabric and impregnated material by any of the processes outlined above for step i-4). Since there is only one layer of reinforcing filaments in the entire tape core and these reinforcing filaments have been introduced in steps i-2) and i-3), any such further impregnation layer 22, 23, 24, 25 is free of reinforcing filaments.

In step i-5-e), one or more further impregnation layers 22, 23, 24, 25 are arranged adjacent to the first impregnation layer 21 and to each other; and any such further impregnation layers 21, 22, 23, 24, 25 and the first impregnation layer 21 are bonded together under heat and pressure. The conditions and apparatus may be as outlined above under steps i-5-c). If the impregnation(s) consist of an impregnating material comprising a thermosetting plastic in the a-stage or B-stage, curing to the final C-stage can be allowed to take place here.

In step i-5), the number of non-woven fabrics (first sub-variant) or the number of impregnated layers (second sub-variant) present on each side of the first impregnated layer 21 is preferably chosen such that the first impregnated layer 21 containing the embedded filament layer 51 will preferably be close to or at the neutral plane of the linear tape cut from the tape core once the tape will be in use. This means, for example, that for a linear belt always having the same belt surface facing all wheels, the first impregnation layer will preferably be at the concave side of the belt and will face the wheels, while all other impregnation layers 22, 23, 24, 25 will preferably be arranged on the outer side of the first impregnation layer 21 and will face away from the wheels.

A second variant ii) of fig. 3) (claim 13) illustrates a method in which the tape core 1 is formed using exactly one layer of filaments 52 sandwiched between two impregnation layers 21, 22. This variant comprises the following steps:

in step ii-1), a first nonwoven 301 is provided; a second nonwoven fabric 302; a first sheet 401 of a first impregnating material comprising or consisting essentially of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and the optional additives mentioned above; a second sheet 402 of a second impregnating material comprising or consisting essentially of a second thermoplastic, a second thermoplastic elastomer, a second elastomer or a second thermoset and the optional additives mentioned above; and reinforcing filaments in the form of a filament layer 52 extending at least partially in one given direction. The reinforcing filaments are pre-oriented such that they are at least partially oriented in a given direction, or are directly provided with such an orientation. Preferably, the total volume of impregnated material provided by the first and second sheets 401, 402 and the weight per unit area and thickness D of the two nonwoven fabrics 301, 302_mpAnd the material density is chosen such that the total void volume of the two nonwoven fabrics 301, 302 can be filled with the impregnating material (see calculation using equation (7) above).

In step ii-2), the filament layer 52A nonwoven 301 and a second nonwoven 302 and a first sheet 401 and a second sheet 402 are arranged adjacent to each other such that on one side of the filament layer 52 there is at least one first nonwoven 301 and at least one first sheet 401 and on the other side of said filament layer 52 there is at least one second nonwoven 302 and at least one second sheet 402 in order to sandwich the filament layer 52 between the first nonwoven 301 and the first sheet 401 on the one hand and between the second nonwoven 302 and the second sheet 402 on the other hand; to form a layered composite 6. Preferably, the first sheet 401 and the second sheet 402 face the filament layer 52, and the first nonwoven fabric 301 and the second nonwoven fabric 302 sandwich the first sheet 401/filament layer 52/second sheet 402 combination, and the total volume of the impregnated material provided by the first sheet 401 and the second sheet 402, and the weight per unit area and the thickness D of the two nonwoven fabrics 301, 302_mpAnd the material density is chosen such that the total void volume of the two nonwoven fabrics 301, 302 can be filled with the impregnating material from the first and second sheets 401, 402 (see calculation using equation (7) above). This ensures that filament layer 52 is and remains surrounded by molten impregnating material during the subsequent impregnation/bonding step ii-3-c) using heat and pressure, and thus avoids filament layer 52 from being distorted or damaged by any adjacent nonwoven fabric.

In step ii-3), there are two sub-variations: a first sub-variant comprising steps ii-3-a) to ii-3-c), and a second sub-variant: comprising steps ii-3-d) to ii-3-f).

In a first sub-variant, step i-3-a) is optionally providing one or more further nonwoven fabrics 303, 304, 305 and one or more further sheets 403, 404, 405 of a further impregnating material comprising or essentially consisting of a further thermoplastic, a further elastomer or a further thermoset and optionally additives, as outlined above (as directly shown in fig. 3). The total number of additional sheets 403, 404, 405, the total volume of impregnating material they provide, and all additional nonwovens 303, 304,305 weight per unit area and thickness D_mpAnd the material density is preferably chosen such that the total void volume of all further nonwoven fabrics 303, 304, 305 can be filled with the impregnating material (see calculation using equation (7) above). This may mean that the number of further nonwoven fabrics 303, 304, 305 is equal to the number of further sheets 403, 404, 405, but this need not be the case.

In step ii-3-b), the optional one or more further nonwoven fabrics 303, 304, 305 and the one or more further sheets 403, 404, 405 are arranged adjacent to the layered composite 6 of step ii-2) and to each other, such that there is at least one further sheet next to any nonwoven fabric and at least one further nonwoven fabric next to any further sheet. This facilitates uniform and complete impregnation of the nonwoven fabric by the impregnating material from at least one adjacent sheet. Preferably, the number of additional nonwoven fabrics is equal to the number of additional sheets on each side of the layered composite 6.

In step ii-3-c), any nonwoven fabric 301 or 302 or 303 or 304 or 305 is impregnated with heat and pressure simultaneously with the impregnation of heat and pressure, respectively, by an impregnation from at least one further sheet immediately adjacent to the nonwoven fabric 401 or 402 or 403 or 404 or 405 to form a respective impregnated layer 21 or 22 or 23 or 24 or 25, respectively; and all such impregnation layers 21, 22, 23, 24, 25 and the laminar composite 6 are bonded together. The conditions and apparatus may be as outlined above under steps i-5-c). If the impregnation(s) consist of an impregnating material comprising a thermosetting plastic in the a-stage or B-stage, curing to the final C-stage can be allowed to take place here.

In a second sub-variant, steps ii-3-d) optionally provide one or more further impregnated layers, each further impregnated layer comprising or consisting of a further nonwoven fabric impregnated with a further impregnating material, each of the further impregnating materials comprising or consisting essentially of a further thermoplastic, a further elastomer or a further thermoset and optionally additives (as outlined above), and being free of reinforcing filaments. This sub-variant is not shown directly in ii) of fig. 3, but is similar to the provision of the impregnated further layers 22, 23, 24, 25 of the variant i) shown in fig. 3. These optional further impregnation layers 22, 23, 24, 25 may be prepared beforehand by any of the processes outlined above for step i-4).

Step ii-3-e) is to arrange an optional one or more further impregnation layers 22, 23, 24, 25 adjacent to the layered composite 6 of step ii-2) and to each other; and in step ii-3-f) any such optional further impregnation layers 21, 22, 23, 24, 25 and the layered composite 6 are bonded together using heat and pressure. The conditions and apparatus may be as outlined above under steps i-5-c). If the impregnation(s) consist of an impregnating material comprising a thermosetting plastic in the a-stage or B-stage, curing to the final C-stage can be allowed to take place here.

As in step i-5) above, in step ii-3), the number of additional non-woven fabrics (first sub-variant) or the number of additional impregnated woven fabrics (second sub-variant) arranged on each side of the layered composite 6 is selected such that the filament layer 52 is at or near the neutral plane of the intended end use of the finished belt and belt, for the reasons outlined above under step i-5).

The third variant iii) of fig. 3 (claim 14) illustrates a method in which the tape core 1 is formed using exactly one filament layer 53 sandwiched between two impregnation layers 22, 23 and the tape core is built up sequentially until the desired number of impregnation layers or the desired thickness of the tape core is obtained. This variant allows to directly form the endless belt core of the invention, since the first impregnation layer 21 and then the bonded laminar composite 7 can be formed into an annular loop, onto which the subsequent impregnation layer is wound and bonded. This third variant comprises the following steps:

in step iii-1) there is provided reinforcing filaments in the form of a filament layer 53 extending at least partially in a given direction, and a first impregnation layer 21, the first impregnation layer 21 comprising or consisting of a first non-woven fabric impregnated with a first impregnation material comprising or consisting essentially of a first thermoplastic, a first thermoplastic elastomer, a first elastomer or a first thermoset and optional additives (as outlined above), but without reinforcing filaments. The reinforcing filaments are pre-oriented such that they are at least partially oriented in a given direction, or are directly provided with such an orientation. The impregnation layer 21 may be prepared beforehand by any of the processes described in the above steps i-4), provided that the nonwoven fabric used is free of reinforcing filaments.

In step iii-2), there are two sub-variations: a first sub-variant comprising steps iii-2-a) to iii-2-d) and a second sub-variant comprising steps iii-2-e) to iii-2-h).

In a first sub-variant, step iii-2-a) is to provide one or more further nonwoven fabrics 306, 307, 308 and one or more further sheets 406, 407, 408 of a further impregnating material comprising or essentially consisting of a further thermoplastic, a further thermoplastic elastomer, a further elastomer or a further thermoset and optionally additives, as outlined above. Here, the number of further nonwoven fabrics 306, 307, 308 must be equal to the number of further sheets 406, 407, 408, since the belt is built up sequentially, wherein each building cycle uses exactly one further nonwoven fabric 306, 307, 308 and exactly one further sheet 406, 407, 408 to form a continuous further impregnated layer adhered to the bonded laminar composite 7. This number is an integer designated as K, which must be at least 1 and can be arbitrarily high. Preferably, however, K is in the range of 1 to 5.

In step iii-2-b), one of the further nonwoven fabrics 306, one of the further sheet materials 406 and optionally the filament layer 53 are arranged on one side of and adjacent to the first impregnation layer 21 such that if a filament layer 53 is provided it is sandwiched between the first impregnation layer 21 on the one hand and the further nonwoven fabric 306 and the further sheet material 406 on the other hand. Preferably, the volume of impregnating material provided by the further sheet 406 and furtherWeight per unit area and thickness D of the outer nonwoven 306_mpAnd the material density is selected such that the void volume of the further nonwoven fabric 306 can be filled with the impregnating material from the further sheet 406 (see calculation using equation (7) above). Preferably, the optional clamping of the filament layer 53 is such that on one side of the filament layer 53 there is a first impregnation layer 21 and on the other side there is a further sheet 406, and the further nonwoven fabric 306 is on the further sheet 406 and faces away from the filament layer 53. This ensures that during the simultaneous impregnation and adhesion steps iii-3-c) with heat and pressure (see immediately below), the filament layer 53 is surrounded by the softened impregnating material and remains surrounded by the softened impregnating material, and thus avoids the filament layer 53 being distorted or damaged by any adjacent nonwoven fabric.

In step iii-2-c), while using heat and pressure, the further nonwoven fabric 306 is impregnated with the impregnating material from the further sheet 406 to form a further impregnated layer 22, and the first impregnated layer 21, the optional layer of sandwiched filaments 53 and the further impregnated layer 22 are bonded together; to form a bonded layered composite 7. The conditions and apparatus may be as outlined above under steps i-5-c).

Step iii-2-d) is repeating steps iii-2-b) and iii-2-c) K-1 above for the bonded layered composite 7 using a further pair of further nonwoven fabrics 307/407, 308/408 and a further sheet of a further impregnating material, provided that in step iii-2-b) and step iii-2-c) and in the repetition of the steps, the filament layer (53) is used exactly once in total. Preferably, the volume of impregnating material provided by each further sheet 407, 408 and the weight per unit area and thickness D of each corresponding further nonwoven 307, 308 are_mpAnd the material density is selected such that the void volume of each further nonwoven fabric 307, 308 can be filled with the impregnating material from the respective further sheet 407, 408 (see calculation using equation (7) above). Here again, if in any repetition of steps iii-2-b) and iii-2-c) a layer of filaments 53 is used, the optional clamping of the layer of filaments 53 is preferably carried outSuch that there is bonded laminar composite 7 on one side of the filament layer 53 and a further sheet 407 or 408 on a further side and a further nonwoven fabric 306 or 307 on the further sheet 407 or 408 and facing away from the filament layer 53. The reason for this layer ordering is given above for step iii-2-b). Performing K-1 repetitions may mean zero repetitions, since K is at least 1. In this case where K ═ 1, the filament layer 53 must have been used in steps iii-2-b) and iii-2-c).

After step iii-2-C) (if K ═ 1) or during the last repetition of steps iii-2-B) and iii-2-C (if K > 1), if the impregnation(s) consist of an impregnating material comprising a thermosetting plastic in the a-stage or B-stage, curing to the final C-stage can be allowed to take place here.

In a second sub-variant, step iii-2-e) provides one or more further impregnated layers 22, 23, 24, 25, each comprising or consisting of a further nonwoven fabric impregnated with a further impregnating material, each comprising or consisting essentially of a further thermoplastic, a further thermoplastic elastomer, a further elastomer or a further thermoset and optionally additives (as outlined above). This sub-variant is not shown directly in iii) of fig. 3, but is similar to the provision of the impregnated further layers 22, 23, 24, 25 in variant i) shown in fig. 3. These further impregnation layers 22, 23, 24, 25 may be prepared beforehand by any of the processes outlined above for step i-4). All these further impregnation layers also have no reinforcing filaments, since the tape comprises only one layer of reinforcing filaments in total, i.e. the filament layer 53. The number of further impregnation layers provided is again designated as K, which is an integer that must be at least 1 and can be arbitrarily high. Preferably, however, K is in the range of 1 to 5.

In step iii-2-f), a further impregnation layer 22 is arranged on one side of the first impregnation layer 21 and adjacent thereto, so that if a filament layer 53 is also provided, the filament layer 53 is sandwiched between the first impregnation layer 21 on the one hand and the second impregnation layer 22 on the other hand.

In step iii-2-g), the first impregnation layer 21, the optional layer of sandwiched filaments 53 and the further impregnation layer 21 are bonded together under the application of heat and pressure; to form a bonded layered composite 7. The conditions and apparatus may be as outlined above under steps i-5-c).

Step iii-2-h) is to repeat steps iii-2-f) and iii-2-g) K-1 above for the bonded layered composite 7, using one of the further impregnation layers 23, 24, 25 in each repetition, as long as in steps iii-2-f) and iii-2-g) and in the repetition of the steps the filament layer 53 is used exactly once in total. This also takes into account that there is only one layer of reinforcing filaments in the entire tape, which is the layer of filaments 53. Performing K-1 repetitions may mean zero repetitions, since K is at least 1. In the case of K ═ 1, the filament layer 53 must have been used in steps iii-2-f) and iii-2-g). After step iii-2-g) (if K ═ 1) or during the last repetition of steps iii-2-f) and iii-2-g (if K > 1), if the impregnation(s) consist of an impregnating material comprising a thermosetting plastic in the a-stage or B-stage, curing to the final C-stage can be allowed to take place here.

In a third variant iii) of fig. 3, a layer of filaments 53 is preferably used for this sequential building step, which will provide a layer of sandwiched filaments 53, which layer of filaments 53 is, for reasons outlined under step i-5) above, close to or in the neutral plane of the linear tape cut from the tape core during its use.

In all process variants of the invention, the orientation of the filaments present in the initial filament layers 51, 52, 53 will constitute the longitudinal direction of the tape, i.e. the running direction of the tape. This means that if a tape formed according to the invention needs to be cut to size so that the two lateral sides are spaced apart by the desired tape width, such lateral side cutting must be performed so that it is oriented parallel to the filaments. Wherein the filament direction will form the direction of travel of the belt.

In all three variants i), ii) and iii) of fig. 3, adjacent layers are bonded together by heat and pressure or without the use of a joint adhesive. This is possible in particular if the impregnations to be joined together are made of chemically compatible thermoplastics or thermoplastic elastomers. Alternatively, an adhesive or primer may be used to bond together two impregnations that are chemically incompatible.

The belt core of the present invention is suitable for cutting, punching or punching a linear conveyor belt, machine belt, power transmission belt or spindle belt of a given length and width therefrom. It is also applicable to cutting, punching or punching rotating conveyor pans or corner belts therefrom. In the case of a linear belt, the cutting should be carried out such that the given direction over which the reinforcing filaments in the filament layer of the belt core of the invention at least partially extend should be or be the longitudinal running direction of the linear belt. Here, the shape of the filament layer may be any such shape provided that the reinforcing filament satisfies the above equation (1). For a disc or corner tape, it appears preferable that the tape core comprises a layer of filaments in the form of a grid of square meshes.

The belt core of the invention or the belt or disc obtained therefrom may optionally be further coated with a top cover layer, giving the belt or belt core suitable advantageous properties, such as chemical resistance, antimicrobial properties, hydrophobicity, different coefficients of friction or a combination of these properties. This top cover layer may preferably be adhered to the belt core or the belt obtained therefrom using a thermosetting (cross-linking) adhesive compatible with the materials to be joined together, such as polyurethane, rubber compounds and phenolic resins. Alternatively or in addition thereto, the surface of the belt core or of the outermost impregnated layer of the belt (the surface that will face the goods to be transported) may be provided by embossing or surface profiling that imparts the surface properties, in particular adhesive and/or frictional properties, required for the respective application. Such embossing or profiling requires in particular the provision of discrete longitudinally running surface sections with different coefficients of static friction, which are arranged adjacent to each other in the transverse direction of the belt. Thus, the application of such top overlays and profiles or embossments is conventional and well known to those skilled in the art.

The tape of the present invention may be made endless using any end joining technique known in the art, such as mechanical joining or finger bonding techniques, or using thermoplastic or thermoplastic elastomer material from one or more of the impregnated layers as a hot melt adhesive, or using such hot melt adhesives together.

The belt of the present invention may be used in any conveying application where prior art belts have been used, such as conveyor belts, machine belts, power transmission belts, or spindle belts.

However, a first preferred application is the so-called "transfer belt". This is the belt that transports goods from one first main belt to another adjacent to but not immediately adjacent to the first main belt. For this purpose, the conveyor belt is usually mounted on a conveyor support having two ends in the form of so-called "transfer tails" (these transfer tails are belt turning points with wheels of very small diameter on the top side thereof), or even only on a pressure ruler, in order to allow the conveyor belt to transport the goods until very close to and to the main conveyor belt.

A second preferred application is the so-called "corner band". This is an application in which a circular band (as a circular arc section having a given section angle β) is cut out from the band core of the present invention and the ends of the circular arc section are joined to form an annular corner band. The finished corner belt will in use have a circular belt travel direction moving along the circular arc and its path length will approach the circular arc radius multiplied by beta/2. That is, for example, cutting a circular arc segment having β ═ pi (═ 180 °) and a given radius r from the belt core, and joining the ends will provide a circular corner belt with a path length approaching pi/2 r. For such applications, the tape core of the present invention will preferably comprise a layer of filaments in the form of a mesh having a square lattice.