Article, in particular drive belt, having textile covering

Abstract

The invention relates to an article comprising an elastomeric body based on at least one rubber compound having a surface of the article, the surface being susceptible to noise and wear and provided with a textile covering. The textile cover of the elastomeric article contains or consists entirely of lyocell fibers.

Description

Technical Field

[0001] The invention relates to an article comprising an elastomeric body based on at least one rubber compound having a surface of the article, the surface being susceptible to noise and wear and provided with a textile covering. Background Art

[0002] Articles which are exposed to dynamic stresses and thus to wear and noise development are, for example, belts, strips, belts, hoses, air spring bellows, expansion joints or multilayer textile webs, of which belts in the form of drive belts are of particular importance. In this case, the elastomeric body of the drive belt comprises a top layer as belt backing and a substructure with force transmission zones.

[0003] Articles comprising an elastic body are provided with a textile covering on the surface in order to adjust the product properties. In addition to wear resistance and noise behavior, in the case of drive belts this also includes improved power transmission. Problems arise when these articles are to be used or have to be used in wet environments. In this case, it is no longer possible to meet all the required physical properties to the same extent. Summary of the invention

[0004] The object of the present invention is therefore to provide an article comprising an elastomeric body having at least one textile covering on at least one surface of the article and wherein the physical properties of the article are maintained at a good level even in the presence of moisture or in a humid environment. Advantageously, the material used for the textile covering is also fully or partly based on sustainable and / or renewable raw materials.

[0005] This object is achieved by the fact that the textile covering of the elastomeric article contains lyocell fibers or consists entirely of lyocell fibers.

[0006] The terms "elastomeric article" and "article comprising an elastomeric body" are used synonymously in this document.

[0007] The good properties of naturally occurring cellulose-based fibers, such as cotton, in wet or humid environments are already known. However, these properties are essentially derived from the special surface structure of the natural fibers. Although previous attempts to imitate this type of fiber in the form of other regenerated fibers, such as viscose, have been found to have a significant reduction in the wet properties. In this regard, it has been found, quite unexpectedly, that the use of lyocell fibers as textile coverings in elastomeric articles has a favorable effect on use in wet or humid environments.

[0008] At the same time, the use of Lyocell makes an important contribution to sustainability.

[0009] Lyocell (CLY) is a cellulosic fiber of regenerated cellulose, which is produced by the Lyocell process (direct solvent process). The solvents used in the production process can be almost completely recycled. Compared with conventional cellulosic man-made fibers (such as viscose), this is accompanied by a significant reduction in environmentally harmful waste. Lyocell is mainly produced from wood from sustainable forestry and is biodegradable.

[0010] The structure of lyocell fibers differs from that of viscose. Special features are long grains, reduced aggregation and extended cavities. There are also differences in the fiber structure. Lyocell fibers consist of fibrils of equal thickness distributed over the entire cross section.

[0011] Lyocell fibers can be formed as staple fibers or filament fibers.

[0012] In an advantageous embodiment, the textile covering consists completely of lyocell fibers, ie the proportion of lyocell fibers is 100% by weight.

[0013] However, it is likewise possible that the textile covering contains lyocell fibers, preferably in an amount of 20 to 95% by weight.

[0014] Preferably, the textile covering consisting of or containing lyocell fibers is formed as a knitted fabric. If the textile covering consists of lyocell fibers, the weight per unit area is preferably 70 g / m 2 With 350g / m 2 and most preferably between 100 g / m 2 With 250g / m 2 between.

[0015] If the textile covering contains lyocell fibers, it may also contain at least one further material in an amount of 5% by weight to 80% by weight.

[0016] If lyocell fibers are used in combination with at least one further material, this is referred to as a hybrid system or a hybrid fiber construction.

[0017] The material of the at least one further material for the textile covering may be any one of the suitable textile materials known in the art, preferably selected from the group consisting of: polyethylene (PE) such as, for example, UHMWPE, LDPE and LLDPE, or polyamide (PA) such as, for example, PA5.6, PA4.10, PA6, PA6.6, PA11, PA12, PA6.10 and PA6.12, or copolyamide, or polyester (PES), or rayon, or polyethylene terephthalate (PET), or polyethylene naphthalate (PEN), or polybutylene terephthalate (PBT), or polycarbonate (PC), or unsaturated polyester resin (UP), or poly(1,4-cyclohexanedimethanol terephthalate) (PCDT), or natural fibers (such as wool, flax, hemp, cotton), or polyvinyl alcohol (PVAL), or polyoxibenzonaphthoate, or polyvinyl acetal (PVA), or polyketone (POK), or polyetheretherketone (PEEK), or polyethylene 2,6-naphthalate (PEN), or polyphenylene, or polyphenylene oxide (PPO), or polyphenylene sulfide (PPS), or polyphenylene ether, or polybenzoxazole (PBO), or polyoxadiazole (POD), or polyetherimide (PEI), or meta-aramid, or para-aramid, or polypropylene, or melamine, or highly crystalline polymer fibers, or polyurethane (TPU). The stated materials can also be used in recycled form, i.e. as recovered materials.

[0018] The textile covering may be formed as a felt, fleece, woven fabric, braid, knitted fabric or a laid net. If the elastomeric article is a drive belt, the textile covering is preferably formed as a woven fabric or a knitted fabric.

[0019] All rubbers known to the skilled person can be used alone or in combination as rubber compound for the rubber compound of the main body. Rubbers are often also referred to as elastomers, so that the two terms are used synonymously in this document.

[0020] The rubber is preferably selected from the group consisting of ethylene-propylene copolymer (EPM), and / or ethylene-propylene-diene copolymer (EPDM), and / or nitrile rubber (NBR), and / or (partially) hydrogenated nitrile rubber (HNBR), and / or fluororubber (FKM), and / or chloroprene rubber (CR), and / or natural rubber (NR), and / or styrene-butadiene rubber (SBR), and / or isoprene rubber (IR), and / or butyl rubber (IIR), and / or brominated butyl rubber (BIIR), and / or chlorobutyl rubber (CIIR), and / or butadiene rubber (BR), and / or chlorinated polyethylene (CM), and / or polyepichlorohydrin (ECO), and / or ethylene-vinyl acetate rubber (EVA), and / or acrylate rubber (ACM), and / or ethylene-acrylate rubber (AEM), and / or silicone rubber (MQ, VMQ, PVMQ, FVMQ), and / or fluorinated methyl silicone rubber (MFQ), and / or perfluoropropylene rubber (FFPM), and / or perfluorocarbon rubber (FFKM), and / or elastomeric polyurethane (PU).

[0021] If the article is in particular a power transmission belt, EPDM, EPM, NBR and HNBR are preferably used alone or in combination.

[0022] However, it is also possible that the rubber compound contains at least one further thermoplastic elastomer and / or also at least one further thermoplastic, such as, for example, polyvinyl chloride (PVC), in an amount of 0 to 50 phr, preferably in an amount of 1 to 50 phr.

[0023] The further components of the compound are usually also crosslinking agents (such as, for example, sulfur, sulfur donors or peroxides), fillers (such as, for example, carbon black and / or silica), processing aids, plasticizers, anti-aging agents, and, if desired, further additives (such as color pigments). Reference is made in this respect to the general prior art in rubber compounding technology.

[0024] In an advantageous configuration, the elastomeric article may also contain at least one additional embedded reinforcing element. Embedded means that the reinforcing element is not on the surface. The embedded reinforcing element may take the form of a cord, as a felt, a fleece, a woven fabric, a braid, a knitted fabric or a laid net.

[0025] If the elastomeric article is a power transmission belt, the embedded reinforcing element preferably takes the form of cords, ie it is formed in a so-called cord construction. DETAILED DESCRIPTION

[0026] The present invention will now be explained in detail with the aid of comparative examples and exemplary embodiments summarized in Tables 1 to 4.

[0027] In each case, a drive belt is produced and provided with the corresponding textile covering. The textile covering consists of the material specified in the corresponding table.

[0028] Particularly important physical properties for textile coverings of drive belts that transmit torque by frictional engagement are, in particular, the degree of slip that occurs during the power transmission or the coefficient of friction of the surface provided with the textile covering. They also include parameters such as the misalignment of the individual strands or the load on the drive pulley, which can be used to determine the occurrence of unwanted noises caused by the contact surface of the belt relative to the pulley.

[0029] Since the object of the present invention is to improve the wetting properties of the article, the results of physical investigations under conditions with high ambient humidity are presented.

[0030] These physical investigations include measurements for determining the coefficient of friction (CoF) in wet conditions according to SAE standard J2432 and for evaluating the noise behavior and sliding behavior.

[0031] The noise behavior was measured in three stages. They all have in common that the belt is driven by a drive pulley with a rotational irregularity of 10% at a speed n.

[0032] In the dry measurement, pulley A is infinitely displaced relative to pulley B by up to 5 mm (corresponding to a 2.86° misalignment of the strands between A and B), and the angle at which a specific misalignment-related noise occurs at the inlet of pulley B is determined. In this measurement, there is no power transfer in the belt drive.

[0033] The wet measurements were made with the power output at the generator adjusted based on the amperage output (between at least 30 A and at most 120 A, in increments of 10 A). At the start of each phase, water was injected into the strand upstream of the generator pulley at 20 ml / min for 2 seconds in variant 1 and at 300 ml / min for 10 seconds in variant 2.

[0034] In the slip-power measurement, the power transmitted by the frictionally engaged belt is determined via the resulting belt slip.

[0035] In the measurements on which the test results are based, the described relationships were determined with continuous water injection on a V-type poly-V belt pulley with a pulley diameter customary for generators in auxiliary units of passenger car engines and a 120° wrap.

[0036] Table 1

[0037]

[0038] Compared with cotton and viscose knitted fabrics of the same construction and similar weight per unit area, the textile covering of the lyocell knitted fabric according to the invention shows a significant improvement in the coefficient of friction (measured at 100% slip) under wet environmental conditions. In this case, a higher coefficient of friction means a greater power transmission capability.

[0039] Table 2

[0040]

[0041] Table 3

[0042]

[0043]

[0044] An improvement in the noise behavior of the Lyocell textile covering can also be seen when humidity is present in the drive (Tables 2 and 3). This advantage becomes even more pronounced when the weight per unit area of ​​the textile is reduced (Table 3), which results in achieving the same wetting properties while using less material than in the case of comparable cellulose-based cotton textiles. This also saves resources.

[0045] Table 4

[0046]

[0047] Table 5

[0048]

[0049] Tables 4 and 5 show that a V-poly belt provided with a textile covering according to the invention can transmit significantly more power with the same slip than a belt of comparable construction with a viscose or cotton textile covering.

Claims

1. An article comprising an elastomeric body based on at least one rubber compound having a surface of the article, the surface being susceptible to noise and wear and provided with a textile covering, characterized in that the textile covering of the elastomeric article contains lyocell fibers or consists entirely of lyocell fibers.

2. The product according to claim 1, characterized in that The textile covering has a thickness of 70 g / m 2 With 350g / m 2 The average weight per unit area between.

3. The product according to claim 1 or 2, characterized in that The textile covering is a knitted fabric.

4. The article according to claim 1, characterized in that The article also contains at least one embedded reinforcing element.

5. The article according to claim 1, characterized in that The article is a belt, a strip, a belt, a hose, an air spring bellows, an expansion joint or a multi-layered textile mesh.

6. The article according to claim 5, characterized in that The belt is a drive belt.

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