FI86894B - BANDMATERIAL FOER TRANSPORTBAND. - Google Patents

Abstract

The invention seeks to provide a band containing non-woven fabric, for drive and conveyor belts, which band does not build up electric charges. The fibre mixture of the non-woven fabric contains about 1 to 10 % by weight of electrically conductive fibres. <IMAGE>

Description

! 86894

BELT MATERIAL FOR CONVEYOR BELTS

The invention relates to a belt material as defined in the preamble of claim 1.

5 Conveyor belts are manufactured, inter alia, by using non-woven felt fabrics with the lowest possible elongation and possibly some elasticity, in order to prevent the conveyor belt from stretching during use and the consequent need for tightening.

10 The problem with the belt is the static charges that easily build up in it, i.e. as is known from a van der Graff generator. This operation is particularly undesirable when transporting sensitive components such as electronic components.

It is previously known to treat felt fabrics antistatically by incorporating conductive fibers, including synthetic fiber-containing materials, into the felt to prevent charging.

DE 2016403 discloses tufted blankets and knitted textile fabrics comprising filament or fibrous yarns from a fiber blend with metallic fibers or metallized fibers for use as a backing fabric to prevent static charges.

DE 1917587 describes the addition of a metal, preferably steel fibers, to a laminate of different fibrous materials.

In order to prevent static charges on the discs of record players, DE 2457542 discloses the use of metal fibers, in particular steel fibers, in the felt covering the disc.

"Textile Institute and Industry", Vol. 7, 1972, p.199, describes conductive fabrics made of nonwoven mat and containing metal fibers for use in filtration purposes.

From DE-FZ "Textilveredelung" 17, 1982, No. 6, pp. 260-263, it has become known that conductive polyacrylonitrile fibers treated with copper salts can be applied to blankets suitable as antistatic protective suits, filters, mats. and also as decoration materials.

In the prior art, the use of nonwoven mat is not subject to special requirements for the duration of linear elongation and is therefore not suitable as conveyor belts.

DE 17 50 073 describes a transmission belt 10 provided with a structure of the belt body which reduces the longitudinal elongation of the belt and in which non-stretchable strips or wires are arranged inside the belt.

DE-GM 83 34 233 discloses a longitudinally elastic drive belt made antistatic on the upper side of the fibers, in which the belt consisting mainly of rubber is coated with metallized fibers.

To reduce the elongation of the strip, fabric-reinforced conveyor belts are known from 20 DE-28 42 837. It comprises a plurality of substantially parallel textile yarns and at least one layer of staple fibers connected by knitting, and these enclosing elastomeric polymer resin matrix with staple fibers. 25 However, this tape does not include any antistatic arrangement and therefore charges during use.

A method for producing this strip is disclosed in DE 32 31 119, in which low-stretch textile bricks are knitted on both sides of the staple fiber felt.

To avoid charges, conveyor belts have already been proposed with binders or coating materials to which a conductive material, usually carbon black or metal dust, has been added. Disadvantage 35 this always results in dark conveyor belts, while in many applications such as electronics and the food industry, light belts are desirable.

86894 3

An additional problem arose when using carbon black for dark strips, with the contamination of the goods being transported due to carbon black, which behavior makes it difficult or impossible to use these belts 5 in the electronics industry.

Known belts are either too complicated to manufacture or disadvantageous due to too rapid surface wear. The problem was exacerbated by the increased use of synthetic fibers, with the fibers having advantageous properties in length-stabilized conveyor belts with an increased tendency to charge.

It is therefore an object of the present invention to provide a belt material with a felt fabric with a binder for conveyor belts so that the conveyance of the conveyor belts can be avoided.

The belt material according to the invention is characterized by what is stated in claim 1.

According to the invention, the problem is solved with a belt material for conveyor belts consisting essentially of a felt fabric and a binder, wherein the fiber mixture of the felt fabric comprises about 1-10% by weight of electrically conductive metallic staple fibers divided over the entire cross-sectional area of the belt material.

Preferred embodiments of the invention appear from the dependent claims.

Felt fabrics can consist of very different types of nonwoven, e.g. knitted nonwoven, fibers mixed nonwoven, etc.

The fiber blend of the felt fabric may include synthetic and / or natural and / or semi-synthetic fibers, such as polyester, polyamide, polypropylene, polyacrylic, cotton, coconut, and wool fiber, or the like.

It is particularly preferred that the belt comprises one or more high tensile and low elongation yarns, threads, fabrics or corrugated fabrics of synthetic and / or natural and / or semi-synthetic fibers. Suitable fibers include, for example, polyester, polyamide, polypropylene, wool, polyaramide, glass, and ceramic fibers, or combinations thereof.

5 Electrically conductive fibers may contain at least one metal or elemental carbon. For example, it is suitable to use steel or copper fibers for this purpose, but metallized such as silver-plated copper fibers can also be used. Here, carbon 10 refers to conductive carbon transformations such as graphite tics.

In a preferred embodiment, the titer of the steel fibers is 0.8-18 and preferably 3-10 dtex and the fiber length is 20-80 mm. Preferably, the tensile resistance of the non-woven fabric pin-15 at 100 V is 102 to 108 and preferably 104 to 106 Ohms.

It is possible to use hydrophobic binders such as nitrile-butadiene rubber and / or styrene-butadiene rubber latex.

The conductive felt fabric conveyor belts preferably include a mechanically knitted synthetic fibrous nonwoven mat comprising conductive fibers and a binder with which the nonwoven mat is impregnated. In the manufacture of a felt fabric, which may alternatively include one or more fabrics or pleated fabrics, conductive fibers are mixed into the fibrous nonwoven mat, the mechanically cured nonwoven mat is then impregnated with a binder, and then dried at 100 ° C.

The fiber blend of the felt fabric may include synthetic and / or natural and / or semi-synthetic fibers. Suitable synthetic fibers are, for example, polyester fibers, polypropylene fibers and mixtures thereof, in particular due to their high stability and low cost.

Particularly preferred electrically conductive fibers are those having at least as well a conductive and flexible metal such as copper, iron, aluminum 86894 5 or conductive metal coated fibers or elemental carbon.

Preferred binders are nitrile-butadiene-rubber and / or styrene-butadiene-rubber-latex. As binders, for example, it is possible to use water-soluble nitrile-butadiene-rubber, styrene-butadiene-rubber latex or solvent-soluble binders, such as polyurethane. polyvinyl chloride, polyacrylate or mixtures thereof. The ratio of fiber to binder is preferably between 1: 2 and 2: 1 and particularly preferably 1: 1 by weight.

The impregnated and dried felt fabric can then be sanded, for example, with sandpaper on one or both sides to improve the surface.

The non-fibrous thickness suitable for making the conveyor belts can be 1-8 mm and preferably 2-5 mm and the weight per unit area is 300-6000, preferably 1000-4000 g / m 2.

The felt fabric of the invention for conveyor belts preferably comprises a synthetic fibrous fibrous mat which is mechanically reinforced, binders and fillers, dyes and vulcanizing agents, wherein the fibrous mixture contains 1-10% by weight of conductive fibers being steel, graphite, wool fiber or ho-25. head-coated or copper-containing fiber.

Additional features and advantages of the invention will become apparent from the following description of a preferred embodiment with reference to the drawing, in which Figure 1 is a plan view of a portion of a belt 30 according to the invention and Figure 2 is a cross-section of a portion of Figure 1.

As shown in Figure 1, the belt according to the invention consists of a non-woven fabric layer 10, in which case 35 are 10% by weight of 6 dtex steel fibers. In the cross-section of Figure 2, the steel fibers are evenly distributed over the entire thickness of the sheath.

6 86894

Example

A polyester fabric or a corrugated fabric weighing about 100 g / ra2 per area with 6: 11a of 1100 dtex longitudinal fiber and 3: 11a 5 of 1100 dtex transverse fiber is sewn on both sides of 950 g / m2 with two parts of 6.7 dtex and one part of 17 dtex polyester fibers to which 2% by weight of 9 dtex steel fibers are added so that the non-fibrous matter has a thickness of 6 mm, a weight of 2000 g / m 2 and a density of 0.33 g / cm 3.

The base fiber mat is then impregnated with 100% by weight of nitrile-butadiene rubber latex with 25% by weight of CaCO3 as filler and 5% by weight of vulcanizing agent consisting of sulfur and zinc oxide, after which it is coagulated in an infrared oven, washed and dewatered. then dried and vulcanized at 150 ° C. The bonded reinforced nonwoven fabric is then sanded on both sides with a grit 120 grit sandpaper, giving a uniform flat surface and a thickness of 5.5mm. The surface resistance of the product 20 is 100 V at a voltage of 1 x 105 Ohm.

Claims (3)

86894 PATE REQUIREMENTS 1. A band material for a transport band is preferably used with a filter and a binder, which means that the filter band is a fiber-bonded device having a ca. 1 - 10% by weight of electrically ledand metal-halter stapelfibrer fördelade över bandmaterialets hela tvärsnittsyta. A belt material for conveyor belts consisting essentially of a felt fabric and a binder, characterized in that the fiber mixture of the felt fabric comprises about 1-10% by weight of electrically conductive metal-containing staple fibers divided over the entire cross-sectional area of the belt material. 2. A band material according to claim 1, and -10 net fibers, having a synthetic fiber to a synthetic or natural or synthetic fiber. Belt material according to Claim 1, characterized in that the fiber mixture comprises synthetic and / or natural and / or semi-synthetic fibers. Belt material according to Claim 1 or 2, characterized in that it comprises one or more high-tensile and low-elongation yarns, threads, fabrics or corrugated fabrics consisting of synthetic and / or natural and / or semi-synthetic fibers. 3. A test material according to claims 1 or 2, which is intended to be used, or to 15 or more of the same or more than one or more of the same or more than one or more of the synthetic or / or synthetic or a synthetic fiber.