JPH03220326A - Yarn conveying belt - Google Patents

Abstract

PURPOSE: To simply and easily produce a transport belt having a smooth internal surface and highly dimensional precision by adopting contracted foil subjected to contraction after stretch as an internal reinforcing layer. CONSTITUTION: A belt 10 having both a thermoplastic contracted foil as an internal reinforcing layer 11 and an external elastic layer 12 is adopted as a transport belt. Since the internal surface of the belt 10 has a lower friction coefficient and more highly dimensional precision than that of the external one, a yarn is gripped with the external elastic surface and the smooth internal surface enables the belt to move around a guiding means with reduced resistance and reduced wear.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transport belt, and more particularly to a belt for a yarn drawing device.

BACKGROUND OF THE INVENTION When processing yarns used in textile weaving, processing machines use transport belts to guide the yarns or rovings between rollers. The yarn transport path is usually provided between two parallel transport belts or between a belt and a roller. Conventional transportation belts are typically made of elastomers or leather and have a reinforcing layer of fibrous material such as cord or yarn bundles embedded within the belt. The manufacture of transport belts of this type requires great care in order to achieve the required dimensional accuracy. The belt is manufactured on a mandrel. First, it is covered with a lower elastic layer, which is then covered with a reinforcing layer of fibrous material, which is then covered with an upper elastic layer.

During a subsequent heat treatment the outer elastic layer is bonded by embedding the reinforcing material. If the dimensions of the lower layer are not accurate, a heald sheath that is too large or too small in diameter will be produced. Furthermore, for reasons of space, belt transport devices of textile machines often do not have belt stretching devices, so the length of the transport heald must be exactly as specified. Even if the length of the thread is slightly different, the thread may slip or become uneven.
This will result in premature wear of the heald. Furthermore, when the heald travels at a high speed such as during weaving, vibrations may occur.

Furthermore, there is a problem in that the outer surface of the belt, which comes into contact with the yarn to be transported, must have a certain amount of force to grip the yarn, whereas the inner surface of the belt must have a low coefficient of friction with the components it comes into contact with. .

In order to bend the belt sharply, there is no room for a guide roller, so the belt must be moved around the edge of the metal plate. At this time, if the friction coefficient of the inner surface of the belt against the metal plate is high, the transport resistance will be high even if a belt stretching device is attached, causing wear of the belt and, in some cases, heald whirring.

West German Utility Model No. 1739433 describes a two-layer spinning apron. The outer layer of the spinning apron is made of rubber, while the inner layer is a woven layer, the pores of which are filled with rubber or another elastic material. A disadvantage of this spinning apron is that it has a portion on the inside surface that is part of the fabric layer but is made of elastic material. Significant friction therefore occurs when the belt passes over the stationary parts, since the inner surface exhibits a high coefficient of friction of the elastic material.

DE 33 41 437 describes an apron for a textile drafting device. This apron is a single layer apron made by extruding a belt sheath made of polymeric material.

A belt sheath, or apron, is then placed over the mandrel, wrapped with fabric or other covering material, and heated.
Then remove the rolled thing.

The apron is then pulled out from the mandrel and allowed to cool.

Such a single-layer apron is composed only of an elastic material, but the relatively high elasticity of this elastic material is not preferred in practical use. In this case, the frictional properties of both sides and the ability to grip objects in contact are essentially the same.

The present invention has been made to solve these problems, and it is a transport system in which the coefficient of friction on one side of the belt is lower than the coefficient of friction on the other side, and products with high dimensional accuracy can be produced in a simple manner. The purpose is to provide a belt and its manufacturing method.

[Means to solve the problem]

The transport belt according to the invention is characterized in that the reinforcing layer consists of a thermoplastic foil which has been previously stretched and then contracted. Since this shrink foil becomes the inner surface of the belt, the reinforcing material satisfies two requirements at the same time. That is, while the strength is increased, an inner surface that is inelastic, free from catching, and smooth and has a low coefficient of friction can be obtained. Normally, a belt having such a structure can be obtained by simply stacking two single layers. First, a shrink foil is shrunk onto a mandrel and the shrink foil is covered with an elastic layer. These two layers are bonded together with an adhesive and heated if necessary.

[Function] By stretching the transport belt of the present invention in the radial direction and then contracting it, the elasticity of the belt sheath or the individual belts becomes extremely small, which is significantly lower than that of the elastomer.

As a result, the stability of the belt dimensions is increased and this stability is maintained during use. For example, based on normal fiber elongation, the belt length tolerance is ±0.151. The transport belt of the present invention easily maintains tolerances of ±0.10 mm even after long periods of use. The inner surface has a low coefficient of friction, so the inner surface remains smooth even after long-term use.

It is sufficient that the thickness of the shrinkable foil reinforcing material that transmits the tensile load of the power transmission belt is 50 μm or less.

Therefore, the thickness of the apron of this invention can be made extremely thin. The outer elastic layer is responsible for transporting and stretching the fibrous material.

Furthermore, the invention relates to a method for manufacturing a transport belt. A shrinkable hose that has been stretched in advance in the radial direction is covered with a zero-order elastic layer that is contracted on a cylindrical mandrel, and both are bonded together using an adhesive at a temperature of 80° C. or higher. After cooling, remove the mandrel. Individual belts are cut from the heald sheath thus produced.

The belt sizing accuracy of the present invention is improved as a result of the shrink hose being precisely sized on the mandrel and having an elastic layer of predetermined thickness adhered thereto. The dimensional inaccuracies that normally occur due to the use of elastic layers as inner layers are thus avoided. Since reinforcing fibers cannot be glued into the belt, it is necessary to embed the fiber material.

In the transport belt of the present invention, the reinforcing layer is a continuous foil so that the reinforcing material can constitute the inner surface of the belt. The use of shrink foil not only improves dimensional accuracy but also provides an extremely smooth inner surface with a low coefficient of friction.

Although the transport belts of the present invention generally do not require fibrous reinforcement, reinforcement may be used to increase tensile strength. This reinforcement can also be embedded at the boundary between the shrink foil and the elastic layer. Even when using fiber reinforcement,
It has the advantage of having a smooth inner surface with no stickiness and wear resistance.

The shrink foil may be, for example, a polyamide or polyester foil. The elastic material may be natural rubber, synthetic rubber or thermoplastic elastomer.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a perspective view of the transport belt, Figure 2 is from ■-■ in Figure 1.
3 is a cross-sectional view showing a method of manufacturing a belt sheath on a mandrel, FIG. 4 is a cross-sectional view of a belt further embedded with reinforcing fibers, and FIG. 5 is a cross-sectional view of a belt in which reinforcing fibers are stretched. FIG. 2 is an embodiment diagram showing a state in which a belt is attached to a high-speed draft filament machine.

The transport belt in FIG. 1.2 is an endless two-layer belt 10. The inner layer is a reinforced shrink foil 11 made of polyamide or polyester, and the outer layer is an elastic layer 12. Both layers 11.12 are firmly bonded by heat vulcanization with a bonding agent (adhesive) if necessary. Glue. The elastic layer 12 is substantially made of thick shrink foil. Regarding the thickness,
The drawing is not to scale. In practice, the thickness of the elastic layer is made to be at least about five times the thickness of the shrink foil. The thickness of the shrink foil is 50 μm or less, preferably 20 to 30 μm.

FIG. 3 is a drawing showing the construction of a belt sheath on a cylindrical mandrel 13, and the thickness and diameter of each of the layers 11, 12 and the dimensional ratio between the thicknesses of the layers are not as in reality.

First, a shrinkable hose that has been stretched in the radial direction and has a diameter larger than that of the mandrel 13 is fitted onto the mandrel, and since the diameter of the shrinkable hose is large, insertion is easy.

Next, when the foil hose on the mandrel 13 is heated, the hose contracts and comes into close contact with the outer peripheral surface of the mandrel 13. Next, an adhesive is applied onto the shrunken shrink foil ll, and then an elastic layer 12 is covered. The elastic layer may be covered in a mesh pattern or may be wound in a spiral shape.

After assembly on the mandrel 13, the shrink foil adheres to the overlying elastic layer 12 by vulcanization at approximately 150°C. Once vulcanization is complete, the assembly is cooled.

During cooling, the temperature is set at approximately 80°C so that the shrink foil maintains its shape and does not become elastic. Since the diameter of the metal mandrel 13 further shrinks below 80° C., the cooled belt sheath can be easily removed from the mandrel 13. The belt sheath is then cut into individual transport belts. The thickness of the transport belt is approximately 1 mm.

The fourth embodiment differs from the first embodiment in that a second reinforcing material 23 made of a fibrous material is embedded between the shrinkable foil 11 and the elastic layer 12. This fiber material may be a helically wound yarn bundle, fiber mat fiber, or the like.

FIG. 5 shows a state in which the transport belt 10 is attached to a spinning machine or a high-speed draft filament machine that stretches the roving 15 supplied to a roving machine.
．． Stretch it out for 17 minutes. At this time, a pair of downstream rolls 1
The circumferential speed of roller 7 is faster than the circumferential speed of the pair of upstream rollers 16. Two guide means 18. between two pairs of rollers 16.17.
19 guides the roving 15. These guide means each include a belt roller 20, around which the transport belt 10
moves. The transport belt 10 must be guided in such a way that the end facing the pair of rollers 17 is as close as possible to the gap between the rollers. Therefore, a guide sea (21) is provided at this end without providing a guide roller, so that the transport belt 10 is bent at the end of this guide sea. Furthermore, leaf spring 22
is provided as a heald extension device.

Since the inside of the transport belt 10 is a shrink foil 11, the guide sheet 21 is in contact with the non-elastic, smooth shrink foil 11, while the rovings 15 are in contact with the non-slip outer elastic layer 12.

〔Effect of the invention〕

The transport belt of the present invention uses a shrunken shrink foil as a reinforcement material, which at the same time forms a smooth inner surface of the belt.

The outer surface of the belt is an elastic layer. The inner surface of the belt is smooth,
The outer surface is an elastic layer that is more sticky than the inner surface. The transport belt of the present invention has high dimensional accuracy, and has the excellent effect of gripping the thread with its elastic outer surface and moving it around the guide means with less resistance and less wear on the smooth inner surface.

In addition, in the method of manufacturing a transportation belt of the present invention, the shrinkable foil is contracted on a mandrel with accurate dimensions so as to be brought into close contact with the mandrel, and then an elastic layer formed in advance with an accurate thickness is bonded with an adhesive or the like. This simple method has the excellent effect of producing a transportation belt with high dimensional accuracy.

[Brief explanation of drawings]

Figure 1 is a perspective view of the transport belt, Figure 2 is from ■-■ in Figure 1.
3 is a sectional view showing a method of manufacturing a heel sheath, FIG. 4 is a sectional view of another embodiment of the transport belt, and FIG. 5 is a diagram of an embodiment of the transport belt. DESCRIPTION OF SYMBOLS 10... Two-layer belt 11... Reinforcement material 12... Elastic layer 13... Core metal 14... Adhesive 23... Second reinforcing material patent Applicant: Horst Botske Mülleuv Renveber

Claims (1)

[Claims] 1. A transport belt for yarn consisting of an outer elastic layer and at least one inner reinforcing layer, in which the reinforcing layer is a pre-stretched and then contracted thermoplastic shrink foil. A transport belt for yarn. 2. A transport belt for yarn according to claim 1, wherein a second reinforcing layer of fibrous material is embedded between the elastic layer and the shrink foil. 3. Transport belt for yarn according to claim 1, wherein the shrink foil is adhered to the elastic layer by means of an adhesive. 4. The method for producing a transport belt for yarn according to claim 1, 2 or 3, comprising: shrinking a shrinkable hose that has been stretched in advance in the radial direction on a round bar-shaped mandrel, covering the shrinkable hose with an elastic layer; A method for producing a transport belt for yarn, which comprises adhering both layers at a temperature of 80° C. or higher and removing a core.