JPH0748718Y2 - Dryer canvas with good weavability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a dryer canvas for papermaking.

(Prior art) The properties required for a dryer canvas used in a multi-cylinder dryer of a paper machine include dimensional stability in the machine direction and width direction,
Surface properties, breathability, heat resistance, chemical resistance, etc. can be mentioned. Rigid synthetic fiber monofilament yarns are used as weft yarns for dryer canvas in order to improve dimensional stability and rigidity in the width direction, but monofilament yarns alone are used to improve surface properties and adjust air permeability more easily. Instead, a bulky and flexible spun yarn or a composite yarn obtained by covering and winding a multifilament yarn has been used.

(Problems to be Solved by the Invention) However, there are the following problems when weaving the conventional dryer canvas.

That is, in order to drive a weft thread using a rigid monofilament into the opening of the diameter thread, a method is used in which a conventional so-called shuttle loom is used to store a weft barn in the shuttle and then pull out and insert the weft thread as the shuttle runs. Impossible to do.

Therefore, a weft insertion mechanism using a rapier, a gripper, etc. is used to insert the weft.

At this time, both ears of the canvas are not folded back in the form of woven selvedges, but are in a form in which the wefts are cut and fixed by using the discarding ears.

The cutting of the weft is due to scissors, etc., but when the spun yarn wound around the thick monofilament yarn is cut, the untwisting phenomenon occurs and peels from the core yarn.
In this state, a defect occurs in which the yarn feeding guide squeezes the yarn into uneven yarn. When weaving in such a state, weaving defects occur on both sides of the canvas, and in severe cases, the weaving operation is stopped and the weaving efficiency is remarkably reduced. Even when it is not very serious, the surface property deteriorates and becomes a problem.

The present applicant has proposed Japanese Examined Patent Publication No. 57-40278 as a weft yarn for canvas which solves the above problems. However, in the Japanese Patent Publication No. 57-40278, the weft yarn of low-melting point that functions as an adhesive is tightly wound around the outer periphery of the core yarn, and the upper-layer coated yarn of high melting point is tightly wound around the outer periphery thereof. , The core coated yarn and the upper coated yarn are adhered and integrated by melting the lower coated yarn by heat treatment, but the outer surface of the finished yarn is rough due to the presence of irregularities in the tightly wound lower coated yarn. And the surface properties are not good, and since the lower layer coated yarn is wound tightly, the amount of adhesive exceeds the required amount, the flexibility of the finished yarn is impaired and the lower layer coated yarn is required. The amount increases.
Further, there is a problem in that at least two steps are required to manufacture the yarn.

(Means for Solving the Problems) The present invention is a weaving technique that keeps the use amount of a low-melting multifilament yarn or spun yarn that functions as an adhesive for preventing the peeling of the covering yarn of the canvas weft yarn to the minimum necessary amount. It aims to improve the quality and the quality. That is, it is composed of a synthetic resin monofilament yarn and a core yarn in which a multifilament yarn having a melting point lower than that of the yarn or a spun yarn is composited in an aligned state, and a bulky spun yarn covered with the core yarn,
Moreover, the core yarn and the bulky spun yarn are bonded and integrated by the low melting point yarn melted by the heat treatment to form a yarn, and the yarn is used as a weft yarn of a dryer canvas to weave a dryer canvas.

Referring to the drawings, FIG. 1 is an explanatory view showing a weft 1 of the present invention. A synthetic fiber monofilament yarn 3 is aligned with a multifilament yarn or spun yarn 4 having a melting point lower than that of the weft yarn 1 to form a double twist yarn. A weft yarn 1 is obtained by winding two bulky spun yarns 5 on the peripheral surface of the composite yarn using a machine as a core yarn.

It is preferable to coat using a double twisting machine (covering machine). In this case, the core yarn is not twisted and only the coated yarn is twisted. When the two are twisted together using an ordinary ring twisting machine, a low melting point yarn also appears on the surface and the effect is significantly reduced. In this case, it is difficult to use thick monofilament yarn. The number of coated yarns is not limited to two, and is not limited to the same type of yarn. The coated twisted yarn is then heat treated to melt only the low melting point yarn and bond and integrate the monofilament yarn and the coated yarn. As the low melting point yarn, polyethylene, nylon, polypropylene or the like is used, but it is preferable that the melting points of both are open at 50 ° C. or more, and it is particularly preferable to use a dedicated yarn for bonding, without thermal influence on other yarn Can be glued. Using this twisted yarn, weaving is performed as the upper and lower weft yarns of the double-woven canvas 2 as shown in FIG.

The type of the diameter yarn 6 is not particularly limited, and the weft yarn can be used only in the upper layer and in the upper and middle layers and in combination with other weft yarns as required.

(Example) When weaving a double-woven dryer canvas as shown in FIG. 2, a polyester monofilament was used as the warp 6, and the weft 1 of the present invention was used as the weft, and a comparative example. A conventional weft is used as. As a low-melting yarn, nylon-based adhesive yarn (melting point 110 ° C-1
20 ° C.) was used.

The results are shown in Table 1.

(Effects of the Invention) This invention is, when a monofilament is used as a core yarn for a weft yarn of a dryer canvas, and a spun yarn is coated and wound, a low melting point multifilament or spun yarn is aligned and used for the core yarn to integrally bond them. Therefore, when the weft is cut by a cutter during weaving, the core yarn and the spun yarn of the cover are integrated without peeling, so they can be grasped reliably by the gripper, etc. I was able to do it. Along with this, the cover yarn separated from the core yarn did not become uneven yarn and was not woven in, and the canvas surface quality was good, and it was possible to manufacture a high-quality canvas.

In addition, since wefts can be produced by twisting in a single process using a double twisting machine, there is no cost difference between the conventional product and the twisting process, and the cost of the low melting point yarn and the heat treatment process depends on the improvement of weavability and quality. It is well-profitable.

In addition, the amount of the low melting point multifilament yarn or spun yarn that functions as an adhesive can be minimized, and the flexibility of the finished yarn is not impaired.

As described above, in the present invention, the amount of the adhesive is appropriate, the flexibility of the bulky spun yarn is not impaired, and the low melting point yarns are simply arranged in a straight line along the core yarn. Therefore, no unevenness is generated and the surface smoothness of the bulky spun yarn wound on the core yarn is not impaired, so the canvas woven with this as a weft yarn has excellent surface smoothness, and high quality paper is obtained. It can be manufactured.

[Brief description of drawings]

FIG. 1 is an explanatory view of a weft used in the dryer canvas of the present invention, and FIG. 2 is a vertical sectional view of the dryer canvas of the present invention. 1: Weft, 2: Dryer canvas 3: Synthetic fiber monofilament yarn 4: Low melting point yarn, 5: Bulky spun yarn, 6: Weft yarn

Claims (1)

[Scope of utility model registration request] 1. A synthetic fiber monofilament yarn, a core yarn in which a multifilament yarn having a melting point lower than that of the yarn or a spun yarn are composited in an aligned shape, and a bulky spun yarn covered with the core yarn, Moreover, the core yarn and the bulky spun yarn are bonded and integrated by the low melting point yarn melted by the heat treatment to form a yarn, and the yarn is woven as the weft of the dryer canvas. Good dryer canvas.