JPH0559686A - Drier canvas for paper-making - Google Patents

Abstract

PURPOSE:To provide the subject product composed of monofilament of a specific polymer alloy as a flexible material, having decreased air-permeability and improved smoothness and effective for preventing the transfer of mark on wet paper because the canvas can have increased count number. CONSTITUTION:The objective product is produced by using monofilament of a polymer alloy of a polyester and a polyethylene (elastomer) as the warp and/or the weft. The amount of the polyethylene (elastomer) in the polymer alloy is preferably 0.1-10%. The monofilament preferably has a flat cross-section having a short side length of 0.1-1mm, a long side length of 0.2-2mm and a long/short ratio of 1.2-3.5 to decrease the air-permeability and improve the smoothness of the objective product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking dryer canvas, and more particularly to a papermaking dryer canvas using a monofilament made of a flexible polymer alloy.

[0002]

2. Description of the Related Art In a conventional paper dryer dryer, monofilaments made of polyethylene terephthalate (PET) having a circular cross section are used for both warp and weft. Since such a monofilament canvas has too high air permeability, it has been dealt with by using a bulky yarn such as a thick spun yarn inside the multi-woven structure in order to adjust the air permeability. Further, in order to adjust the ventilation of the canvas and improve the smoothness, the cross-sectional shape of the monofilament is flattened.

[0003]

However, if a bulky yarn such as a thick spun yarn is used inside the multi-woven structure using the monofilament made of PET for controlling ventilation, the air permeability can be controlled. On the other hand, spun yarn is made of fine short fibers, is bulky, and has fluffs, so that the fluffs are liable to be soiled, and stains are likely to be produced inside the yarns. Further, since the monofilament made of PET is hard, there is a limit in increasing the yarn density to reduce the smoothness and air permeability of the canvas. The present invention has been made in view of the above points, using a monofilament made of a polymer alloy, which is a flexible material, makes it possible to increase the number of implants even with the same thickness, reduce air permeability, and smoothness. The present invention aims to provide a dryer canvas for papermaking, which improves adhesion and prevents the adhesion of marks to wet paper produced in the papermaking process. Further, in the case of multiple weave, it is a bulky spun yarn as a filling yarn for adjusting ventilation. The purpose of the present invention is to provide a canvas in which the air permeability can be adjusted without using, the canvas does not become clogged, and the dirt does not easily get stuck.

[0004]

A dryer canvas for papermaking according to the present invention comprises a monofilament made of a polymer alloy of polyester and polyethylene or a polymer alloy of polyester and polyethylene elastomer at least among warp and weft. It is used on one side. Furthermore, a polymer of polyester and polyethylene
A monofilament made of an alloy and a monofilament made of a polymer alloy of polyester and polyethylene elastomer are used in combination for a warp and a weft.
The amount of polyethylene or polyethylene elastomer mixed in the polymer alloy monofilament is 0.1 to 10%. The mixing amount of polyethylene or polyethylene elastomer is specified in this range because polyethylene or polyethylene elastomer is P
Since its melting point is lower than that of ET, the tensile strength of a monofilament made of a polymer alloy by melting polyethylene or polyethylene elastomer in an atmosphere of 100 to 140 ° C,
It is based on the range that can be used without adversely affecting physical properties such as elongation. If the polyethylene or polyethylene elastomer content is less than 0.1%, the desired flexibility cannot be obtained. If the content of polyethylene or polyethylene elastomer exceeds 10%, the physical properties such as tensile strength and elongation of the monofilament made of polymer alloy are adversely affected.

Further, when the cross-sectional shape of the monofilament made of polymer alloy is flat, the short side is
0.1 ~ 1.0 mm, long side 0.2 ~ 2.0 mm, long side to short side ratio 1.2 ~ 3.5. As described above, when the monofilament has a flat cross section, the monofilament is more easily bent, and since it is made of a flexible material, the number of implants can be further increased, the air permeability can be lowered, and the canvas can be reduced. The smoothness of the paper is further improved, and the adhesion of marks to the paper produced during the papermaking process is improved.

[0006]

A monofilament made of a polymer alloy of polyester and polyethylene or a polymer alloy of polyester and polyethylene elastomer has a conventional P
Since it is a softer material than the monofilament made of ET, the number of implants can be greatly increased even with the same thickness. Therefore, the canvas in which the number of impacts is increased by using the monofilament has a large contact area with the wet paper, the load per unit contact area is reduced, and the adhesion of the mark to the wet paper is reduced. At the same time, in the case of multiple weaving, PET is used without using bulky spun yarn as the ventilation yarn.
The air permeability can be lowered by using monofilament twisted yarn and the like, so that a canvas that does not clog the canvas and is resistant to dirt can be obtained.

[0007]

【Example】

Example 1 A flat type monofilament (PE content in the polymer alloy is 0.5%) having a double weft structure and made of a polymer alloy of PET and PE (polyethylene) 0.40 mm × 0.60 mm as warp 1 and weft 2. Using a PET monofilament twisted yarn 3000d, which is difficult to get dirty, as the ventilation yarn 3 was used to obtain a dryer canvas for papermaking (see FIG. 2). The number of wefts driven was up to 54 / in. The air permeability and the contact area ratio with respect to the wet paper using this canvas are shown in Table 1. Comparative Example 1 The structure was the same as in Example 1 except that flat monofilament filaments of PET were used as the warp and weft, and PET spun yarn was used as the air flow adjusting filling yarn. The number of wefts to be driven was limited to 40 / in. The results are shown in Table 1. As is clear from Table 1, the number of wefts driven in Example 1 was improved by 35% as compared with Comparative Example 1. Further, in Comparative Example 1, a bulky spun yarn is used as the ventilation adjusting filler yarn, whereas in Example 1, a monofilament twisted yarn is used without using a bulky spun yarn and the same degree as in Comparative Example 1 is used. The air permeability can be lowered, and there is no clogging on the canvas,
A canvas that is hard to get dirty was obtained. Also, the markability for wet paper was improved. To increase the number of weft threads,
Weaves with less knotting points such as 1/5, 5/1 weft double design, 1/7, 7/1 weft double line design can be used.

[0008]

[Table 1]

Example 2 A flat monofilament having a single structure and composed of a polymer alloy of PET and PE (PE content in the polymer alloy is 0.5%) 0.40 mm × 0.60 mm is used as a warp, and PE
A flat type monofilament (PE content in the polymer alloy was 0.5%) 0.40 mm × 0.60 mm composed of a polymer alloy of T and PE elastomer was used as a weft yarn to obtain a dryer canvas for papermaking. The number of wefts to be driven was possible up to 26 / in. The air permeability and the contact area ratio with respect to the wet paper using this canvas are shown in Table 2. Comparative Example 2 The procedure of Example 2 was repeated except that flat PET monofilaments were used as the warp and the weft. The number of wefts to be driven was limited to 20 / in. The results are shown in Table 2.

[0010]

[Table 2]

As is clear from Table 2, the number of wefts driven in Example 2 was improved by 30% as compared with Comparative Example 2. Also,
The air permeability was smaller than that of Comparative Example 2, the contact area ratio of the canvas was improved from 17% to 22%, and the markability for wet paper was improved.

[0012]

As will be understood from the above description, the present invention uses a monofilament composed of a polymer alloy of polyester and polyethylene or a polymer alloy of polyester and polyethylene elastomer for at least one of warp and weft. Or, since both monofilaments are used in combination for the warp and the weft, it is a synthetic material that is softer than the conventional monofilament made of PET. As a result, there is an excellent effect that the air permeability can be reduced and a canvas with improved smoothness can be obtained. Due to this improvement in smoothness, the canvas has a large contact area with the wet paper, the load per unit contact area is reduced, and the adhesion of the mark to the wet paper is reduced. Further, in the case of a multiple woven fabric, the air permeability can be lowered to the same extent as when the air permeability is adjusted with the spun yarn by using a monofilament twisted yarn or the like without using a bulky spun yarn that is easily soiled as a ventilation yarn. , The fluff is completely clean, and the clogging of the canvas is eliminated, resulting in a canvas that does not easily get dirty. Furthermore, the amount of polyethylene or polyethylene elastomer mixed in the polyester is 0.
Since it is set to 1 to 10%, it has flexibility as a monofilament, and polyethylene or polyethylene elastomer melts in an atmosphere of 100 to 140 ° C to adversely affect physical properties such as tensile strength and elongation of the monofilament. Therefore, it can be sufficiently used as a dryer canvas for papermaking. Furthermore, the cross-sectional shape of the polymer alloy monofilament is flat and the short side is 0.1 to 1.0 m.
m, long side 0.2-2.0 mm, long-side to short-side ratio 1.2-3.5
In this case, the flat cross-sectional shape and the fact that it is made of a flexible material work together to increase the number of implants, reduce the air permeability, and improve the smoothness of the canvas. As a result, the adhesion of marks to the paper produced during the papermaking process is further improved.

[Brief description of drawings]

FIG. 1 shows a flat cross section of a monofilament, where (A) shows an elliptical shape and (B) shows a rectangle.

FIG. 2 is a double structure diagram containing a filling yarn for weft ventilation adjustment.

[Explanation of symbols]

 1 Warp 2 Weft 3 Filling yarn for ventilation adjustment

Claims (4)

[Claims] 1. A dryer canvas for papermaking, wherein a monofilament made of a polymer alloy of polyester and polyethylene or a polymer alloy of polyester and polyethylene elastomer is used for at least one of warp and weft. 2. A dryer canvas for papermaking, wherein a monofilament made of a polymer alloy of polyester and polyethylene and a monofilament made of a polymer alloy of polyester and polyethylene elastomer are used in combination as warp and weft. .. 3. The amount of polyethylene or polyethylene elastomer mixed in the polymer alloy monofilament is 0.1 to 10%.
Alternatively, the papermaking dryer described in 2. 4. The cross-sectional shape of a monofilament made of a polymer alloy is flat and has a short side of 0.1 to 1.0 mm and a long side of 0.
The dryer canvas for papermaking according to claim 1, 2 or 3, which has a length of 2 to 2.0 mm and a ratio of long sides to short sides of 1.2 to 3.5.