JPS6059360B2 - Manufacturing method of needle felt for paper making - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing needle felt for paper making which has excellent strength and air permeability.

As is well known, needle felt for paper making, which is made by integrally laminating a web on a base fabric using the needle punching method, has the advantage of flexibly pressing wet paper against the dryer surface and producing paper with a smooth surface. Therefore, it is widely used for making and drying high-quality paper. However, it is expected that there will be a problem that the fibers on the felt surface will fall off. In order to improve this problem, the punching conditions, especially the punching density, have been increased. Part of the fibers constituting the felt layer is held by a base fabric, and more preferably, low melting point fibers are mixed into the web and heat treated to prevent the fibers from falling off due to the melt adhesive strength of the low melting point fibers. The reality is that it is. However, in general, needle felt for papermaking is formed by laminating a fiber web on the surface of a base fabric woven from synthetic resin monofilaments or multifilaments, and then needling is performed. Therefore, the needle punching density of the fiber web is equal to the needle penetration density of the base fabric, and if the needle punching density is increased to prevent the fibers from falling off, the damage to the base fabric will increase and the strength will decrease significantly. This causes the inconvenience of not only causing problems but also deteriorating air permeability. In particular, when the base fabric is a monofilament fabric, the strength decreases significantly, and when the base fabric is a multifilament fabric, the air permeability decreases significantly. The present invention provides a method for producing needle felt for paper making, in which the above-described problems of fiber shedding and the disadvantages of reduced strength and air permeability in the needle felt for paper making are rationally improved, A needle felt layer is formed on at least one side of the base fabric, and in order to make the needle penetration density of the base fabric smaller than the needle penetration density of the needle felt layer by needle punching, first, a low melting point thermoadhesive synthetic material is used. A fiber web is layered on a mesh-like auxiliary sheet made of resin and subjected to needle punching to form a needle felt sheet of a desired thickness.Then, the needle felt sheet is superimposed on one or both sides of the base fabric and needle punching is applied to bond both. The auxiliary sheet is bonded and then heat-treated to melt the auxiliary sheet.

The method for producing needle felt for paper making of the present invention will be described below. First, a mesh-like auxiliary sheet 1 made of a low-melting point thermoadhesive synthetic resin, for example, a polyolefin film, is coated with polyester short fibers, polyamide short fibers, Alternatively, a fiber web 2 such as acrylic short fibers is layered and needle punched to form a needle felt sheet 3 of a desired thickness, and then the needle felt sheet 3 is
Polyester filaments or polyester multifilaments are superimposed on one or both sides of a base fabric 4 woven in the warp and weft directions, and then needle punched.
After that, heat treatment is performed to melt the auxiliary sheet,
A needle felt layer 3a is polymerized and fixed on one or both sides of a base fabric 4 to form a needle felt 5.

The above-mentioned auxiliary sheet 1 is a temporary sheet whose main purpose is to support the fibrous web 2 and to assist in the transfer of the fibrous web 2 to the punching machine and the formation of the needle felt sheet 3. It is desirable that the material has good penetration properties, and for example, a coarse fabric made of a flat type fabric such as a synthetic resin film cloth or a slit yarn is preferable.

Then, the fiber web 2 placed on the auxiliary sheet 1 is subjected to needle punching at 200 to 250 points/Ai, and at this stage, a needle felt sheet 3 with a high degree of entanglement between fibers is formed. The base fabric 4 may be a conventionally commonly used fabric, such as a synthetic resin monofilament or a double woven fabric woven with multifilament twisted yarns arranged vertically and horizontally. The needle felt sheet 3 described above is polymerized and needle punched to a relatively coarse density of about 100 to 200 points/d to bond the two sheets 3 and 4 to form a needle felt 5 for paper making.

The thus obtained needle felt for paper making 5 has a base fabric 4
The needle penetration density for the base fabric 4 is significantly lower than that of conventional fabrics, so the threads constituting the base fabric 4 are less damaged, resulting in less strength loss and better air permeability.

Furthermore, by using a low-melting-point thermal adhesive film sheet, film yarn fabric, split cloth, etc. as the above-mentioned auxiliary sheet 1, and bonding it with the base fabric 4, heat treatment is performed to melt the auxiliary sheet 1. The bonding strength and air permeability between the two are further improved.

[Brief explanation of the drawing]

The drawings are explanatory diagrams schematically showing the method for manufacturing needle felt for paper making according to the present invention. 1 is an auxiliary sheet, 2 is a fiber web, 3 is a needle felt sheet, 4 is a base fabric, and 5 is needle felt.

Claims (1)

[Claims] 1. A fiber web is layered on a mesh-like auxiliary sheet made of a low melting point thermoadhesive synthetic resin and needle punched to form a needle felt sheet of a desired thickness, and then the needle felt sheet is applied to one or both sides of the base fabric. Overlap and needle punching to combine the two,
A method for manufacturing needle felt for papermaking, which comprises subsequently heat-treating to melt the auxiliary sheet.