JPH0226960Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a papermaking felt suitable for application to a papermaking machine.

[Background of the idea]

Generally, papermaking felt is made by laminating fiber batts on one or both sides of a base fabric and integrating them by needling. However, the papermaking felt constructed in this manner has difficulty in precisely adapting to the density depending on the type of paper due to the nature of the fiber butt layer, and moreover, troubles have occurred due to hair loss. In addition, there is a permissible limit to water absorption, and if the water squeezed out of the wet paper before passing the nip point of the press roll moves again to the wet paper, which is made of dense pulp after passing the nip point, rewetting occurs. This phenomenon was difficult to avoid, the moisture profile of the wet paper was not well-uniformed, and the fiber web was sagging, resulting in various problems such as the paper being unable to withstand long-term use.

[Purpose of invention]

This idea was devised in consideration of the above points, and it does not cause hair loss, has a long life, minimizes rewetting, contributes to a uniform moisture profile, and can be freely adjusted to suit the paper texture. The purpose of this papermaking felt is to provide papermaking felt that can be used for papermaking.

[Structure of the idea]

In order to achieve the above object, this invention has a plurality of resin foam layers laminated on the surface of a fluffy base fabric, at least the bottom layer is entwined with napped fibers, the top layer surface is smoothed, and each of the resin foam layers The structure is such that the air bubbles become finer from the bottom layer to the top layer.

〔Example〕

Next, this invention will be explained based on embodiments shown in the accompanying drawings.

In the figure, reference numeral 1 denotes the felt of the present invention, which is formed by laminating a plurality of resin foam layers 3a, 3b, and 3c on the surface of a fluffy base fabric 2 so that at least the bottom layer is entwined with the napped fibers 2a.

The base fabric 2 may be one made of woolen yarn woven into a single weave (or multiple weave) as shown in FIG. It may also be made by weaving a single layer (or multiple layer) of yarns, laminating the batts 2' on the back side, and fluffing the surface by needling. The former case has the advantage that manufacturing is simple, and the latter case has the advantage that the strength of the base fabric itself and the felt of the present invention as a whole is even higher. The batt 2' used for the latter base fabric may be a synthetic fiber batt or a blended batt.

The foamed resin layers 3a, 3b, and 3c are made of a resin with good elasticity, such as polyurethane or silicone rubber. The means for forming this resin foam layer is not particularly limited, but as an example, a continuous foam coating device 10 as shown in the third figure can be used satisfactorily. In this device 10, an emulsion 12 contained in a tank 11 is injected together with air into a mixer 15 via an injector 14, and the emulsion 12 is mixed and stirred in the mixer 15 to foam. The mixer 15 stabilizes the foam uniformly by adjusting the stirring speed, and supplies the foam to the surface of the base fabric 2 running endlessly from the supply hose 16 at a desired foaming ratio. This foam is coated with a coating means 17 consisting of a knife or a roll coater.
It is adjusted to a certain thickness in the oven 18, and is applied over and over again while being foamed. When layering is done by this method, the foam in the bottom layer 3a applied directly to the surface of the base fabric 2 is well entangled with the napped fibers 2a standing on the surface of the base fabric 2. The foam supplied onto the base fabric 2 changes the foaming ratio when the base fabric 2 goes around once, and the bubbles become finer as they move toward the upper layer (for example, 60μ for the bottom layer, 40μ for the middle layer, and 40μ for the top layer). 20μ
The water absorbency is increased and the texture of the paper contacting surface is formed into a fine-grained texture.

After curing, the foamed resin layer obtained as described above or by other suitable means is applied to the surface (contact) of the top layer (three layers in the example, but it is not always necessary to have three layers). In order to adjust the texture of the surface (paper surface) or to adjust the overall thickness, it is split or polished, and the resin oozing out on the back side of the base fabric 2 is polished to make it smooth. In addition, the physical properties of the felt for papermaking in this application include a longitudinal strength of 300 kg/5 cm width or more, and an overall density of 0.40~
0.65 and an air permeability of 1/2 inch water column 7 ml/sec/cm ² or more.

〇 Specific example: A conventional felt (needle felt) with an initial density of 0.35 and the felt of the present application with an initial density of 0.49 were used for 30 days on a press part of high-quality paper, and the change in density was investigated.The change in density was found to be 0.70 in the conventional felt. However, in the case of the felt of the present application, it was 0.55, and the change was slight.

[Effect of idea]

As described above, the papermaking felt according to this invention has a plurality of foamed resin layers laminated on the surface of a fluffy base fabric, at least the bottom layer is entangled with napped fibers, the surface of the top layer is smoothed, and each of the resins is The foam layer is characterized by the fact that the cells become finer from the bottom layer to the top layer, so it is possible to integrate the base fabric and the resin foam layer, and there is no delamination between the layers. It has a great effect.

That is, it is possible to freely change the foaming ratio (size of bubbles) of the resin foam layer, and it is possible to create a felt with a surface texture that corresponds to the type of paper. There is no problem caused by shedding fibers that occur in needle felts made of wool or synthetic fibers. The resin foam layer can ensure uniform water absorption, and its water absorption is better than that of needle felt, so it can minimize rewetting and have a good effect on uniformizing the moisture profile of wet paper. Become. Compared to the butt, the resin foam layer does not sag and can withstand long-term use.

[Brief explanation of the drawing]

The figures show an embodiment of this invention; FIG. 1 is an enlarged sectional view of the felt of the present application, FIGS. 2A and B are sectional views of the base fabric, and FIG. 3 is a schematic illustration of the continuous foam coating device. . DESCRIPTION OF SYMBOLS 1... Felt of this application, 2... Base fabric, 2a... Napped fiber, 3a, 3b, 3c... Resin foam layer.

Claims (1)

[Claims for Utility Model Registration] (1) Multiple resin foam layers are laminated on the surface of a fluffy base fabric, at least the bottom layer is entangled with napped fibers,
1. A papermaking felt characterized in that the surface of the uppermost layer is smoothed and the cells in each of the resin foam layers become finer from the lower layer to the upper layer. (2) Utility model registration claim 1, in which the base fabric is woven from woolen yarn and has a raised surface.
Felt for paper making as described in section. (3) Claim 1 of the utility model registration claim, in which the base fabric is woven using synthetic fibers such as monofilament or multifilament, with batts laminated on the back side and the surface fluffed by needling. Felt for paper making mentioned above. (4) The papermaking felt according to any one of claims 1 to 3, wherein the resin used for the resin foam layer is polyurethane or silicone rubber with good elasticity retention.