JPS63145498A - Elastic felt base material structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to woven fabrics used in paper making and more particularly to felt substrates used in the wet section of a 7-o liner paper machine.

The 7 air A/) used in paper machines is subjected to severe mechanical stresses such as repeated pressure and vacuum changes and external changes in humidity and temperature. Despite these changes, felt remains flexible, durable, compaction resistant, and durable throughout its useful life.
Dimensional stability and water resistance must be maintained. A variety of felts have been made, both woven and non-woven, but none have been completely satisfactory.

A primary object of the present invention is to provide a felt that maintains its durability and compaction resistance throughout its useful life.

A second object of the invention is to provide a "knuckle"-free felt that increases abrasion resistance by reducing the possibility of mechanical damage.

A third object of the present invention is to provide a single layer base felt that has the water retention and durability properties of a multilayer structure.

Other objects and advantages of the invention will become apparent from the following detailed description of the invention. According to the present invention, the felt substrate consists of a number of alternating threads extending in the machine direction (MD), each having high elasticity and high strength. The shaggy monofilament yarns are woven into long floats in the cross direction (CD) to form highly oriented drainage channels. Small diameter multifilament yarns may be used to bind the MD yarns together.

As shown in the accompanying drawings, felt 10 constructed in accordance with the present invention is comprised of a plurality of longitudinally extending threads. Use two types of thread in this direction. namely, elastomeric yarn 12, which is a highly elastic composite yarn suitable for deformation when subjected to shear or vertical double-edging or stretching; and high strength, relatively inelastic load-bearing yarn 14. Both types of yarns are preferably arranged in an alternating manner, as shown, with each load-bearing yarn being placed between two elastic yarns, or vice versa. However, other variations are also possible.

For example, two or more elastic threads can be alternated with one, two or more load-bearing threads.

The weft yarns that join the warp (i.e. machine direction) yarns are placed between 6 and 12 warp yarns to form highly oriented drainage channels for the water that is squeezed out during paper production. It consists of monofilament yarns 16, which are woven into long floating yarns that span the length of the yarn.

All of the threads 16 are on the same side of the high-strength warp threads 14, as it is important that six threads 16 are engaged, or wound around a swivel of multiple elastic threads 12. Preferably, relatively small diameter high strength threads 18 are woven in the transverse direction as shown to improve the dimensional stability of the assembly. These threads 18 thus bind the warp threads 12, 14 together and keep them in the same plane. However, thread 18 may also be omitted.

The resulting felt has a number of properties that are desirable in papermaking technology. Since the long float yarns 16 only engage the elastic yarns, any pressure applied to the intersection between these elastic yarns, such as 20, will force the weft yarns down, so that said intersection points are on the upper surface 22 of the warp yarns. and becomes flat K (Figure 2). Therefore, by carefully minimizing the thread knuckles, a quasi-cross-free structure that behaves like a multilayer structure was achieved. Additionally, since cross knuckles are removed, this felt forms a uniform pressing surface.

In addition, this structure provides a uniform pressure distribution and is less prone to weft thread failures caused by flex fatigue at intersection points.

The weft yarns 16 also create a structure for the warp yarns 12, 14 that provides a structure with high resistance to permanent deformation due to repeated compressive loads. Additionally, the two platforms allow the felt to maintain its nominal thickness over extended periods of time.

A long float as mentioned above results in a weft drainage conduit;
This improves the dewatering ability of the felt. The small size weft multifilament yarns do not interfere with water treatment and drainage lines and aid in holding the yarns together and maintaining the dimensional stability of the felt.

It will be obvious to those skilled in the art that numerous modifications of the invention can be made without departing from the scope of the invention as defined by the appended claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a felt constructed according to the present invention, and FIG. 2 is a cross-sectional view of FIG. 1 taken in the lateral direction. 10...Felt, 12.14...Warp, 16.
...Weft, 18...High strength thread.

Claims (1)

[Claims] 1. A plurality of elastic yarns extending in the longitudinal direction; a plurality of high-strength elastic yarns extending in the longitudinal direction and sandwiched between the plurality of elastic yarns; made into a long floating yarn and interwoven with the plurality of warp yarns; A felt for dewatering a paper web consisting of a plurality of first weft threads. 2. The felt according to claim 1, comprising a plurality or relatively thin second weft yarns interwoven with the plurality of warp yarns. 3. The felt according to claim 1, wherein each of the plurality of first weft threads engages only with the plurality of elastic warp threads. 4. The felt according to claim 1, wherein the plurality of first weft yarns are arranged and arranged on one side of the plurality of high strength warp yarns.