US2996786A - Papermaker's felt - Google Patents

Description

Aug. 22, 1961 H. M. HELLAND PAPERMAKERS FELT Filed Aug. 21, 1958 INVENToR:

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United States Patent O 2,996,786 PAPERMAKERS FELT Howard M. Heiland, Newfane, NSI., assignor to Lockport Felt Company, Inc., Newfane, N.Y. Filed Aug. 21, 1958, Ser. No. 756,405 7 Claims. (Cl. 2S-78) This invention relates to an improved construction in papermakers felts such as are used for example in the manufacture of paper, paper board, pulp, asbestos shingles, transite pipes, and like products. For example, the invention relates generally to improvements in the art referred to in my previously filed application Serial No. 743,624, led June 23, 1958.

It is` a prim-ary object of the present invention to provide rfor the papermakers felt art specifically, an improved felt constructed of any of the conventionally used grades of wool, cotton, or other natural or synthetic fibres or combinations thereof; fabricated in novel manner so as to provide an improved papermakers felt of many advantages.

A more specific object of the invention is to provide a felt as aforesaid which presents a working surface of improved smoothness and pulp supporting and cushioning characteristics.

Another object is to provide a felt as aforesaid which functions with improved efficiency as a drainage filter in its intended ruse.

Another object is to provide an improved felt yas aforesaid which is of maximum strength in the direction of the felt load.

Still another object of the invention is to provide a lfelt as aforesaid which is also of improved dimensional stability characteristics.

Another object is to provide an improved felt as aforesaid which is of such construction that whenever the load on the felt is relaxed the pores of the fabric tend to open, thereby facilitating cleaning of the felt.

Other objects and advantages of the invention will appear from the specification hereinafter, and the accompanying drawings, wherein:

FIG. l is a diagrammatic perspective View of one form of plied yarn such as may be employed in construction of a felt of the present invention;

FIG. 2 is a laterally distorted diagrammatic plan view (at reduced scale) of a swatch of fabric, illustrating the weave pattern employed in manufacture of the felt;

FlG. 3 is a diagrammatic plan view corresponding to FIG. 2 but of a swatch of the fabrication as it actually appears subsequent to initial weaving thereof; and

FIG. 4 is a diagrammatic fragmentary sectional view taken along line lV-IV of iFlG. 3, but subsequent to final processing of the fabrication.

In the papermakers wet felt art a prime desideratum is to provide a fabric structure which is longitudinally strong while at the same time comprising an efficient water-drainage or `filter membrane in the form of a resilient mass. [For such purposes the wool and/or other fibres used must be so integrated fas to present to the pulp being treated a uniformly smooth and level yet resilient surface. rIlhe present invention provides the desired results through use of a novel fabrication of yarns wherein the individual fibres subsequent to the yarn interlocking operation are as free as possible to move relative to one another during the fabric fulling or milling operations.

Thus, the invention contemplates that the yarns be relatively interlocked in a novel manner in this art, so that when the yarns are worked into the Ifabrication the individual iibres thereof are under minimum constraint. This effect may be obtained by employing an -interlock pattern involving only generally parallel yarns which Iare intertwined in novel manner. Preferably, at least a large Patented Aug. 22, 1961 ice percentage of these yarns Iwill be of such form that the ibres thereof `are substantially untwisted, as compared to conventionally twisted fibre yarns as are usually employed in this art. The yarns employed may be produced by either the so-called woolen system or any of the so-called worsted systems, and may tbe either singles or plied yarns. More specifically, the invention contemplates a felt fabrication comprising solely generally parallel yarns which are preferably of substantially untwisted form, so integrated during the fabrication process as to produce a novel felt construction wherein the relatively soft yarns are entwined upon themselves so as to provide mutual mechanical reinforcements, thereby producing an overall strong fabric of improved wet felt characteristics, as will now be described in detail.

As a first step, a singles yarn lmay be yused. Or, in the alternative, -a conventional plied yarn may be employed. Or, `as still another alternative, as` a separate operation, a plurality of singles yarns made with a minimum singles twist such as the pair of yarns 12-12 shown in FIG. 1 may be plied as by means of neutralizing Z twist. Hence, the resultant plied yarn designated generally at 15 comprises intertwined singles yarns, the individual fibres 10` of which are as near as possible untwisted. By way of a specific example, the card roping may be initially drafted and S twisted at the rate of say 4.0 t.p.i. (twists per inch), 'according to the fibre lengths and other variables. The two singles yarns so produced may then be relatively entwined by means of a neutralizing Z twist in such manner las to provide a plied yarn of say 4.5 t.p.i. Experience indicates that approximately such .a ratio of singles and plied yarn twists will result in production of a plied yarn as indicated at 15 in the drawing wherein the individual iibres are only very slightly twisted (in one direction or the other) or are substantially untwisted about their own axes, while gently winding spirally about the neutral axis of the yarn. In the alt-ernative, the card roping may be formed into singles yarn stock by means of a Z twist openation, and the singles yarns may thereupon be S twisted into plied yarnform, to provide the plied yarn stock 15 as explained hereinabove. In either case the yarn stock may be described as comprising two groups of untwisted Viibres gently rolling around one another. Due to the fact that the singles yarns ,are relatively entwined the overall structure of the plied yarns 15 has Iadequate strength to Iwithstand the subsequent weaving operation, in spite of the fact that the individual iibres are substantially untwisted.

As the second phase of the manufacture of the fabric, pluralities of the yarns 15 are intertwined as shown in FIG. 2 wherein the construction is illustrated as when being laterally stretched out of natural condition to facilitate understanding of the natureof the yarn interweaving system. Thus, when the structure is relaxed to its normal condition as shown in FIG. 3, the yarns 15 are interlinked and nested together in a manner quite unique in the wet felt art. It will be noted that each plied yarn member of the system runs generally longitudinally of the belt into which the fabric is made, although it follows a slightly zig-zag course; and that along each leg of the zig-zag course each yarn passes lirst over two adjacent yarns and then under two yarns before it reverses course when it first passes under two yarns and then over two yarns, and so on. In my prior application Serial No. 743,624 referred to hereinabove, each yarn passes either over or under all of the adjacent yarns throughout each leg of its zig-zag course. Thus the two constructions differ to suit different functional characteristic requirements. Subsequent to weaving this fabric is then submitted to any suitable shrinking and fulling or milling operations; and thus the fabric is shrunk and fulled as into the form illustrated by FIG. 4. As

shown in FIG. 3, the yarns 1S are substantially straightened out in plan view to their conditions of maximum eiciency with respect to resistance to tension loads on the felt. It will of course be understood that the fabric of the invention may be constructed by any suitable type machine.

Whereas, the yarns 15, due to their relatively entwined positions in the interlock pattern acquire optimum felt tension resistance characteristics, the locally soft nature of the yarn stock permits them to easily deform and bulk out and respond in improved manner to the fulling treatment because the individual fibres thereof are of improved mobility. Hence, in the resulting felt fabrication the fibres provide a mat of superior surface smoothness and cushioning characteristics. At the same time the double thickness and laterally unrestrained nature of the interlock pattern permits the fabric to breathe and to operate with maximum efliciency in accord with the phenomenon of capillarity and in response to the pumping action within the felt when passing through compression rolls; thereby improving its water removing abilities. For the same reason the fabric is f improved inherent selfcleaning characteristics and is more responsive to conventional cleaning devices than are felts of other construction. Thus, each fibre 0f the fabrication is disposed to act more efiiciently in its assigned task.

By virtue of the present invention a wet felt of more open or coarser structure may be made to meet specifications heretofore met only by felts of finer construction. Yet, by reason of the more eiiicient bulking of the fibres in the felt of the invention, it is also of superior surface or finish characteristics. Hence, these new felts will be of superior drainage characteristics because the total felt weight may be lowered.

[It is a particular feature of the invention that in the finished felt belt the individual yarns and libres are disposed at only slightly oblique angles to the direction of belt travel (FIG. 3); thereby providing a felt of increased total load pulling power for the same felt weight, and avoiding head-on impacts of yarn rises or floats against stationary equipment such as suction boxes, cleaning shoes, etc.

It will of course be appreciated that the invention is not limited to the precise constructions illustrated herein nor to the specific wet felt usage described hereinabove, and that the construction may be modified without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A new article of manufacture comprising a papermakers felt for supporting and draining paper making material, said felt comprising an endless belt-like fabric structure having only `substantially untwisted yarns running generally parallel and lengthwise of the belt with adjacent yarns interlocked by means of a weaving pattern disposing each yarn member to follow a slightly zig-zag course lengthwise of the belt, each leg of the zig-zag course of each yarn member passing both over and under yarns of adjacent courses, the individual fibres of said yarns being spirally wound but substantially untwisted about their own axes, said yarns each comprising card roping twisted only slightly into twisted yarn form, said fabric being fulled.

2. A new article of manufacture comprising a papermakers felt for supporting and draining paper making material, said felt comprising an endless belt-like fabric formed solely of relatively soft twisted yarns running lengthwise thereof in side-by-side relation and interlocked by means of a weaving pattern disposing each yarn member to follow a slightly zig-zag course lengthwise of the belt, each leg of the zig-zag course of each yarn member passing both over and under yarns of adjacent courses, the individual fibres of said yarns being substantially untwisted about their own axes, said fabric being fulled.

3. A new article of manufacture comprising a papermakers felt for supporting and draining paper making material, said felt comprising an endless belt-like structure having only substantially untwisted plied yarns running generally parallel and lengthwise thereof with adjacent yarns interlocked by means of a weaving pattern disposing each yarn member to follow a slightly zig-zag course lengthwise of the belt, each leg of the zig-zag course of each yarn member passing both over and under yarns of adjacent courses, the individual fibres of said yarns being spirally wound but substantially untwisted about their own axes, said plied yarns each comprising a pair of singles yarns each comprising card roping twisted into conventional S twisted yarn form and Z twisted together in opposite direction into plied yarn form, said interlocked yarns being fulled.

4. A new article of manufacture comprising a papermakers felt fabric for supporting and draining paper making material, said felt comprising an endless beltlike structure having relatively soft twisted plied yarns running lengthwise thereof in side-by-side relation and interlocked by means of a weaving pattern disposing each yarn member to follow a slightly zig-zag course lengthwise of the belt, each leg of the zig-zag course of each yarn member passing both over and under yarns of adjacent courses, the individual fibres of said yarns being substantially untwisted about their own axes, said yarns each comprising a pair of singles yarns twisted together into plied yarn form, said fabric being fulled.

5. A new article of manufacture comprising a papermakers felt fabric for supporting and draining paper making material, said felt comprising an endless belt-like structure having relatively soft-twisted plied yarns running lengthwise thereof in side-by-side relation and interlocked by means of a weaving pattern disposing each yarn member to follow a slightly zig-Zag course lengthwise of the belt, each leg of the Zig-zag course of each yarn member passing both over and under yarns of adjacent courses, said yarns having their individual fibers substantially untwisted about their own axes and each comprising a pair of singles yarns S twisted together into plied yarn form, each of said single yarns comprising card roping Z twisted in opposite direction into singles yarn form, said fabric being fulled.

6. A papermakers felt for supporting and draining paper making material, said felt comprising an endless belt-like fabric structure having plied yarns running lengthwise thereof in side-by-side relation and interlocked by means of a weaving pattern disposing each yarn member to follow a slightly zig-Zag course lengthwise of the belt, each leg of the Zig-zag course of each yarn member passing both over and under yarns of adjacent courses, said yarns each comprising a plurality of singles yarns twisted together into plied yarn form, each of said singles yarns comprising card roping twisted into yarn form, said fabric being fulled.

7. A new article of manufacture comprising a papermakers felt for supporting and draining paper making material, comprising an endless belt-like fabric structure having only yarns, said yarns running lengthwiseof the fabric and in side-by-side relation, each yarn being interlocked alternately with the yarns oppositely adjacent thereto by means of a weaving pattern disposing each yarn member to follow a slightly zig-zag course lengthwise of the belt, each leg of the zig-zag course of each yarn member passing both over and under yarns of adjacent courses, said fabric being fulled.

References Cited in the file of this patent UNITED STATES PATENTS 255,407 Beals Mar. 28, 1882 1,497,068 Collingbourne June 10, 1924 2,019,777 Cloutier Nov. 5, 1935 2,257,649 Pierce Sept. 30, 1941 2,423,828 Chagnon July 15, 1949 OTHER REFERENCES Effect of Ply Twist on Single Twist, from Textile World, Feb. 21, 1931, page 38.

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