US1712587A - Web carrier for papermaking machines - Google Patents

Description

May 14, 1929. w. E. sHEEHAN 1,712,587

WEB CARRIER FOR PAPERMAKING MACHINES Filed April l5, 1927 55cm/p 5w/DLE.

WEB FUR/WEE WEB Fa/WEE mi PLfJ-r/c PHL?) A WE@ 0F fsf/PEE; a a Q 6 WEB Irak/VIER ENDLEJJ Pol/Nago F117 l I N VEN TOR.

F15 ATTORNEY.

Patented May 14, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM E. SHEEHAN,

QF ALBANY, NEW YORK.

Application led April 13, 1927. Serial No. 183,527.

This invention relates Vto paper making machines, particularly to the endless belts which are used on all such machines to handle or carry the web or sheet ofA pulp or paper, as from the web forming` device to and through the press rolls, and from the press rolls to the dryers.

endless felted belts Since the time when were first used on paper making machines it 1U' has been the practice to weave these belts of wool yarns, and afterward subject them to a fulling or felting process in the carrying out of which the belts become shrunken and the size thereof greatly reduced.

As is of course well known to all skilled in the art of making papers, papermakers felts are used in varying circumstances. In some cases it is required that they be of high porosity, as when used as a drainage felt which receives the wet web; while in others it is desirable that they be substantially air-tight, as when used as a pick-up felt. Various surface finishes are also used. being' produced by napping the yarns of which the felt is composed or is woven.

The usual woven ers felts are costly and comparatively short lived, the average length of service which can be reasonably expected from a well made 3U felt being probably less than four weeks. '.llhese'usual felts have a further drawback in that the nap which forms the working surface thereof will not wear for a great while, and when it is worn away the web of paper comes into direct contact with the underlying yarns of which the fabric is woven, and so becomes yarn marked. When the working surface of a. felt has become worn to such a degree that yarn marks are visible on the product in the manufacture of which it is employed, it is no longer fit for use and should be replaced.

'It has long been recognized as afact that 'the ideal papermakers felt must have a longer wearing working surface than can be produced on the usual woven and fulled felt, and a number of efforts to produce such felts have been made. The result of one such effort being disclosed in U. S. Patent No. 1,062,877, dated May 27, 1913, and issued jointly to myself and another, and which while the improved felt there disclosed accomplished our object to a degree, it failed to gain the approval of users by reason of the fact that after the sheet of carded wool which we attached to the top and fulled papermak of a woven belt to form a working surface, although it would last for an appreciably longer period than a surface napped from the woven belt itself, it too would wear off and the underlyingr yarns be exposed and cause yarn marks on the product.

For a number of years there hasbeen a constant increase in the cost of wool. and in the cost of producing the usual papermakers felts, and these increasing costs have led to numerous efforts being made to devise a satisfactory and comparatively inexpensive substitute for the usual web carr ing felts, both drainage felts and pick-up flelts. The result of two such efforts are disclosed, one

in U. S. Patent No. 1,536,533, granted to me under date of May 5, '1925, the other in my pending application Serial No. '(6,071 now U. S. Patent No. 1,651,476, issued Dec. 6, 1927.

The object of this present invention is to provide web carrying felts, for use on papermaking machines, the character or texture of the working face whereof will not change as this surface wears; felts which will have as great or even greater strength than do the usual felts of equal weight; and which will give as good or even better drainage than, or be as nearly air-tight as, any present usual feltwhich is employed to convey a wet web of paper to and through the press rolls, orthe web of paper from the press rolls to the dryers.

In the accompanying drawing Figs. 1, 2, 3, and 4 illustrate varlous forms of papermaking machines to Whichthis invention is applicable; through a fragment of an endless belt of pounded felt such as I substitute for the usual papermakers felts at the points indicated on the various paper-making machines "illustrated by the preceding figures.

Probably the oldest known method of producing a fabric without weaving was to spread woolinto a sheet, then work it by rolling and pressing until the Wool fibers were so interlocked and compacted that they became a fabric.

I, and seemingly all others interested in the production of papermakers felts which are to be used as a web-carrier which is called upon to spaced supports upon which they travel, have heretofore considered a woven base to be a necessary part of a satisfactory felt for such services. But as a result of a long and Fig. 5 is a cross section bridge the gaps between the series of experiments and tests I have discovered that a pounded felt which is made in substantially the manner in which the early felt fabric above mentioned was made, but by and with the aid of modern methods and machinery, will be of as great or even greater strength, weight for weight than are the usual woven and `fulled elts; will be as eilicient, if not better as a drainage felt, or as a pick-up felt so called; and that the working surface thereof will show no appreciable change in its texture due to the wearing away of said surface and not being formed of yarns can not, of course, cause yarn marks on the product in the manufacture of which it is employed.

I claim:

1.. In a 'paper making machine, in combination with the usual press rolls and spaced web-carrier supporting rolls: a webcarrier consisting of an endless belt of nonwoven pounded felt such as may be produced by fulling an endless belt of carded wool, said non-woven pounded felt carried by the spacedv supporting rolls and bridging the gaps therebetween.

2. In a paper making machine, in combination with the usual press rolls and spaced web-carrier supporting rolls: a webcarrier consisting of an endless belt of nonwoven pounded felt such as may b'e produced by falling an endless belt of carded wool, said non-woven pounded felt carried by the spaced supporting rolls and bridging the gaps therebetween.

3. In a, paper making machine, in conlbination with the usual press rolls and spaced web-carrier supporting rolls: webcarriers consistin of endless belts of nonwoven pounded Ielt such as may be produced by fulling an endless belt of carded wool, said non-Woven pounded felts carried on the spaced supporting rolls and bridging the gaps therebetween, one of said nonwoven pounded felts adapted to receive the wet web of paper from a web-forming device and carry it to and through the press rolls, another of said non-Woven pounded felts adapted to receive the pressed web and carry it to a dryer.

In testimony whereof, I have aixed my signature.

WILLIAM E. SHEEHAN.

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