US2041976A - Lapping cloth - Google Patents

Description

7 May 26, 1936. v J c s s 2,041,976

LAPPING CLOTH Filed Feb. 24, 1954.

V I I I I I I I E-"ii-ilF I Patented May 26, 1936 UNITED STATES PATENT OFFICE Claims.

My invention relates to cloth or fabric and particularly to so-called lapping cloth which is wound or wrapped about the platen rolls of machines used for printing textiles or wall and 5 fancy papers.

In the printing of textiles and some kinds of papers, the pattern to be imparted to the cloth or paper is carried by an engraved printing roll, and the cloth or paper to be printed is carried between the printing roll and a platen roll. Very high pressures are employed between the printing and platen roll and it is quite essential to have a resilient, yielding cushion between the material being printed and the platen. This is obtained by wrapping a particular type of cloth, well known in the art .as lapping cloth about the platen. Such cloth while forming a resilient, yielding cushion to high compressive stresses must also be firmly woven to oifer substantial resistance to stretching and must be fairly thin, as compared with the printing blanket, to prevent imperfections in the printing directly over the cut or free end of the cloth from which the filler is usually pulled out for a short distance to make the transition smoother.

About 90% of all the lapping cloth used in this country is imported from England, and the :type furnished has a linen warp and an .all wool filling or weft.

'While breaks in the warp threads of the lapping cloth frequently occur, the resilient yielding characteristics of the fabric are largely dependent upon the weft 0r filling, and to this extent the useful life of the fabric is also dependent .upon how long the filling retains these properties. Due to the extremely high pressures exerted by the printing rolls and their grinding action on the fabric, the wool filling rapidly disintegrates or powders and the cloth must then be replaced.

40 The principal object of my invention therefore is to provide a lapping cloth which will possess substantially all of the resilient, cushioning characteristics of the imported cloth, but in which the weft or filling will not disintegrate or pow- 45 der as rapidly as the all wool filling. Another object is to provide a lapping cloth which will be cheaper than that now available.

With these objects in view my invention resides in the lapping cloth described below and illustrated in the acompanying drawing in which- Fig. 1 illustrates one form of thread or yarn which may be used in my invention;

Fig. 2 is an enlarged and distorted View of one 55 species of my lapping cloth; and

Fig. 3 is a view similar to Fig. 2 of another species.

It has heretofore been thought necessary, in order to attain the desired resilient, cushioning characteristics, and in order to prevent the lapping cloth from slipping upon the cylinder, that the weft or filling should be entirely of wool. I find that instead of making the weft or filling entirely .of wool, much better results are obtained by forming the weft or filling partially of 0 W001 and partially of cotton. Some wool is necessary in the filling in order to prevent slipping of the fabric on the cylinder, but the quantity thereof may be very substantially reduced and the resulting fabric will be much longer lived 15 than a lapping cloth having an all wool filling.

It will also be very much cheaper. Wool is now, and always has been, very much more expensive than cotton. At the present time, the cost of wool is about seven times the cost of cotton so 20 that the addition of only small proportions of cotton to the filling results in a rather substantial saving in cost.

The cotton may be incorporated in the filling in any one of several diiferent ways. For example, 25 I may card the wool and cotton together and spin the same into a composite yarn or thread which will be used in the weft or filling of my fabric. On the other hand, I may make a plied yarn, such as shown in Fig. l, by twisting to- 30 gether a strand or strands I of cotton with a strand .or strands 2 of wool, thus forming a composite yarn of a somewhat different type which may be used in the filling. Again, I may make the filling partly of threads or yarns which are composed entirely of cotton and partly of threads or yarns which are composed entirely of wool.

In Fig. 2 of the drawing, I have illustrated a fabric in which the filling consists partly of cotton threads .3 and partly of woolen threads 4, alternating in pairs, that is, two cotton threads and then two wool threads. In such .a case, if the threads are the same size, half the area of the filling will be wool and half will be cotton, although since the wool is heavier than the cotton, the proportion, by weight, of the wool will be somewhat in excess of In Fig. 3 I have shown another species in which three filling threads 5 of cotton are placed between single threads 6 of wool. 50

Inasmuch as lapping cloth having an all wool filling is used at present, it is obvious that the minimum percentage of cotton which may be used in the filling and yet produce a cloth as good as those now available is zero. However, I find that percentage of cotton in the weft as small as about 15% by weight not only appreciably prolong the life of the lapping cloth but also effect a substantial saving in the cost of the material. On the other hand, where the percentage of cotton in the weft exceeds about 80% by weight of the weft the cloth is lacking in that degree of resilience which is desirable and does not adhere well to the cylinder under all pressures. For all around uses I prefer to have about by weight of the filling composed of cotton, although it is to be understood that any percent-ages of cotton in the weft within the broader ranges stated above will give more satisfactory service for many purposes and pressures and will produce a more durable and cheaper lapping cloth than those now available.

In the warp, it has heretofore been customary to use linen. While I may use a linen warp in my fabric, I find that cotton will, in most cases, provide sufiicient strength in this direction and, moreover, it is softer and less wiry than the linen and there is therefore less tendency for it to cut and powder the wool fibres.

While I have illustrated, in the drawing, only two species of my lapping cloth, it is to be understood that the cotton may be incorporated in the filling in any of the ways described in the foregoing specification, either singly or in combination.

What I claim is:

l. A cloth for wrapping or lapping about the platen roll of a printing machine to provide a yielding cushion between said roll and the material being printed comprising a comparatively thin woven fabric having a warp of yarns formed from vegetable fibres and the filling thereof comprising both wool yarns and cotton yarns; the wool yarns in said filling providing the fabric with the yielding resilient characteristics essential for printing and preventing the cloth from slipping on the roll, and the cotton yarns in said filling reducing the tendency of the wool yarns to powder and disintegrate under the high pressures employed in the printing operation; the relative proportions of the wool and cotton filling in the face and back of the fabric being substantially the same.

2. A cloth for wrapping or lapping about the platen roll of a printing machine to provide a yielding cushion between said roll and the material being printed comprising a comparatively thin woven fabric having a Warp of yarns formed from vegetable fibres and the filling thereof comprising both wool and cotton; the wool in said filling providing the fabric with the yielding resilient characteristics essential for printing and preventing the cloth from slipping on the roll, and the cotton in said filling constituting from about 15% to about 80% of the weight thereof and reducing the tendency of the wool to powder and disintegrate under the high pressures employed in the printing operation; the relative proportions of wool and cotton filling in the face and back of the fabric being substantially the same.

3. A cloth for wrapping or lapping about the platen roll of a printing machine to provide a yielding cushion between said roll and the material being printed comprising a comparatively thin woven fabric having a warp of yarns formed from vegetable fibres and the filling thereof comprising both wool and cotton; the wool in said filling providing the fabric with the yielding resilient characteristics essential for printing and preventing the cloth from slipping on the roll, and the cotton in said filling constituting from about 40% to about of the weight thereof and reducing the tendency of the wool to powder and disintegrate under the high pressures employed in the printing operation; the relative proportions of wool and cotton filling in the face and back of the fabric being substantially the same.

4. A cloth for wrapping or lapping about the platen roll of a printing machine to provide a yielding cushion between said roll and the material being printed comprising a comparatively thin woven fabric having a warp of yarns formed from vegetable fibres and the filling thereof composed partially of cotton yarns and partially of wool yarns; the wool yarns providing the fabric with the yielding resilient characteristics essential for printing and preventing the cloth from slipping on the roll, and the cotton yarns constituting from 15% to about by weight of the filling and reducing the tendency of the wool to powder and disintegrate under the high pressures employed in the printing operation; one or more of the wool yarns alternating with one or more of the cotton yarns, and the relative proportions of wool and cotton filling in the face and back of the fabric being substantially the same.

5. A cloth for wrapping or lapping about the platen roll of a printing machine to provide a yielding cushion between said roll and the material being printed comprising a comparatively thin woven fabric having a warp of yarns formed from vegetable fibres and the filling thereof composed partially of cotton yarns and partially of wool yarns; the wool yarns providing the fabric with the yielding resilient characteristics essential for printing and preventing the cloth from slipping on the roll, and the cotton yarns constituting from 40% to about 60% by weight of the filling and reducing the tendency of the wool to powder and disintegrate under the high pressures employed in the printing operation; one or more of the wool yarns alternating with one or more of the cotton yarns, and the relative proportions of wool and cotton filling in the face and back of the fabric being substantially the same.

JOHN C. STANDISH.

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