US 2175051 A
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Oct. 3, 1939. BRQMLEY 2,175,051
METHOD OF AND APPARATUS FOR PRINTING CLOTH Filed A ril 15, 19:59
Inventor (Ittomegs Patented Oct. 3, 1939 UNITED STATES METHOD OF AND APPARATUS FOR PRINTING CLOTH Frank Bromley, Moylan, Pa., assignor to Joseph Bancroft & Sons 00., Wilmington, Del., a corporation of Delaware Application April 13, 1939, Serial No. 267,555
This invention relates to apparatus for printing cloth, and its nature, objects and advantages will be clear from the following description.
A printing machine ordinarily is primarily composed of a relatively large diameter printing cylinder against which bear one or more engraved rolls which serve not only to apply the dyes or coloring materials in the pattern desired but also to drive the printing cylinder.
It has been customary in this art to lap or cover the cylinder with a fabric such as felt, this being known as the machine lapping. An endless blanket of heavy material (usually rubberized) such as a Mackintosh or Baker blanket, is run on the cylinder, the necessary tension and guide rolls being also provided.
Still further, it has been common to run a blotting material on the cylinder between the blanket and the cloth to be printed in order to prevent the blanket from picking up coloring material which penetrates the cloth being printed. This blotting material-is a cloth commonly known as back-grey, and the present invention is particularly concerned with improvements thereover.
In considering the advantages of the invention it should be noted that the common prior practice is to employ discontinuous lengths of relatively inexpensive unbleached back-grey which are fed serially to the printing cylinder between the blanket and the cloth to be printed. Usually several layers of such back-grey are employed and when a length of the back-grey has passed through the machine, the layers are washed, dried and straightened for subsequent reuse.
This prior practice involves heavy expense, both from the standpoint of the number of yards of back-grey required to be carried in service, and also from the standpoint of the excessive handling necessary to efiect washing, drying and straightening and then the return of the lengths to the printing machine.
Another difiiculty incident to the prior practice arises from the fact that the back-grey is of relatively loose weave having large interstices and is subject to substantial shrinkage. Such goods due to the shrinkage are very diflicult to straighten at 'the seams where lengths of cloth are sewn together, in consequence of which it very frequently occurs that scrimps form near the seams, which cause imperfections in the printed goods.
Certain substitutes have been proposed for this common type of back-grey. In accordance with one proposal it has been contemplated to use an endless blanket of rubberized fabric in addition to the usual Mackintosh or Baker blanket before mentioned, but this has not proved satisfactory, at least for most purposes and especially where blotch type or heavily covered motif patterns are being printed, because of, the non-blotting or inabsorbent nature of the blanket, which results in building up of color on the rubberized surface so that smearing occurs.
Another proposedsubstitute for the common type of back-grey is an endless run of metallic 1o fabric, such as fly screen, which has proved highly impractical for the reason that application of the coloring is interfered with, being irregular and efiectively applied only in spots. Such a screen arrangement also prevents smooth appli- 15 cation of the coloring, the pattern of the screen itself showing up in the coloring on the printed cloth.
The present invention is directed to overcoming problems of the character referred to above, and 20 in materially reducing the expense of the blotting material and also the excessive handling incident to prior practice. Still further, the improved blotting material in accordance with the present invention, not only does not interfere with the printing but in fact substantially improves th character of the printing.
How these improvements are effected will be apparent from the following description in which reference is first made to the drawing illustrating 30 a printing machine constructed and operating in accordance with the present invention and adapt ed to utilize the improved back-grey contemplated.
Referring to the drawing, the reference nu- 35 Ineral 1 indicates the usual printing cylinder, which is provided with a felt orother suitable lapping. The engraved printing roll or rolls are shown at 8 and are likewise of customary construction and arrangement. The endless blanket a of Baker, Mackintosh, or usual construction, is shown at 9, and runs over suitable guides as, being provided with a tension adjusting means H.
The improved blotting material l2 runs between the blanket 9 and the cloth 13 being print- 5 ed. It is in the form of an endless belt, running on suitable guides l4 and being provided with tension adjusting means 1%.
Engagement of the printing rolis 3 against the several layers of material running on the cylinder 50 I serves to drive the cylinder I and to advance the several layers of material thereon. The pressure is sufficient to prevent slippage of the cloth being printed, the endless belt I 2, and the blanket with respect to the cylinder.
- 18 play upon the cloth.
In a run of the endless belt 1! remote from the cylinder 1, I provide a washing apparatus indicated generally by the reference character A, and also a drying apparatus indicated generally by the letter B, the latter being located beyond the washing apparatus with respect to the direction of travel of the material therethrough. Thus after the blotting cloth leaves the printing cylinder it runs first through the washing apparatus, then to the dryer and then back to the cylinder.
In the washing equipment the cloth is subjected to brushing by the brushes l6 operating against the backing boards I'I. Hot water sprays On leaving the washing machine the cloth passes through a scrimp remover l9 and rubber squeeze rolls 20, after which it passes through a second scrimp remover 2| and then over the heated cans 22 of the drying apparatus.
By the foregoing arrangement, the endless belt of blotting cloth is continuously being washed, dried and straightened while the apparatus is in operation. By virtue of this, only a relatively small yardage of cloth is required to be carried in service, the belt being continuously used until its blotting power has become impaired, when it 'is discarded and a new belt substituted.
As a material or cloth for the belt the present invention contemplates the use of a cloth having the following characteristics:
(a) High tensile strength, the cloth preferably being formed of plied yarns;
(1)) Low shrinkage;
(c) Substantial body and thickness and high surface absorption; and
(d) Smooth surface.
As examples of materials meeting these requirements I mention sateen, twill, and duck, although it is to be understood that other fabrics could be used, provided they have the absorption and other characteristics which render sateen, twill and duck suitable for the purpose.
The high tensile strength is of importance for the basic reason that such cloth has high wear resistance and will therefore have long life.
As to the shrinkage characteristic, it may be noted that with the customary back-grey which has substantial shrinkage, misfit and creeping would occur in the printing machine, resulting in impairment of the patterns printed. The shrinkage characteristic of fabrics of the type which I prefer to use, as above recited, is preferably so low that upon running the fabric through the machine a few times before commencing the printing of a roll of cloth, the washing will quickly shrink the cloth to its maximum point, after which substantially no additional shrinkage will take place during the printing.
The cloth which I have chosen is one having suificient thickness and compactness of fibers to provide for absorption of coloring matter which penetrates-through the cloth being printed, without complete penetration through the blotting belt. Thus the absorption of coloring material takes place more or less as a surface absorption on the cloth, preventing contact of coloring matter with the underlying blanket.
Providing for absorption of the coloring matter on the cloth substantially only at the surface of the cloth is of importance in facilitating the washing. Furthermore, bearing in mind that the cloth must be driven by virtue of the pressure between the printing cylinder and the cooperating rolls, it will be seen that if greatly extended washing and drying equipment were required (as would be necessary where the cloth was subjected to deep penetration of coloring) an excessively heavy drag or load would be placed on the cloth, and this might result in slippage thereof on the printing cylinder. The shallow penetration in the cloth, therefore, is of importance not only in positively providing against coloring matter reaching the blanket, but also in facilitating washing to an extent such that it becomes possible to drive the entire equipment, including the washing and drying elements, from the printing cylinder.
The smoothness of the surface of the cloth is important in avoiding irregularity in the printing, particularly on blotch prints where light weight cloths, such as lawn, are being printed.
The cloth should have a selvage which not only has high tensile strength but which is of a character tending to remain flat, that is, not curl over, and it must be neither tight or loose in relation to the body of the goods, since if the selvages are tight, the center of the goods will bag, causing imperfect printed goods, while if loose, bagginess along the selvage develops, also resulting in imperfect printed goods.
Another important feature of the invention resides in the improvement in the quality of the printing which is secured by controlling the degree of drying of the cloth so that the cloth is returned to the cylinder in a moist or slightly damp condition, i. e., in a condition having slight sensible wetness. The effect of this is that the cloth to be printed is very slightly moistened at its under surface, in consequence of which the coloring matter penetrates more readily all the way through the fibers of the cloth being printed.
To illustrate the saving of the invention herein disclosed over the prior and common method of employing discontinuous lengths of unbleached back-grey of prior types, on an actual run of 114,000 yards of printed goods, there were utilized only 91 yards of the blotting cloth in the form of an endless belt, whereas for printing 114,000 yards employing the discontinuous lengths of back-grey of prior types, about 1600 yards are required, and in addition considerable expense is involved in the washing of such a large quantity of cloth and also in the other handling of it to and from the machine.
Thus in accordance with the invention numerous of the difliculties heretofore encountered have' been overcome, the production costs are greatly reduced, and in addition by the delivery of the cloth to the printing cylinder in a slightly moist condition which can accurately be maintained at a uniform value, the colors printed are more even and brighter, as the result of the better penetration through the goods being printed.
1. Cloth printing apparatus including in combination with a printing cylinder, a blanket running on said cylinder under the cloth to be printed, and a blotting belt running on said cylinder intermediate the blanket and the cloth to be printed, said belt comprising a single endless strand of cloth of sufficient thickness and compactness to absorb substantially all coloring matter passing through the cloth being printed without penetration through the cloth belt to the inner surface thereof, and washing means for the cloth belt associated therewith in a run removed from the printing cylinder.
2. Cloth printing apparatus including in combination with a printing cylinder, a blanket running on said cylinder under the cloth to be printed, and a blotting belt running on said cylinder to be printed, said belt comprising a single endless strand of cloth of suflicient thickness and compactness to absorb substantially all coloring matter passing through the cloth being printed without penetration through the cloth belt to the inner surface thereohwashing means for the cloth belt associated therewith in a run removed from the printing cylinder, and drying means for the cloth belt associated therewith in a run removed from the cylinder and beyond the washing means with respect to the direction of movement of the cloth belt.
3. Cloth printing apparatus including in combination with a printing cylinder, a blanket running on said cylinder under the cloth to be printed, and a blotting beltn'unning on said cylinder intermediate the blanket and the cloth to be printed, said belt comprising a single end-' less strand of cloth of suflicient thickness and compactness to absorb substantially all coloring matter passing through the cloth being printed without penetration through the cloth belt to the inner surface thereof, washing means for the cloth belt associated therewith in a run removed from the printing cylinder, and drying means for the cloth belt associated moved from the cylinder and beyond the washing means with respect to the direction of movement of the cloth belt, the speed of travel of the cloth belt and the characteristics of the washing and drying means being such that the cloth belt is returned to the printing cylinder in a moist condition.
intermediate the blanket and the cloth s therewith in a run re- -printed,
4. In the art of printing cloth on a printing cylinder having an endless blanket running thereon at the inner surface of the cloth to be printed, the method which includes the step of feeding a blotting cloth in a moist condition to the printing cylinder intermediate the blanket and cloth to be printed.
5. In the art of printing cloth on a printing cylinder having an endless blanket running thereon at the inner surface of the cloth to be printed, the method which includes feeding a run of a continuous blotting cloth to the cylinder intermediate the blanket and the cloth to be printed, washing the blotting cloth in a run thereofremoved from the printing cylinder, drying the blotting cloth in a run thereof removed from the printing cylinder and beyond the washing with respect to the direction of travel, and so controlling the washing and drying and rate of operation of the printing cylinder that the blotting cloth is returned to the cylinder from the drying step in a moist condition.
6. Cloth printing apparatus including in combination with a printing cylinder, a blanket running on said cylinder under the cloth to be printed, and a blotting belt running on said cylinder intermediate the blanket and the cloth to be said belt comprising a single endless strand of cloth having absorptive characteristics such as those of sateen, duck or twill, and washing means for the blotting belt associated therewith in a run removed from the printing cylinder.