US3442211A - High speed web-fed rotary printing press with drier and chill roll - Google Patents

Description

F. w. BEACHAM 3,442,211 FED ROTARY PRINTING PRESS WITH DRIER AND CHILL ROLL May 6, 1969 HIGH SPEED WEB- Filed June 13,- 1966 INVENTOR. FRANC/S m 85/) CHAN BY @QAwZ QM @8444. A TTOPNEYSI May 6, 1969 F. w. BEACHAM HIGH SPEED WEB-FED ROTARY PRINTING PRESS WITH DRIER AND CHILL ROLL L x Q m INVENTORQ Fm/vc/s w. BEACHAM @LMQWQM MM A TTO/P/VEYS United States Patent US. Cl. 101-416 4 Claims ABSTRACT OF THE DISCLOSURE In a high speed printing press having a means for printing ink on a web traveling at a high speed and ink drying and setting means for rapidly drying and setting the ink on the web, which include a heat dryer operating to heat the ink and initiate vaporization of the volatile constituents of the ink and a chill roll following the heat dryer and operating to set the ink constituents remaining on the web, the web training at a high speed around a substantial extent of the peripheral surface of the chill roll while the vaporized constituents of the ink are enveloping the web, the improvement comprising a squeegee roll disposed in bearing engagement with the web and squeezing the web against the chill roll surface whereby the accretion of vaporized constituent condensate products on the surface of the chill roll of a thickness sufiicient to periodically produce streaking of the web thereby is prevented.

This invention relates to high speed web-fed rotary printing presses; and as illustrated and described herein by way of example the invention may be used to advantage for example on presses that include dryer and chill roll sections.

Such presses typically embody impression, plate, and/or blanket cylinders, through or about which .the web trains and is thereby brought into printing operation. From the printing unit the web travels to a dryer unit which as shown herein by way of example may comprise a steam-heated dryer drum; although it is to be understood that other type dryers are sometimes employed. From the dryer the web typically travels to one or more cooling devices, such as around chill rolls as shown by way of example in the drawing herewith. In any event the purpose of the heating and chilling system is to cause the ink which transfers to the web to dry or set rapidly, so that the ink will not pick up on subsequently encountered guide rolls or the like as the web runs through the press.

As is well known in the art, with the advent of modern ink chemistry and the development of certain pigments, solvents, driers, plasticizers, etc., tremendous strides have been made with respect to speeding up the drying cycles of such printing operations. However, a problem of condensate streaking has been plaguing the industry, arising from the fact that in a high speed press, as the heated web approaches the first chill roll the ink volatiles exude from and through the web, thereby creating a gaseous aura enveloping the web. When the web then arrives at the first chill roll (in a conventional high speed system as explained hereinabove) the gas cushion forces developing between the roll and the web typically operate to literally hold the web out of contact and in spaced relation from the chill roll. By virtue of this phenomenon the ink volatiles exuding from or otherwise enveloping the web operate to form condensate products which tend to deposit and build up on the surface of the chill roll; and periodically these deposits slough ofi. and attach to and streak the surface of the passing web.

It is a primary object of the present invention to pro- 3,442,21 l Patented May 6, 1969 vide an improved system for post-conditioning a previously printed and heated web as it passes around the first chill roll, whereby to eliminate condensate streaking on the web. Otherwise stated, it is an object of the invention to provide a novelsqueegee roll in the web train hearing against the web at the first chill roll, which by reason of specific surface-active characteristics operates to avoid condensate streaking on the ink.

Other, more specific objects and advantages of the invention will appear from the following specification and the accompanying drawing wherein:

FIG. 1 is a fragmentary vertical sectional view through a portion of a typical letter press printing machine, including an impression cylinder; dryer drum; and a chill roll unit, and showing by way of example in combination therewith a web transport system including a squeegee roll device of the present invention;

FIG. 2 is a fragmentary enlarged scale view of the portion designated FIG. 2 of FIG. 1;

FIG. 3 is a fragmentary sectional gested by line 33 of FIG. 2;

FIG. 4 is an enlarged scale sectional view taken as suggested by line 44 of FIG. 2; and

FIG. 5 is an enlarged scale fragmentary view of the portion designated FIG. 5 of FIG. 2.

As shown solely by way of example herein, the invention is illustrated as being embodied in a printing press of the so-called letter press type which includes an impression cylinder 10 journalled on frame plates 11 and about which a paper web 12 trains and is thereby brought into printing relation with a plurality of plate cylinders as indicated at 14, 15, 16, 17, 18, respectively (FIG. 1). The web thereupon typically travels over guide rolls 19 to a heating drum 20, and thereupon trains around a first chill roll as shown at 22.

Conventionally the web 12 thereupon moves around one or more additional chill rolls as indicated at 24 (FIG. 1) and thence to a second-side printer and/or to web-cutting and folding operations, or the like. However, in the case of the present invention a novel squeegeeroll device as indicated at 25 is provided to run against the web to press it against the chill roll 22. As shown in better detail in FIGS. 2-5, inclusive, the squeegee-roll 25 comprises a drum or cylinder having support shaft devices 26-26 extending at opposite ends thereof and iournalled in bearing blocks as indicated at 28. The hearing blocks 2828 are mounted in bearing slide-supports 30 which are mounted on the machine frame 11, whereby the squeegee-roll 25 may be positionally adjustable relative to the web 12 as it leaves the chill roll 22 (FIG. 5).

It is essential, in accordance with the present invention, that the roll 25 operatively bears against the web 12 uniformly at a predetermined pressure, as will be explained hereinafter. Accordingly, as best shown in FIG. 2, the bearing blocks 28 are positionally controlled in their slides 30 by means of pneumatic or hydraulic cylinders 34 operating through link members 36 to provide means for quickly retracting the roll 25 from operative position, incidental to replacement of the web supply or the like. Set screws as indicated at 40 extending from the stationary view taken as sug frame portion of the slide structures 30-30 are readily adjustable to limit the motions of the roll 25 toward the web to the optimum pressure-applying condition.

It is a particular feature of the present invention that the squeegee-roll 25 is coated or covered as indicated at 42 in the drawing herewith, with a layer of ink-resistant material such as a silicone compound or a synthetic plastic such as polytetrafluorethylene which is known in the trade as Teflon; or any other like material having the property of being nonreceptive to the ink being used and/or its constituents. This may be applied to the squeegee-roll 25 by any suitable process such as by dipping, spraying, or

painting it on, or by shrinking a pre-molded or extruded sleeve of the material onto the roll. In any case the inkresistant roll 25 is arranged as explained hereinabove to hold the web 12 in close-bearing relation against the chill roll 22. This operates to squeeze the web 12 against the chill roll 22, thereby serving to prevent the buildup of ink condensate products on the surface of the chill roll of a thickness sufiicient to affect streaking of the web thereby, which buildup would otherwise be permitted due to the spacing of the web from the surface of the chill roll occasioned by the gaseous aura which tends to envelop the web. In this respect, it will be understood that although ink volatiles still tend to condense on the surface of the chill roll, direct contact of the web with such surface permits the condensates to be constantly wiped away by the web, while they are of a thickness or size sufficiently small to prevent noticeable discoloration of the web.

Accordingly, it will be appreciated that by means of a mechanically simple and inexpensive device in accordance with the present invention an effective deterrent is provided against streaking of the ink volatiles on the finished product. Therefore, the invention may be utilized without other changes in an existing system to provide a superior streak-free product; or, it may be used to provide an acceptable quality product in an increased speed system.

I claim: 1. In a high speed printing press, in combination, means for printing ink on a web travelling at high speed, ink drying and setting means for rapidly drying and setting the ink on s id web wherein said ink drying and setting means includes a heat drier operating to heat the ink and initiate vaporization of the volatile constituents of the ink and a chill roll following said heat drier and operating to set the ink constituents remaining on said web, said web being trained around a substantial extent of the peripheral surface of said chill roll and said chill roll being disposed adjacent said heat drier whereby the vaporized constituents of the ink are enveloping said web so as to create a gas cushion of said vaporized constituents between said chill roll surface and said web which tends to force said web away from said chill roll surface and allow space for vaporized constituent condensate products to accrete on said chill roll surface to a thickness sufiicient to produce periodic streaking of said web,

and means for preventing the aforesaid periodic streaking of said web comprising a pressure applying member disposed in parallel opposition to said chill roll, said pressure applying member being mounted for movement toward and away from said chill roll, and means for continuously urging said pressure applying member uniformly at a predetermined pressure against said web to squeeze said web against said chill roll surface while the web is travelling at high speed as aforesaid, whereby accretion of condensate products on said chill roll surface of a thickness sufficient to produce periodic streaking of said web is prevented.

2. The improvement in a high speed printing press according to claim 1, wherein said pressure applying member comprises a freely rotatable squeegee roll, and said squeegee roll has a web contacting surface which is non-receptive to constituents of the ink printed on said web.

3. In a high speed printing press according to claim 2, including adjustable means adapted to limit movement of said squeegee roll in the direction of said chill roll.

4. In a high speed printing press as defined in claim 1 wherein said means for printing ink on a web comprises an impression cylinder having the web trained thereover and plate cylinder means for printing ink on said web as it trains over said impression cylinder, said heat drier comprising a heating drum disposed in spaced, parallel relation to said impression cylinder, said web issuing from said impression cylinder to train substantially completely around said heating drum, and said chill roll being disposed parallel to and closely adjacent said heating drum.

References Cited UNITED STATES PATENTS 1,792,414 2/1931 Cole.

2,157,387 5/1939 MacArthur 101416 2,526,318 10/1950 Battin 3462 XR 2,598,346 5/1952 Burke et a1 101416 3,079,699 3/1963 Fry 3413 3,081,206 3/ 1963 Remer 29-132 3,146,490 9/ 1964 Cooney 29-132 XR ROBERT E. PULFREY, Primary Examiner.

I. REED FISHER, Assistant Examiner.

US. Cl. X.R.

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