US2298803A - Drying of printed matter - Google Patents

Description

` DRYING oF PRNTED MATTER Filed Feb.` `8,1938 1 s sheets-Shen 1 Oct. 13,-1942-. KH. N. MORRIS 2,298,303 l DRYING'OF PMNTD MATTE? Filed Feb. 8, 19:58 3 sheets-shaet Oct. 13, 1942. H. N. MORRIS g 2,298,803

` DRYINGYNOF PRINTED MATTER Filed Ferl. a, 19:58 3 sheets-sheet 5 T AWWZ I I//l yPatented Oct. 13, 1942 -UNITED 'A STATES PATENT, oFFIcE l' Dama orziig'lomrrm y pplicationFebruary 8, 1938, Serial No. 189,296

In Great Britain March 3, 1937 11 Claims. (Cl. lill-416) over which the printed matter is passed, by subjecting the printed sheets to blasts of` hot or cold air or by the suction of air over or under the printed matter, by electrical discharge andby the ignition of the vapours. f

The object of the present invention is to provide improved means `whereby the drying of printed mattez" is under control and can be effected asrapidly as desired so as to'eiiminate the occurrence of foisettingt l .l

My invention consists ina method for effecting rapid drying o! printed matter according to which the surface of the papertuponi which the print has been applied is subjected to the Vaction of superheated steam at 'a `temperature so regulated with relation to thespeed of movement oi the paper that the temperature to which the surspeed of work, for tuning up at the beginning of a run. The necessity for a totally enclosedy inkliountain is eliminated since it isunnecessary to use the highly volatile and toxic solvents which are'subjectfto special and onerous regulations on account of 4 their low flash point, and

` their risk of iire and explosion when mixed with face of the paper is raised bythe superhe'ated y steam is above 'that ofthe boiling pointeoi` the volatile constituents oi the printing ink `when subjected to the superheated steam but below that at which the paper can be damaged in the period during which it is subjected to the infiuence of the superheated steam. so that the volatile constituents of the printing ink are evaporated in a very short time.A By the expression a very short time is meant a time so short that ,l the print is dry `before itis subsequently touched. In multiple printing, `for example, the print from one impression cylinder will be completely dry-before the next impression cylinder is reached. b

to proposed follow from the adoption oi'my invention. For example, the vapours oi the volatile constituents of the` ink are not mixed with air to make them either explosive or diiiicult ot.recovery. It is unnecessary even for the highest speed of printing to use any dangerously innammable and toxic inks and thus yprinting Vwhich z lhas hitherto been only possible by using dangerously inflammable, explosive and toxic inksk may be done withinirs of a character and in a vmanner which is safe and non-injurious to workpeople. Further printing at varyingspeeds may be carried out with the same ink andit is unnecessary b f l4.o Y Manifest advantages over the methods hitherair, and their beinginjurious to the health of operators.

y In order that the invention may be readily understood and carried into practice reference is hereby made tothe accompanying diagrammatic drawings wherein Figure 1 is a diagrammatic `side ,elevational view illustrating the simplest forniV of `myV invention where the paper passes through a single chamber; Figure 2 is a similar view illustrating the use of a pretreatment chamber in'addition to the drying chamber; Fig. 3 is a similar `view ,illustrating one suitable arrangement where printing is effected onboth sides ofthe paper; Figure 4 is a similar view illustrating another application of the invention to' printing on both sides of the web; Figure 5 is a similar view illustrating the application of the invention tothe case where successive printings on the same side of theweb have to be effected; Figure 6 is a similar view illustrating an application of the invention to permit six successive printings on one web,.three printings oneach side, whereby threemcolors can be applied to each side of` the web alternately in one continuous l run, and Figures 'l and 8 are more detailed diagrams of `the essential part of printing plant according to my invention, Figure 7 being a sectional plan'oi Figure 8 to an enlarged scale.

Referring to these drawings and particularly to Figure 1,` the numeral I rdesignates the web of paper or other material to be printed, which after leaving the reel passes over a roller 2 into the printing machine Ain the usual way through or between-the impression cylinder 3 and the forme cylinder I. The web I then passes into and through the rectangular vertical drying chamber B which is partly closed at each end by the rollers 5 and 6. The chamber is constructed of non-conducting material or ci material such as steel or iron lagged inside and/or outside withnon-conducting material. `Inside the chamber and located at oney or both sides is a ,metal heating coil 1 through whichsuperheated steam or rsteam of high pressure is passed, this steam `entering at 8 andrpassing out at 9. The chamber is as nearly as possible totally enclosed at both ends, allowing only slots I0 at each end through to use several inksvarying in volatility with .the which the paper web can pass.

In order to prevent condensation of any steam on the web the chambers are heated before printing is commenced to a suitable temperature usually not less than 100 C. This is eilected in the apparatus illustrated by passing steam through the coils 1 but it should be here mentioned that any system of heating such for instance as by electrical heaters can be employed in place of these steam coils.

As soon as printing begins low pressure steam is introduced by means of a pipe II fitted withy nozzles I2 into the chamber B at a pressure which may suitably be about 2 lbs. per sq. inch, the jets discharging in the direction in which the web is passing. This direct steam may be supplied from a superheater, or the necessary superheat may be derived from the internal heating device which in this instance is the steam coil l by using high pressure or superheated steam for heating the coil;

The outlet I3 for the steam and vapours ex tracted from the' printed material is provided as near the top of the chamber as possible and may be connected with any suitable condenser or recovery plant in which the gases can be condensed and the solvent recovered. The suction caused by the cooling and condensing of the vapours may be sufficient to overcome any slight pressure in the chamber, but a suitably disposed fan or steam ejector may be provided to give full control of the working pressure of the chamber.

The printed web passes out of the chamber B through the narrow slot I and over the roller I4 and the volatile solvents contained `in the inks and thinners used are recovered in the usual way as before indicated.

Referring to Figure 2 the web I passes over a roller 2 and through the pretreatment chamber C which may be of similar construction and design to the drying chamber B illustrated in Figure 1 and therefore for brevity and convenience the same figures Vof reference are used to indicate corresponding parts throughout.

Inside the pretreatment chamber C and close to the sides is a steam heating coil 1 through which superheated or high pressure steam may be passed so as to keep the inside of the chamber above 100 C. and thus prevent internal condensation. The inlet of steam to the coil is at 8 and the outlet at'9.

Direct steam is provided as in the case of the drying chamber B and is introduced at I I through nozzles I2'.` The direct steam may be superheated and of low pressure, or if the temperature of the chamber be raised to a much higher temperature than 100 C. by means of the coil 'I saturated steam of low pressure may be used this being superheated as it passes through the chamber.

An outlet for the direct steam is provided at I3 as near the top of the chamber as possible. This may be connected with a condenser` or steam boiler or with the superheater which may be required for the drying and/or pretreatment chambers.

The entrance to the pretreatment chamber is totally enclosed by two rollers 6-5 through `or between which the web passes. 'I'he outlet is also closed by two rollers -5 in the same way and the web passes through these and, directly into a printing machine A and between the impression and forme cylinders 3 and 4 to be printed and dried in the chamber B.

In fact this pretreatment chamber C only differs from the drying chamber B in the arrangement of the double rollers 5-5 and B-l which close the chambers.

Referring to Figure 3, it will be seen that the paper I passes from the reel over a roller 2 through the printing machine A, through a drying chamber B, constructed and arranged to operate as before described, and thence over suitablydisposedy guiding. rollers through the second printing machine AI, a second drying chamvber BI to the cutting, folding or re-reeling machine. The path taken by the web can be readily traced by following the direction of the arrows applied to the web.

Referring to Figure 4, the web I passes over a roller 2 into and through the pretreatment chamber C, through the first printing machine A through a drying chamber B, over rollers into and through a second pretreatmentchamber CI, through the second printing' machine AI and thence throughA the second drying chamber BI for its further normal treatment.

Referring to Figure 5, paper web I passes from the reel over a roller 2 into and through a pretreatment chamber C, through a printing ma-A chine A, then through a drying chamber B, through a second printing machine AI, a second drying chamber BI, a third printing machine A2, a third drying chamber B2, a second pretreatment chamber CI, a fourth printing machine A3, a fourth drying chamber B3, a fifth printing machine A4, a fifth vdryingl chamber B4, a lsixth printing machine A5 and thence through a final drying chamber B5 onward as previously described. It will be observed that the drying chambers B and BI, B3 and B4 are provided with both top rollers closing the chambers and there is also indicated at 5a and 6a small rollers which'are only engaged adjacent the edges of the web. I-t -will be understood that the pretreatment and drying chambers can be arranged horizontally kvertically or at any desired angle and the relative disposition of the printing machines will be such as to ensure the proper tension being maintained on the web.

For example, in the case of the pretreatment chambers the rollers under and over the web completely enclose the chambers. In the case of the drying chambers the upper rollers extend the whole width of the chamber, but the rollers under the web -act as clips or runners so that only the edges of the web come into contact with them. 'I'he under rollers may be parallel with the upper rollers, or they may be set at a slight angle so as to give a pull or stretch to the web as will be readily understood by printing engi neers. Y

By means of the foregoing arrangement printing in three colours can be effected on both sides oi' the web.

In the arrangement shown in Figure 6 the web I from the reel'passes over a roller 2 through a pretreatment chamber C and is printed on one .side by the printing machine A. 'I'he web then passes through Vthe drying chamber B over rollers to the pretreatment chamber CI, through the printing machine AI in which it is printed on the reverse side. From the printing machine AI ity passes through the drying chamber BI over rollers to and through the pretreatment chamber C2, printing machine A2, drying chamber B2, pretreatment chamber C3, printing machine A3,V drying chamber B3, pretreatment chamber C4, printing machine A4, `drying chamber B4, pretreatment chamber C4, printing machine A5 aaoasos l before. y j

` Insome cases the directsteamjmaybe omitted v from the pretreatment chambers and these chambersu'sed as Miers/conditioners or coolers tolkeep theweb in uniformconditionas to moisture Acontent and temperature., Infact in Vsonrie cases both .the directandgindirect steam may be omitted from these Vpretreatment `chambers when it is desiredto keep the 'temperature'lowbefore printing. It should also be mentionedthat instead of direct steam, or `in} addition tov `it there may be'introduced into oneonmore of the `pre-- treatmentor drying chambers a spray of varnish or wax solutionto improve thegloss or finish of the printed material and the same `may be trans-` parent orc'oluredto produce a variee'tyfof effects.

` Inl'gures '7 anda there is illustrated one ofthe drying'chambers'Bon a larger scale to indicate one possible'constructionandarrangement of the vvarious parts, Figure 17 beingjasection on the line 'i+1-1 and Figure 81a section on ,theiliiie-U ci Figrel. e e l ,l What vI` claim andy desire to secure by Letters Pateni'fisz'y p .y e y i, e v1". method for `effecting Vrapid. drying of printed .matter consistingin subjectingthe surfacer of a single reach of paper` immediately 4following'the making o f an impression thereon 'with a low volatile. non-toxic ,ink tothe action of an atmosphere,substantially free from air and containing superheated steam at a temperature above the`;boi1ing point ofvolatile constituents in theink of the impression andubelowthat which will damage the paper, `and maintaining a cur-f rent ofsuperheated steam about the paper by continuouslyl withdrawing from adjacenttthe paper, the steam and the volatile constituents removed frointhe inkby theaction of the steam. e 2. A method for effecting rapid drying `of printed matter consisting in continuously passing a singlereach of paper immediately. following the making of an yimpression thereon with a low vola-` ti1e,`n`ontoxic ink, through a substantially closedl chamber, displacing air within said chamberv by a continuous supply of superheated` steam. at, a temperature above the boiling point of volatile constituents of the ink of the impression and below that at which the paper will be damaged, and maintaining a 'continuous' current of the'steam about the paper by continuouslywithdrawing the steam and the volatile constituentsof the ink of the impression from said chamber. e

3. A method for effecting ,rapid drying of printed matter consisting in subjecting the surimpression and below that which will damage the paper, and maintaining a current of superheated steam about the paper by continuously withdrawing from adjacent the paper the steam and the volatile constituents removed fromthe ink by the action of the steam;`

4. A method for effecting rapid drying of printed matter consisting in passing paper in a single reach immediately following the making of an impression thereon with aflow volatile, nontoxicink through asubstantially closed chamber deliveringmsaturated steam of low pressure into said chamber in sudicient volume to create therein an atmosphere substantially free of air, superheating the, steam within the chambervby a suitl able'heating element, `regulating the temperature of `said superheated steamwith relation to the speed of movement of the paper, whereby the temperature ofthe surface of the paper is raised above thetboiling point of the volatile constituents of the ink but is 4maintained. below that at which the paper will be damaged while passing through e the chamber, and maintaining a current of superheated Vsteam about the paper by continuously withdrawing from adjacent the paper the steam andthe volatile constituents removed from the inkfby theaction `of the steam.` Y i y5. A v. method for effecting rapid drying of printed matter consisting in subjecting the sur- .i'ace of 4the paper to the action of superheated steam immediately before the printi operation and thereafter passing paper Auponrfwhich an ink impression has been applied through a substantiallyclosed chamber, delivering saturatedsteam of `low pressure into said chambery in suilicient volume tocreate'thereinan atmosphere substantially free of air, -superheating the steam within the chamber by asuitable heating element, regulating the temperature of. said superheated steam Vwith relation tothe speedrofrmovement of the paper, whereby the temperature ofthe surface of the paper is raisedV above the boiling point of the volatileconstituents of the ink but is maintained below that at which the paper will be damaged while passing `through the chamber, and main-` tainingacurrentof superheated steam about the paper Vby continuously withdrawing from adjacent the paperthe steam and the volatile constituents removed from the ink bythe action of the steam.

6. A method -for effecting `rapid `drying of printed matter containimr, asequence of impres-v sions :made `with aulowvolatila non-toxic. ink upon either or both sides of the paper consisting in4 subjecting the surface of a single reach of the papier following the making of each` impression to the action ofV an atmosphere substantiallyfree from air and containing superheated steam, regulating the temperature of said steam with relation to the speed of movement of the paper so that the temperature to which the surface of the paper is raised by the superheated steam is above that ofthe boiling point oi the volatile constituents of the ink but below that at which the paper can be damaged in the period during which it is subjected to the action of the superheated steam, and

maintaining a current of superheated steam about the paper by continuously withdrawing from adjacent the paper the steam and the volatile constituents removed from the ink by the action of the steam.

7. A method for effecting rapid drying of printed matter containing a sequence of ink impressions upon either or both sides of the paper consisting in subjecting the surface of the paper immediately before the making o1' each impres sion, to the action of an atmosphere substantially free from air and containing superheated steam at a temperatuije below that which will damage the paper, regulating the temperature of said steam with relation to the speed of movement of the paper, immediately thereafter making an ink impression on said paper, subjecting lthe surface of the paper following the making of each impression to the action of an atmosphere .substantially free from air and containing superheated steam, regulating the temperature of said steam with relation to the speed of movement of the paper so that the temperature to which the surface of the paper is raised by the superheated steam is above that of the boiling point of the volatile constituents of the ink but below that at which the paper can be damaged in the Aperiod during which it is subjected to the action of the superheated steam, and maintaining a current of superheated steam about the paper by continuously withdrawing from adjacent the paper the steam and the volatile constituents removed from the ink: by the action of the steam.

' a low volatile, non-toxic ink to the action of an atmosphere substantially free from air and containing superheated steam at a temperature above the boiling point of volatile constituents in the ink of the impression and below that which will damage the paper, and maintaining a unidirectional current of super-heated steam about the paper, the ow of which is in the same direction as the movement of the paper, by continuously withdrawing from adjacent the paper the steam and the volatile constituents removed from the ink by the action of the steam.

9. A method for effecting rapid drying of printed matter consistingin subjecting the surface of paper immediately before the making of an ink impression thereon to the action of an atmosphere substantially free from air and containing superheated steam at a temperature below that which'will damage the paper, making an ink impression on the paper, and thereafter sub- J'ecting the surface of paper having an ink impression thereon to the action of an atmosphere` substantially free from air and containing superheated steam at a temperature above the boiling point of volatile constituents in the ink of the impression and below that which will damage the paper, and maintaining a uni-directional current of superheated steam about the paper, the ilow of which is in the same direction as the movement of the paper, by continuously withdrawing from adjacent the paper the steam and the volatile constituents removed from the ink by the action of the steam.

10. Apparatus for practicing the herein described method embodying therein the combination with a printing couple of a plurality of substantially closed chambers, one of said chambers being positioned upon the feed side, andthe other of said chambers being positioned upon the delivery side, of said printing couple, each chamber having an entrance opening adjacent one end thereof and an outlet opening adjacent the other end thereof permitting a single reach of paper to be passed through the chamber immediately prior to and immediately following the making of an ink impression thereon by said printing couple, guide rollers adjacent and substantially closing each opening,the guide rollers of the chamber positioned upon the delivery side of said printing couple being positioned so as to be engaged by the unprinted side of the paper, a steam inlet adjacent one of said openings of each chamber, and a steam outlet adjacent the other said opening, whereby a continuous circulation of steam is maintained through, and volatile constituents of ink continuously withdrawn from, each chamber.

11. Apparatus for practicing the herein described method embodying therein a plurality of substantially closed chambers each having an entrance opening adjacent one end thereof 'and an outlet opening adjacent the other end thereof permitting a single reach of paper to be passed through the chamber, guide rollers adjacent and substantially closing each opening, a steam inlet adjacent one of said openings of each chamber, a steam outlet adjacent the other said opening, whereby a continuous circulation of steam is maintained through, and volatile .constituents of ink continuously withdrawn from, each chamber, one oi said chambers being located adjacent the feeding side of a printing mechanism and another chamber being located adjacent the delivery side of the printing mechanism, and suction creating means connected with said steam outlet whereby the rate of flow of 'superheated steam and volatile constituents of ink from the chamber may be accelerated and controlled.

HERBERT NEWALL MORRIS.

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