US3202532A

US3202532A - Glossy coating machine and method

Info

Publication number: US3202532A
Application number: US369654A
Authority: US
Inventors: Raymond A Labombarde
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-05-13
Filing date: 1964-05-13
Publication date: 1965-08-24
Anticipated expiration: 1982-08-24

Description

Aug- 24, 1955 R. A. LABOMBARDE 3,202,532

GLOSSY COATING MACHINE AND METHOD ATTORNE X5' Aug. 24, 1965 R. A. LABOMBARDE 3,2@2532 GLOSSY COATING MACHINE AND METHOD Original Filed Nov. 14, 196D 8 Sheets-Sheet 2 1N V EN TOR. RAY/wom) A. LA BOMBA/m5 PQM *M A TTORNEYS BLANK TRAVEL Aug. 24, 1965 R. A. LABOMBARDE GLOSSY COATING MACHINE AND METHOD 8 Sheets-Sheet 5 Original Filed Nov. 14, 196D L w A Dn T m m RR mm WW 1B A L am D W M .on

LM A T TRNEYS Aug. 24, 1965 R, A. LABOMBARDE GLOSSY COATING MACHINE AND METHOD Original Filed NOV. 14, 1960 INVENIUR. RAWND A LABMBARDE 7D n a ,a A am.. Pla/wmv .AT T ORNE YS Aug 24, 1965 R. A. LABOMBARDE GLOSSY COATING MACHINE AND METHOD 8 Sheets-Sheet 5 Original Filed Nov. 14, 1960 All.

mzON @23000 mzON :Alli

l mzON @mmm INVENTOR. 'AMND A. LABOIMBARDE PJM 7 ATTORNEYS Aug. 24, 1965 R. A. LABOMBARDE GLOSSY COATING MACHINE AND METHOD 8 Sheets-Sheet 6 Original Filed Nov. 14, 1960 All!! mZON @z mam;

mZON 023000 mzON @z mmamh I' mzON Dumm mzON ummm INVENTOR. RmlND A. LBMBARDE BY P #-75 TTRNEYS Aug. 24, 1965 R. A. LABOMBARDE GLOSSY COATING MACHNE AND METHOD 8 Sheets-Sheet 7 Original Filed Nov. 14, 1960 COOLING E M T IF. S RN w. D P E Mz L E H. n. T H f C o 1 7 L Y E E T s D E T E N 0 u.b O H ulr. Z E C G E m v T E M R C FEED ZONE INVENTOR. RAYMND A. LAB MBARDE PM 2wum ATTORNEYS Aug- 24, 1965 R. A. LABQMBARDE 3,202,532

GLOSSY COATING MACHINE AND METHOD Original Filed Nov. 14, 1960 8 Sheets-Sheet 8 FEED ZONE GOATING ZONE COOLING ZONE REVERSE HOT 48 CHILLED ROLL F z'g.13.

FEED ZONE COATING ZONE COOLING ZONE REVERSE HOT RUBBER PRE HEATING 55 75 ROLLS 28 4 29 55 30 17| 8| 52 ,f 36 U I CHILLED ROLL INVENTOR. RAYZMNA.LABOMBARDE BY I 75mm 75W flTTfuNE'lffS1 United States Patent O 3,2il2,532 GLGSSY CUATENG MACiil-.NE AND METHD Raymond A. Labombarde, Lowell Road, Nashua, Nid. Continuation of application Ser. N 69,955, Nov. 1d, 1960. application May 13, '1964, Ser. No. 369,654 36 Claims. (Ci. 117-64) This application is a continuation of my application Serial No. 69,055, tiled November 14, 196i), now aban doned, and entitled Glossy Coating Machine and Method.

This invention relates to -a machine and method for producing a glossy coating on waxed paper box blanks.

rl`his terml waxed paper box blanks is intended to mean blanks which are coated with hot melt coating compositions containing paraflin wax, microcrystalline Wax, polyethylene or similar ingredients and which are used to make folding cartons for frozen foods. Ordinary wax coatings lack lustre and .it is desirable to impart a gloss to the same to increase the visual impact and customer appeal of the frozen food cartons.

It has been proposed in U.S. Patent No. 2,892,735 to Curler of June 30, '1959, to press the wax coated blanks on a smooth, hard surfaced, endless belt, having a stretch about fifteen feet long, to smooth the coating into a high gloss finish and then to strip the blanks from the belt. In the copending application of Philip D. Labombarde, Serial No. 862,192, led December 28, 1959, Patent No. 3,070,457, Dec. 25, 1962, the subject matter which is in application Serial No. 280,760, led May 15, 1963, for reissue and entitled Apparatus and Method for Glossy Wax Coating the blanks are first coated with a thin layer of hot melt coating composition. Then the top of the layer is removed and replaced by not, reverse coating rolls, reliquiiied by hot flames and then quenched by a cooling waterfall all for producing a high gloss finish.

Both of these systems require a relatively lengthy machine, and iioor space is usually at a premium in box making or foodstuhc packing plants. ln addition, both of these systems operate on the principle of applying the hot melt coating to the blank and then seeking to smooth the coating to a high gloss while on the blank.

The object of this invention is to provide a low coat, relatively short machine for producing a glossy finish, the nish being glossy when it leaves the coating zone as a result of the coating operation.

Another object of the invention is to provide a machine and method whereby both the upper and lower faces of individual and successive hat box blanks may be coated in one pass through a :short roll coating Zone, at least one face being glossed before it leaves the coating zone.

A further object of the invention is to provide reverse roll coating means for applying a smooth, glossy coating to one face of a plurality of flat, individual, successive box blanks each of which has been coated in the same zone on its opposite face with a hot melt coating composition and is, therefore, slippery and difficult to handle.

Still another object of the invention is to provide a roll coating machine for coating box blanks on both faces with a hot melt coating composition, wherein the roll of the final pair of rolls may be either la cold steel roll for hardening a coating, a hot burnishing roll for polishing the coating or a hot reverse coating roll for applying a final smoothing layer.

An important object of the invention is to provide novel roll coating apparatus for handling individual and successive sheets which may be uncoated and dry, coated, dry and slippery or coated, wet and slippery cn either or both faces. Tne apparatus successfully grips and advances such sheets through the nip of opposed coating rolls, one of which is reversely rotating ice and applying a hot melt coating to the adjacent face of the sheets, because the other roll is rotating and chilled to secure frictional contact suihcient to overcome the reversing etfect of the opposite roll.

A still further object of the invention is to provide a roll type machine for reverse roll coating a smooth glossy layer on the adjacent faces of individual blanks advancing along the paper line of the machine, the machine including a thin flexible wiper blade in tangential contact with the coating on the roll for smoothing and glossing the coating just before it is deposited on the blanks.

Other objects and advantages of the invention will be apparent from the claims, the description of the drawings and from the drawings in which FIG. l is a side View of the preferred form of the invention.

FIG. 2 is a plan view of the machine shown in FlG. l.

FIG. 3 is an end View, in section on line 3--3 of FlG. 2.

FiG. 4 is an enlarged, detail, side view of the tangential, flexible, smoothing blade of the invention.

FIG. 5 is a side view in section on line 5-5 of FG. 2 showing the drive means for the rolls.

FIG. 6 is adiagrammatic, perspective view of the coating rolls illustrating the means for continuously gripping and advancing the blanks even though wet, slippery and being reverse roll coated.

FXGS. 7, 8, 9, 10, 11, 13 and 14 are diagrammatic side views illustrating the various capabilities of the machine of this invention for producing finishes ranging from commercially acceptable to commercially superior.

FIG. 12 is a view similar to FIG. 5 showing the drive means for the rolls when the coating treatment of FIG. 11 is desired.

In the drawings the coating apparatus 20 is shown occupying a relatively short coating zone 2li, which may be four to six feet in length. The machine 22 also includes a feeding zone 2.3 for a blank feeding apparatus 24 of any well known type and a cooling zone 2S for cooling apparatus 26 of any well known type. The blank feeding .apparatus 2d is preferably the Speed King manufactured by the international Paper Box Machine Company of Nashua, New Hampshire, this apparatus permitting three lane operation, although any equivalent feed can be used in this invention which will advance flat blanks individually and successively along the paper line P into the coating zone 21. The cooling apparatus 26 may be of the HW type manufactured by the said )international Paper Box Machine Company or any equivalent device for carrying coated blanks through a cooling zone while immersing or showering the same with a coolant uid such as water.

The coating apparatus 20 includes the frame 27 upon which three

pairs

28, 29 and 5l), of opposed, upper and lower rolls are journalled, each having a nip such as 32, 33 and 34 along the paper line P. The lrst pair of rolls 23 is for the purpose of applying a thin layer of hot melt coating composition to one face 35 of the flat box blanks such as 36 and 37 fed into the nip 32 by the feeding apparatus 24. Suitable blank carrier rolls 38 are provided to bridge the gap between the nip 32 and the feed apparatus 2li. The face 35, which is the lower face of the blanks, will be the inside face of the carton folded from each blank and it is, therefore, unnecessary that it have a glossy Wax nish. It should also be noted that the upper face 39 of each blank is dry and uncoated, and that the blank is usually at room temperature when it enters the nip 32 so that slippage has not yet become a factor. The upper roll 41 of the first pair of rolls 2S may thus have a hard steel face 40 or a yieldable rubber face and still secure a good friction grip on the blanks to advance the blanks through the nip 32 toward the nip 33. The

i lower roll 42 of the pair of rolls 28 is a coating roll and it is preferred that it have a yieldable rubber cylindrical face 43' formed by a rubber'sleeve 44 on a metal roll body 45. The roll body 45 is hollow and heated to a temperature substantially the same as the melting point of the coating composition.Y The yieldable rubber face 43 .is supplied with the coating composition by a suitable feed roll 46 rotating in a coating tank-47, the roll 46 also serving as a doctor roll for metering the thickness of the coating. The coating composition 48 in, tank 47 is maintained at a temperature above the melting point by continual circulation from a heated reservoir in a manner to upper anda lowerla'yer thereon, this is not possible withk Y a succession of individual blanks'.vr The nip fof Vthe rolls would move the blanks rearwardly rather than forwardly if it moved the blanks at'all. It is also apparent that reverse roll coating the'upper faces of a succession of individual blanks while the lower faces are wet and slippery 4 face 60 of roll 51, the pressure of the blade 66 being adjustable by a hand wheel 67.

The engagement of the chilled face 6@ withpthe lower layer '59 of each individual andsuccessive blank at nip 33 not only chills and hardensV the layer but tends to chill the body of the blanks thereby preventing the thin upper layer 49 from impregnating into the body of the blank and causing the lower portion of the upper layer to harden on the upper'face 3970i the blanks. The blanks are frictionally advancedby the chilled face 60 from nip 33 to nip 34 of the third pairV of rolls 39 even though the coating roll 52 is reversely rotating relative to the direcwith a hot melt coating presents Vthe problem ofY securing provided for frictionally gripping the blank by its still Y hot and slippery layer 50. This is accomplished by the second pair of rolls 29 which include the chilled, hard faced, lower roll 51 and the heated, yieldable faced, upperY vroll 52 which form the nip 33. VThe upper roll 52V is provided with a rubber sleeve 53 having a yieldable rubber cylindrical face 54 which deposits the coating in any recesses, creases, etc., inthe blanks and also along the edges of the

blanks

36 and 37 in the same manner as does the rubber faced coating roll 42. A hard faced, steel doctor roll 55 is provided to'form Aa nip reservoir 56 Vof,

hot melt coating composition with roll 52, the roll 55 being adjustable to meter the thickness of the coatingSV on the face 54.'V VThe roll 52 is reversely rotated bythe Y coating roll drive means of the invention Vand the speed of the blanks also permits the thickness of coating to Vbe controlled. It has been found that the Vcoating applied byV the reverse coating roll 52 tends to pile up at the nip 33, as shown diagrarnmatically herein, and tends to be smoothly applied to the material being Vcoated without.

nip marks, and with a glossy finish. The body 57 of roll 52 is hollow and heated to a temperaturerabove the melting point of the hot melt coating composition 48 as tion supply means 58 of the machine 22.

' The lower roll' 51 is called a blank advancing and chilling roll since it is Yof steel and provided with a hard, i. smooth cylindrical face 60. Roll5r1 is hollow and connected by conduits lsuch vas 61 to a refrigerant reservoirV 62 "there being suitable chilling mechanism 63 of any well known typeand a suitable pump 64 andV motor'65 for maintaining circulation. Preferably the faced@ is maintained at a temperaturewell below themelting point of the `composition 48, forfexample, if the meltingpoint tion of advance of the blanks.

The pair of rolls 30 includes the lower roll 7? of metal suc/h as steel, the roll 70 having a hard smooth cylindrical face '71 and being hollow for the passage ofthe refrigerant fluid. Roll'7ti is thus an adyancing'and chilling roll, Vrotated, forwardly,'in the same manner as roll 51 and connected by conduit 72 to the refrigerant circulation system 63 of the machine. A frictional grip on the lower layer of coating on each blank is thus assured to Vadvance each blank throughrnip 34 and into the cooling zone 25 orY into a tempering `Zone to be hereinafter described and located inY advanceV of the cooling zone. A scraper blade 73, similar to blade 66 isfprovided for'removing accumulations from the face 71, the blade 73 being also adjustable by the hand wheel 67 through a common rod and spring mechanism 74. Y

The upper roll 75 of thefpair of rolls 30 is called a glossingV roll herein V*and the machine 22 is so constructed that glossing'roll 75 may be a second heated reverse coating roll, a heated reversely rotating burnishing roll or a chilled forwardly rotated advancing and chilling roll.

As shown, roll 75 is preferably a second, heated, reverse coating roll identical with'reverse coating roll 52 and includes aY rubber sleeve "76, a yieldable rubber cylin-t dricral face 77,V a hollow metal body 78, and conduits 79 and 80 connecting the interior of 'body 78 to the roll heating systemV 8l of the invention. The roll l75 is reversely rotated by theVV coating roll drive meansV 82 of i supply means 58. i The speed of the reverse coating'roll 75, or the clearanceof the doctor roll 83 may be adis thedoctorroll 55. A conduit 59 feeds the composition 48 to the tnip reservoir 56 as part of the coating composiof the composition is 135 ,F. to 250V F. the ,cylindrical`V face 60V is at 60-70 F. The roll 51V is forwardly rotated' so as to advance the blanksv36 and 377, atrtheV nipr33,v Valong the paper linefP and because the roll is chilled, it is Y. Inasmuch asvthe chilled 'rollface 93 wouldl frictionally.

grip and retard the blanks, if reversely rotating, the drive able to frictionally gripthe slippery lower layerA Stl'and` i also to harden the layer. A suitablefscraper blade e6 is providedV to scrapeany hard waxV accumulations from the justed for the ydeposit of aV layer 90 of coating Vcomposition, equal in thicknessrtothe layer 49, on the layer 49, both layers being extremely thin and the overlying layer tending to Vlill in any nip marks, crows feet, pock marks or theV like in the underlying layer.

Each of the

upper rolls

41, 52 and 75 are mounted in bearings such as 87, 88V and 89j, spring pressed downwardly lby coil springs such as 91. VTo convert roll to a reversely rotating burnishing roll it is only necessary to slidably remove the rubber sleeve 76 and shut olf the supply of Vhot melt coating composition to nip reservoir 84 by shut-off valve 92.", The upper layer 49 on the

blanksV

36 and 37 is thus polished toa high gloss asV it passes through Athe nip V34,.V The cylindrical face 93 of the roll body 78 isV hard and smooth forV producing a high gloss on the layer 49 when the springs 91 press the roll downwardly intoiengagement with the coating. To Vconvert the roll'b'ody 78 into an advancing andichillg ving'roll, similiar to rolls 51V and 70 the conduits 79 and Vare disconnected from attachment to roll body 78 and Y the

Vconduits

94 and 95 are substituted therefor, thus connecting the rolly bodyV 78 to the refrigerantrsystem 63.

lconnectionl 96fto the reverse roll Vrotating meansY 82is reversednto cause theroll Vbody 78 to forwardly rotate.'v Y VIn FIGJS, Ythe normaland standard drive means 82,V

for accomplishing the various possible treatments illustrated diagrammaticaliy in FIGURE-S 7, S, 9 and l0, is illustrated. The electric motor 99 drives a speed regulator 1Gb, and one shaft 191, of regulator 108, is connected by a power train 1%2 to drive the interrneshed gears 103 and 16,31%, gear 1&3 being carried by the shaft 195 of the upper coating roli 52 and reversely rotating the roll 52. The gear d rotates the doctor roll 55 in the direction of the arrow. In the preferred embodiment, the shaft 195 is connected by the sprocket and chain power train 1%, to also rotate the upper roll 75 reversely on its shaft 1t7. The intermeshing gears 163 and 199, cause shaft 1li? to rotate the shaft 111B of doctor roll 33 in the direction of the arrow.

The other shaft 114, of regulator lili? through power train 115, rotates the shaft 116 of the lower roll 7d in the direction of the arrow. A power train 117 connects the shafts 11?, 118 and 116 of the lower rolls 4Z, 51 and 76 to cause all of these rolls to rotate forwardly in the direction of the arrows. on

shaft

119, and 121 on shaft 122 of upper roll lll, cause these rolls to rotate as shown and intermeshing gears 123 on shaft 122 and 124 on shaft 125 cause a doctor roll 126 on shaft 125 to rotate in the direction shown, if such a roll is desired, as in FIG. 7. The gear 120 on shaft 119 also drives a gear 127 on shaft 123 of doctor roll 46 to rotate the roll in the direction shown.

The roll heating system S1 includes the jacket 131 containing hot oil 132 and encircling the reservoir 133 which contains the hot melt coating composition i8 of the supply means 5S. Suitable heating elements 134 maintain the oil 132 at well above the melting point of composition 4d and also maintain the composition 48 in reservoir 133 at a temperature above the melting point thereof, for example, 350 to 400 F. The hot oil 132 is continuously circulated through the coating rolls 42, 52 and 75, the doctor rolls 46, 5S and S3 and the jacket 131 by hot oil conduits such as 79, S0 and 135, 13S and a hot oil pump 136. The composition 4S is continuously fed to the coating tank 47 and to the nip

reservoirs

56 and 34 by the conduits such as 59 and S5 from the reservoir 133 of the supply means 53 through pump 137. The chilling mechanism 63 for the lower rolls 51 and 70 may be of any well known commercially available type capable of circulating a refrigerant from the reservoir 62 through conduits such as 61. The

refrigerant conduits

94 and 95 form part of the system for chilling roll 75 when the hot oil conduits 79 and gli are disconnected therefrom.

The upper, heated, reverse coating roll 52, and the glossing roll 75, when serving as a secondary upper heated reverse coating roll, are preferably each equipped with a thin, iiexible, wiping blade such as 140 or 141. The wiping blades 1li@ or 141 are about three one-thousandths inch in thickness and formed of flexible, resilient material such as sheet metal. Each blade such as 14h includes longitudinally spaced slots 143 in which the pins 144 of a clamp bracket 1115 are enclosed as best shown in FIG. 4. The jaw 146 of bracket 11i-5 is fixed to the bracket body 147 by the machine screws 148 and both the bracket and the blade are coextensive in length with the

rolls

52 or 75. Bracket body 147 is journalied at each opposite end in the frame of machine 22 and carries a clamp link u pivotally connected to a push rod 151 slidable in a iixed bracket 152. The rod 151 is normally spring loaded upwardly by coil spring 153 to maintain the bracket 147 in the desired position but downward pressure on the knob 154A ot rod 151 will cause the bracket to turn on its longitudinal axis and then spring back to its normal position.

As shown in dotted lines in FIG. 4 the blade 149 would be in extension of the clearance slot 155, if there were no coating roll, but, as shown in full lines, the roll exes the blade into the curve shown. The free terminal edge 156 of the blade extends along the line of tangency with the intermeshing gears 12) roll, but the blade is deformed away from a tangential plane as shown. The pressure and the flex of .the blades and 141 is adjusted by moving the collar 157 ,on the push rod 151. It has been found that the wiping blades can be adjusted, while the operator examines the coating carried from the nip reservoir around to the roll nip, until that coating has been smoothed and leveled to an unbroken, high gloss, mirror-like finish on the roll. The blanks are then passed through the machine and the coating which has been so glossed on the roll is transferred to the blanks by reverse coating with the high gloss finish retained. A small accumulation of the coating cornposition occurs in advance of the edge 156 but the thinness of the metal and the heat of the composition and the coating roll prevents the same from hardening. The blade is caused to remain hot by forming the bracket of a low heat conductive material such as Formica. If specks or particles become trapped in advance of the edge 156, .the operator pushes down on knob 151!- which flexes the blade toward the roll and causes the edge 156 to move slightly away from the face 77 to release the speck 4or particle. Any longitudinally extending depressions caused in the upper layer coated on the blanks, by such a speck or particle is covered and eliminated by the second layer reverse coated thereon by the roll 75.

In FlG. 7 the machine and method of the invention is illustrated diagrammatically as producing a commercial-ly acceptable glossy finish. In FIG. 7 there are no wiper blades such as 141i and 14.11 and the upper roll 75 of the third pair of rolls is a chilling and advancing roll. The upper layer 49 reverse coated by the upper roll 52 on the blanks 36 is glossed by the quick chilling action of the roll body 78 of upper rol-l 75 and retains the gloss after cooling in the cooling Zone 25.

As shown, the upper roll 41 and Ithe lower roll i2 can both apply a coating simultaneously if desired because both are rotating forwardly to advance the blanks through the nip. A rubber sleeve 164, identical with sleeve de, is mounted on roll 41 and it is supplied with coating cornposition, by means of the doctor roll 126. In the embodiments of FIGURES 8, 9, l0 and 1l, however, the upper roll di is merely a dry, blank-advancing roll without the sleeve 1de.

In FIG. 8 a wiper blade 14? has been provided for the reverse coating roll 52, thereby smoothing and leveling the coating to a greater degree and producing a finish with more `gloss and the equivalent of products now on the market.

In FIG. 9 the preferred form of the invention is shown in which the upper rolls 52 and 75 are both reverse coating rolls` and each is equipped with a wiper blade 144B or 141. The iinish achieved by this apparatus and method is highly glossy since both the primary and the secondary layers have been leveled on the rolls prior to deposit on the blanks. The high gloss finish achieved by this apparatus is mirror-like and of a superior character.

In FIG. l0 .the roll 75 is a reversely rotating burnishing roll, in order to show that this capability of machine 22 is possible although not preferred. In this modication the coated blanks are passed through a commercially available hot lair oven 16d for slightly softening but not liquefying the exposed area of the upper 'layer or layers. This zone is called a tempering zone because it a'lso includes a waterfall type quenching device 161 for quickly cooling the finish softened in lthe oven. It has been found that while a hot melt coating composition may be given a gloss, .or a high gloss, by the apparatus of this invention, or by the devices of the prior art heretofore mentioned, the finish may still remain tacky and soft. By tempering the finish as described above the nish is hardened and set without adversely affecting the gloss.

The coating composition 43 may be paraffin wax, microcrystaline Wax, polyethelene or various desired Icombinations of the same, or may be other suitable coating compositions. It will be noted that in the diagrammatic views of FIGURES 7, 8, 9 and 10 the three lower 7 rolls 42, 51 and 70 all rotate forwardly'rathcr than reversely, the upper ro'll 41 rotates forwardly and the upper roll 52 rotates reversely.v The upper roll 75 rotates reversely in the preferred embodiment of FIG. 9, as well as in the embodiment of FIG. l0. VForrotating roll 75 forwardly, as in FIGS. 7 and 8, the power train 166 is disconnectedfrom shaft 105 and connectedto a sprocket 123 on shaft 122.

.The treatment 'capability shown in FIG. ll is similar to that shown inFIGURE 8 except that the coating on the underface of the blanks is applied by reverse coating. As shown 'in FIG. 12 the power trainy 106 connects shafts 122 and 197 to rotate

rolls

41 and 75 for-1 wardly. The shaft 119 is disconnected from the power train 117 and is reversely rotated by means of intermeshing gears 120 and 179, the latter being rotated by a power train 171to the drive shaft 161 of regulator 16). Y

It Should be noted that in the embodiment of FIG. 1,V

and in FIG. ll, upper roll 41, while opposing a reversely 'rotating coating Vroll 42, need not be chilled because the sheets arriving at the nip of the rolls are dry, uncoated and not slippery. However, if for some reason itk was deof said second pair to a temperature causing hardening of pleting the coating Y blanks.

sirable to deliver the sheets to this particular ynipl with Y .therupper face wet and coated, the roll 41 wouldrbe chilledV to become an advancing and chilling roll suchV as rolls 51band 70. Y

In FIG. 13 the most simplified form fof the coating apparatus 2f) is illustrated to represent what is believed to be the basic invention herein. Y 28, V29 and 3f) in the coating ,zone 21 of machine 22 are illustrated, but the thirdpair 3i) serve merely as. conventional blank carrier rolls similar to carrier rollsV 38. The blanks 36 are coated on the underface 35 by the coat- The three pairs of roll-s ing roll 42 wherebyV they arrive individually and succes- )sively at the nip 33 of rolls 51 andSZ with, one face 35 wet and slippery with coating. Y A layer 49V is applied to theuncoated faces of the blanks, at nip 33by the reversely rotating, heated, roll which is supplied with coat- Ving from theV reservoir 56 as described above, the reverse coating actionY providing a smooth glossy surface. AThe other roll 51V of the pair of rolls 29 rotates forwardly relative to the path of the blanks and securesa frictional gripy on the wet slippery underfaces `of the blanks by reason of being chilled. Unlike a knurled roll, the smooth chilled face .ofroll 51 does not damageor mark the coating and also tends to harden the cioatingon the blanks. i

In =FIG.-14, the same basic structure is illustrated as in vFIG. 13 with the` addition 4of atleast .one pair 170 of opposed rolls l171V and 172 which are pre-,heating rolls as Y Well as carrier rolls.V lThe rolls 171 and 172may lbe connected Yby suitable c-onduits, to the hot Voil heating system 81 of themachine 22 and will thus be maintained at about the same temperature as the heated coatingrolls of the apparatus; Pre-heating by the nip of la Ypairyof heated Yrolls has been lfound to improve the smoothness and gloss 'of the coating applied in coating zone 21 and serves to iron o utl and flatten the fibrous faces'of the blanks just before they are coated. I Y

- I claim: n

` 1. Apparatus for coating a'plurality of box blanks in one pass through a short coating zone,V of a coating machineg'said apparatus comprising means for feeding said blanks Yindividually 'and successivelyinto saidfcoat-ing.

Zone; a first pair ofl opposed rrolls said zone, said rolls having a nip for receiving and advancing said blanks along slippery' coating tovat least one Vroll of said first pair foi coating at least one face of said advancing blanks, thereclosely spaced in rear of, and receiving each saidblank from, the nip of said first pair of rolls while the said coatedA face Vthereof. is still hot, Vwet and slippery; -means for reversely rotating one 'roll of said second pair'and for,-

'2. Apparatus as specified inclaim 1 wherein the for- War-dly rotating, chilled roll of said second pair of rolls -includes a smooth, hard cylindrical face `of metal.,V

' 3. Apparatus asy specified in claim 1 wherein each roll of said first pair of roll's to which said coating is applied includes a blank engaging'face of yielding rubber-like material.

V4t. Roll -coating apparatus for reverse roll coating one face of aiplurality'of fiat blanks advancing individually and successively along a path with the other face of said blanks wet and slippery withhot melt coating, and for hardening said coating, said `apparatus comprising a pair of opposed rollsY havinga nip in said path for receiving Vsaid blanks while said/coating is still hot, Wet and slippery, and radvancing said blanks; means for continuously supplying a hot melt coatingV composition to the face of the roll of said pair in engagement with the uncoated faces of said blanks; 'means'for revers'elyrrotating the said roll in relation to the'path of said blanks for reverse roll Vcoating the uncoated faces thereof; means for forwardly rotating the other said roll in relation to the path of said blanks, a hard, -smooth cylindrical face on said forwardly rotated troll, and refrigerant means for chilling the face of said forwardly rotated roll to cause the hot, wet, slippery coating engaged thereby Vto harden while frictionally gripping and `advancing said blanks through said nip `against the reversing effect of the said reversely rotating rollof said pair. v Y i 5, Apparatus for producing a Vglossy coating onpaper 'boxablanks, said apparatus comprisinga first pair of opposed, nip-forming rolls including a lower blank coating roll'and-an upper blank `advancing roll; a second pair of opposed, nip-forming rolls including anupper blank coat.V

' ing roll and a lower blankadvancing and chilling roll; a

, -blank advancing lrolls and drive means for rotating said said Zone; means on Ysaid mach-ine for applying a h ot,wet,

composition,

Vglossingroll; means for supplying hot melt coatingcomlposition to the faces of Vsaid coating rolls and means for chilling the faces of saidblank advancing Vand chilling`V Y rolls', whereby ,said blanks are Vadvanced, individually and Y successively through the ni-ps -of vsaid rollslby said chilled rolls andthe Yupper coating thereon is glossed by said glossing roll.

`-6. Apparatus-asl specified in claim 5'V wherein each said Y blank advancing and chi-lling roll includes a hard, smooth, cylindrical face and eac-h said `coating roll includes a yield-` able, rubber, cylindrical face. Y f v 7. Apparatus as specified in claim 5 wherein saidV coating rol-1s each'include a yieldable, rubber, cylindrical face A for depositing said coating in any depressions in said box blanks. t. t Y t 8. Apparatus'ias specified in claim-S wherein Ysaid means for chilling the faces of said blank advancing and chilling d rolls includes-means for chilling the faces Vof said rolls to well below the'melting point of VSaid hotV melt 'coating 9. Apparatus,asV specified in'claim 5 plus a steel Ydoctor roll rotatably engaging each said coating roll for'metering Y the thickness `ofthe'coat'ing thereon and means for heating each saiddoctorroll. Y I Y Y Q10. Apparatus as specified in claim 5 plus'a thin, flex ible smoothing blade of sheet material about three thon-V sandths'inch in thickness Vassociated with each said coati1v chilling `an-d frictionally engaging said -coated upper and lower faces to advance said blanks further along said path; a hot air oven mounted further along said path for softening the exposed Varea of the upper coated face of said blanks nearly to the melting point of said composition and waterfall quenching means mounted further along said path for quenching said exposed area into a hard iinish. Y

26.-A method for producing a high gloss finish on a plurality of dat paper box blanks advancing individually and successively along a path into the nip of a pair -of opposed rolls, with a wet, slippery hotmelt coating on one face thereof, one said roll having a hard smooth metal face and the other said roll having a yieldable rubber face, said method comprising the steps of simultaneously reverse roll coating a layer of said hot melt coating composition onto the other face of each successive blank from said rubber faced roll at said nip, thereby tending'to urge said blanks rearwardly on said path, while chilling said hard, smooth faced roll at said nip and rotating same forwardly to harden the said wet, -slippery hot melt coating on the said one face of each successive blank and advance the said 'blank through said nip.

27. Apparatus for producing a glossy coating on paper box blanks, said apparatus comprising a rst pair of opposed, nip-forming rolls including a lower blank coating roll and an upper blank advancing roll; a second pair Vof opposed, nip-forming rolls including an upper blank coating roll and a lower blank advancing roll; a third pair of opposednip-forrning rolls including an upper blank glossing roll and a lower blank advancing `and chilling roll; drive means for reversely rotating said glossing roll, forwardly rotating said lower blank advancing and chilling roll and rotating the other said rolls; means for supplying hot melt coating composition t-o thefaces of said coating rolls, and means for chilling the face of said lower blank -advancing and chilling roll whereby said blanks are :advanced individually .and successively through the nips of said first and second pairs of rolls and advanced through the nip of said third pair of rolls, despite said reversely rotating glossingy roll, by said forwardly rotating chilling'roll. Y i

28. Apparatus for coating a plurality of box blanks in Vone pass through the coating zone of a coating machine,

said apparatus comprising means for feeding said blanks individually and successively into said coating zone; a iirst pair of opposed rolls in said Zone, said rolls having a nip for receiving `and advancing said blanks along said zone; means on said machine for applyinga coating to atV least one roll of said first pair for coating atleast one machine for applying a coating to yat leastone roll'of said rst pair for coating at least one face of said advancing blanks; aY second pair of yopposed rolls in said zone, said rolls having anip for receiving said blanks from the nip` of said first pair of rolls; means for reversely rotating one roll of said second pair and forwardly rotating the other roll of said sec-ond pair; means for chilling the forwardly rotating roll of said second pair to grip land further ad-` vance said blanks through saidnip and further along said zone and means for'applying a coating on the said face of said reverselyV rotating roll of said second pair for completing the coating ofsaid advancing blanks.

31. Apparatus for coating a plurality lof box blanks in t one pass through the coating zone of a coating machine,

said ,apparatus comprising means for feeding Isaid blanks individually and successively into said coating zone; aV

lfor reversely rotating one roll of said second pair and forwardly rotating the other roll of said second pair; means for chilling the forwardly rotating roil of said second pair to grip and further advance said blanks through said nip andV further along Vsaid Zone;fmeans for applying a coating on the said face of said reversely rotating roll of said second pair for completing the coating of said advancing blanks, and a'thinV flexible, resilient, continuous, wiping'V blade, mounted between said coating application means face of said advancing blanks; a second pair of opposed j rolls in said zone, said rollslhaving a nip for receiving said blanks from the nip of said first pair of rolls; means for reversely rotating one roll of said second pair and for-` wardly rotating thev other roll of said second pair, means for chilling the Vforwardly rotating roll of said second pair to grip and further advance said blanks through said nip and further along said zone; a coating face lof rubber-like material onthe reversely rotating roll of said second pair and means for applying a coating on the said face of said t blank; a thin, yiiexible, Vresilient,-wiping blade of heat ab-` sorbing material mounted :between said coating applicaof said reversely rotating coating roll and the nip of saidA second pair of roils for levelling the coating thereon in advance of the nip of said rolls. i

32. Apparatus for coating a plurality of box blanks inY one pass through the coating zone of a Ycoating maohine, said apparatus comprising meanspfor feeding said blanksindividually andts'uccessively into said coating zonewa ,first pair of opposed rolls'lin said zone, said rolls having a nip for receiving and advancing said blanks .along saidf zone; means on said machine for applying a coating to at least one roll of said tirst pair for coating at least one face of .said `advancing blanks; a second pair of opposed rol-1s 4in said zone, .said rolls having a nip for receiving said blanks from the'nip of said Vtirst pair of rolls; means for reversely rotating one roll of said second pair and for-vv wardly rotating the other roll of said second pair; means` for chilling the forwardly rotating roll of said second pair to grip'and further advance saidblanks through said nip and :further along said zone; means for applying a coating on the said face of said reversely' rotatingV ro-ll of said sec-` ond Vpair for 'completing the coating of said advancing tion means of said reversely rotating coating roll and the reversely rotating roll of said second pair for completing y,

said apparatus comprising means for feeding said blanks 'V individually and successively into said coatiing zone; said means comprising at least-one Vpair of opposed rolls andV means for heating said rolls to pre-heat said blanks priorV to arrival in said coating zone; a iir'st pair ofropposedY rolls in said zone, said rolls having a nip for'receiving and advancing said Vblank-s along said zone; means on sald nip of said second pair of rolls for levelling the coatingV thereonV in advance of the nip of saidrolls Yand blade mounting means of heat insulating material supporting` said blade whereby the heat of hot coatings is'absorbed Vby said bladeV but not dissipated by said mounting.

33; VA machine for producing high Ygloss wax iinish on at paper box blanks, said machine'comprising:

roll coating means depositing a layer of hot meltl waxV i for rotating said glossing roll reversely relative to the path'ofsaid blanks;

Yrwhile advancing said blanks individually and succesa smooth, blank-glossmeans vfor maintainingsaid blank-'glossing roll at least at the melting point of said composition to .burnish .the coating engaged thereby;

and means for maintaining said forwardly rotating blank-advancing roll at a temperature Well below the melting point of said composition to harden and grip the coating engaged thereby for advancing the same through said nip against the reversing effect of said glossing roll.

34. A machine as specified in claim 33 wherein said roll-glossing means includes a scraper lblade for removing accumulations from at least one of the rolls of said means.

35. A machine Vas specified in claim 34 plus endless lconveyor means, in rear of said rollglossing means, advancing said glossed blanks individually and successively further along said path;

heating means, mounted along the path of said conveyor means, for softening, but not liquefying the glossed coatings on said blanks, and

water fall type quenching means mounted further along said -path for quickly cooling said softened coating to temper and harden said coatings Without adversely .affecting the gloss thereof.

36. A method for continuously producing a high gloss, smooth coating on at box blanks, said method comprising the steps of advancing said blanks individually and successively along a path while roll coating a thin layer of hot melt coating composition on one face thereof;

roll .coating a thin layer of -hot melt Icoating composition on the other face thereof;

and then advancing said blanks individually and successively further along said path by chilled forward roll contact with the said coated one face thereof while reverse roll glossing the coating on the said other coated face thereof.

References Cited by the Examiner UNTED STATES PATENTS RCHARD D. NEVIUS, Prz'nmry Examiner.

Claims

26. A METHOD FOR PRODUCING A HIGH GLOSS FINISH ON A PLURALITY OF FLAT PAPER BOX BLANKDS ADVANCING INDIVIDUALLY AND SUCCESSIVELY ALONG A PATH INTO THE NIP OF A PAIR OF OPPOSED ROLLS, WITH A WET, SLIPPERY HOT MELT COATING ON ONE FACE THEREOF, ONE SAID ROLL HAVING A HARD SMOOTH METAL FACE AND THE OTHER SAID ROLL HAVING A YIELDABLE RUBBER FACE, SAID METHOD COMPRISING THE STEPS OF SIMULTANEOUSLY REVERSE ROLL COATING A LAYER OF SAID HOT MELT COATING COMPOSITION ONTO THE OTHER FACE OF EACH SUCCESSIVE BLANK FROM SAID RUBBER FACED ROLL AT SAID NIP, THEREBY TENDING TO URGE SAID BLANKS REARWARDLY ON SAID PATH, WHILE CHILLING SAID HARD, SMOOTH FACED ROLL AT SAID NIP AND ROTATING SAME FORWARDLY TO HARDEN THE SAID WET, SLIPPERY HOT MELT COATING ON THE SAID ONE FACE OF EACH SUCCESSIVE BLANK AND ADVANCE THE SAID BLANK THROUGH SAID NIP.