US3451872A

US3451872A - Method and apparatus for removing backing sheets from thin laminates

Info

Publication number: US3451872A
Application number: US512763A
Authority: US
Inventors: Edwin F Townsend
Original assignee: Easco Leasing Corp
Current assignee: Easco Leasing Corp
Priority date: 1965-12-09
Filing date: 1965-12-09
Publication date: 1969-06-24
Anticipated expiration: 1986-06-24

Description

June 24, 1969 7 I E. F. T OWNSEND 3,451,872 METHOD AND APPARATUS FOR REMOVING BACKING SHEETS FROM THIN LAMINATES Filed Dec. 9. 1965 Sheet 01'4 M ra/me.

[/w'zr fil /ward Q June 24, 1969 E. F. TOWNSEND METHOD AND APP ARATUS FOR REMOVING BACKING SHEETS FROM THIN LAMINATES Filed Dec. 9. 1965 Sheet hill 4073. ia'wrmmj 1/ 4, yy/wf4wwzm June 24, 1969 E. F. TOWNSEND 3, 1, METHOD AND APPARATUS FOR REMOVING BACKING SHEETS FROM THIN LAMINATES Filed Dec. 9. 1965 I Sheet 3' of 4 June 24,1969 ERTOWNSEND 3,451,872

"Filed Dec, 9, 1965 Sheet 4 METHOD AND APPARATUS FOR REMOVING BACKING SHEETS FROM THIN LAMINATES JWPPZV 3,451,872 METHOD AND APPARATUS FOR REMOVING BACKING SHEETS FROM THIN LAMINATES Edwin F. Townsend, Palos Hills, Ill., assignor to Easco Leasing Corporation Filed Dec. 9, 1965, Ser. No. 512,763 Int. Cl. B32b 31/18 US. Cl. 156-254 22 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to the removal of backing sheets from thin laminates having intermediate layers of adhesive, and more particularly to the removal of paper backing sheets from individual pre-cut metal foil appliques.

Adhesive-backed appliques are presently in wide general use, serving as labels, name plates and filling a variety of decorative functions. They are conventionally prepared by laminating the applique material, such as plastic or metal foil, to an adhesive-coated backing paper which is treated with a release agent so that the adhesive has greater ailinity for the applique than for the backing sheet. When the applique and backing sheet are subsequently separated, the adhesive is transferred to the applique which then maybe applied to the desired surface. An alternative process utilizes a heat or solvent activatable .ad hesive which is applied to the underside of a sheet of appliques, activated slightly, ably treated backing sheet. p

The most'eiiicient method of producing such appliques, including those of relatively heavy metal'foil and those which are embossed with lettering or a decorative pattern, is to coat a sheet of the applique material with a heat or solvent activatable adhesive, V activate the adhesive slightly, and-cover the adhesive surface with a suitably treated backing sheet. Thus the applique material, the adhesive and a backing sheet are bonded into ashee't laminate prior to stamping out the individual appliques. This technique greatly facilitates the task of applying adhesive to the applique material. Difficulties arise, however, in separating the backing paper from each individual applique as it is prepared for use. The stamping operation which cuts them from the laminated sheet commonly leaves a tightly crimped edge about the edges'due to the forces applied by the cutting edge of the stamping die. In addition, conditions of shipping and storage prior to use tend to cause the adhesive to set up or harden, making it even more difiicult to split the plies apart. The separation of backing sheets must be done with care because some appliques are thin and easily buckled or damaged, and the separation must be accomplished without scraping or gouging the thin layer of adhesive from the underside of the applique.

In order to separate the backing sheet from an individual applique, it is necessary to initiate the separation at some point. The backing sheet may then be grasped and peeled back, exposing the adhesive surface. The difiiculty with this procedure is that the initial splitting and then covered with a suit- 3,451,872 Patented June 24, 1969 must be accomplished without damaging the applique or its adhesive coating, and without tearing the backing sheet. When backing sheets are removed by automatic machinery, there exists the additional problem that they may become folded back over themselves rather than being lifted away from the adhesive surface. When this occurs, it is necessary to reintroduce a fresh edge of the applique into the machine, or to unfold and peel off the backing sheet by hand. Another problem lies in stripping the backing sheets from embossed, bowed, or perforated appliques by automatic machinery. Where splitting is initiated by a relatively narrow blade, the penetration required may tend to tear or damage the backing sheet before it can be pulled away, especially in the case of appliques which have been embossed with a raised design, or perforated to provide shaft openings in a control panel, for example.

It is therefore a principal object of this invention to provide a method and apparatus for automatically separating the backing sheets from individual pre-cut adhesive-backed laminates. A related object is to provide such a method and apparatus which will accomplish such removal without folding back or tearing the backing sheet, and without damaging the applique or its adhesive coating.

Another object is to provide such a method and apparatus which is capable of automatically removing the backing sheets from embossed or perforated adhesivebacked laminated appliques without bending, tearing or flattening of the applique.

Still another object is to provide a method and apparatus of the above description which is capable of receiving a stack of individual unstripped appliques, and which automatically initiates the removal of the backing sheet from each applique by advancing the entire stack into engagement with a stripping blade.

A further object is to provide an improved method and apparatus of the type described which will accommodate shifts in the alignment of the laminate relative to the apparatus as the backing sheet is being removed. A related object is to provide such a method and apparatus which is capable of applying solvent to appliques coated with solvent-activatable adhesive.

Other objects and advantages will be apparent upon reading the following description and appended claims and upon reference to the drawings, in which:

FIG. 1 is a perspective of the splitting machine of the present invention;

FIG. 2 is a perspective of an adhesive-backed applique as used 'with the present invention, with a portion of its backing sheet pulled away; g

FIG. 3 is a plan view of the machine of FIGURE 1, with a portion broken away to expose the inner mechanism and the laminate feeding mechanism shown in the rear-most position;

FIG. 4 is a detail of an applique as: splitting is initiated by the machine;

FIG. 5 is a partial plan view of the splitting machine with the laminate feeding mechanism shown in the forward-most position;

FIG. 6 is a section taken along the planejG-fi in FIG. 3;

FIG. 7 is a section taken along the plane 7-7 in FIG. 5;

q FIG. 8 is a diagrammatic section of the splitting maa preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment, but intend to cover all alternatives and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings, there is shown in FIG- URE 1 a splitting machine constructed according to the present invention. In use, the operator simply loads a stack of individual unstripped appliques into the machine, and presses the actuator switch 11 whenever a stripped applique is needed. On actuation of the switch 11, the machine automatically advances the stack 10 into a stripping blade 12, whereby the stripping process is initiated. The backing sheet 13 is then removed from the applique 15 by the machine to expose the adhesive surface 16. At this point the machine activates the adhesive 16 with solvent, if desired, and delivers the applique to a wire rack 18 ready for use.

The machine is constructed with a smooth, fiat table 20, which serves as a reference surface against which the stack of 10 of un-stripped laminates is positioned. The laminates are received and carried within an adjustable crib 21 which is translatable across the table and has a pneumatic hold-down cylinder 22 which serves to press the laminate stack 10 against the table 20 when actuated. Mounted at the end of the table 20 and within the swing of the crib 21 is the splitting blade 12, the upper surface of which slightly overlies the plane of the table 20 by an amount approximately equal to the thickness of the backing sheet to be removed. The blade height may be adjusted by means of shims 23. A pneumatic actuating cylinder 25 is provided to swing the crib 21 and the laminate stack 10 into engagement with the splitting blade 12.

In operation, the advancing edge of the laminate stack 10 is held firmly against the table 20 by the hold-down cylinder 22 as the crib 21 is swung forward by the actuating cylinder 25. As the laminate stack 10 passes over the splitting blade 12, the backing sheet 13 of the bottom laminate 14 is split away from the applique 15, exposing the adhesive coating 16. As the backing sheet 13 is split away, it enters the slot formed between the table 20 and the splitting blade 12, and is guided by the curved lower edge 27 of the blade into the nip of a pair of powered

pinion rollers

30, 31. These rollers engage the backing sheet 13 and pull it in a downward direction. As the

rollers

30, 31 begin to exert their pull, the hold-down force of the cylinder 22 is automatically released, allowing the bottom laminate 14 of the stack 10 to be drawn forward by the pull of the pinion rollers. The applique 15 is thereby carried forward over the splitting blade 12 as its backing sheet 13 is pulled away.

As is best shown in FIG. 10, the stripping machine is started by closing a motor switch 32, which energizes a motor 33 and commences the rotation of the

pinion rollers

30, 31 and also powers two sets of

solvent applicator rollers

35, 36, 37, 38 through a gear train 39. Triggering of the operating sequence which will deliver a stripped applique ready for use to the rack 18 is accomplished by operating the actuator switch 11. This energizes a relay 40, causing two circuits to be completed. The first is a latching circuit, completed by contacts 41 within the relay 40, and serves to keep the relay energized throughout the operat ing cycle of the machine even though the actuator switch 11 may be released. The second circuit, the solenoid valve circuit, is actuated by the contacts 42 which cause a solenoid valve 43 to be actuated and thereby permit air pressure to reach the actuating cylinder 25 and hold-down cylinder 22. Air pressure for operation is obtained from a supply 45 and is reduced to operating levels by a pressure regulator 46.

'The hold-down cylinder 22 receives the full regulated pressure instantly through a supply line 47, but a flow regulator 48 is placed in the actuating cylinder supply line 50 to effect a controlled rate of movement of the crib 21. When the crib 21 and laminate stack 10 have advanced to a point where the backing sheet 13 of the bottommost laminate 14 has been engaged by the

pinion rollers

30, 31, the cage movement will trip a limit switch 51, which causes the relay 40 to drop out and return the solenoid valve 43 to its normal position, in which the air pressure in the

cylinders

22, 25 is released. The flow from the hold-down cylinder 22, being unregulated, will cause instant release of the hold-down pressure on the stack 10. The pressure in the actuating cylinder 25 is released slowly, being controlled by the flow regulator 48, allowing the crib 21 to return to its starting position under the force of a return spring 52 contained within the actuating cylinder 25. The laminate 14 has been mean while stripped of its backing sheet 13 as has previously been described, and the applique is carried forward by the solvent applicator rollers 35, 36, 38 to the rack 18. This concludes the operating sequence, which may then be initiated once again by the operator by closing the actuator switch 11.

It is a feature of the invention that a stack 10 of laminates is carried across the table 20 under hold-downpres sure until the backing sheet 13 of the bottom-most laminate 14 has been split away and has been engaged by the

pinion rollers

30, 31, at which time the hold-down force is relieved and the laminate 14 is released from the bottom of the stack 10. To accomplish this function, air pressure in the hold-down cylinder 22 is controlled by a limit switch 51 which is tripped by the crib 21 at the end of its forward motion into the blade 12. The switch position is adjusted so that the limit switch 51 is tripped just at the point when the backing sheet 13 of the bottom-most laminate 14 has been stripped sufficiently far to engage and be gripped by the

pinion rollers

30, 31. At this point, the limit switch 51 is tripped and causes the relay 40 to drop out, allowing the solenoid valve 43 to return to its normal position in which the air pressure in the hold-down and

actuating cylinders

22, 25 is released. The hold-down force on the stack 10 is thereby removed, and the bottommost laminate 14 is free to be pulled past the stripping blade 12 by the

pinion rollers

30, 31 and by the

applicator rollers

35, 36, 37, 38.

Another feature of the invention lies in the manner in which the hold-down cylinder 22 exerts pressure on the laminate stack 10. As best shown in FIG. 7, the forward portion of the crib 21 carries the hold-down cylinder 22 and a pair of feed gate fingers 53. The latter are vertically adjustable by means of clamping screws 55 so that the gap remaining between the base of the stack 10 and the table 20 is just suflicient for a single laminate to slip through. Hold-down pressure is supplied only at the forward, or advancing edge portion of the stack 10. For this purpose, the plunger 56 of the hold-down cylinder 22 is fitted with a shoe 57 having a narrow ridge 58 which contacts the stack 10 along its advancing edge where it abuts the feed gate fingers 53. The stack is further supported by a rear gate 60, rear ledge 61, and side supports 62 which locate the stack 10 and serve to carry it into engagement with the splitting blade 12. These elements are made adjustable by means of setscrews 63 to accommodate laminate stacks of varying sizes and shapes. In accordance with the invention, the hold-down pressure is thereby concentrated at the advancing edge of the laminates where splitting is initiated, and the balance of the stack area is relieved of pressure which might bend, crush, or warp the laminates. In addition, arched laminates, laminates which are heavily embossed and tend to interlock, and other types of applique laminates which will not naturally lie completely flat or slip freely from a tight stack may be accommodated in the splitting mechanism with no loss of efiectiveness. Since only the advancing edge where splitting is initiated is under significant holddown pressure, the balance of the stack 10 is free from excessive compressive forces.

As a further feature of the invention, the stack 10 is advanced into engagement with the splitting blade 12 in a manner such that the entry angle of the laminates r into the blade is most favorable for initiation of the splitting process. In the illustrated embodiment, this is accomplished by making the crib 21 swingable across the table 20 about a pivot 66 which is cantilevered out from the side of the machine. It will be noted that the pivot 66 is located somewhat forward of the leading edge of the splitting blade 12, and that the laminate stack is there.- by caused to engage the blade 12 at an angle as the crib 21 swings forward. This causes the laminate to move into the blade with a slight rotating or slicing movement as well as a predominantly head-on movement to more efficiently begin separation of the backing sheet 13. It has been found in practice that best results are obtained when the nearest edge of the bottom-most laminate 14 is ad,- vanced into the blade 12 at an angle, as shown in FIG, 4. Entry at'an angle is favored because it allows bowed, arched, embossed or perforated appliques to be fed into the blade 12 without tearing or punching through the backing sheet as is often the case when a narrow pointed or chisel-edged blade is used to initiate stripping. To fulfill the requirement of entry at an angle, the crib 21 is adjusted so that a corner of the laminate constitutes the advancing edge portion which makes initial contact with the blade 12. It will be appreciated that the corner .need not be square, but may comprise any protruding rounded edge of the laminate. i 1

Further in accordance with the invention, the sharpened edge of the blade 12 extends straight across the table 20, and has a smoothly ground lower surface 27 which curves do'wna nd away from the sharpened edge. to guide the backing sheet 13 into the

pinion rollers

30, 31. This configuratiori allows the backing sheet 13 to assume a uniform curvature across its entire width, and avoids], the problems of bunching and tearing which result when a narrow pointed or chisel-edged blade is employed which forces the backing sheet to acquire a'degree of compound 1 curvature as it passes. In addition, the backing sheet .13 is relatively strong when in a smoothly curved condition, and the wide, uniform engagement afforded by the

pinion rollers

30, 31 allows a firm pull to. be exerted on the laminate 14 as it is drawn across the bladev 12 without encountering 'difliculties' of crushing or tearing of the backing sheet. p

As an additional feature of the illustrated construction, the crib21 is constructed so that. removal of the actuator completely: around to'the rear of the machine and away from the table 20. Should a laminate at the bottom of the stack '10 become jammed for any reason, it may; thereby be conveniently removed by the operator without disrupting the operation ofthemachine. by necessitating removal of the entire, stack of laminates fromthe crib 21. Also, .since heavy embossed foil laminates are relatively, expensive parts, this feature allows. a laminate which would otherwise be lost' to be saved and in many cases re-used. .When the'jam has been cleared by the operator, the crib 21 is simply swung. backinto operating position abovethe table 20 and the actuator cylinder connecting pin 67' is reinserted, The machine is then ready for the nextoperating .Icycle.

Once the splitting has been initiated by entry of one corner of the laminate-into the splitting blade 12, the crib 21 and the stack 10 of laminates contained therein is swung forward by the actuating cylinder 25 until thecrib 21 is aligned Withthe table 20 and the roller train, includ ing the

pinion rollers

30, 31 and the solvent applicator rollers 35, 36, 37,138. At this point, thecrib 21 contacts the limit switch 51 which effects the releaseof the holddown pressure and allows the bottom-most laminate 41 to slip out from beneath the stack'10 and to be drawn across the blade 12. One corner of, the stripped backing sheet first enters the nip of the

pinion rollers

30, 31, and as the crib 21 is swung into its-final position, the backing sheet is drawn into the rollers across its wholewidth. At

jcylinder connecting pin'67 allows the crib to beswung the instant the limit switch 51 is tripped to release the holddownpressure, the pinion rollers 3(1), 31' are in complete engagement with the advancing edge of the backing sheet and will continue to draw it past the splitting blade 12. FIG. 7 illustrates the condition of the various parts of the machine immediately after the crib 21 has reached the limit of its travel, with the bottom-most laminate 14 beginning to emerge from beneath the feed gate fingers 53.

In accordance with another aspect of the invention, the

pinion rollers

30, 31 which engage the emerging corner of the backing sheet 13 are allowed to slip slightly as the stack 10 and bottom laminate 14 are carried into final alignment with the roller train prior to the release of the hold-down pressure. One pinion roller 30 is driven by the, gear train 39 from the motor 33, and is mounted within the machine on fixed journals. To allow acontrolled degree of slippage, the second roller 31 is swingably mounted on pivot levers 68 at each end, with a spring 70 to provide biasing force to draw the rollers into mesh. When no backing sheet is passing through, the

rollers

30, 31 mesh as gears, with full tooth engagement. When a backing sheet enters the nip of the rollers, the movable roller 31 is forced slightly away from the fixed roller 30, but the pressure from the springs 70 maintains a degree of engagement sufficient to exert a steady pull on the backing sheet, but not so much as would tear or otherwise damage it. When the hold-down pressure is re,- leased and the bottom laminate 14- is free to move forward, the backing sheet is then pulled downward by the

rollers

30, 31, the laminate slips forward over the splitting blade 12, and the backing sheet is completely removed. The sheet passes through the

rollers

30, 31 and falls downward into any convenient receptacle for disposal. It has been observed that backing sheets which have passed through the machine in this manner have a corrugated etfect caused by the engagement of the

pinion rollers

30, 31. Further in accordance with the invention, the operation of the

pinion rollers

30, 31 in pulling the backing sheet away from the laminate is coordinated with means for applying solvent to the exposed adhesive 16 on the back of the applique 15. The primary pull-through of the laminate is achieved by theaction of the

pinion rollers

30, 31 as has been previously described, and this force serves to draw the laminate across the blade 12 until the backing sheet 13 is completely removed. In the illustrated embodiment, however, the emerging edge of the stripped applique 15 enters the nip of the first two pairs of solvent applying rollers 35, 36,-37, 38 which also serve to draw the applique past the-blade 12. The lower rollers 36, 38 operate in a, bath of ,solvent when appliques having a solvent-activatable adhesive are being prepared. The solvent level is 'rnaintain'edbya simplebottle-feed system in which a reservoir 71 feeds-the solvent tray'72 by an inlet line 73 and anair return line 75. The solvent level in thejtray 72 fills by gravity so long as the return line 75 is above the solvent level so that air may pass back to the reservoir 71. When the level rises above this point the return line 75 is blocked, and no more'solvent'will flow. The level is thereby continuously maintained as the solvent is used. A cover 76 is provided. to retard evaporation from the tray 72.

The upper rollers 35, 37 are geared to the lower rollers 36, 38 and are contained in slotted journals 77 which allow for variations in roller center distance when the machine isinoperation. Alternative journal slots 78 are provided to allow flexibility of. operation with different types of appliques and varied operating conditions. Roller pressure is obtained by constructing the upper rollers 35, 37 from solid bar stock, so that their weight supplies the desired degree of compression between each pair of rollers. It may be seen that the rotation of the lower solvent rollers 36, 38 in the bath solvent serves to evenly apply a controlled amount of solvent to the adhesive coating 16 on the back of the applique 15. While some solvent will be carried over to the upper rollers 35, 37 as the rollers idle when no applique is present, the introduction of an applique between the rollers will cause all of the transferred solvent to be applied to the adhesive surface. Alternatively, the upper rollers 35, 37 may be constructed with a number of raised peripheral ridges so that contact with the lower rollers 36, 38 is over a very small area and the solvent carried to the upper rollers 35, 37 will be reduced by a corresponding amount. Further to control the rate of solvent application, adjustable doctor blades 80 are provided for each lower roller 36, 38 which serve to strip off excess solvent as the roller surface emerges from the solvent bath. The doctor blades 80 are adjusted by a simple screw means 81.

In the preferred embodiment, the peripheral speed of the

solvent rollers

35, 36, 37, 38 is essentially the same as that of the

pinion rollers

30, 31, As has been described, when the backing sheet has been pulled from the applique by the

pinion rollers

30, 31 and the applique has been engaged by the first pair of solvent applicator rollers 35, 36 it is given a thin coating of solvent 'on its underside and carried into the second pair of

solvent applicator rollers

37, 38 where an additional coating of solvent is applied to ensure uniform coating. The applique continues forward from the second pair of rollers 37 38 onto a rack 18 which is preferably constructed of thin wires so that a minimum amount of contact is made with the activated adhesive on the back of the applique 15. The applique then rests on the rack 18 from which it may be picked up by the operator and applied to the desired surface.

I claim as my invention:

1. A stripping machine for removing backing sheets adhering to individual laminates comprising, in combination, a reference surface, a stripping blade overlying said reference surface by a distance approximating the thickness of the backing sheets to be stripped, releasable transport means for advancing one edge portion of an unstripped laminate across said reference surface into engagement with said stripping blade while holding said advancing edge portion against the reference surface, pullthrough means for gripping the advancing edge portion of the stripped backing sheet and pulling it past said stripping blade as the edge is split from the laminate by the stripping blade, thereby drawing the laminate past the blade and removing the backing sheet, and means for actuating said transport means to release said laminate when said pull-through means has begun to draw the backing sheet past said stripping blade.

2. The stripping machine of claim 1 in which the advancing edge portion comprises a corner of the laminate.

3. The stripping machine of claim 1 in which said stripping blade has a straight sharpened leading edge and a surface which curves uniformly back from said sharpened edge and away from the plane of said reference surface toward said pull-through means.

4. The stripping machine of claim 1 in which said pull-through means comprises powered rollers in cooperating relationship, said rollers being located adjacent said stripping blade whereby the advancing edge portion of the stripped backing sheet as it emerges from the stripping blade is seized in the nip of said rollers, and means for spacing said rollers in slippable frictional engagement with the emerging backing sheet, whereby changes in alignment of the laminate and stripped back ing sheet relative to said reference surface may be accommodated as the laminate and backing sheet are pulled past said stripping blade.

5. The stripping machine of claim 1 having a second pull-through means for drawing the stripped portion of the laminate past said stripping blade.

6. A stripping machine for removing backing sheets adhering to individual laminates comprising, in combination, a reference surface, a stripping blade overlying said reference surface by a distance approximating the thickness of the backing sheets to be stripped, stack advancing means for advancing a stack of unstripped laminates across said reference surface and bringing the bottom laminate of said stack into engagement with said stripping blade, said stack advancing means also releasably holding the advancing edge portion of said stack against said reference surface, pull-through means for gripping the advancing edge portion of said bottom laminate and pulling it past said stripping blade, thereby removing the backing sheet, and means for actuating said stack advancing means to release said bottom laminate when said pull-through means has gripped the bottom laminate and begun to draw it past said stripping blade.

7. The stripping machine of claim 6 in which said stripping blade has a straight sharpened leading edge and a surface which curves uniformly back from said sharpened leading edge and a surface which curves uniformly back from said sharpened edge and away from the plane of said reference surface toward said pullthrough means. 1

8. The stripping machine of claim 6 in which the advancing edge portion comprises a corner of the stack of laminates.

9. The stripping machine of claim 6 in which said stack advancing means comprises a stack-enclosing crib which is transportable across said reference surface, and means for holding the advancing edge portion of said stack against said reference surface.

10. The stripping machine of claim 6 in which said pull-through means comprises powered rollers in cooperating relationship, said rollers being located adjacent said stripping blade whereby the advancing edge portion of the stripped backing sheet as it emerges from said stripping blade is seized in the nip of said rollers, and means for spacing said rollers in slippable frictional engagement with the emerging backing sheet whereby changes in alignment of the laminate and stripped backing sheet relative to said reference surface may be accommodated as the laminate and backing sheet are pulled past said strip-ping blade.

'11. The stripping machine of claim 10 having a second pull-through means for drawing the stripped portion of the laminate past said stripping blade.

12. The method of removing backing sheets adhering to individual laminates comprising the steps of moving an unstripped laminate across a reference surface into engagement with a stripping blade overlying said reference surface by a distance approximating the thickness of the backing sheet to be stripped, holding the advancing edge portion of said laminate against said reference surface during the initial engagement with said stripping blade, drawing said advancing edge portion of the stripped backing sheet past said stripping blade as the edge is split from the laminate, thereby drawing the stripped laminate past the blade and removing the backing sheet, and releasing the holding force on the laminate when the backing sheet, and releasing the holding force on the laminate when the advancing edge portion of the stripped backing sheet has begun to be drawn past said stripping blade.

13. The method of removing backing sheets of claim 12 in which said stripping blade has a straight sharpened leading edge and a surface which curves uniformly back from said sharpened edge and away from the plane of said reference surface.

14. The method of removing backing sheets of claim 12 in which the advancing edge portion comprises a corner of the laminate.

15. The method of removing backing sheets of claim 12 in which the backing sheet and laminate are allowed to change in alignment relative to said reference surface as they are drawn past said stripping blade. I

16. The method of removing backing sheets of claim 12 in which said stripped laminate is drawn away from 9 said stripping blade as the backing sheet is being drawn past said blade.

17. The method of removing backing sheets adhering to individual interlocking embossed laminates comprising the steps of moving a stack of laminates across a reference surface and into engagement with a stripping blade overlying said reference surface by a distance approximating the thickness of the backing sheet of the bottom laminate in said stack, holding the advancing edge portion of said stack against said reference surface as said bottom laminate engages said stripping blade, drawing said bottom laminate across said blade to thereby remove the backing sheet, and releasing said holding force when said bottom laminate has begun to be drawn past said stripping blade.

18. The method of removing backing sheets of claim :17 in which said stripping blade has a straight sharpened leading edge and a surface which curves uniformly back from said sharpened edge and away from the plane of said reference surface.

19. The method of removing backing sheets of claim 17 in which the advancing edge portion of said stack comprises a corner of the stack of laminates.

20. The method of removing backing sheets of claim '17 in which the backing sheet and laminate are allowed to change in alignment relative to said reference surface as they are drawn past said stripping blade.

UNITED STATES PATENTS 1,739,322 12/1929 Moore 156-254 XR 2,484,619 10/ 1949 George 156-254 XR 3,107,193 10/1963 De Neui et al. 156-584 XR 3,111,872 111/1963 Tiippler 156-254 XR 3,357,699 12/1967 Attwood 156-344 XR EARL M. BERGERT, Primary Examiner. M. E. McCAMISH, Assistant Examiner.

US. Cl. X.R. 156-344, 353, 510, 584