WO2000046027A1

WO2000046027A1 - Pre-laminate machine

Info

Publication number: WO2000046027A1
Application number: PCT/US2000/002844
Authority: WO
Inventors: Marshall H. Krone; Orville R. Phillips
Original assignee: Crown Automation Corporation
Priority date: 1999-02-05
Filing date: 2000-02-05
Publication date: 2000-08-10
Also published as: AU2868600A

Abstract

Disclosed is a lamination machine. The machine, which is preferably for use in laminating PVB/PET prelaminates, includes a paired set of rollers including a flexible roller (1) and an inflexible roller (2) mounted on support frame (A). The rollers laminate together PVB and PET sheeting without introducing wrinkles or other mechanical defects which will appear as optical defects when the prelaminate is incorporated into a laminated glass product.

Description

PRE LAMINATE MACHINE

FIELD OF THE INVENTION

The present invention is a laminating machine for producing laminates containing flexible, stretchable, tacky, and temperature-sensitive polymeric layers of differing compositions. More specifically, the invention is directed to a laminating machine which allows polymeric sheets having different physical properties (stretch, temperature-resistance, etc.) to be laminated together without wrinkling, orange-peeling, creeping, or displaying any other mechanical defects or optical defects when incorporated into laminated glass products. In the preferred embodiment, the invention is specifically designed to fabricate solar control

"prelaminates" for use in laminated glass products for the automotive, architectural, and specialty glass markets. In this preferred embodiment, the invention laminates a polyethylene terephthalate (PET) sheet bearing a solar control coating on one or both surfaces thereof between two layers of polyvinylbutyral (PVB) or similar polymer (e.g. , EVA), to form a PVB/PET/PVB laminate.

BRIEF DESCRIPTION OF THE PRIOR ART

Impact-resistant glasses, such as those used in automobile windshields, large aquariums, skylights, window-clad buildings, and the like, generally consist of one or more layers of a polymeric material (an "interlayer") laminated between two or more layers of glass. The interspersed polymeric layer functions to absorb and disperse forces which impact upon the glass, thereby providing increased impact resistance to the glass. In the event the glass laminate does break from an impact, the interspersed polymer interlayer binds the shards together so that while the glass may break or otherwise fail from an extreme impact, the glass will not shatter.

As used herein, the term "prelaminate" is used specifically to designate polymeric laminates whose generally intended use is to be incorporated into a finished laminated glass product. (Of course, the actual end use of the "prelaminates" fabricated by the invention described herein has no bearing on the scope of the present invention.) Therefore, as used herein, the term "prelaminate" means a laminate comprised of at least two sheets of the same or different polymeric materials laminated together. The term "prelaminate" is used in this fashion because the glass industry customarily uses the noun "laminate" to refer to a finished glass product itself (as opposed to any other laminated product which might be incorporated in the finished glass product).

In recent years, interlay ers have come to incorporate not only shatter- resistant properties, but also solar control properties. Solar-reflecting window assemblies find use in automobile and architectural applications. In these uses, there is a dual objective to be accomplished by the glass laminate: 1) to manage heat loads within an enclosed structure by reflecting a portion of the near-infrared wavelengths of the solar spectrum which cause heating; while 2) simultaneously maintaining good visible wavelength transmissibility. These coatings are generally referred to herein as "solar control films. " In general, most solar control films consist of a series of thin metal and/ or metal oxide layers deposited upon a flexible, optically clear substrate, most commonly PET. Numerous solar control films of varying composition and construction are described in the patent literature. See, for instance, U.S. Patent Nos. 4,413,877 to Suzuki et al ; 4,462,883 to Hart; 4,488,775 to Yamamoto; 4,497,700 to Groth et al ; 4,504, 109 to Taga et al ;

4,546,050 to Amberger et al. ; 4,548,691 to Dietrich et al. ; 4,799,745 to Meyer et al ; 4,828,346 to Jacobson et al. 4,834,857 to Gillery; 4,847, 158 to Gillery; 4,891 , 113 to Criss; 4,973,511 to Farmer et al ; 5,059,295 to Finley et al ; 5,071 ,206 to Hood et al ; 5,201,926 to Szczyrbowksi et al ; 5,279,722 to Szczyrbowski et al ; 5,494,743 to Woodard et al ; 5,563,734 to Wolfe et al ;

5,579, 162 to Bjornard et al. ; 5,584,902 to Hartig et al. ; and 5,589,280 to Gibbons et al.

A significant problem encountered during the manufacture of solar control prelaminates is that the outermost PVB layers (the plastic which provides impact resistance to the final glass laminate) is far more tacky, temperature-sensitive, and prone to stretch than is the interspersed coated PET film which provides solar control. Because of its extreme temperature sensitivity, PVB sheeting must be handled and worked at reduced temperatures. Even then, PVB sheeting is prone to blocking (i.e. , sticking to itself when rolled onto a core). Consequently, prelaminates which incorporate PVB must also be handled at reduced temperatures prior to, during, and subsequent to processing to avoid blocking of the rolled product.

Further still, in order to satisfy the demands of the laminated glass industry, a machine which fabricates solar control prelaminates (or any other type of prelaminate to be incorporated into a glass laminate) must do so without any wrinkling in the prelaminate. Wrinkling in the prelaminate causes unacceptable optical defects (such as "applesauce" and "turkey tracks") in finished glass laminates containing the prelaminate.

Consequently, there has been a long-felt need in the industry for a laminating machine which will reliably and accurately encapsulate an inner polymeric film of one type of plastic within two outer polymeric films of a different type of plastic which has physical characteristics which are different from the inner polymeric film.

SUMMARY OF THE INVENTION For purposes of brevity and clarity, the description of the invention which follows refers to a machine for the manufacture of a prelaminate which is a trilayer comprising two outermost PVB layers which encapsulate a PET inner layer. This is one of the preferred embodiments of the machine. An equally preferred embodiment is a machine specifically configured for the manufacture of a prelaminate which is a bilayer laminate of PVB and PET. These types of prelaminates best illustrate the problems which the present invention overcomes due to the vastly different physical characteristics displayed by PVB sheeting and PET sheeting. However, the invention is not limited to manufacturing such prelaminates. The invention can be used to fabricate any type of flexible laminate wherein at least two flexible sheets of the same or different composition are brought into intimate contact and fused to each other by heat and pressure, with or without the presence of an intermediate adhesive layer, to yield a uniform, wrinkle-free laminated product.

In short, the preferred embodiment of the present invention is a machine which laminates an intermediate PET layer, either with or without a solar control film deposited thereon, between two outermost PVB layers, using heat and pressure, to yield a prelaminate whose intended use is in the manufacture of laminated glass products. The invention then cools and rolls the PVB/PET/PVB prelaminate and stops automatically at a preset length.

To laminate the PET between the PVB layers so that the finished prelaminate will be suitable for use in laminated glass products, it is essential that the machine heats the PVB to a suitable temperature and applies a suitable unwind resistance to the PET and PVB during lamination to minimize wrinkles, ripples, orange-peeling, creep, curls, and also to minimize the adverse effects of non-uniform thickness in the finished product. The balance between temperature and unwind resistance must be carefully controlled to limit stretch of the laminated product. This done by utilizing a novel combination of resilient rollers (urethane, rubber, or other suitable flexible material) and steel rollers to apply the proper pressure during lamination and by infrared (IR) feedback for heater control and proportional tension control and proportional, integral, derivative (PID) speed control on the unwind and rewind.

Properly cooling the finished prelaminate is also essential for shipping the PVB/PET/PVB prelaminate as a rolled product. PVB laminates are typically shipped either as a sheet or as a roll. If shipped as a roll, the rolled product must either be refrigerated constantly to prevent blocking, or the rolled PVB product must be interleaved with a release layer to prevent blocking of the PVB to itself in successive winds on the core. The present invention is capable of rolling PVB- containing prelaminates either without an interleaving layer, or with an interleaving layer, such as polyethylene, between each PVB laminate layer to prevent fusion of the layers. Once interleaved with a release layer, PVB-containing laminates can be stored and shipped without refrigeration. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a left elevation schematic illustrating the preferred embodiment of the invention and the material flow of PET, PVB, interleaving release layer, and finished prelaminate through the apparatus. Fig. 2 is a right elevation schematic of the preferred embodiment shown in

Fig. 1 , which illustrates the various motors and actuators which power the apparatus.

Fig. 3 is a left elevation of the preferred embodiment illustrated in Fig. 1, showing the cooler/heater, and the water cooling system for roller temperature control.

DETAILED DESCRIPTION OF THE INVENTION

Referring particularly to the drawings, Fig. 1 depicts a schematic of the preferred embodiment of the invention. Fig. 1 illustrates the following components of the pre-laminate machine : a flexible nip roller 1 ; an inflexible nip roller 2 ; a first cooling roller 3; a second cooling roller 4; feed rollers 5 and 6; an idler roller 7; front and rear parent PVB rollers 8 and 9 respectively; a parent PET roller 10; heaters 11; a parent PET static roller 12 disposed on a rotatable arm 12a (12 ' indicating the position of static roller during loading of the machine); parent PVB static rollers 13, 14, 15, and 16; post-cooling static rollers 17; pre-uptake static rollers 18 and 19; slitter mandrel 20; daughter prelaminate rollers 21 and 22; interleaving rollers 23 and 24; cutter 25; and light box 26, all of which are mount inside support frame A.

Fig. 2 depicts the placement of the motors and the associated drive belts which operate the rollers of the pre-laminate machine. Fig. 2 illustrates the following motors and belts: heater lift actuater 11a; feed nip roller motors 28 and

29 and associated belts 28a and 29a respectively; main drive motor 30 and associated belts 30a and 30b; daughter prelaminate roller rewind motors 31 and 32.

Fig. 3 depicts the heating system and the water cooling system of the pre- laminate machine. Illustrated in Fig. 3 is a cooler 33 and its associated outbound conduit 33a and inbound conduit 33b, and water heater/ cooler 34 and its associated outbound conduit 34a and inbound conduit 34b.

With reference to the drawings, the invention functions as follows: The PET is loaded on the parent PET roller 10 with the solar control coating, if any, preferably but not necessarily, coming off the top of the roller; that is, with the coated side of the film facing toward the left side of Fig. 1 as the PET film descends past the heaters 11. The parent PET roller 10 is held back against the pull of the flexible nip roller 1 and inflexible nip roller 2 by means of an air operated brake mounted on the shaft of roller 10 (not shown) . The tension-retarding force is preset by the operator, and diminishes as the roll gets smaller through the use of a sensor, a ratio device, or any other suitable means for measuring the roll diameter and adjusting the tension-retarding force in response thereto.

In its preferred operating mode, the apparatus of the invention utilizes two rolls of PVB, which are mounted on parent PVB rollers 8 and 9. A first roll of PVB is loaded on the front parent PVB roller 8. Generally, PVB has a rough side and a smooth side. When manufacturing certain types of prelaminates, tt is essential that the smooth side of the PVB be presented either to the PET when laminating or to the nip roller. For example, if it is critical that the smooth side of the PVB be presented to the PET, if the smooth side is in on roller 8, the roll will be loaded so that the PVB will come off the bottom of the roller. However, if the smooth side is out on roller 8, the roll will be loaded so that the PVB will come off the top of the roller. The PVB coming off roller 8 is threaded around static rollers 13 and 14; and then over the feed nip roller 5. As illustrated in Fig. 2, the feed nip roller 5 is driven by the feed nip roller motor 29. The feed nip roller motor 29 drives the feed nip roller 5 so as to unroll the PVB from roller 8 at a user selected rate in direct proportion to the line speed of the machine, and is variable within a limited range.

In exactly the same fashion, a second roll of PVB is loaded on the rear parent PVB roller 9. The PVB from roller 9 is threaded over static rollers 15 and 16; and over the feed nip roller 6. As illustrated in Fig. 2, the feed nip roller 6 is driven by the feed nip roller motor 28. The feed nip roller motor 28 drives the feed nip roller 6 so as to unroll the PVB from roller 9 at a user selected rate in direct proportion to the line speed of the machine, and is variable within a limited range. As a general proposition, although not required, the feed nip roller motors 28 and 29 are set to provide the identical surface speed to ensure that the same amount of PVB is dispensed to uniformly encapsulate both sides of the intermediate

PET layer.

As the two sheets of PVB exit the feed nip rollers 5 and 6, they are fed through a mated pair of rollers, a flexible nip roller 1 and an inflexible nip roller 2. Preferably, the flexible nip roller 1 is fabricated of a temperature-controllable metal core surrounded by a flexible polymeric sleeve, such as urethane or rubber

(urethane is most preferred). The inflexible roller 2 is preferably made of temperature-controllable steel or other suitable metal. In the preferred embodiment, the roller 2 comprises a plain steel core which is chrome plated and which is coated with a release agent to inhibit the materials being laminated from sticking to the roller. Controlling the temperature of the nip rollers can be accomplished using any means for temperature control now known or developed in the future, such as electric heaters and/or refrigeration. The preferred means for temperature control of the nip rollers is by circulating process water of desired temperature through hollow cores within the nip rollers, as described below. The combination of an inflexible steel nip roller and a flexible urethane nip roller (or a flexible roller of suitably flexible equivalent material) is critical to the operation of the invention because with this combination the invention will successfully manufacture a PVB/PET/PVB laminate which is substantially wrinkle- free. By substantially wrinkle-free, it is meant that the prelaminate formed by the invention is free of wrinkles to the extent that the prelaminate exhibits no optical defects due to wrinkling when incorporated into a laminated window product. This result is a substantial improvement from laminating machines known in the prior art.

At the same time the PVB sheeting is being fed through nip rollers 1 and 2, the PET sheet is also fed through the mated flexible nip roller 1 and inflexible nip roller 2. As shown in Fig. 1 , the heaters 11 are directly below the parent PET static roller 12 and directly above the flexible nip roller 1 and the inflexible nip roller 2. The heaters 11 do not touch either the PVB sheets or the PET sheet which pass through mated nip rollers 1 and 2, but are disposed in close proximity to the PVB sheets to allow the heaters to heat the PVB. The PET is not heated by the heaters

11. The heaters 11 can be of any conventional design, although radiant electrical heaters are preferred. Such heaters are exceedingly well known in the art and can be purchased from several suppliers, such as Ogden, Tempco, Watlow, and Heraeus. For laminating PET between two layers of PVB , the heaters generally should be capable of uniformly heating the PVB surface to a temperature of between 120°F and 250 °F and most preferably between 150°F and 200 °F.

The two layers of PVB and the layer of PET are laminated together with the PET layer in the middle as all three of the layers simultaneously pass through the flexible nip roller 1 and the inflexible nip roller 2. As illustrated by Fig. 2, the inflexible nip roller 2 is driven by the main drive motor 30. As shown in Fig. 2, the flexible nip roller 1 is not driven separately, but is rotated frictionally by contact with nip roller 2. Alternatively, the nip roller 1 and the nip roller 2 are both belt driven by the main drive motor 30. As shown in Fig 2, the main drive motor 30 turns the inflexible nip roller 2 toward the flexible nip roller 1, thus drawing the PVB and PET through the nip rollers 1 and 2 at user- selectable rate.

The centers of both the flexible nip roller 1 and the inflexible nip roller 2 are preferably thermostatically controlled within user-definable temperature ranges via means for temperature control. The preferred means for temperature control is a water circulation conduit through which is pumped heated or cooled water. Water of user-selected and regulated temperature is which is pumped through each roller which is desired to be heated or cooled. Each roller can be independently heated/ cooled to a user selected temperature, generally preferred to be less than the surface temperature of the PVB. As illustrated by Fig. 3, water to heat or cool the inflexible nip roller 2 is heated or cooled by the cooler/heater 34 and travels through conduit 34a to the nip roller 2 and then back to the water cooler/heater 34 via conduit 34b. In this fashion, the surface temperature of the inflexible nip roller 2 can be kept at a constant temperature.

In a similar approach, the center of the flexible nip roller 1 is temperature controlled via water cooler 33. Water to cool the flexible nip roller 1 is cooled by the cooler 33 and travels through conduit 33a to the nip roller 1 and then back to the water cooler 33 via conduit 33b. The flexible nip roller 1 is heated via heat transferred from nip roller 2.

The pressure exerted upon the PVB and PET as it passes through nip rollers

1 and 2 must be sufficient to fuse the three layers together uniformly. As a general proposition, the application of this pressure does not and should not significantly alter the thickness of the resultant prelaminate (such non-uniformities being detrimental to the optical performance of the prelaminate). Both the pressure and the temperature across the entire length of rollers 1 and 2 can be maintained in uniformity at a user selected temperature and pressure to ensure that the resultant product is free of wrinkles and has a uniform thickness and density.

The pressure applied by the nip rollers 1 and 2 is adjustable via mated air cylinders and actuators to accommodate the needs of different products being run through the machine. The rollers 1 and 2 can be also be separated to facilitate loading product onto the machine. As shown by the arrow in Fig. 1 , because the flexible nip roller 1 is not driven by motor 30 it is a simple matter to make the mounting for nip roller 1 adjustable so that the distance between the rollers 1 and

2 can be expanded, either manually or via electronically-controlled actuators (preferred), so that the machine may be easily loaded..

For PVB/PET/PVB prelaminates, the pressure exerted by the rollers is empirically determined and is dependent, to a greater or lesser extent, on the temperature of the two nip rollers 1 and 2 and the heat imparted to the incoming sheeting by heaters 11. The amount of pressure required will also depend to a large extent upon the thickness of the materials being bonded together. Generally, the nip rollers 1 and 2 should be adjustable to provide an applied pressure of from 15 to 30 pounds of force per lineal inch of web to the sheeting as it passes between the nip rollers. Immediately after the prelaminate exits the nip rollers 1 and 2, it is quite warm and quite easily ruined by non-uniform tension. The prelaminate must be cooled in a controlled fashion and under controlled forces to ensure that the product does not delaminate, wrinkle, stretch, or otherwise suffer any mechanical deformations. This is done by passing the warm prelaminate over a series of cooling rollers to uniformly cool the prelaminate to the desired temperature and a series of idler rollers to maintain the proper tension as the cooled prelaminate is interleaved and rolled onto a core.

After exiting the nip rollers 1 and 2, the prelaminate is threaded past idler roller 7, around the cooling rollers 3 and 4 as shown in Fig. 1, and then through post-cooling static rollers 17. The cooling rollers 3 and 4 are rotated at the same speed as nip rollers 1 and 2 via belt 30b. As shown in Fig. 3, the centers of cooling roller 3 and cooling roller 4 are maintained at a user-selected temperature, generally between 50° and 55° F by the use of cold process water. As shown in Fig. 3, the process water is generated in the water cooler 33 which pumps the cold water through suitable conduit to the cooling roller 3 and the cooling roller 4 and then back to the water cooler 33.

As shown in the figures, it is much preferred that the machine be oriented such that the workpieces to be laminated pass vertically through the nip rollers (as if being pulled by gravity) , and pass , substantially vertically , around cooling rollers

3 and 4. Only after the laminated workpiece has been cooled by rollers 3 and 4 is it preferred to have the web redirected into a horizontal position for ultimate take- up onto a daughter roller.

As illustrated in Fig. 1 , the PVB/PET/PVB laminate then passes over a light box 26. An operator of the device can stand near the light box and visually inspect the prelaminate as it passes over the light box. This allows for a quick and relatively easy gross inspection of the product prior to its being rolled onto a core and processed further.

The prelaminate is then passed through static rollers 18 and 19, as shown in Fig. 1 , and then under the slitter mandrel 20. At this point the prelaminate can be slit in the web direction to produce daughter rollers of narrower width than the parent rolls. Also, slitting can be omitted and the product simply rollered onto cores of the same length as the parent rollers and shipped in bulk. The cutter 25 is oriented as shown in Fig. 1 to cut lengthwise only through the prelaminate so that a core of shorter length than the parent PET or PVB rollers can be used. This allows rollers of finished prelaminate to be cut to order at the same time the prelaminate is being rewound onto cores.

If the desired product is to be shipped in bulk, it can either be interleaved with a release layer or rolled onto cores without a release layer. If no release layer is used, PVB-containing prelaminates must be shipped under refrigeration or the rolls will irreversibly block and be ruined. If the product is to be shipped without a release layer, the cooled prelaminate is wrapped around one of daughter prelaminate rollers 21 or 22. The provision of two daughter prelaminate rollers is to facilitate the smooth slitting operation of the machine, as described below. Also, it must be born in mind that the prelaminate product is at least twice as thick as the either of the parent PVB layers. Consequently, a shorter length of product (which is three-layer laminate) results in a full-thickness daughter roll, as compared to the thinner PVB starting materials.

The daughter prelaminate rollers 21 and 22 are driven by daughter prelaminate roller rewind motors 31 and 32 respectively, as shown in Fig. 2. These motors drive the rollers 21 and 22 in the direction shown in Fig. 1.

If the prelaminate product is to be interleaved, which allows shipment of the product without refrigeration, a roll of polyethylene with the film coming off of the top is provided on one or both of parent PE rollers 23 and/or 24. Referring now to rollers 23 and 21, the operation being identical for rollers 24 and 22, the polyethylene film is wrapped around the core of the daughter prelaminate roller 21.

Then, the prelaminate is passed from slitter mandrel 20 to the daughter prelaminate roller 21. Using this arrangement, the daughter prelaminate roller 21, driven by the daughter prelaminate roller rewind motor 31 in the direction shown in Fig. 1 , will wrap the finished prelaminate onto the daughter prelaminate roller 21, along with a layer of polyethylene between each layer of the prelaminate. In the same fashion as noted above, when the daughter prelaminate roller 21 is full, the prelaminate is cut by hand and is started on daughter prelaminate roller 22.

As a general proposition, the invention can be set to process sheeting material at a rate of about 5 to about 15 feet per minute. Improper speed can cause deformations mentioned earlier.

One critical functionality of the machine which distinguishes it from all other devices in the prior art is the use of mated urethane and steel nip rollers 1 and 2 respectively, to apply uniform heat and pressure to laminate the PVB layers to either side of a PET solar control film. The invention is not limited to the embodiments described herein, but encompasses all equivalent and obvious variants thereof.

Claims

CLAIMSWhat is claimed is:

1. A laminating machine comprising: a frame; a paired first and second nip rollers rotatably disposed within the frame so as to apply pressure to two or more sheet workpieces passed therebetween, the first nip roller having a flexible surface, the second nip roller having an inflexible surface; at least two parent sheet rollers rotatably disposed within the frame, the parent sheet rollers dimensioned and configured to bear the sheet workpieces to be laminated together and positioned to feed the sheet workpieces between the paired first and second nip rollers; means for heating at least one of the sheet workpieces disposed within the frame and positioned to heat at least one of the workpieces immediately prior to the workpieces passing between the paired first and second nip rollers; at least one temperature-regulatable cooling roller rotatably disposed within the frame and positioned to contact the sheet workpieces subsequent to the workpieces passing between the paired first and second nip rollers; and at least one prime mover operationally linked to at least the second nip roller.

2. The laminating machine according to claim 1 , further comprising means for regulating the temperature of the first and second nip rollers.

3. The laminating machine according to claim 2, wherein the first and second nip rollers are hollow and the means for regulating the temperature of the rollers is process water passed through the hollow rollers.

4. The laminating machine according to claim 1 , wherein the first nip roller comprises a flexible urethane cover.

5. The laminating machine according to claim 1 , wherein the first nip roller comprises a flexible rubber cover.

6. The laminating machine according to claim 1 , wherein the second nip roller comprises a metallic core coated with a release agent.

7. The laminating machine according to claim 1 , wherein the paired first and second nip rollers, the at least two parent sheet rollers, and the at least one temperature-regulatable cooling roller are disposed within the frame such that the workpieces to be laminated pass vertically through the nip rollers.

8. The laminating machine according to claim 1, further comprising a first feed roller and a motor therefore and a second feed roller and a motor therefore, the first feed roller dimensioned and configured to feed sheet workpiece to the first nip roller, the second feed roller dimensioned and configured to feed sheet workpiece to the second nip roller.

9. A laminating machine comprising: a frame; a paired first and second nip rollers rotatably disposed within the frame so as to apply pressure to two or more sheet workpieces passed therebetween, the first nip roller having a flexible surface, the second nip roller having an inflexible surface; at least three parent sheet rollers rotatably disposed within the frame, the parent sheet rollers dimensioned and configured to bear three sheet workpieces to be laminated together and positioned to feed the three sheet workpieces between the paired first and second nip rollers; means for heating the sheet workpieces disposed within the frame and positioned to heat two of the three workpieces immediately prior to the three workpieces passing between the paired first and second nip rollers; at least one temperature-regulatable cooling roller rotatably disposed within the frame and positioned to contact the sheet workpieces subsequent to the workpieces passing between the paired first and second nip rollers; and a first motor operationally linked to the second nip roller, a second motor operationally linked to one of the three parent sheet rollers; and a third motor operationally linked to another of the three parent sheet rollers.

10. The laminating machine according to claim 8, wherein the first nip roller comprises a flexible urethane or rubber cover; and wherein the second nip roller comprises a metallic core coated with a release agent.

11. The laminating machine according to claim 9, wherein the paired first and second nip rollers, the at least three parent sheet rollers, and the at least one temperature-regulatable cooling roller are disposed within the frame such that the workpieces to be laminated pass vertically through the nip rollers.