JPH06182796A - Method and device for continuously laminating foil material - Google Patents

Abstract

PURPOSE: To provide a method for laminating a foil material continuously which can control machine expenses considerably and process a thin multilayer film at considerably low production costs and an apparatus for the method. CONSTITUTION: An endless belt 6 circulating horizontally is used, and guiding is made through the roll gaps of a pair of hot rolls 2, 3 and a pair of cold rolls 4, 5. A material to be laminated is pre-heated by the first roll gap of a pair of the hot rolls 2, 3 and guided into the second roll gap of a pair of the hot rolls 2, 3, and the thermoplastic liquefaction of a multilayer material takes place. The material on the endless belt which has passed through the hot roll gap is conveyed immediately into the roll gap of a pair of the cold rolls 4, 5, the material which is still thermoplatically moldable by the first roll gap is set, and the final bonding of the material to be laminated by the second downstream roll gap of a pair of cold rolls 4, 5 takes place. The material can be treated by collaborating texture films on one or more surfaces.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method and apparatus for continuously laminating foil materials.

[0002]

2. Description of the Prior Art Methods of this kind are described, for example, in the German patent.
It is known for the proposal of DE 37 19 976.
This known method employs a belt press in which the upper circulating belt is guided by its lower belt side in a direction parallel to the green body to be coated. The coating film laminated by pressure and temperature on the cooperating backing plate is introduced into the space between the green body to be coated and the lower belt side. To apply a film in this manner on the green body to be coated, there is a hot zone in which the film is heat melted. This hot zone is immediately followed by a cold zone, which is said to provide some shape stabilization of the applied film.

[0003]

However, with this known method, it is not possible to coat a relatively thin body, since the stability of the shape of the body to be coated is no longer guaranteed. In this known press, the hot zone and cold zone descend to the surface to be coated with a descending foil stamping die method,
Moreover, the die also provides a hermetic seal for the introduction of one or more pressure media. The need to use a descending foil stamping die with a sealed lip around creates the drawback of exerting pressure on the green body to be coated, deforming the green body and eliminating the possibility of thin designing the green body. Since the known method lacks the proof that the downward pressure can be moderated appropriately, the strip of material coated or laminated using the known method must be relatively thick.

In fact, it is also known in this known method to use an underlay backing plate, which does not move and which in turn is associated with disadvantages. During the implementation of such a method, machines designed in this manner suffer from the drawback of being relatively expensive to manufacture due to the need for heavy-duty steel belts, inside of which a descent hot and A cold chamber is arranged, with high machine outlay. Furthermore, the known method has the disadvantage that heating is carried out only by zones, which is disadvantageous for laminating relatively thin multilayer film products.

Another drawback is that in this known method it is only possible to work with the pressure exerted by the flat surface, which is likewise found to be disadvantageous for the processing of strips of thin film.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and apparatus for continuous lamination of foil materials which, as well as improving processing accuracy, can keep machine costs fairly low and process thin multilayer films at a fairly low manufacturing cost. Is.

[0007]

The invention is based on the fact that the upper circulation belt is guided in a direction parallel to the green body to be coated and a coating film is introduced into the space between the belt and the green body to be coated, and A method for continuous lamination of film material, wherein a coating film is laminated on a green body to be coated by applying pressure and temperature, the method comprising preheating the multilayer material in a first roll gap of a hot roll pair. And first
The multilayer material is thermoplastically liquefied in the second roll gap of the hot roll pair immediately following the roll gap and the material above the belt, which is an endless belt, is rolled into the roll gap of the first cold roll pair. The step of delivering the material into the roll gap of the second cold roll pair, where the thermoplastically formable material is still set therein, and the material is finally set in the multilayer material. I have.

[0008]

The method according to the present invention is characterized as follows. In the gap between the first rolls of the hot roll gap, the multi-layer material is first preheated without the thermoplastic bonding of the individual layers thereof, and then the material of the second hot roll gap, which is arranged in close proximity to the first gap. Thermoplastic liquefaction of the strip takes place, the material still liquefied being conveyed immediately after this liquefaction by the steel belt below it to the closely following cold roll zone with the first cold roll gap, where: The material is still thermoplastically mouldable, but sticky, without any further strain at this location and the material is carried to the cold roll gap of the next cold roll pair downstream. Finally, the joining of the materials is done.

[0009]

The device according to the invention will be described in more detail with reference to FIGS. 1 and 2 depict only one embodiment within the scope of the present invention as considered herein. The device for carrying out the method shown in the figure is basically a machine frame 1 (see FIG. 2); two hot roll pairs 2 and 3; two cold roll pairs 4 and 5; a driven guide roll 7 And a driven endless belt 6 using a second guide roll 8 whose axial position is movable; strip edge control 9; braking at the lower portion (generally at a winding width of 0 to 30 Kpm (300 Nm) with a strip width of 0.5 m) The texture film 10 to be driven, the texture film 11 to be driven at the lower portion (by sending out), and the upper portion (generally 0 to 30 Kpm for a 0.5 m strip width)
Various winding and feeding parts driven and braked for the texture film 12 which is braked at (300 Nm)} and the texture film 13 which is driven at the top (at delivery); (In the zone)
It consists of a dampened overlay film 14; an insert 15; and a finished laminated product take-out 16.

The hot roll pair 2 is pressed together by the air cylinders 17 and 18 and opened in an emergency (excessive temperature). For hot roll 3 by cylinders 19 and 20, and cold rolls 4 and 5
The cylinders 21 and 22 are supplied with pressure. A suitable electronic cabinet should have the necessary power supplies, control elements,
Alternatively, it has a programmable process controller.

As a round of operation, a patterned or plain film sheet or a film bundle, the product to be laminated (laminate), is inserted into the insert 15 and on the lower texture film or endless steel. It is placed on the belt and further conveyed by the presser / take-in roll 23. Instead, the overlay film is in the form of a sheet or the overlay film portion 14
From the upper texture film section through the guide roll 24, and the upper texture film or separation film 12 from the upper texture film section is pressed onto the film packet by the pressure guide roll 25 and the first hot roll. Proceed to roll pair 2. At a typical conveying and laminating speed of 1-2 m / min, the first hot roll pair 2 performs preheating, and the second hot roll pair 3 passes the laminating packet through various texture films and conveying films to obtain the laminating temperature required. , Typically 150 ° C to 25
Heat to 0 ° C. For special products, it is also possible to carry out additional radiant heating from the hot roll to the cold roll from the top or upstream of the hot roll. Two
Two cold rolls 4 and 5 cool, press and emboss the laminate. Typical pressures for hot and cold rolls are 100-400 kg / cylinder. The finished laminate is removed in the form of sheets at the take-off 16 or in the form of "endless", separating the take-up and the place for further processing.

In another embodiment of the invention, the endless belt 6 comprises only lower texture films 10 and 11. In this case, the endless steel belt 6
Are omitted, and only the lower texture films 10 and 11 running underneath parallel to the product are used as carrier medium. In this case the stretching of the lower texture films 10 and 11 is
The surfaces of the hot and cold rolls should be as close as possible to each other so that there is no difference.

According to the present invention, it is not necessary to use an expensive large belt press having a hot zone and a cold zone inside, but instead the hot zone and the cold zone are outside the belt. In fact, there is provided a continuous laminating method and apparatus that is actually placed facing or facing the belt. This allows the belt to be used as a bearing surface for the film to be laminated carried by the belt and the hot zone and the cold zone to be located opposite the belt and outside the belt. It brings a very important advantage.

In particular, if hot rolls and cold rolls, which are appropriately designed as hot zones and cold zones, are used, the hot rolls and cold rolls need to be supplied with a specific liquid medium. It is considerably cheaper to manufacture than the hot and cold zones described in one of the cited patents, thus providing further cost savings advantages. Such a roll arrangement has the further advantage that the multilayer material to be laminated is passed between the gaps so that heating and cooling are first applied in points (to the strip), which improves the process quality. This has the advantage that heating and cooling can be applied along the length of the material at relatively short intervals without having to arrange the hot and cold zones as planes. As a result of the hot and cold zones being close and contiguous, it is even possible to alternate between hot zones and cold zones, which can lead to materials being processed in a controlled manner with a specific point as the target. The advantage is that heating can be incorporated. However, this is not possible with prior art methods. The use of such hot and cold rolls and auxiliary rolls, such as a straightening roll, smoothes the film and ensures that any air pockets that occur between the films are avoided by the rolls. There are other advantages. However, this is not always guaranteed by prior art methods.

The known method has the further disadvantage that it cannot always guarantee a uniform heat transfer over the entire surface of the material, because heat is applied zone by zone to the material to be treated. Such a flat hot zone has a perimeter that is surrounded by cold edges as compared to the warmer hot zone inside. Therefore, in the peripheral portion, the materials to be treated are joined differently from those in the central portion, resulting in uneven treatment quality. In the present invention, on the other hand, the configuration of the hot rolls creates a well-defined gap between the rolls, at which point the material is strip-shaped and uniformly heated across its width, as occurs in the prior art. The edge phenomenon is unlikely to occur in the present invention. German Patent No. DE 37 1
In the method according to No. 9 976, pressure is applied towards the layer of material to be treated inside the steel belt,
The disadvantage is that the layers of material are distorted during thermoplastic molding, that is, they lose their shape laterally, vertically or randomly, which adversely affects the dimensional accuracy (reproducibility). as a result,
In the arrangement according to German patent 37 37 996, P
It is possible to process thin film-like materials such as VC films, paper and magnetic films, strips and, in general, relatively thin material thickness composites and paper products, for example ranging from 60 μm up to about 2 mm. I can't.

Therefore, in the present method, by using a bottom cooperating belt facing the side of the hot and cold rolls where the gap between the rolls is located, there is practically no pressure on one side only. Therefore, it is possible to process a very thin film material with high reproducibility. In German Patent DE 37 197 976, pressure on one side only is caused by the assembly item moving as a die arranged in the circulation belt, a phenomenon which is avoided in the present invention. In the present invention, the actual pressure is exerted on the strip of material to be treated, but since this material passes between the uniformly heated gaps between the rolls or between the cooling gaps between the rolls, both from the top and the bottom. It is uniform. This has the advantage that a constant pressure is applied uniformly from the top to the bottom, which leads to an increase in the shape stability of the material strip to be processed.

Another feature of the preferred embodiment of the method according to the invention is that the patterning can also be carried out on the strip of material to be treated, which patterning according to the invention is very simple, The texturing occurs in an additional processing step, the texturing preferably occurring in the space between the first cold roll gap and the second cold roll gap.
It is important here that a cooperating texture belt must always be present in order to ensure sufficient guidance from the upper end of the material strip to be processed.

Here, according to the preferred embodiment of the present invention, there are several possibilities in the design of the texture belt. In a first embodiment, the texture belt is made from a high gloss paper material that gives the treated material strip a glossy surface. In another embodiment, the texture belt provides any texture such as leather, grain, rough, matte, etc., and a structure that imparts a particularly three-dimensional shape to the surface of the treated strip of material. Can have.

Attention is drawn to the two belt presses of the prior art which are known in which the bottom belt is placed face-to-face with the top steel belt and the layer of material is processed in the space between these two steel belts. There is a difference. In these two belt presses, the cooperating steel belt in the upper part is very expensive and has the notable drawback that heating and cooling can no longer be applied in the advantageous manner described above in the present invention. Such two belt presses with expensive machines are not suitable for products of thin film construction because of the high risk of damaging the circulating steel belt. If one of the steel belts is only damaged by a scratch, this scratch is imaged on the strip of material and the steel belt must be replaced in an expensive way. This is avoided according to the invention by using a coacting texture belt, preferably made of paper or other relatively cheap material.

Thus, the above-mentioned method has the notable advantage that it is possible to stack even thin material strips without problems as long as the material strips have the above-mentioned size range. They are laminated with very high form stability, for example, a cosmetic coating on eyeglasses, watch bands, credits and customer cards,
And it becomes possible for the first time to attach it to other objects which are three-dimensionally coated with these films. The coating with the film produced according to the invention occurs, for example, in a molding treatment step, in which the film produced by the method is placed, for example, in an injection mould, and then sprayed directly onto the object.

The process according to the invention thus makes it possible for the first time to act directly from the roll, a continuous layer of material being drawn from the roll and processed according to the invention. A press that operates repeatedly, for example, 30 x 50 cm
Alternatively, presses capable of processing material sizes of 50 × 70 cm have been used up to now, which was not possible before. These multi-stage presses have thin steel press plates, in packets with a material layer between them, the press plates are introduced into a heating device, where they are appropriately laminated under pressure and temperature, Due to the arrangement of the packets, the irregular pressure is applied to the individual layers of the material, which leads to the disadvantage that the irregular heat is applied. This fact causes a deterioration in the quality of the laminate. As a result, the reproducibility is also adversely affected, and the packet arrangement of the press plate needs to be heated and cooled as a whole, so that the process time is very long.

This is where the advantages of the method of the present invention become necessary. This is because this method provides a continuous process in which each point of the treated material strip passes through one and the same roll gap after the same thermal step, so that the material undergoes one and the same treatment. is there. However, this is not the case with the multi-stage press.

As an alternative to the above continuous process carried out by the action of rolls, it is also possible to process sheet products which are always processed in continuous processes, such as roll products. It is also possible to use a laminating process to create a continuous strip of material from the sheets fed to its input.

In the preferred embodiment of the invention, the bottom rolls of the hot and cold rolls are made of steel material, as no deformation of the steel belt running through the roll gap is allowed. On the other hand, all the upper rolls of the heating and cooling section are each made of an elastomer material such as a silico rubber-coated steel roll core.

In another embodiment of the invention, the removal of the texture belt has already occurred in the space between the first cold roll gap and the second cold roll gap, but the second cold roll gap Thereafter, it is possible for the upper coacting texture belt to move onto the corresponding guide roll without moving away from the process layer of material. It is therefore possible to place an independent texture roll in this zone, where the texture belt is no longer in contact with the material strip, to give the laminated material strip the necessary surface texture. The textured roll is, for example, a paper-coated roll with a textured surface, which rotates and imparts its structure (transfers the texture) on the strip of material to be treated under pressure.

It has been mentioned above that it is particularly advantageous to use rolls arranged in pairs, ie to provide two hot roll gaps and two cold roll gaps with as short a space between them as possible in the process direction. did. The spacing selected will depend on the type and thickness of material strip being processed, its rate of passage and other process parameters.

According to another embodiment of the invention, instead of choosing two hot roll gaps and two cold roll gaps, each pair being arranged opposite each other, for example, two cold roll gaps are used. It is also possible to choose three hot roll gaps for the gap or, conversely, two hot roll gaps for the three cold roll gaps. Each roll gap is defined by at least two opposite rolls.

According to another embodiment of the invention, all upper hot and cold rolls designed as rubber rolls are torque controlled in order to obtain perfect synchronization with the lower cooperating steel belts. To be done. The overall configuration is such that the main drive is obtained from a steel belt, and the upper texture belt is carried by a cooperating material strip, and a forming torque adjusting rubber roll in the upper roll configuration carries the paper belt and hence the material strip below it. It is chosen to press and carry those materials in perfect synchronization with the cooperating metal belts underneath.

To prevent warping in the zone of the material strip, a smooth roll is placed in the space between the last hot roll gap (hot roll gap) and the first cold roll gap, and the smooth roll is a steel belt. Other improvements are made below to support the steel belt across its entire width within this zone. In this way, a smoothing effect is obtained on the steel belt, which eliminates possible wrinkling of the steel belt and also flattens the texture belt running over the strip of material,
It also contributes to maintaining the shape stability of the texture belt.

The braking action of the take-up roll for the texture belt ensures synchronous control of the texture belt, since the texture belt is carried on one side by the upper rubber roll and on the other side by the strip of material. In order to be accurately controlled.

According to the invention, the 0.1 described in the literature
65 g / m ² or less in the range of 5 to 0.30 N / mm or 65 g / m ^{2 in} the range of 0.35 to 0.50 N / mm
For a specific web force of m ² or more of paper, this double or triple braking force and driving force should be used. Furthermore, the ability known in the literature to balance the vertical shift of the working point of the paper and the support strip is utilized, i.e. in order to compensate for the longitudinal stretch, a pair of downstream rolls Before that (upstream side)
Will roll a little faster than the Roll Pair.

Furthermore, it is preferred that the central roll pair, which preferably has a hard roll surface, has an adjustable roll gap so that the acceptance angle of the support of limited thickness is kept small. This is particularly important in the area of the Laminator, where the layers to be joined are present in a sufficiently plastic state.

Improvements have been made in that so-called smooth rolls having a wrap angle of less than 15 ° are provided upstream and downstream from the laminating roll and the intake and feed rolls. They are intended to reduce or prevent the possibility of so-called wrinkling.

Furthermore, all paper strip braking and driving devices are designed to be absolutely free of jerk, even at relatively slow laminating speeds of 0.5 to 3.0 m / min.
It has been empirically shown that even the slightest unevenness in the paper strip can result in unacceptable warpage or deformation in the laminate bond.

The pressure rolls are preferably pressed against their opposite rolls by means of special movable cylinders via a high constant pressure precision decompressor. In this way the required lamination quality is obtained with a uniform bond thickness.

Further, the hot roll is preferably designed to be heated to a suitable temperature so that the temperature rises at its ends. This allows the temperature difference between the center and the ends of the roll to be minimized with a heating element that is cost effective and easy to maintain.

It is also preferred that a hot fluid be used for heating the hot roll. This relatively expensive method is only used for temperature-sensitive processing.

[0038]

INDUSTRIAL APPLICABILITY The present invention can realize a continuous laminating method and apparatus for foil materials capable of processing a thin multilayer film at a considerably low production cost as well as at an improved processing accuracy. And, various advantages are simultaneously obtained by the method and apparatus of the present invention. A considerably cheaper design is obtained, for example, because the installation items required up to now for circulating steel belts can be dispensed with and the size of the steel belts according to the invention can also be considerably reduced. By locating the hot zone and the cold zone outside the steel belt, the possibility of leak tightness as seen in the prior art is no longer found and the machine as a whole is considerably cheaper to manufacture.

[Brief description of drawings]

1 is a schematic side view of an embodiment of the device of the present invention.

FIG. 2 is an end view of the embodiment of FIG.

[Explanation of symbols]

 1 Machine frame 2, 3 Hot roll pair 4, 5 Cold roll pair 6 Driven endless belt 7 Driven guide roll 8 Second guide roll whose axial position can be moved 9 Strip edge control 10 Texture film 11 braked by lower part Texture film driven by 12 Texture film 13 braked on top 13 Texture film driven by top 14 Overlay film 15 braked on top 15 Insert part 16 Completed laminated product take-out part 17,18 Air cylinder 19,20,21, 22 Cylinder 23 Presser / take-in roll 24 Guide roll 25 Pressure guide roll 26 Smooth roll

Claims (9)

[Claims] 1. An upper circulation belt is guided in a direction parallel to the green body to be coated, a coating film is introduced into the space between the belt and the green body to be coated, and the coating film is pressured. A method of continuously laminating a film material to be laminated onto the green body to be coated by applying a temperature and a temperature, the method preheating the multi-layer material in a first roll gap of a hot roll pair, The multilayer material is thermoplastically liquefied in a second roll gap of a hot roll pair immediately following the gap and the material above the belt, which is an endless belt, is transferred to the first cold roll pair. Conveying into the roll gap, where the thermoplastically formable material is still set, and conveying the material into the roll gap of a second cold roll pair, The method of continuous lamination of a film material characterized by comprising the step of finally setting the materials bonded in. 2. The method of claim 1, wherein the material is textured on its surface in the area between the first pair of cold rolls and the second pair of cold rolls. 3. A machine frame and, subsequently, through a roll gap of at least two hot roll pairs immediately arranged, and subsequently through a roll gap of at least two cold roll pairs immediately arranged. A continuous laminating apparatus for coatings on a green body, which is arranged with an upper belt side and which comprises a horizontally circulating endless belt on which the multilayer film material to be laminated is placed above the belt. 4. The apparatus according to claim 3, wherein the lower roll of the hot roll pair and the lower roll of the cold roll pair are made of a steel material. 5. The apparatus according to claim 3, wherein the hot roll pair and the upper roll of the cold roll pair are made of a steel material having an elastomer coating. 6. The apparatus of claim 3, wherein at least one texture roll treating the surface of the material is located in the space between the hot roll pair and the cold roll pair. 7. The apparatus of claim 3, wherein the endless belt is driven and the upper rolls of the hot roll pair and the cold roll pair can be driven and braked by torque control. 8. A smooth roll is disposed below the endless belt in a space between the last hot roll pair and the first cold roll pair.
The described device. 9. Device according to claim 3, characterized in that the lower endless belt is designed as a texture belt.