JPS5940086B2 - Lamination method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for laminating thermoplastic synthetic resin films or sheets, and more particularly to a method for manufacturing products by laminating and laminating highly transparent thermoplastic synthetic resin films or sheets.

Conventionally, waterproof fabrics have been made by laminating synthetic resin films or sheets of the same or different colors (colors), or by laminating synthetic resin films or sheets on one or both sides of a base fabric, and have been used as waterproof fabrics, seat covers, etc. Among these laminated films or sheets (hereinafter referred to as laminated films), laminated films for agricultural coatings are particularly suitable for use in the field of seeds, but they require sufficient light transmittance and long-term durability for plant growth. It must be strong enough to withstand use, and for this purpose, laminated films are often used, in which two transparent films are laminated and bonded together with a mesh or lattice-like coarse base fabric sandwiched between them.

Generally speaking, laminated films are produced by (a) bonding using an adhesive, bonding by thermal fusion, etc., but both of these methods require the use of metal rolls and pressure-bonded rubber rolls. The material is pressed and bonded by passing through the gap between two pressure rolls.

At this time, the surface of the film that comes into contact with the metal roll surface has a sufficiently beautiful surface condition by mirror-finishing the surface of the metal roll, but the surface of the film that comes into contact with the pressure rubber roll surface is smooth due to the transfer of the pressure rubber roll surface. It loses its beauty and inevitably becomes cloudy and opaque. As a result, the light transmittance of the laminated film decreased, making it impossible to obtain a good transparent product. In order to obtain a laminated film with good transparency, an attempt was made to press and laminate using two mirror-finished metal rolls instead of using a pressure-bonding rubber roll, but metal rolls were not as flexible as rubber rolls. Therefore, compared to the case of pressure lamination between a pressure rubber roll and a metal roll, a product with sufficient adhesive strength cannot be obtained between a metal roll and a metal roll because the pressing area is very small. However, pinholes are likely to occur, and the metal roll is scratched, resulting in a poor mirror surface, which poses a problem in terms of practicality. In view of the above-mentioned circumstances, the present invention has been made to
When manufacturing laminated film, during press lamination work,
This was completed after intensive research on a method to prevent the surface traces of the pressure-bonding rubber roll used from being transferred to the film surface and impairing the transparency of the film. When sheets are passed between a plurality of pressure rolls to be heat-sealed and laminated, heated liquid is supplied to the position where the film or sheet contacts with the pressure roll, and a bank of the liquid is formed while laminating and bonding. The goal is to do the following.

The present invention will be described in detail to make it easier to understand.

Examples of the thermoplastic synthetic resin film or sheet that can be laminated by the method of the present invention include synthetic resins having thermal adhesive properties, such as polyvinyl chloride, polyethylene, ethylene monovinyl acetate copolymer, etc. Among them, vinyl chloride resin 10
A suitable material is a film or sheet containing 20 to 80 parts by weight of a plasticizer per 0 parts by weight. It is preferable for the laminated film or sheet to be of the same type from the viewpoint of adhesiveness, but it goes without saying that synthetic resins of different types or colors may be used as long as they are fused. Although it is not necessary to use an adhesive for heat-sealing, it is perfectly acceptable to use an adhesive that does not impair the transparency of the laminated film, if necessary. The laminated film may be two films or sheets, or three or more films may be laminated as necessary.
It is also possible to use a base fabric and laminate a film or sheet on one or both sides of the base fabric.

When a base fabric is used for the laminated film, the base fabric is a relatively coarse cloth made of natural or synthetic fibers woven in a lattice or net shape with a weave interval of 5 tons or more, so-called cheesecloth. This is preferable because it does not block the passage of sunlight in some cases. In order to make the present invention easier to understand, the present invention will be explained based on the drawings.

Fig. 1 is a vertical cross-sectional front view showing an example of an apparatus suitable for carrying out the method of the present invention, Fig. 2 is a side view of a pumping roll, and Fig. 3 is a side view of a pumping roll.
The figure is a partially enlarged side view showing the state of contact between the pumping roll and the pressure-bonding rubber roll, and FIG. 4 is a plan view showing the lamination state of the pressure-bonding metal roll and the pressure-bonding rubber roll.

In Figures 1 to 4, 1 is a pressure-bonding metal roll, 2 is a pressure-bonding rubber roll, 3 is a pumping roll, 4 and 5 are thermoplastic synthetic resin films (hereinafter referred to as films), 6 is a base fabric, and 7 is a liquid , 8 is a sponge roll for absorbing, 9 is a metal roll, 10 is a bank for liquid 7, 11 is a guide roll for films 4 and 5, 12 is an adhesive tape, 13 is a gap between pressure rubber roll 2 and pumping roll 3, 14, 14' is the end of the laminated film;
Reference numerals 15 and 15' indicate stepped portions of the pressure-bonding rubber roll. To explain the case of laminating films on both sides of one base fabric using the apparatus shown in the drawings, first, a preheated base fabric 6 is laminated.
and films 4 and 5 that have been heated and softened by a heating source (not shown) such as a heating drum or an infrared heater are fed and pressed between a pressure-bonding metal roll 1 and a pressure-bonding rubber roll 2 that are rotating in opposite directions. .

The pressure-bonding metal roll 1 is pressed against the pressure-bonding rubber roll 2 by a pressing device (not shown) such as an air cylinder, and since the pressure-bonding rubber roll 2 is flexible, its surface is concave, so that the pressure-bonding rubber roll 2 and the pressure-bonding metal roll are 1 becomes larger, and the thermal fusion (thermal adhesion) between the films 4 and 5 and the base fabric 6 is reliably performed. At this time, the thickness of the fibers and the spacing between the weaves that make up the base fabric 6 are relatively arbitrary, but if the spacing between the weaves is narrow, the area where the two films are thermally bonded through the weaves becomes small. It is not preferable that the weave spacing be too narrow as it will reduce the adhesive strength, and it is preferable that the weave spacing be at least 5 or more. Note that the drawing shows an example in which there is one metal pressure roll 1 and one pressure rubber roll 2, but in addition to these, there is another set of pressure bonding rolls, ie, a pressure bonding metal roll and a pressure bonding rubber roll. It should be understood that it is also possible to provide a combination of two pressure rollers connected in the same direction, or, if necessary, to press them with two pressure rubber rolls. As described above, the laminated film is laminated by pressing the base fabric 6 and the films 4 and 5 between the metal pressure roll 1 and the pressure rubber roll 2. At this time, important points are as shown in the figure. Then, a heated liquid 7 is supplied to a position where the film 5 and the pressure bonding rubber roll 2 are in contact with each other.
What is required is that the liquid 7 be laminated while forming a bank 10.

The reason for forming the bank 10 of the liquid 7 is that by uniformly forming a thin liquid film on the surface of the pressure-bonding rubber roll 2, the surface of the pressure-bonding rubber roll 2 is given mirror smoothness by the liquid film, and at the same time, it is free from dirt caused by the liquid film. It is possible to obtain a fiber-reinforced thermoplastic synthetic resin laminated film with good transparency and excellent light transmittance, which can provide protection and cushioning properties and prevent the film from becoming cloudy due to transfer of the pressure rubber roll surface to the film surface. It's all about what you can do. To explain this with the drawings, a pumping roll 3 is pressed against and in contact with the pressing rubber roll 2 by a pressing device (not shown) such as an air cylinder, and the pumping roll 3 pumps the liquid 7 onto the surface of the pressing rubber roll 2. feed on top. Examples of the pumping roll 3 include (a) a metal or rubber roll with shallow spiral grooves, (c) a sponge roll, and (c) a back-up roll. As shown in FIG. 2, it is preferable that the surface of a rubber or metal roll is spirally wound with adhesive tape 12 having a thickness of 70 to 250 μm at uniform intervals.

The adhesive tape can be wound and removed freely, and the spacing and depth of the spiral portions can be adjusted freely, so one roll can be used for many purposes, which is preferable. When the soil roll 3 is pressed against the pressure rubber roll 2 by a pressing device such as an air cylinder (not shown), the scooping roll 3 rotates in the opposite direction to the pressure rubber roll 2 as the pressure rubber roll 2 rotates.

The pumping roll 3 is immersed in the heated liquid 7, and as the pumping roll 3 rotates, the liquid 7 is pumped up as a liquid film on the surface of the pumping roll 3. Since the pressure-sensitive adhesive tape 12 is wound spirally around the pumping roll 3 at uniform intervals, when the pumping roll 3 is pressed against the pressure-bonding rubber roll 2, the surface of the pressure-bonding rubber roll 2 and the pressure-sensitive adhesive tape 12 are separated from each other as shown in FIG. A narrow gap (slit) 13 is formed by this. Since the adhesive tape 12 is spirally wound around the pumping roll 3, the gap 13 moves continuously, and a thin liquid film can be uniformly supplied onto the pressure rubber roll 2 surface. Thickness (amount) of liquid film on two sides of pressure bonding rubber roll
The desired thickness (amount) can be achieved by appropriately selecting the width and thickness of the adhesive tape 12 wound around the scooping roll 3 and adjusting the spiral winding interval and depth. When a uniform liquid film is formed on the pressure rubber roll 2, a bank 10 is formed at the position where the film 5 and the pressure rubber roll 2 come into contact, as shown in FIGS. 1 and 4. A portion of the banter 10 enters into the recess in the rough surface of the pressure-bonding rubber roll 2, and can change the surface of the pressure-bonding rubber roll 2 into a mirror-like state. The bank 10 is discharged little by little along the surfaces of the pressure rubber roll 2 and the film 5. Therefore, if the amount of liquid supplied by the pumping roll 3 is A, and the amount of liquid discharged from the pressure rubber roll 2 and the surface of the film 5 is B, then A=B, and the bank 10 of the liquid 7 is kept stable at all times. It is important to maintain a constant amount of bank 10. If A
>B, the bank 10 gradually becomes larger, and therefore the contact area between the bank 10 and the film 5 becomes larger, and the temperature of the film 5 is lowered to a greater degree, which causes a decrease in the adhesive strength between the film 4 and the film 5. In addition, the bank 10 flows in the width direction of the compression rubber roll 2, and the bank 10 expands to the end of the film 5, and the film 5 and the film 4 are
This is inconvenient because the liquid 7 enters between the two. On the contrary, A<
If it is B, the bank 10 will disappear and the laminated film will not be a uniform transparent film, but will be a film with vertical streaks or mottled transparent parts, or a film with reduced transparency as a whole, which is not preferable. Therefore, as a means to make A=B, as shown in FIG.
Slightly smaller than 14-147) in Figure 4, 15-
15', this problem can be solved.

In other words, if 15,157 steps are provided at the end of the pressure-bonding rubber roll 2, A is not equal to B, and even if slightly more A than B is supplied and the bank 10 becomes larger and spreads laterally, , because the gap between the pressure-bonding rubber roll 2 and the pressure-bonding metal roll 1 suddenly increases at the step portions 15 and 15', 14 and 14
The bank 10 is not formed outside the gap 1, and the liquid 7 is discharged below this gap, and as a result, the bank 10 does not become large but is controlled to a constant size.
Examples of the liquid 7 in the bank 10 formed at the position where the pressure-bonding rubber roll 2 and the film 5 are in contact include water, alcohols, glycols, etc. In addition to using these alone or in combination, the viscosity (characteristic) of the liquid In order to appropriately adjust the surface tension and the like, organic or inorganic salts, surfactants, etc. may be added and used without any problem. Among the liquids 7 mentioned above, from the viewpoint of cost, flammability, post-processing work, etc.
Water is cited as the most preferred liquid. If the temperature of the liquid 7 supplied to the position where the pressure-bonding rubber roll 2 and the film 5 come into contact is below the glass transition temperature of the laminated films 4 and 5, the films will be rapidly cooled and the adhesive strength will be reduced.

Furthermore, if the temperature of the supplied liquid 7 is too high, the surface of the pressure-bonding rubber roll 2 will be overheated and the surface condition of the laminated film will deteriorate, which is also undesirable. From these points, the temperature of the liquid 7 used in carrying out the present invention should be lower than or equal to the glass transition temperature of the films to be laminated.
It is necessary to use it within a range of 120°C or lower. The laminated film is pressed between the pressure bonding metal roll 1 and the pressure bonding rubber roll 2, and the remaining liquid 7 on the laminated film is removed by a suction pump roll 8 provided next.
After absorbing it, if necessary, it is further dried and cooled by hot air drying to obtain a product.

A laminated film obtained by the conventional method of passing through a gap between a pressure-bonding metal roll and a pressure-bonding rubber roll, pressing and laminating the films has rough surfaces due to transfer of the pressure-bonding rubber roll marks on the back surface thereof.

Particularly in the case of transparent films, this rubber roll mark is transferred, which significantly impairs the transparency of the film and worsens its appearance, whereas the laminated film produced by the method of the present invention prevents the pressure rubber roll mark from being transferred and is transparent. Since a laminated film with excellent properties can be obtained, its industrial utility value is great. Examples of the present invention will be described below, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example Klenet E-5000(
Product name: 2 500d Tetoron threads for both warp and weft threads
(Cloth woven at intervals of m; manufactured by Kurashiki Boseki Co., Ltd.) was sandwiched in between and laminated.

For lamination, CLENET E5OOO was supplied between two films preheated to 153 to 155 DEG C. using a heating drum, and the films were pressed and laminated using two pressure rubber rolls. The method of the present invention was carried out by using two scooping soil rolls and supplying warm water heated to 60° C. as a liquid to the locations (two locations) where the film and the pressure-bonding rubber roll came into contact.

The light transmittance of the thus obtained laminated film and a film laminated using the conventional method, that is, without using liquid (water) for comparison, were measured and the results are shown in Table 1 below.
The results shown are obtained.

Films laminated using the conventional method (well, the impression of the pressure rubber roll was transferred, which impaired the transparency of the laminated film and gave it a poor appearance.

However, the film laminated by the method of the present invention has excellent transparency and a good appearance, and is suitable not only for use as an agricultural covering material but also for general miscellaneous goods.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing an example of an apparatus suitable for carrying out the method of the present invention, Fig. 2 is a side view of a pumping roll, and Fig. 3 is a side view of a pumping roll.
The figure is a partially enlarged side view showing the state of contact between the pumping roll and the pressure-bonding rubber roll, and FIG. 4 is a plan view showing the lamination state of the pressure-bonding metal roll and the pressure-bonding rubber roll. 1... Crimp metal roll, 2... crimping rubber roll, 3... pumping roll, 4, 5...
...Thermoplastic synthetic resin film, 6...Base fabric,
r...liquid, 8...absorption sponge roll, 9...metal roll, 10...bank, 11...guide roll, 12...
・Adhesive tape, 13...Gap, 14,141・
...End of laminated film, 15, 15'...
・Danbe.

Claims (1)

[Claims] 1. When heat-sealing and laminating a plurality of heat-softened thermoplastic synthetic resin films or sheets by passing them between a plurality of pressure rolls, heat is applied to the position where the film or sheet contacts the pressure roll. A method for laminating thermoplastic synthetic resin films or sheets, which comprises laminating a thermoplastic synthetic resin film or sheet while supplying a liquid and forming a bank of the liquid.