JPS5942135Y2 - Intermittent adhesive applicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for intermittently applying an adhesive, and more particularly to an apparatus for intermittently applying an aqueous adhesive to the surface of a water-absorbing material such as a foamed polyurethane sheet.

There are various methods for applying adhesives, such as roller coating, spray coating, plush, and tube extrusion.
When applying an adhesive to the surface of a material such as a polyurethane sheet, it has conventionally been common to apply it directly using a coating roll.

However, when applying an adhesive to the surface of a web material such as a polyurethane sheet using a conventional coating device, the polyurethane layer is strongly compressed, resulting in a large amount of adhesive being absorbed into the water-absorbing polyurethane side. 1. It was very disadvantageous in terms of cost.

In order to avoid these drawbacks, an attempt was made to apply the adhesive once without compressing the web, but the adhesive did not blend well with the uneven shape of the polyurethane surface, making it impossible to form a coating film.

In addition, attempts have been made to limit the coating range in the width direction by bringing a doctor blade or the like into contact with the conventional coating roll, but since it was not possible to limit the coating range in the machine direction, it was not possible to limit the coating range in the machine direction. Adhesive is easily applied, which significantly impairs the aesthetic appearance, and requires post-treatment of excess applied adhesive, which poses problems in terms of cost and work efficiency.

Furthermore, in order to obtain even stronger adhesion, a thin and uniform coating film is required, but with some water-based adhesives, if the film thickness is controlled to be thin, the distance between the rolls is very narrow, causing friction in the adhesive. It also had the disadvantage of hardening and causing streaks and cracks in the paint film.

The present invention solves the problems of the conventional technology by using an intermittent application method that can form a smooth and uniform adhesive film on the required areas of an elastic water-absorbing web surface such as a polyurethane sheet. It provides equipment.

The present invention consists of a coating roll having blades in contact with both ends to regulate the adhesive application range in the width direction of the web, a backup roll for bringing a transfer belt into contact with the coating roll, and the backup roll. This is an intermittent application device for adhesive, which comprises means for bringing the adhesive close to and away from the coating roll at arbitrary time intervals, and means for transferring the adhesive applied on the transfer belt to the web.

In the present invention, the endless belt is preferably made of a material that can quickly transfer the adhesive to the polyurethane material, such as a silicone-coated belt.

According to the so-called transfer method of the present invention, compression of the web is reduced and absorption of adhesive into the web is suppressed, so the amount of adhesive applied is significantly reduced. The application range in the width direction and machine direction, that is, the vertical and horizontal directions, can be limited by the coating rolls provided on both sides and the movable backup roll, so the required amount of adhesive is only 1 JIJI.
It increases the yield of adhesive and enables significant cost reductions.

In addition, since the web is heated and dried from the underside of the belt using a heater while applying a small amount of pressure to the adhesive surface applied to the belt, the smoothness of the adhesive surface is ensured and there are no streaks or cracks. , it is possible to obtain a uniform and thin coating film.

If the adhesive is a sticky type, heating with a heater may be performed before superimposing it on the web.

The present invention will be explained in more detail below with reference to the drawings.

FIG. 1 schematically shows the configuration of the present invention, and elements such as a pedestal and a drive unit are omitted.

Adhesive a is stored in tank 1.

The roll 2 rotates in one direction with its lower half immersed in the tank 1, and the adhesive a in the tank 1 is
It is lifted by 20 rotations of the roll, and the surface of the roll 20 is constantly wetted.

On the surface of the coating roll 4 that rotates in the same direction while contacting this roll 2, the adhesive a transferred from the roll 2 is adhered in a more uniform state than on the surface of the roll 20, but on both sides of this roll 40. The excess adhesive is scraped off by two blades (baffle plates) provided on the holder, thereby regulating the adhesive application range in the width direction to a desired width.

FIG. 3 shows a perspective view of the blade contact portion.

Next, the belt 5 is attached in an endless form as shown in FIG. 1 and is coated with silicone, and the backup roll 6 is attached to the coating roll 4.
The adhesive a applied to the coating roll 4, the coating roll 4, and the backup roll 6 are installed with a certain clearance between them.
It is transferred to the surface of the belt 5 at the part where it comes into contact with the belt.

This backup roll 6 is movable and electrically controlled, and is controlled by an external signal such as a timer or a photocell to further increase the clearance by a certain amount (approximately 10 mm) from the normal clearance.
) The system is such that it separates from the coating roll 4.

As a movable mechanism for this backup roll 6, it is desirable to use an air cylinder or the like so that it can be separated instantly.

By separating the backup roll 6 in this way, the adhesive a on the coating roll 4 that had been transferred to the surface of the belt 5 is interrupted, and as a result, the application range in the flow direction of the belt 5 is restricted. become.

On the other hand, a polyurethane material (hereinafter referred to as urethane material) b as a web is previously set on the table 7 at specified positions in both the width direction and the flow direction using a guide 8 or the like.

At this time, the end of the urethane material is held and peeled by the nip roll 9, and as the belt 5 with the adhesive transferred moves in the flow direction, the detector 10 detects the end of the adhesive application area. is designed to issue a drive command to the nip roll 9.

The urethane material is pulled out by a drive command and the belt 5 and the pressure roll 11 are brought into contact with each other at the position of the belt 5 and the pressure roll 11. objectives are achieved.

Pressure roll 11 (/'i) used at this time, there is almost no penetration of the adhesive into the urethane material side.

In this way, the urethane material and adhesive transported to the top of the heater 12 stop at the top of the heater 12 as shown in FIG. 2, and are heated from the bottom surface of the belt 5. In order to heat the adhesive a through the belt 5, a panel heater or an aluminum casting heater, which is a conduction type heater, is preferable.

At this time, water in the water-based adhesive evaporates at a temperature of 100' or more, but the presence of the urethane material prevents the water from bubbling, making it possible to form a uniform film.

Furthermore, since the heating temperature can be raised by about 130℃,
Adhesive drying time can be greatly reduced.

Next, the belt 5 moves further, and at the guide roll 13, the belt 5 has a small radius (10R to 2
0R), the urethane material on the belt naturally separates from the belt, and the adhesive a is transferred from the belt to the surface of the urethane material.

At this time, a silicone coating belt is used so that the adhesive is quickly transferred to the urethane material, that is, to make the bonding force between the adhesive and the belt smaller than the bonding force between the adhesive and the urethane material. Good.

By the above-described operations according to the present invention, it is possible to form an adhesive film smoothly on the surface of a water-absorbing material such as a urethane material, and only in the necessary areas.

Furthermore, according to the device of the present invention, not only the scale of the equipment can be reduced, but also the drying time of the adhesive can be significantly shortened.

Some of the test results are shown in the table below. Similarly, prevention of moisture evaporation in the water-based adhesive and prevention of solidification due to friction can be achieved by setting each roll clearance larger than the required coating film and constantly returning the liquid, as shown in FIG.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the configuration of the present invention, Fig. 2 is a coating state diagram using the inventive device, Fig. 3 is a perspective view of the blade contact portion, and Fig. 4 is a side view of the coating roll portion. represents a diagram. In the figure, a...adhesive, b...polyurethane material, 1...tank, 2...roll, 3...blade, 4...Coating roll, 5...Belt, 6...Backup roll, 7...Table, 8...
...Guide, 9...Nip roll 10...
...Detector, 11...Pressure roll 12.
... Heater 13 ... Guide roll.

Claims (1)

[Scope of utility model registration request] A coating roll with blades in contact with both ends to regulate the adhesive application range in the width direction of the web, a backup roll for bringing the transfer belt into contact with the coating roll, and a An intermittent adhesive application device comprising means for moving close to and away from the coating roll at time intervals, and means for transferring the adhesive applied on the transfer belt to the web.