JPS6212457Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an adhesive supply device for a solvent-free laminator. The objects of the present invention are to: 1. Minimize the capacity of the adhesive bank to prevent gelation of one-component or two-component adhesives with short pot lives in an adhesive supply device;

2. To prevent air entrainment in the adhesive bank and to prevent gelation of one-component moisture-curing adhesives.

3. To simplify the structure of the adhesive nozzle and apply non-adhesive surface treatment to the surface to facilitate disassembly and cleaning of the nozzle. …It is in.

FIG. 1 shows the coating/laminate portion of a known solvent-free laminator. The coating part 8 is 1
It is composed of a No. 1 roll, a No. 2 roll 2, a No. 3 roll 3, a No. 4 roll 4, and an adhesive supply nozzle 10. Reference numeral 5 denotes a first web, which is coated with an adhesive at a coating section 8 and laminated with a second web 6 at a laminating section 9 to form a laminate web 7.

The first roll 1 is a rubber roll and is pressed against the second roll 2 to uniformly form a thin film of adhesive in the width direction. The second roll 2 is an iron roll and is heated by hot water circulation. The third roll is a rubber roll whose shoulder is dropped to the coating width and transfers the adhesive onto the first web 5.

The No. 4 roll 4 and the No. 3 roll 3 rotate at the same speed as the web. No. 2 roll 2 is the web speed
It rotates at a speed of 1/2 to 1/20, and the first roll 1 rotates at a speed of 1/100 to 1/1000 of the web speed, and the difference in peripheral speed makes the adhesive a thin film.

The adhesive supplied from the supply nozzle 10 to the entrance side of the No. 1 roll and the No. 2 roll (roll nip entrance side) is due to the rolling effect due to the high nip pressure of the No. 1 roll 1, and
Due to the difference in circumferential speed from the first roll to the third roll, the film is thinned as shown in Figure 2, and the first web 5 is coated with 0.5 to 5 g/
Apply ^m2 coats.

The adhesive is distributed in the width direction by a supply nozzle 10 by a pump from a tank (not shown) heated to 60 to 120°C, and is applied to the first roll 1 and the second roll 2.
supplied between. The viscosity of the adhesive at this temperature is 500-5000 CPS.

FIG. 3 shows details of a known adhesive supply device.
The supply nozzle 10 has an adhesive flow path 13 and an adhesive outlet 1
4 with nozzle member 17 and adhesive at 60~120℃
A nozzle part 16 having a hot water flow path 12 for maintaining
and a clamp member 18 that connects these two nozzle members 16 and 17.

Now, the adhesive supplied from the tank to the nozzle member 17 of the supply nozzle 10 from the adhesive pipe (not shown) via the pump is transferred to the adhesive flow path 13 and the adhesive outlet 1.
4, it is evenly distributed in the width direction and sent out between the No. 1 roll 1 and the No. 2 roll 2. The adhesive dispersed by the supply nozzle 10 forms an adhesive bank 15 on the roll nip entry side of the first roll 1 and the second roll 2, causing a flow within the bank as shown in FIG.

It has been found that the above-described supply nozzle 10 has the following drawbacks. That is, 1. The amount of adhesive stored in the adhesive channel 13 and adhesive bank 15 of the supply nozzle 10 is large;
Because the residence time in this area is long, when using one-component or two-component adhesives with short pot lives,
When gelation occurs and is applied to the web, it spoils the appearance of the laminate web. If gelation progresses further, the lifespan of the rubber roll will be shortened.
This will eventually damage the rubber roll.

2. Since the volume of the adhesive bank 15 is large, air bubbles 23 are formed along the flow inside the bank as shown in FIG.
to speed up the gelation of moisture-curing adhesives.

3. When cleaning after stopping the machine, remove the clamp member 18 of the supply nozzle 10 and remove the nozzle members 16, 17.
It takes time to separate the parts and clean the parts with adhesive.

Due to the background described above, current one-component or two-component adhesives, especially polyester-based one-component adhesives and two-component adhesives, have a short pot life. cannot be manufactured without sacrificing the performance required for For this reason, there is a demand for a supply device that can be used even with adhesives that have a short pot life so that the original adhesive performance can be exhibited.

The present invention was developed by paying attention to the phenomenon that the pot life in the coater head is shorter than the pot life in the table test of adhesives, and as a result of pursuing the causes thereof.
This will be explained with reference to the figures.

Reference numeral 19 denotes a wedge-shaped dam, which engages with the roll nip entry side of No. 1 roll 1 and No. 2 roll 2 and is provided close to the circular arc portion. Inside Dam 19,
A hot water flow path 12 is built in to circulate hot water at a temperature approximately equal to the temperature of the adhesive through the dam 19.

The surface of the dam 19 that comes into contact with the adhesive is No. 1 roll 1.
and the second roll 2 as close as possible to the arc portion. Although it depends on the viscosity of the adhesive and the coating speed, it is preferable that the distance between the arc portion of the roll and the surface of the dam 19 be as close as possible, 1 to 10 mm. Furthermore, a mechanism for adjusting the spacing depending on the viscosity and coating speed can be added. It is also effective to apply non-adhesive treatment to the surface of the wedge-shaped dam 19, such as Teflon coating or Teflon impregnation treatment.

Now, according to the present invention, dams 19, 1 and 2
Since there is a gap 24 between the number rolls 1 and 2, the adhesive supplied from the top of the dam 19 is
It is pulled by the rotation of the number roll 2, producing a flow as shown in FIG. Wedge-shaped adhesive upper bank 2 in the narrow gap between No. 2 roll 2 and dam 19
1 generates a fluid wedge pressure by the tensile force of the second roll 2, and uniformly distributes the adhesive supplied from the supply pipe 20 in the width direction. No. 1 roll 1 and dam 19
The lower bank 22 of intervening adhesive also produces the same effect as the upper bank 21.

As mentioned above, the upper bank 21 and the lower bank 2
2 together generate a liquid wedge pressure, and the upper bank 2
1. The amount of adhesive stored in the lower bank 22 is minimized. This not only shortens the residence time of the adhesive, but also increases the flow velocity within the bank, preventing air entrainment and reducing the contact time with air.
The contact area can also be reduced.

According to the present invention, 1. The fluid wedge pressure (roll nip pressure) generated between the wedge-shaped dam 19 and the second roll 2 distributes the adhesive evenly in the width direction, the amount of adhesive bank is small, and no air is entrained, preventing gelation of one-component or two-component adhesives which have a short pot life.

2 For this reason, the appearance of the film due to the gel is poor,
Roughness and damage to the rubber roll can be reduced.

3 Furthermore, since the volume of the adhesive bank is substantially reduced by the wedge-shaped dam, the residence time of the adhesive is short, and the flow velocity within the bank is high, so that old and new adhesives can be replaced quickly, reducing pot life. It is now possible to use high-performance adhesives with shorter lengths and greater adhesive strength. This made it possible to produce a more sophisticated and wide range of products.

4. When the machine is stopped, there is no need to disassemble and clean the supply nozzle as in the past, making cleaning easier and reducing downtime. Furthermore, the above effects can be further enhanced by applying non-adhesive treatment to the dam surface.

[Brief explanation of drawings]

Figure 1 shows the coating of a solvent-free laminator.
The laminated part is shown. Figure 2 is an enlarged detailed view of the coating part. FIG. 3 is a detailed view of a known adhesive supply device. FIG. 4 shows the adhesive supply device of the present invention. In the diagram: 1...1st roll, 2...2nd roll, 3...3rd roll, 4...4th roll, 5
...First web, 6...Second web, 7...
Laminate web, 8...Coating part, 9
...Laminating section, 10... Supply nozzle, 11...
...Adhesive, 12...Hot water channel, 13...Adhesive channel, 14...Adhesive outlet, 15...Adhesive bank, 16...Nozzle member (1), 17...Nozzle member
(2), 18... Clamp member, 19... Dam, 20
... Supply pipe, 21 ... Upper bank, 22 ... Lower bank, 23 ... Air bubble, 24 ... Minimum gap part.

Claims (1)

[Scope of utility model registration request] In a solvent-free adhesive supply device for a laminator, a supply nozzle is installed on the roll nip entrance side of the first roll and the second roll, and the roll nip entrance side of the first roll and the second roll is used as an adhesive bank. A solvent-free adhesive supply device for a laminator, characterized in that a wedge-shaped dam is disposed close to the circumferential surfaces of the first roll and the second roll.