KR890009443Y1 - Adhesive coating apparatus for plastic tube(pipe) - Google Patents

Abstract

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Description

Adhesive coating device of plastic pipe

1 is a schematic view of a conventional resin coating device.

2 is a process chart of the present invention.

3 is a cross-sectional view of the device of the present invention

Figure 4 is a perspective view of the tip dice that is the main part of the present invention.

5 is an enlarged cross-sectional view of the main part of the present invention.

* Explanation of symbols for main parts of the drawings

2: housing 5: tip die

6: odyssey 7: connector

41: middle dice 51: rib

43, 62: vertical portion 64: horizontal portion

71: high information bolt 72: injection hole adjustment bolt

The present invention is designed to uniformly apply a hot-melt adhesive to the outer surface of the hard vinyl chloride tube by a crosshead die extruder to lining the hard vinyl chloride tube on the inner surface of the metal tube. It relates to an adhesive coating device of the plastic tube.

In general, in order to manufacture a plastic-lining metal tube, there are those that insert the extruded plastic tube into the inner surface of the metal tube, and then expand and line the lining, and insert the plastic tube smaller than the inner metal diameter to reduce the diameter of the metal tube. It is common to use an adhesive when lining a platy tube on the inner surface of the plastic pipe, and the quality of the plastic-lining metal tube will vary according to the type and characteristics of the adhesive.

Adhesives used for lining plastic pipes on the inner surface of metal pipes include organic solvent diluent adhesives and hot-melt adhesives. In the case of organic solvent diluent adhesives, the coating method is brushing, spraying, dipping and showering. It is relatively simple and easy to work with. However, when using organic solvents, there are labor safety problems, risks of fire and explosion, etc. To prevent these things, it is economically disadvantaged due to the necessity of safety equipment. If the plastic pipe is inserted into the metal pipe before the volatilization is sufficiently volatilized, a part sound may occur due to the volatilization of the residual solvent, and the plastic pipe may be partially cracked. It will have a big problem in quality such as progressing, and also scattering organic solvents sufficiently It takes 8-24 hours to make it necessary, so that it is difficult to serialize the adhesive application process, and the amount of adhesive loss at the time of application is also economically disadvantageous.

Hot-melt adhesives are solid at room temperature, melt by heating, and exert adhesion by cooling.

Therefore, it is difficult to apply it by brushing, dipping, etc., because it needs to be dissolved by heating, and there is a disadvantage that a specific coating device must be used. However, since the thermoplastic melt is a heat-melting solid adhesive starting from the resin, the organic solvent dilution adhesive It is possible to manufacture high quality lining pipes because the labor stability and the risk of fire and explosion are eliminated, and the plastic pipe pipes are not swelled or cracked due to solvents. And high efficiency can be obtained.

As a means for applying the hot-melt adhesive on the outer surface of the plastic pipe, there is a device for spraying the hot-melt adhesive heated and melted at 180-200 ° C using compressed air of 6-7kg / cm2, but this has to rotate the plastic pipe. It is difficult to control the spray amount of the adhesive to be sprayed, and it is difficult to continuously apply high-efficiency continuous coating work because it is limited by the conveying speed and rotation speed of the pipe according to the outer diameter of the plastic pipe at the time of application, and the applied adhesive layer is not uniform. have.

In addition, there is also a method of winding the adhesive on the outer surface while rotating the plastic pipe by hot-melt adhesive in the form of a tape, but there is an economically disadvantageous problem because the hot-melt on the pellet must be manufactured in the form of a tape again.

On the other hand, in the technical field similar to the present invention, a device for coating a resin on the outer surface of the steel pipe to prevent rust on the steel pipe coating device, that is, as shown in FIG.

As can be seen in this figure, the steel pipe coating apparatus moves the steel pipe (e) to be coated on the central pipe (d) of the die (a) in which the inner die (a) and the outer dice (b) are combined at a predetermined speed. When the melted resin is supplied to the resin liquid supply pipe (bar) on the upper portion of the die (c), the viscous resin liquid flows out into the outflow hole (h) at the tip of the die through the resin liquid supply path (corporate), and E) is applied to the outer surface of the product, and the supply inhaler (i) strongly inhales the air inside the central pipe line (D) to facilitate the supply of the resin solution and at the same time, the applied resin solution is completely adhered to the outer surface of the steel pipe. It is to be made.

The problems in the steel pipe coating apparatus as described above are as follows.

First, since the outflow hole is formed at the tip of the die and has an inclination with respect to the plastic pipe, the resin liquid coming out of the outflow hole is applied to the plastic pipe and moved out of the die at the same time. The liquid flows down to the lower part of the steel pipe due to the viscosity, so that the thickness of the coating layer is not uniform. Second, the diameter of the central conduit of the whole die composed of inner dice and outer dice is fixed. Since it is constant, steel pipes of different diameters can not be covered other than steel pipes of predetermined positions. Third, the whole die is heated due to the supply of heated resin liquid. Therefore, the steel pipe does not bend or deform to a certain degree because it is heated. No problem, but the heat In the case of plastic pipes, which are easy to bend, the gap between steel pipe and outflow pipe moving the central pipe due to the bending of the pipe or fluctuation due to external force is not uniform, so that the coating layer is not uniform or the coating cannot be made. It was.

Therefore, an object of the present invention is to provide a hot-melt adhesive on the outer surface of the plastic tube, which is excellent in continuous application workability of high efficiency, and uniformly forms an adhesive layer having a thickness of 150-200μ, and is also economically advantageous. It is providing the adhesive coating apparatus.

Another object of the present invention is to provide an adhesive coating device for a plastic tube that enables to uniformly apply the adhesive regardless of the diameter of the tube even by the simple parts exchange, even if the plastic tube having a different diameter.

Prior to describing the present invention in detail, the hot-melt adhesive in the present invention includes ethylene vinyl acetate copolymer, vinyl acetate, polyvinyl butyral, ethylene ethyl acetate copolymer, polyester, polyamide, and the like as main components. This is a solid adhesive that is a solid at room temperature, is a heat-melting type of thermoplastic resin that has a property of being heat-melted and cured by cooling when applied to a fluid, and exhibiting adhesive strength.A plastic pipe to which the adhesive is applied is a polyethylene pipe or a polypropylene. Thermoplastic plastic tube, such as a tube and a vinyl chloride tube.

Hereinafter, the adhesive coating device of the present invention will be described in detail with reference to the accompanying drawings.

2 is a process chart of the present invention, illustrating a schematic process of the present invention coating device.

The plastic pipe (8) mounted on the inlet side and the outlet side and the transfer roll (a) (a ') is transferred to the cross head die (1) through the trumpet-shaped die (42) by a conventional plastic pipe feeding device (b). The feeding speed at this time is 10-25 m / min, and moves at a speed that can prevent the plastic pipe from being softened by heat generated from the die and the melt-extruded adhesive when the crosshead die 1 passes.

When the plastic pipe (7) enters the crosshead die (1) by the feeding device (b), the hot melt hot melt adhesive is injected into the injection hole inside the crosshead die (1) by the extruder (e), and the plastic before entry The outer surface of the tube 8 is applied.

Adhesive-coated plastic pipe (8) is passed through the tip die (5) and then transferred to the cooling device (c) to cool, and the plastic pipe (8) coated with the adhesive is re-heated by a separate device after It will be lining inside the steel pipe.

3 is a cross-sectional view of the crosshead die 1 which is the present invention adhesive application device.

Inside the housing 2, which is cylindrical from the side and the adhesive entry hole 21 is formed at the bottom, an inner die having a jaw 31 formed at the tip thereof so that the adhesive entry path 32 can be formed when the housing 2 is combined. The holder 3 is inserted into the housing 2 and fixed to the bolt 33.

The inner dice holder 3 is provided with an inner dice 4 having an intermediate dice 41 and a trumpet-shaped dice 42 so as to be moved forward and backward. A vertical portion is provided at the tip of the intermediate dice 41. 43 is formed, and the rear flange 44 of the inner die 4 is provided with an injection hole adjusting bolt 45, and according to the adjustment of the injection hole adjusting bolt 45, the internal dice 4 and The intermediate die 41 coupled thereto moves forward and backward inside the inner dice holder 3 so that the vertical portion 43 of the tip of the intermediate dice 41 and the vertical portion 62 and the horizontal portion of the outer dice 6 described later are horizontal. It is possible to adjust the injection amount of the adhesive to be injected by changing the interval of the injection hole 63 formed between the portions 64 according to the viscosity.

As shown in FIG. 5, the outer die 6 having the tip die 5 is coupled to the housing 2 by the connector 7 at the tip of the housing 2. ) Is fixedly installed on the housing 2 by a high information bolt 71, while the upper and lower adjustment bolts 72 adjust the distance d between the outer dice 6 and the connector 6 up and down. The center of the outer dice (6) and the front end dice (5) fixed to it to be able to exactly match the center of the intermediate dice (41).

The inner surface of the outer dice 6 is divided into an inclined portion 61, a vertical portion 62 and a horizontal portion 64, the inclined portion 61 is combined with the housing 2, the intermediate dice ( The adhesive access path 32 is formed between the outer surface of the 41 and the vertical portion 62 and the horizontal portion 64 are also injection holes 63 between the vertical portion 43 of the tip of the intermediate dice 41. By forming a) it is possible to spray the adhesive entering the access path 32 to the plastic pipe (8) at right angles through the injection hole (63).

The tip dice 5 fixed to the tip of the outer die 6 by bolts 52 are provided with several ribs 51 on the inner surface, as shown in FIG. ), The plastic pipe 8 is made to make the coating layer of the adhesive uniform by correcting the deviation of the upper, lower, left and right, the unevenness of the roundness of the tube, the warpage phenomenon and the half-shape caused by the external force. The height is preferably about 0.1-0.3mm.

Referring to the operation and effects of the present invention configured as described above are as follows.

The plastic pipe 8 entering the crosshead die 1 by a conventional plastic pipe feeding device (b) has a smooth entry by the trumpet die 42, and the inner die 4 and the middle die 41 The hot-melt adhesive, which is heated and melted at the same time, is extruded from the melt-extruder (e), so that the inlet 21 at the bottom of the housing 2 and the inner surface of the housing 2 and the outer surface of the inner die holder 3 and It is applied to the outer surface of the plastic pipe 8 while being injected into the injection hole 63 through the access path 32 formed between the inclined portion 61 of the outer surface of the outer die 6 and the outer surface of the intermediate die 41. (63) is formed at right angles to the plastic tube (8) by the vertical portion (62) of the inner surface of the outer dice (6) and the vertical portion (43) of the tip of the horizontal portion (64) and the intermediate dice (41). Since the injection is also performed inside the horizontal portion 64 of the outer die 6, the conventional inner, as shown in FIG. When the outer die (b) (a) is sprayed at an angle to the pipe in an outward direction, the applied resin liquid flows to the lower part of the pipe by viscosity, thereby preventing the thickness of the coating layer from being uneven.

And the injection amount of the adhesive is injected by adjusting the injection hole adjusting bolt 45 in the rear flange 44 of the inner die 4 according to the melt viscosity of the adhesive, the inner die 4 and the intermediate dice 41 ) Moves back and forth within the inner dice holder 3 and is formed between the vertical portion 43 of the tip of the middle dice 41 and the vertical portion 62 and the horizontal portion 64 of the inner surface of the outer dice 6 described above. This is achieved by adjusting the distance d 'of the pores 63.

In this way, the plastic tube 8 coated with the adhesive passes through the lip 51 of the inner surface of the tip die 5, and this lip 51 is formed when the plastic tube 8 passes the injection hole 63. The difference between the lower, left and right sides and the unevenness of roundness occurring after molding during extrusion, the bending of the pipe, deformation due to external force, etc., between the injection hole 63 and the plastic pipe 8 In order to prevent the gap between the injection hole 63 and the plastic pipe 8 to be kept constant so as to prevent the non-uniformity of the applied adhesive layer accordingly, the plastic pipe coated with the adhesive ( When 8) passes through the tip die 5, it is in direct contact with the inner surface of the tip die 5 to prevent the applied adhesive from peeling off.

In the present invention, when the adhesive is to be applied to the plastic pipes having different diameters, the outer connector 6 and the tip die 5 are replaced by releasing the connector 7 fixing bolt 71 at the tip of the housing 2. At the same time, if only the middle die 41 at the end of the inner die 4 and the trumpet-shaped die 42 at the rear end are simply replaced, a plastic pipe having a different diameter can be simply applied.

Claims (2)

The inner dice holder 3 having the locking jaw 31 formed therein is fixed to the inside of the housing 2 in which the access path 21 is formed by the bolt 33, and has an intermediate die 41 and a trumpet-shaped die 42. Insert the inner dice 4 into the inner die holder 3, the injection hole 63 is adjustable by the injection hole adjusting bolt 45, the lip 51 is formed on the inner surface The outer die 6 having the die 5 and the tip die 5 is coupled to the front end of the housing 2 by the connector 7, and the connector 7 is fixed by the fixing bolt 71. It is fixed to the housing (2), the coating device, characterized in that configured to be able to adjust the center of the outer dice (6) by the adjustment bolt (72) provided in the connector (7). The inner surface of the outer dice (6) is formed with a vertical portion (62) and a horizontal portion (64), the front end of the intermediate dice 41 is provided with a vertical portion (43) to the vertical portion ( 62) The injection hole (63) formed by (63) is an adhesive coating device of a plastic pipe, characterized in that the right angle to the plastic pipe (8).