JPH0423626Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cylindrical body heating device for a plastic cylindrical body manufacturing apparatus.

[Conventional technology]

Traditionally, molten plastic is extruded into a cylinder through an extruder die, cooled to form a cylinder, and then
A method of heating and stretching or heat-setting this cylindrical body is known.

As a heating means for this cylindrical body,
There are methods that use an electric heater or infrared heater as described in Japanese Patent No. 57-36629, methods that use a heated liquid tank, and methods that use heated air.

[Problem that the invention attempts to solve]

However, electric heaters and infrared heaters take time to heat up, and because the heat source is high temperature, there is a risk of overheating.Also, heating liquid tanks can heat quickly and have little risk of overheating, but
It is necessary to remove the adhering liquid from the surface of the cylindrical body taken out from the heated liquid tank. Although some of the above-mentioned drawbacks are solved by blowing heated air, it is difficult to uniformly heat the device in a short period of time.

This invention was made in view of the above matters,
The technical challenge is to create a heated air heating device that can heat uniformly in a short time.

[Means for solving problems]

In the present invention, a guide 40 through which the plastic cylindrical body 6 is inserted is provided at the center of one end of an outer cylindrical body 33 formed in a cylindrical shape, and a guide 40 through which the plastic cylindrical body 6 is inserted is provided at the center of the other end of the outer cylindrical body 33. A conduit 34 is provided, into which the conduit 34 can be inserted with a gap 35, an opening 41 at one end of the conduit 34 is located near the one end inside the outer cylinder 33, and A heated air inlet 36 is provided on the outer periphery of the outer cylindrical body 33 near the other end.
This is a heating device for a plastic cylindrical body manufacturing apparatus with an opening facing in the circumferential direction.

[Effect]

The heated air blown from the heated air inlet 36 in the circumferential direction of the outer cylindrical body 33 reaches the periphery of the opening 41 while swirling around the conduit 34 . Then, the reached heated air enters the gap 35 between the conduit 34 and the cylindrical body 6 from the opening 41 at a substantially uniform temperature over the entire circumference of the opening 41, and comes into contact with the cylindrical body 6 while rotating. The cylindrical body 6 is heated and the conduit 34 is heated.
is discharged outside.

〔Example〕

FIG. 1 shows a heating device 32 according to an embodiment of the present invention, in which a plastic cylindrical body 6 of an object to be heated is placed in the center of one end of an outer cylindrical body 33 formed in a cylindrical shape.
A cylindrical guide 40 is provided through which the cylindrical body 6 is inserted, and both ends of this guide 40 are formed to have a diameter close to the outer diameter of the cylindrical body 6 to prevent hot air from flowing out. At the center of the other end of the outer cylindrical body 33, an outer diameter
A 350 mm long conduit 34 into which an 18 mm cylindrical body 6 can be inserted with a gap 35 of about 3 mm is provided, and an opening 41 at one end of this conduit 34 is located near the one end inside the outer cylindrical body 33. Furthermore, a heated air blowing port 36 is opened toward the circumferential direction of the outer cylinder 33 on the outer periphery of the outer cylinder 33 near the other end.

The length of the conduit 34 is determined by the heating time.

Next, referring to FIG. 2, an example of a plastic cylindrical body manufacturing apparatus equipped with the heating device of the present invention will be described. In this manufacturing device, an extruder 1 equipped with a hopper 2 is provided with a die 3 equipped with an annular extrusion port, and next to the die 3, a 1 m cooling liquid tank 7a equipped with a sizer 9 is installed, and a cooling liquid tank 7a is installed. A second cooling liquid tank 7b having a length of 1 m is provided adjacent to the tank 7a via a partition 18 and a liquid sealing device 19, and
This partition 18 is designed to be movable left and right. Further, liquid sealing devices 19, 19 are provided at the end of the second cooling liquid tank 7b. The cooling liquid tanks 7a, 7b are of a closed type, and are provided with liquid suction pipes 17, 17, so that the internal pressure of the cooling liquid tanks 7a, 7b is reduced to a negative pressure of 100 mm to 500 mmHg at the upper part of the liquid tank. It is becoming more and more common. In this manufacturing equipment, by using two cooling liquid tanks,
This is designed to prevent fluctuations in the negative pressure within the cooling liquid tank 7a. Furthermore, a liquid feeding cylinder 13 is provided in the cooling liquid tank 7a.

Further, an air pipe 4 having a length of 3.5 m is provided from the extruder 1 through the center of the die 3.
is provided with a regulating valve 5, and is provided through the cooling liquid tanks 7a, 7b, with an air supply port 2 at the tip.
7 is opened, and an air sealing device 23 is provided at the tip. A take-off machine 28 is provided next to the air sealing device 23.

Next to the take-off machine 28, a heating device 32 of the present invention is provided.

A cooling device 37 is provided next to the heating device 32,
The outside of the cylindrical body 6 heated by the heating device 32 is brought to approximately the same temperature as the inside of the cylindrical body 6. Next to the cooling device 37, the external mandrel 3
8, a cooler 39 is provided on the outlet side of the external mandrel 38, and then a take-off device 44 is provided. This pulling device 44 includes first clipping tools 45a, 45b and second clipping tools 46a, 46b. While the other clip is being picked up, the other clip opens its tip and advances beyond the one clip to the external mandrel 38 side;
It is designed to sandwich the stretched pipe, and 2
A set of clamps 45 and 46 alternately pinch and pull the stretching pipe 43.

[Effect of idea]

In the present invention, the heated air reaches the opening 41 of the conduit 34 while swirling.
The temperature is approximately uniform throughout the entire circumference, and
Since the heated air is discharged while swirling inside the conduit 34, the relative velocity between the cylindrical body 6 and the heated air becomes higher than the residence time of the heated air. Therefore, each part of the cylindrical body 6 can be heated uniformly and in a short time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a device to which the present invention is installed. 6... Cylindrical body, 32... Heating device, 33... Outer cylinder, 34... Conduit, 35... Gap, 40... Guide, 41... Opening.

Claims (1)

[Scope of utility model registration request] A guide 40 through which the plastic cylindrical body 6 is inserted is provided at the center of one end of the cylindrical outer cylindrical body 33.
A conduit 34 is provided at the center of the other end of 3, into which the plastic cylindrical body 6 can be inserted with a gap 35, and an opening 41 at one end of this conduit 34 is located near the one end inside the outer cylindrical body 33. The heating device for a plastic cylindrical body manufacturing apparatus is provided in such a manner that a heating air inlet 36 is opened in the circumferential direction of the outer cylindrical body 33 on the outer periphery near the other end of the outer cylindrical body 33.