JPH0726096Y2 - Parison extrusion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a parison extrusion device used for blow-forming a laminated structure in which different types of resins are layered.

[Prior Art] Conventionally, as a blow molding machine for blow molding a multi-layered plastic container or the like, the one described in Japanese Patent Laid-Open No. 51-101069 is known. Ring pistons are slidably provided in a plurality of resin passages formed in a shape, and the vertical position of these ring pistons is hydraulically controlled by each hydraulic cylinder to adjust the wall thickness ratio of each layer. There is.

[Problems to be Solved by the Invention] However, in the molding means for a multilayer structure in the above-mentioned conventional blow molding machine, the applicant of the present application filed the first application of Japanese Utility Model Publication No. 1-85594.
It has been difficult to manufacture a molded product having a partially different wall thickness with an accurate wall thickness ratio as shown in Japanese Patent Laid-Open Publication No. H11-242242. That is, with the above-mentioned conventional molding means, it is difficult to maintain the pressure balance of the hydraulic cylinder that controls the vertical position of the ring piston when the parison is extruded, and the parison that is extruded is wavy without the thickness of each layer being constant. This is because it is difficult to control each hydraulic cylinder so that the thickness of each layer is constant at each molding.

In view of such drawbacks of the conventional ones, the present invention forms the outlet side end of the annular resin passage in a shape that expands or reduces the diameter, and divides the resin passage into a first resin passage and a second resin passage. The movable annular body is provided so as to be movable in the resin path direction, and the end portion on the outlet side of the resin path of the movable annular body is formed in a shape that expands or reduces the diameter along the shape of the annular resin path. By interposing it in the outlet portion, it is possible to finely and precisely adjust the opening degree of the outlet side end portions of the first resin passage and the second resin passage with respect to the movement of the movable annular body in the resin direction. Also, the wall thickness ratio of the second resin layer can be kept arbitrary and constant, and the wall thickness ratio can be changed reliably and easily even during the extrusion of the parison. Blow molding of laminated structure with different wall thickness ratios It is an object to provide an extrusion apparatus Parisun capable Rukoto.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following technical means.

That is, in an extrusion device that laminates a first resin and a second resin and extrudes them in layers, the outlet portion of the annular resin passage is formed in a shape that expands or reduces the diameter thereof, and the outside of the annular resin passage is formed inside the annular resin passage. A movable annular body that divides the first resin passage and the inside into a second resin passage is movably provided in the resin passage direction, and the outlet side end of the resin passage of the movable annular body is expanded so as to follow the shape of the annular resin passage. Alternatively, the present invention is a parison extrusion device characterized in that it is formed in a diameter-reducing shape and is interposed in the outlet portion of the annular resin passage.

[Operation] According to the parison extrusion device of the present invention, in the extrusion device for laminating the first resin and the second resin and extruding them in layers,
The movable annular body is formed in the annular resin passage so as to expand or contract the diameter of the annular resin passage and divide the outside into the first resin passage and the inside into the second resin passage to move the movable annular body in the resin passage direction. It is provided freely, and the end portion on the outlet side of the resin passage of the movable annular body is formed in such a shape that the diameter is expanded or reduced so as to follow the shape of the annular resin passage, and it is interposed in the outlet member of the annular resin passage. Therefore, when the movable annular body provided in the annular resin passage is moved in the resin passage direction, the opening degree at the outlet side end portions of the first resin passage and the second resin passage is changed, and the first extruded parison is pressed. The thickness ratio of the first resin layer and the second resin layer is adjusted. And, in particular, the outlet side end portion of the resin passage of the movable annular body is formed in a shape that expands or contracts in diameter so as to follow the shape of the annular resin passage and is interposed in the outlet portion of the annular resin passage. So the parison won't wavy.

That is, those having different thicknesses of the first resin layer and the second resin layer, those having the same thickness of the first resin layer and the second resin layer, and those having only the first resin layer or the second resin layer It can be extruded as a parison. Further, even during the extrusion of the parison, the wall thickness ratio between the first resin layer and the second resin layer can be finely and highly accurately adjusted by moving the movable annular body without causing the parison to wavy.

[Embodiment] An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 illustrates a parison extrusion device, in which 1 is an annular die, 2 is a mandrel, and a vertical annular resin path is formed between them. A movable annular body 3 is provided in the resin passage so as to be movable up and down in the resin passage direction. The movable annular body 3 allows the resin passage to be divided into an outer first resin passage 4 and an inner second resin passage 5. It is divided. The outlet side end of the resin passage is formed so as to expand its diameter, and correspondingly, the end of the movable annular body 3 is also formed in a shape in which the diameter is expanded outward, and 6 is the expanded diameter. The enlarged diameter portion 6 is interposed in the outlet portion of the resin passage. Reference numeral 7 is a first resin injecting portion, 8 is a second resin injecting portion, the first resin injecting portion 7 communicates with the first resin passage 4, and the second resin injecting portion 8 has the passage 9 through the second resin passage 5. Is in communication with.

In the Paris extrusion device configured as described above,
If different types of molten resin are injected from the first resin injecting section 7 and the second resin injecting section 8, respectively, those resins are
The first resin passage and the second resin passage 5 divided by the movable annular body 3 respectively flow into and are filled.

On the other hand, when the movable annular body 3 is moved in the resin passage direction, the opening degree of the first resin passage 4 and the second resin passage 5 is adjusted by the enlarged diameter portion 6 of the movable annular body 3 at the outlet side end portion of the resin passage. It Therefore, as shown in FIG. 2, if the opening degrees of the first resin passage 4 and the second resin passage 5 are made equal, the parison 10 extruded from the outlet side end portion of the resin passage becomes the same as the first resin layer 11. Second resin layer 12
Are laminated to have the same thickness. When the movable annular body 3 is moved downward from the state shown in FIG. 2, the opening degree of the first resin passage 4 becomes larger than the opening degree of the second resin passage 5 at the outlet side end of the resin passage. In the parison 10, the first resin layer 11 has a larger thickness ratio than the second resin layer 12, and if the movable annular body 3 is moved upward in the opposite direction, the first resin layer
The thickness ratio of the second resin layer 12 to 11 is large.

Further, as shown in FIG. 4, if the enlarged diameter portion 6 of the movable annular body 3 is lowered so as to block the second resin passage 4, the parison 10 becomes only the first resin, as shown in FIG. When the movable annular body 3 is raised so that the expanded diameter portion 6 closes the first resin passage 5, the parison 10 is made of only the second resin.

In this way, the wall thickness ratio between the first resin layer 11 and the second resin layer 12 to be extruded can be adjusted reliably and easily by simply moving the movable annular body 3 in the resin path direction. 1
It is also possible to use only the resin layer 11 or the second resin layer 12.
Further, even during the extrusion of the parison 10, the wall thickness ratio of the first resin layer 11 and the second resin layer 12 can be partially changed by moving the movable annular body 3. Since the thickness ratio of the first resin layer 11 and the second resin layer 12 can be adjusted and maintained in a reliable and constant state only by the movement of the movable annular body 3 in the resin direction, the resin layer of the parison 10 should be wavy. It is extruded neatly without.

Therefore, by using the parison extrusion device having the above-mentioned configuration, various containers having resin laminated structures having different inner and outer layers, various hollow bodies such as bellows-like ones can be blow-molded, and further, a function having a different wall thickness ratio depending on each part. Blow molding can be easily carried out.

Although the diameter of the outlet side end portion of the resin passage is expanded in the above-mentioned embodiment, even if the outlet side end portion of the resin passage is reduced in diameter as shown in FIG. can do.

[Advantages of the Invention] According to the present invention, the outlet portion of the annular resin passage is formed to have an enlarged or reduced diameter, and the outlet end of the resin passage of the movable annular body is made to follow the shape of the annular resin passage. The diameter of the first resin path and the second resin path on the outlet side of the movable annular body in the resin direction is increased because the diameter of the movable annular body is increased or reduced to be interposed in the outlet of the annular resin path. It is possible to finely and precisely adjust the opening degree of the part, and it is possible to arbitrarily adjust the wall thickness ratio of the first resin layer and the second resin layer even during the extrusion of the parison, and at the same time, to adjust the thickness of each layer of the parison to be extruded. The thickness can be adjusted finely and highly accurately, and it is possible to obtain the effect that the corrugation of the parison is prevented and the thickness can be kept constant.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a parison extruding device according to the present invention, FIGS. 2 to 5 are cross-sectional views of essential parts for explaining the operation, and FIG. 6 is another embodiment of the present invention. It is a principal part sectional view similar to FIG. 2 which shows the extrusion apparatus of the parison which diameter-reduced the exit side edge part of the resin passage which is an Example. 1 ... Die, 2 ... Mandle, 3 ... Movable annular body, 4 ...
… 1st resin path, 5 …… 2nd resin path, 6 …… expanded diameter section, 7…
... 1st resin injection part, 8 ... 2nd resin injection part, 10 ... Parison, 11 ... 1st resin layer, 12 ... 2nd resin layer

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Claims (1)

[Scope of utility model registration request] 1. An extrusion apparatus for laminating a first resin and a second resin and extruding them in a layered form, wherein an outlet portion of an annular resin passage is formed in such a shape as to expand or contract in diameter, and in the annular resin passage. A movable annular body that divides the outside into a first resin path and an inside into a second resin path is movably provided in the resin path direction, and the end of the movable annular body on the outlet side of the resin path follows the shape of the annular resin path. An extruding device for a parison, characterized in that the extruding device is formed in such a shape as to have an enlarged or reduced diameter and is interposed in the outlet portion of the annular resin passage.