JPH10166433A - Manufacture of multilayer parison, blow molding method and its device using the multilayer parison - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand the range of application of a blow-molded item by easily improving the gloss of surface of the blow-molded item. SOLUTION: An innermost layer of parison of synthetic resin C1 is extruded from a first delivery port 10 of a blow die head A1 and an outer layer of parison of synthetic resin D is delivered from other delivery port 20 and the outer periphery of the parison C1 is covered integrally with the parison D outside the die head A1. The parison D is molded from different or the same kinds of resin as the parison C1. A blow molding is performed using the multilayer parison P. And, if necessary, ABS is employed for the inner layer parison and HDPE is used for the outer layer parison, which parisons may be used for blow molding as a multilayer parison.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a multilayer parison, a blow molding method using the multilayer parison, and an apparatus therefor.

[0002]

2. Description of the Related Art An example of this type of blow molding apparatus is disclosed in Japanese Patent Publication No. Hei 8-25230.

[0003]

In the above prior art,
The surface of the foam molded product is porous, and the gloss of the product is inferior to that of the injection molded product. The present invention relates to a method for producing a multilayer parison, in which the gloss of the surface of a blow molded article such as a foam molded article is easily increased and the range of use thereof is expanded, a blow molding method using the multilayer parison, and an apparatus therefor. The purpose is to provide to the market. It is another object of the present invention to produce glossy multilayer parisons and to be blow moldable.
Another object of the present invention is to make it possible to perform blow molding with a multilayer parison in which the thickness of each layer is made uniform. A further object of the present invention is to enable blow molding with a multilayer parison in which the boundary between the outer layer and the inner layer is not mixed.

[0004]

In order to solve the above problems, a specific invention extrudes a parison made of a synthetic resin of the innermost layer from a first discharge port of a blow die head, and is concentric with the first discharge port. A synthetic resin parison of the outer layer is extruded from another discharge port located at a desired distance in the radial direction of the die head, and the outer peripheral surface of the innermost parison is covered with the outer parison outside the die head to be integrated. According to another aspect of the present invention, there is provided a method for manufacturing a multilayer parison.

[0005] In order to solve the above-mentioned problem, a related invention is a blow molding method characterized by blow molding a hollow molded article using the multilayer parison of the first aspect.

[0006] In order to solve the above-mentioned problems, a related invention includes:
A foamed resin parison is extruded from a first discharge port of a blow die head, and a non-foamed resin parison is concentric with the first discharge port and is separated from another discharge port located at a desired distance in a radial direction of the die head. An outer layer parison is extruded, and the outer peripheral surface of the foamed resin parison is covered with the outer layer parison made of the non-foamed resin outside the die head and integrally blow-molded.

In order to solve the above problems, the blow molding method is characterized in that the foaming resin is obtained by adding a foaming agent to a molding resin such as PE, and the non-foaming resin is a molding material such as ABS. is there.

In order to solve the above-mentioned problem, it is preferable that the outer parison is formed of a plurality of layers of resin by providing a plurality of the other discharge ports concentrically in this blow molding method. .

In order to solve the above problems, a related invention is a multi-layer parison manufacturing apparatus which implements the multi-layer parison manufacturing method according to claim 1.

[0010] In order to solve the above-mentioned problems, a related invention is a blow molding apparatus for performing the blow molding method according to the second, third, fourth, or fifth aspect.

In order to solve the above-mentioned problem, a related invention relates to a blow molding apparatus for extruding foam resin from a first discharge port of a blow die head into a molding die opened as a parison and performing blow molding. At least one other for discharging a non-foamed resin outer layer parison covering the outer peripheral surface of the foamed resin parison, at a position concentric with the first discharge port of the die head and at a desired distance in the radial direction of the die head. According to another aspect of the present invention, there is provided a blow molding apparatus having a discharge port.

In order to solve the above problem, it is desirable that the synthetic resin of the outer layer parison in the blow molding apparatus is a molding resin such as ABS.

In order to solve the above-mentioned problem, an outer periphery of the foam resin parison is concentric with a first discharge port of the blow die head in the blow molding apparatus and is located at a desired distance in a radial direction of the die head. It is preferable that a plurality of other discharge ports for discharging a non-foamed resin outer parison covering the surface are formed.

In order to solve the above-mentioned problem, a related invention extrudes a parison made of a synthetic resin of the innermost layer from a first discharge port of a blow die head, and is concentric with the first discharge port and radially extends from the die head. An outer layer of a synthetic resin parison is discharged from another discharge port located at a desired distance, and the outer peripheral surface of the innermost layer parison is covered with the outer layer of the parison outside the die head and integrally blow-molded. There is a blow molding method.

In order to solve the above-mentioned problem, a plurality of the other discharge ports are formed concentrically in this blow molding method, and the outer layer parison is formed into a plurality of layers with a resin different from or similar to the innermost parison. It is desirable to be characterized.

[0016] In order to solve the above problems, a related invention is as follows.
In a blow molding apparatus for extruding synthetic resin from a first discharge port of a blow die head into a molding die opened as a parison and performing blow molding, the blow head is concentric with the first discharge port of the blow die head. A blow molding apparatus, wherein at least one other discharge port for discharging an outer layer parison made of a synthetic resin covering the outer peripheral surface of the innermost parison is formed at a position separated by a desired distance in the radial direction. There is.

In order to solve the above problem, in this blow molding apparatus, the synthetic resin of the inner layer parison is made of HDP.
E and the like, and the synthetic resin of the outer layer parison is characterized as being an engineering plastic such as ABS.

In order to solve the above-mentioned problems, in the blow molding apparatus, the innermost parison of the innermost parison is located at a desired distance in the radial direction of the die head concentric with the first discharge port of the blow die head. It is characterized in that a plurality of other discharge ports for discharging the outer layer parison covering the outer peripheral surface are formed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the invention according to claims 6, 7, 8, and 9 will be described. In FIG. 1, A is a blow die head of a blow molding apparatus B. The blow die head A has a first discharge port 10 for discharging a parison C made of a foamed resin. The outermost parison D made of a non-foamed resin that covers the outer peripheral surface of the parison C made of foamed resin is discharged at a position concentric with the first discharge port 10 and at a desired distance in the radial direction of the die head A. Discharge port 20 is formed. The discharge directions of the discharge ports 10 and 20 are oriented such that the parisons C and D are separated from the die head A and integrated above the mold clamping position (see FIGS. 1 and 2). ). The interval between the discharge ports 10 and 20 is in the range of 5 mm to 50 mm, preferably 5 mm to 30 mm, and more preferably 5 mm to 15 mm.
Range. For example, if the diameter of the first discharge port 10 is 120
φ, other outlet 12 diameter is 150φ combination, or the first
The diameter of the discharge port 10a is 70φ, and the diameter of the other discharge ports 20a is 100.
φ, and the discharge port (1
Combinations (0, 20) (10a, 20a) are shown in the left and right schematic half sectional views, respectively, of FIG. As the outermost parison D, a molding resin such as ABS is used. In addition,
When the number of parisons is three or more, the plurality of discharge ports 20 are formed concentrically (corresponding to the invention of claim 10).

The operation of this embodiment is described in claims 1, 2, 3, 4,
A description will be given in conjunction with a typical embodiment of the method invention described in 5. A non-foamed molten foam resin (for example, a resin obtained by adding a foaming agent to a molding resin such as PE) is supplied to the die head A by an extruder, and extruded from a discharge port 10 thereof as a thick inner layer parison C.

On the other hand, the outermost parison D made of a non-foamed resin made of a molding resin such as ABS is discharged in a thin film form from the other discharge port 20, and the outermost parison D is formed outside the die head A on the outer periphery of the inner parison C. The surface is coated to form a multilayer parison P as one body.

This multi-layer parison P is blown up, and the inner parison C is foamed by about 50%, inserted into a pair of molds (not shown) and blow-molded, and the inner layer is a foamed resin layer. A blow molded article whose outer layer is made of a non-foamed resin layer is formed.

Since the outer surface of the blow-molded article is covered with the resin of the non-foamed layer, it is mirror-finished. Further, since the foamed resin layer as the inner layer is thicker (for example, in the range of 5: 1, preferably 3: 1) than the outer layer, the blow-molded article has rigidity and light weight. Examples of the blow molded product include building materials such as a desk top plate, an automobile bumper, a cool box, a wall, and a floor.

Embodiment 2 This embodiment is a typical embodiment of the present invention. In FIG. 1, B1 is a blow die head A
This is a blow molding apparatus that extrudes a synthetic resin from a first discharge port 10 into a molding die (not shown) opened as a parison and blow-molds it. The blow die head A
The innermost parison C is concentric with the first discharge port 10 and at a desired distance in the radial direction of the die head A1.
At least one other discharge port 20 for discharging the outer layer parison D made of a synthetic resin that covers the outer peripheral surface of the liquid crystal panel 1 is formed. The synthetic resin of the inner layer parison C is HDPE,
The synthetic resin of the outer layer parison D is ABS. Preferably, an outer parison covering the outer peripheral surface of the innermost parison C1 is discharged concentrically with the first discharge port 10 of the blow die head A1 and at a desired distance in the radial direction of the die head A1. Multiple other outlets 2
0, 20... Are formed. This form of action
A description will be given together with a typical embodiment of the method invention according to claims 1, 2, 11, and 12. A parison C1 made of synthetic resin of the innermost layer from the first discharge port 10 of the blow die head A1
Is discharged from the other discharge port 20, and the outer layer of the innermost parison C1 is covered with the outer parison D outside the die head A1. Blow molding is performed using this multilayer parison P. The outer parison D is the innermost parison C
It is molded with a resin different from or the same as that of No. 1. The outer parison D may be formed of a plurality of resin layers (corresponding to claim 15). If necessary, use ABS for the inner parison C and HDPE for the outer parison D.
May be blow-molded as a multilayer parison.

[0025]

According to the first aspect of the present invention, the blow
The innermost layer of the synthetic resin parison is extruded from the first discharge port of the die head, and the outer layer of the synthetic resin parison is concentric with the first discharge port and separated from the other discharge ports located at a desired distance in the radial direction of the die head. Since the parison is extruded and the outer peripheral surface of the innermost parison is covered with the outer parison outside the die head, the inner and outer parisons are discharged from separate discharge ports. After molding, the two can be integrated to produce a multilayer parison. Further, a multi-layer parison having a uniform thickness of each layer can be formed, and the boundary between both layers can be sharpened.

According to the second aspect of the invention, a hollow molded article having a uniform thickness can be blow-molded using the multilayer parison. According to the third aspect of the present invention, in addition to the above-described effects, the inner foamed resin layer is covered with the non-foamed resin layer and is integrally formed. Surface roughness and glossiness can be increased. Even if this inner layer is formed from recycled pellets, the appearance quality of the hollow molded article can be maintained.

The inventions according to claims 4 and 5 can exhibit the effects of the invention according to claim 3. In particular, according to the invention described in claim 5, the outer layer parison can be molded with a plurality of layers of resin. According to the invention described in claim 6, the method invention described in claim 1 can be implemented, and the effect can be obtained. Claims 7, 8, 9
In the invention described in the above, the method invention of the second, third, fourth and fifth aspects can be carried out, and the effect thereof can be exhibited. In particular, in the inventions according to the eighth and ninth aspects, the surface of the foamed molded article can be covered with a non-foamed resin, and the gloss and transferability of the surface can be enhanced.

In particular, in the invention according to claim 8, in addition to the above-mentioned effects, a wide variety of combinations of a plurality of types of foamed resin and outer layer resin in at least the two-layer parison can be selected, and the outer layer resin is appropriately melted. At the temperature, it can be discharged along the outer peripheral surface of the inner layer parison from the discharge port to cover and be integrated.

According to the tenth aspect of the present invention, in addition to the effects of the eighth and ninth aspects of the present invention, an outer layer parison made of a plurality of layers of resin can be formed on the outer peripheral surface of the inner layer foamed resin parison by discharging. Each resin layer of the outer parison can be discharged to the outside of the die head with a uniform thickness.

According to the eleventh aspect of the present invention, in addition to the effects of the second aspect of the present invention, the parison is integrated outside the die head, and the thickness of the parison of each layer is uniform and does not coexist at the boundary. A multi-layer parison composed of inner and outer parisons is supplied to a mold, and a blow molded article containing no foam layer can be blow-molded. In the invention according to claim 12, in addition to the above effects, the outer layer can be easily formed of a plurality of layers of resin, and the outer layer is formed by discharging various resins from separate discharge ports so as to overlap each other. be able to. According to the thirteenth aspect, the method inventions according to the eleventh and twelfth aspects can be implemented, and the effects thereof can be exerted.

In the invention according to the fourteenth aspect, the inner layer parison is formed of HDPE resin, and AB is easily obtained in glossiness.
By using S for the outer layer parison, the surface of the blow-molded product can be more easily mirror-finished than the conventional blow-molded product. Claim 1
In the invention of the fifth aspect, the method invention of the twelfth aspect can be implemented, and its effects can be exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of a main part showing Embodiments 1 and 2.

FIG. 2 is an enlarged view showing a production state of a multilayer parison at the discharge port.

[Explanation of symbols]

 A, A1 Blow die head 10 First discharge port 20 Other discharge ports C, C1 Innermost layer parison D Outer layer parison

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[Procedure amendment]

[Submission date] November 28, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 This embodiment is a typical embodiment of the invention described in claims 6, 7, 8, and 9. In FIG. 1, A is a blow die head of a blow molding apparatus B. This blow
The die head A has a first discharge port 10 for discharging a parison C made of foamed resin. The outermost parison D made of a non-foamed resin that covers the outer peripheral surface of the parison C made of foamed resin is discharged at a position concentric with the first discharge port 10 and at a desired distance in the radial direction of the die head A. Outlet 20 of
Are formed. The discharge directions of the discharge ports 10 and 20 are oriented such that the parisons C and D are separated from the die head A and integrated above the mold clamping position (see FIGS. 1 and 2). ). In addition, these discharge ports 1
The interval between 0 and 20 is in the range of 5 mm to 50 mm, preferably 5 mm to 30 mm, and more preferably 5 mm to 15 mm. For example, a combination of the first discharge port 10 having a diameter of 120φ and the other discharge ports 12 having a diameter of 150φ, or the first discharge port 10a having a diameter of 70φ and the other discharge port 20a having a diameter of 100φ is used. Outlets (10, 2
Combinations 0) (10a, 20a) are shown in the left and right schematic half sectional views, respectively, of FIG. As the outermost parison D, a molding resin such as ABS is used. When the number of parisons is three or more, the plurality of discharge ports 20 are formed concentrically (corresponding to the invention according to claim 10).

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

Embodiment 2 This embodiment is a typical embodiment of the present invention. In FIG. 1, reference numeral B1 denotes a blow molding apparatus for extruding a synthetic resin from a first discharge port 10 of a blow die head A1 into a molding die (not shown) opened as a parison and performing blow molding. This die head A is concentric with the first discharge port 10 of the blow die head A1.
1 is a synthetic resin outer layer parison D which covers the outer peripheral surface of the innermost layer parison C1 at a desired distance in the radial direction.
At least one other discharge port 20 for discharging the ink is formed. The synthetic resin of the inner parison C is HDPE, and the synthetic resin of the outer parison D is ABS. Preferably, an outer parison covering the outer peripheral surface of the innermost parison C1 is discharged concentrically with the first discharge port 10 of the blow die head A1 and at a desired distance in the radial direction of the die head A1. A plurality of other discharge ports 20, 20,... Are formed. The operation of this embodiment will be described together with a typical embodiment of the method invention according to claims 1, 2, 11, and 12. Blow die head A
The innermost parison C1 made of synthetic resin of the innermost layer is extruded from the first discharge port 10 and the outer parison D made of synthetic resin is discharged from the other discharge port 20. The surface is covered with the above-mentioned parison D as an outer layer and integrated. Blow molding is performed using this multilayer parison P. The outer parison D is formed of a resin different from or similar to the inner parison C1. The outer parison D may be formed of a plurality of resin layers (corresponding to claim 15). If necessary, use ABS for the inner parison C and HD for the outer parison D.
In some cases, PE is used and blow molded as a multilayer parison. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 16, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 This embodiment is a typical embodiment of the invention described in claims 6, 7, 8, and 9. In FIG. 1, A is a blow die head of a blow molding apparatus B. This blow
The die head A has a first discharge port 10 for discharging a parison C made of foamed resin. The outermost parison D made of a non-foamed resin that covers the outer peripheral surface of the parison C made of foamed resin is discharged at a position concentric with the first discharge port 10 and at a desired distance in the radial direction of the die head A. Outlet 20 of
Are formed. The discharge directions of the discharge ports 10 and 20 are oriented such that the parisons C and D are separated from the die head A and integrated above the mold clamping position (see FIGS. 1 and 2). ). In addition, these discharge ports 1
The interval between 0 and 20 is in the range of 5 mm to 50 mm, preferably 5 mm to 30 mm, and more preferably 5 mm to 15 mm. For example, a combination of the first discharge port 10 having a diameter of 120φ and the other discharge ports 20 having a diameter of 150φ, or a combination of the first discharge port 10a having a diameter of 70φ and another discharge port 20a having a diameter of 100φ is used. Outlets (10, 2
Combinations 0) (10a, 20a) are shown in the left and right schematic half sectional views, respectively, of FIG. As the outermost parison D, a molding resin such as ABS is used. When the number of parisons is three or more, the plurality of discharge ports 20 are formed concentrically (corresponding to the invention according to claim 10).

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

Embodiment 2 This embodiment is a typical embodiment of the present invention. In FIG. 1, reference numeral B1 denotes a blow molding apparatus for extruding a synthetic resin from a first discharge port 10 of a blow die head A1 into a molding die (not shown) opened as a parison and performing blow molding. This die head A is concentric with the first discharge port 10 of the blow die head A1.
1 is a synthetic resin outer layer parison D which covers the outer peripheral surface of the innermost layer parison C1 at a desired distance in the radial direction.
At least one other discharge port 20 for discharging the ink is formed. The synthetic resin of the inner parison C is HDPE, and the synthetic resin of the outer parison D is ABS. Preferably, an outer parison covering the outer peripheral surface of the innermost parison C1 is discharged concentrically with the first discharge port 10 of the blow die head A1 and at a desired distance in the radial direction of the die head A1. A plurality of other outlets are formed. The operation of this mode is described in claim 1,
A description will be given together with typical embodiments of the method invention described in 2, 11, and 12. The innermost parison C1 made of synthetic resin is extruded from the first discharge port 10 of the blow die head A1.
The outer parison D made of synthetic resin is discharged from the other discharge port 20, and the innermost parison C1 is formed outside the die head A1.
Is covered with the above-mentioned parison D as an outer layer to be integrated.
Blow molding is performed using this multilayer parison P. The outer parison D is formed of a resin different from or similar to the inner parison C1. The outer parison D may be formed of a plurality of resin layers (corresponding to claim 15). In addition, if necessary, ABS is used for the inner parison C and HDPE is used for the outer parison D,
In some cases, blow molding is performed as a multilayer parison.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 9:00 22:00

Claims (15)

[Claims] 1. An innermost layer of a synthetic resin parison is extruded from a first discharge port of a blow die head, and another parison is positioned concentrically with the first discharge port and at a desired distance in the radial direction of the die head. A method for manufacturing a multi-layer parison, comprising: extruding a synthetic resin parison of an outer layer from an outlet, and covering an outer peripheral surface of the innermost parison with the outer parison outside the die head to form an integral unit. 2. Use of the multilayer parison according to claim 1.
A blow molding method characterized by blow molding a hollow molded product. 3. A parison made of foamed resin is extruded from a first discharge port of a blow die head, and is concentric with the first discharge port and is separated from another discharge port located at a desired distance in a radial direction of the die head. The blow molding according to claim 2, wherein an outer parison made of a non-foamed resin is extruded, and an outer peripheral surface of the foamed resin parison is covered with the outer parison made of the non-foamed resin outside the die head and blow-molded integrally. Method. 4. The blow molding method according to claim 3, wherein said foaming resin is obtained by adding a foaming agent to a molding resin such as PE, and said non-foaming resin is a molding material such as ABS. 5. The blow molding method according to claim 3, wherein the outer parison is formed of a plurality of layers of resin by providing a plurality of the other discharge ports concentrically. 6. An apparatus for manufacturing a multilayer parison, wherein the method for manufacturing a multilayer parison according to claim 1 is carried out. 7. A blow molding apparatus for performing the blow molding method according to claim 5. 8. A blow molding apparatus for extruding a foamed resin from a first discharge port of a blow die head into a molding die opened as a parison and performing blow molding, wherein the blow resin is concentric with the first discharge port of the blow die head. At a position distant by a desired distance in the radial direction of the die head, at least one other discharge port for discharging a non-foamed resin outer layer parison covering the outer peripheral surface of the foamed resin parison is formed. The blow molding apparatus according to claim 7, characterized in that: 9. The blow molding apparatus according to claim 8, wherein the synthetic resin of the outer layer parison is a molding resin such as ABS. 10. A non-foamed resin outer layer parison which covers an outer peripheral surface of the foamed resin parison at a position concentric with a first discharge port of the blow die head and at a desired distance in a radial direction of the die head. The blow molding apparatus according to claim 8 or 9, wherein a plurality of other discharge ports for discharging the liquid are formed. 11. A parison made of an innermost layer of synthetic resin is extruded from a first discharge port of a blow die head, and another discharge port located concentrically with the first discharge port and separated by a desired distance in a radial direction of the die head. 3. The blow molding method according to claim 2, wherein an outer layer of a synthetic resin parison is discharged from an outlet, and the outer peripheral surface of the innermost layer parison is covered with the outer layer parison outside the die head and blow-molded integrally. 12. The parison according to claim 11, wherein a plurality of the other discharge ports are formed concentrically, and the outer layer parison is formed into a plurality of layers with a resin different from or similar to the innermost parison. Blow molding method. 13. A blow molding apparatus for extruding synthetic resin from a first discharge port of a blow die head into a molding die opened as a parison and blow molding, wherein the blow resin is concentric with the first discharge port of the blow die head. At least one other discharge port for discharging a synthetic resin outer layer parison that covers the outer peripheral surface of the innermost parison is formed at a position separated by a desired distance in the radial direction of the die head. And blow molding equipment. 14. The synthetic resin of the inner layer parison is HDPE.
The blow molding apparatus according to claim 13, wherein the synthetic resin of the outer layer parison is an engineering plastic such as ABS. 15. A method for discharging an outer parison covering the outer peripheral surface of the innermost parison, at a position concentric with the first discharge port of the blow die head and at a desired distance in the radial direction of the die head. 15. The blow molding apparatus according to claim 13, wherein a plurality of discharge ports are formed.