JPS6350262B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plastic container consisting of a double-walled main body, a lid, and a hinge that connects these together, and the container surface is made of a fiber layer. Relating to a manufacturing method.

[Conventional technology]

BACKGROUND ART It has been known to attach a fiber layer to the surface of a container such as a bag for the purpose of improving the surface appearance, texture, etc.

[Problem to be solved by the invention]

In the conventional manufacturing method as described above, it is difficult to uniformly apply the fiber layer to the surface of the container, and the application process is also difficult.

The present invention was created in view of the above drawbacks, and
The present invention provides a method for manufacturing a plastic container, characterized in that fiber sheets are laminated during molding of the container, and the surface of the container is made of a fiber layer.

[Means for solving problems]

In the present invention, a parison is extruded between opposed and spaced apart molds, a fiber sheet is placed between the mold and the parison, the mold is closed, and then two opposing sheets of the parison are extruded in the compression section of the mold cavity. The walls and fiber sheets are clamped and compressed together and are in a molten state.The fiber sheets are laminated by the heat and adhesiveness of the parison, and the fiber sheets are in a molten state by the pressurizing force in the compression part where the clamping pressure of the mold directly acts. The parison is inserted into small gaps in the fiber sheet to form a thin hinge, and pressurized fluid is blown into the parison to expand the parison and form it into the external shape of the main body and lid in the mold cavity. The present invention also relates to a method for manufacturing a plastic container, characterized in that a fiber sheet is laminated on the surface of the main body and the lid under the pressure of expansion of the adhesive or parison.

[Effect]

While the method of laminating fiber sheets on the body and lid of a plastic container uses the inflation pressure of pressurized fluid (usually 3 to 7 kg/cm ² ),
As a means of laminating fiber sheets on the hinges of plastic containers that require repeated bending characteristics, mold clamping pressure (usually 50 to 1000 kg/cm ² ), which is completely different from the inflation pressure of pressurized fluid, is directly applied. This is done in a compression section formed opposite the mold cavity. The two opposing walls of the parison and the fiber sheet are then integrated into a single, laminated, thin-walled hinge, which resists the heat and stickiness of the parison in its molten state. It is formed by inserting the parison in a molten state into the fine gaps of the fiber sheet due to the extremely high compression force in the compression section where the pressurizing force from high-pressure mold clamping is directly applied. The repeated bending characteristics of the thus manufactured hinge are far superior to those obtained by simply laminating other reinforcing sheets by means such as welding or gluing. In addition, if the pressure applied to the lamination is extremely high, the parison bitten into the surface of the laminated fiber sheets from the opposite side may be partially exposed, or the texture of the fiber sheets themselves may be impaired; however, in the present invention, Since the pressure applied when laminating the fiber sheet on the surface of the body or lid is much lower than the pressure applied when forming the hinge, the fiber sheet laminated on the surface of the body or lid of the resulting plastic container is A plastic container with high commercial value without damaging the appearance can be obtained.

〔Example〕

Hereinafter, the present invention will be explained based on examples.

In the figure, numerals 1 and 2 are split-type molds, and numeral 3 is a parison extruded from an extrusion head 4. One of the molds 1 and 2 has concave cavities 1a and 1b forming the outer walls of the main body and the lid, and a compression part 1c forming a hinge, and the other mold 2 has concave cavities 1a and 1b forming the outer walls of the lid body and a compression part 1c forming the hinge. It has convex cavities 2a, 2b that face the concave cavities 1a, 1b and form the inner walls of the main body and lid body, and a compressed part 2c that faces the compressed part 1c and forms a hinge. Further, 5 is a blow pin for blowing pressurized fluid such as compressed air into the parison 3, 6 is an exhaust hole for exhausting the fluid in the cavity to the outside, and 7 is a fiber sheet held by clamps 8.

However, as shown in Figure 1, polyethylene,
A thermoplastic such as polypropylene is melt-kneaded in an extruder (not shown) and the molten parison is extruded from an extrusion head 4 between molds 1 and 2 spaced apart from each other. A fiber sheet 7 held by clamps 8 is placed between the mold 2 and the parison 3 that form the inner walls of the main body and lid. Next, both molds 1 and 2
is closed, the blow pin 5 is inserted into the parison 3, and a pressurized fluid such as compressed air (3 to 14
Kg/cm ² ). At the same time, the fluid in the cavity may be forcibly discharged from the exhaust hole 6 to the outside. In this way, the parison 3 expands into a shape corresponding to the cavities, and the hollow double-walled main body 9 is formed in the cavities 1a and 2a, and the hollow double-walled body 9 is formed in the cavities 1b and 2a.
The hollow double-walled lid 10 is compressed at 2b, and the parison 3 is further compressed at compression parts 1c and 2c to form a thin hinge 11. During this molding, the fiber sheet 7 located between the mold 2 and the parison 3 comes into contact with the surface of the expanding parison 3, and in the cavities 2a and 2b, the main body 9, the inner wall 9' of the lid 10,
10', the fiber sheet 7 is closely laminated on the surface of the parison 3 due to the heat (100 to 280 DEG C.), adhesiveness, and expansion pressure of the parison 3 in a molten state. Further, the fiber sheets 7 are compressed together with the parison in the compression parts 1c and 2c, and a hinge is formed on the surface of which the fiber sheets 7 are closely laminated. In particular, the pressure applied by the compression parts 1c and 2c of the mold allows the parison 3 in a molten state to fit into the small gaps, thereby improving the adhesion between the fiber sheet 7 and the parison 3. Next, after cooling and solidifying the molded product, the molds 1 and 2 are opened, and the molded product is taken out and unnecessary flash is removed to form a main body 9 and a lid 10 having a double wall structure as shown in FIG. The main body 9, the inner walls 9, 10' of the lid 10, and the hinge 11 that connect these together.
A plastic container 1 whose surface consists of a fiber layer 7
2 is obtained.

The above-mentioned embodiment describes in detail the method for manufacturing a plastic container in which the entire surface of the inner wall of the container is made of a fiber layer, but the present invention is not limited to the above-mentioned embodiment. The entire surface, the entire surface of the outer wall of the container,
The container of the present invention can also be obtained by forming a fiber layer on the outer wall or inner wall of the container, or on a part of the surface of the main body or the lid, by arranging the fiber sheet at a desired position.

In addition, when manufacturing a container, a latch consisting of a fitting protrusion and a fitting recess is integrally provided on the mating surfaces of the main body and the lid, and the inner or outer walls of the main body and the lid are shaped to correspond to the stored items. The formation can be performed arbitrarily by known means. Alternatively, the inner wall or outer wall of the main body and the lid may be partially cut and opened by secondary processing, so that the main body and the lid have a single-wall structure. In addition, means for applying adhesion to one or both of the parison or the fibrous sheet, such as an adhesive, may be used to increase the lamination strength of the fibrous layer.

Plastics used in the present invention include soft materials such as polyethylene (low density, medium density, and high density), polypropylene, ethylene-vinyl acetate copolymer, vinyl chloride, ABS, nylon, and polyester.
A hard and elastic thermoplastic, fiber sheets include natural fibers such as cotton, linen, wool, and silk, recycled fibers such as viscose rayon and copper ammonia rayon, semi-synthetic fibers such as acetate and rayon, nylon, and polyester. , acrylic, vinylon, polypropylene, polyurethane, and other synthetic fibers, as well as woven, knitted, and nonwoven fabrics obtained by processing synthetic fibers such as acrylic, vinylon, polypropylene, polyurethane, and blended fibers. In particular, in order to obtain a container with a complex shape and a good appearance and feel, it is desirable to use a highly elastic knitted fabric containing 20% or more of thermoplastic synthetic fibers.

〔Effect of the invention〕

As described above, in the manufacturing method of the present invention, it is possible to efficiently obtain a plastic container consisting of a double-walled main body with excellent surface appearance characteristics, a lid body, and a hinge connecting these parts, and whose surface is made of a fiber layer. be able to. In addition, the container obtained by the manufacturing method of the present invention has an excellent appearance, texture, and feel because the desired surface is composed of a fiber layer, and especially when the outer wall of the container is made of a fiber layer, The decorativeness of the container is improved, and when the surface of the inner wall of the container is made of a fiber layer, the protective properties of stored items are improved, and the commercial value of the container is improved. Furthermore, since a fiber layer is inserted into the surface of the hinge that connects the main body and the lid, the repeated bending characteristics (hinge life) are improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a partially cutaway perspective view of a container obtained by the present invention,
FIG. 3 is an enlarged sectional view of the hinge portion. 1, 2: mold, 3: parison, 7: fiber sheet, 9: main body, 10: lid, 11: hinge.

Claims (1)

[Claims] 1. A parison is extruded between opposingly spaced molds, a fiber sheet is placed between the mold and the parison, the mold is closed, and the two opposing walls of the parison are extruded in the compression section of the mold cavity. The fiber sheets are sandwiched together and compressed, and the fiber sheets are laminated using the heat and adhesiveness of the parison in a molten state. At the same time, the parison is in a molten state due to the pressurizing force in the compression part where the clamping pressure of the mold directly acts. A thin hinge is formed by inserting it into the small gap of the fiber sheet, and pressurized fluid is blown into the parison to expand the parison and form it into the external shape of the main body and lid in the mold cavity, while also reducing the heat and adhesion of the parison. A method for manufacturing a plastic container, characterized in that a fiber sheet is laminated on the surface of a main body and a lid under the expansion pressure of a parison.