JPH01115618A - Manufacture of vessel-like molded body - Google Patents

Abstract

PURPOSE:To manufacture efficiently a vessel-like molded body having double structure of thermoplastric resin sheet, by a method wherein the thermoplastic resin sheet is softened, an air-contained body formed by wrapping air between two sheets is formed and vacuum molding is performed by pressing the body by placing between a top and bottom forces. CONSTITUTION:A top and bottom two thermoplastic resin sheets 2, 2 are transferred to a heating region 3. The two sheets 2, 2 are heated by blowing air 4 into a space between them, the sheets 2, 2 cured through heating by lowering a shutter 5 provided at an outlet part of the heating region and constituted movably vertically are pressed vertically and the sheets 2, 2 are fused together along a widthward direction. When a part fused through an action of the shutter 5 arrives at the vicinity of an outlet of the molding tool 6, the sheets 2, 2 are fused together along the widthward direction by lowering the shutter 5 again, through which an air-contained body 7 obtained by wrapping the air between the sheets 2, 2 is formed. A vessel-like molded body 10 is formed by performing vacuum molding by pressing the air-contained body 7 by placing the same between a top and bottom forces 8, 9 of the molding tool 6.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a container-like molded body.

[Conventional technology and Problems that the invention attempts to solve]

In recent years, packaging containers consisting of a container body made of a thermoplastic resin sheet and a lid have been widely used as packaging containers for small electrical products such as small cassette players, hair dryers, and electric razors. However, in conventional containers of this kind, the lid and container body are made of a single plate made of a thermoplastic resin sheet molded into a predetermined shape, so they easily deform when external force is applied. For this reason, conventional packaging containers have poor protection effects for the products stored in them, and especially in the case of electrical products, there is a risk that the product may be deformed or may not be able to maintain its original performance due to impact, resulting in loss of product value. was there. In addition, some containers of this kind are configured so that a locking protrusion is provided on the lid, and a locking piece provided on the container body is engaged with the projection to close the container body with the lid. In the lid of a conventional container, the strength of the locking protrusion is weak, and there is also a problem that the locking protrusion is damaged if the lid is repeatedly engaged and disengaged.

As a solution to these problems, a container with a double structure of thermoplastic resin sheets has been proposed. Conventionally, this type of container consists of a sheet extruded into a tube shape, sandwiched between molds, and air inside. It is molded by the so-called blow molding method. However, the blow molding method has the drawbacks of being able to mold many molds at once, resulting in poor production efficiency and difficulty in molding complex shapes.Furthermore, when a transparent sheet is used, the resulting There was also the problem of reduced transparency.

[Means for solving problems]

The present invention has been made in view of the above points, and aims to provide a manufacturing method capable of solving the drawbacks of conventional methods and efficiently manufacturing a container-like molded body having a double structure of thermoplastic resin sheets. purpose.

That is, in the present invention, two upper and lower thermoplastic resin sheets are transferred to a heating area, and in the heating area, air is sent between the two sheets to heat them, softening the thermoplastic resin sheets, and heating the two sheets. A method for manufacturing a container-like molded body, which comprises forming an air-containing body by enclosing air therebetween, and then compressing the heated and softened air-containing body between upper and lower molds to form it under vacuum. The main points are as follows.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, 1 and 1 are rolls of thermoplastic resin sheets, and two upper and lower thermoplastic resin sheets 2.2 sent out from the roll 1.1 are first transferred to a heating area 3. In the heating area 3, the longitudinal edges of the sheet 2.2 are sandwiched between chain helds, etc. while the sheet is being transported.
Air 4 is blown between the sheets 2 and 2 to heat them. On the other hand, a shutter 5 provided at the exit of the heating area 3 and configured to be able to move up and down is lowered to soften the heated sheet 2.
2 is pressed from above and below, and the sheets 2.2 are fused along the width direction. The shutter 5 is configured to descend at predetermined intervals, and when the sheet 2.2 is further transported and the portion previously fused by the action of the shutter 5 reaches the vicinity of the exit of the mold 6, the shutter 5 is lowered again. descends and seats 1
2.2 is fused along the width direction, thereby forming sheet 2
．． An air-containing body 7 that encloses air between the two is formed.

A container-like molded body 10 is formed by vacuum forming the air-containing body 7 by compressing it between the upper mold 8 and the lower mold 9 of the mold 6.

Examples of the thermoplastic resin sheet 2.2 used in the present invention include olefinic resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polystyrene, styrene-butadiene copolymers, and styrene-propylene copolymers.
Examples include styrene resins such as mixtures of butadiene copolymers and polystyrene, polyvinyl chloride, polycarbonates, and the like. Further, a transparent resin is appropriately selected and used depending on the purpose. The thermoplastic resin sheet 2 preferably has a thickness of 0.1 to 2 mm.

In the method of the present invention, it is preferable to use a mold having a plurality of molding recesses 11 as shown in FIG. 2 to simultaneously mold a plurality of container-like molded bodies 10. Also, upper mold 8 or lower mold 9
around the molding recess 11 in at least one mold of
It is preferable to provide a through groove 13 in a portion 12 forming a fused portion at the peripheral edge of the container-like molded body IO. By providing such a through groove 13, the upper mold 8 during molding can be
, the air inside the air-containing body 7 is properly vented when compressed by the lower mold 9, and there is no risk of the air-containing body 7 bursting during molding, and even if the air inside the air-containing body 7 is Even if it escapes, there is no risk that air will be sucked into the air-containing body 7 during vacuum forming and a collapsed container-like molded object IO will be obtained.

After forming as described above, cutting is performed in the width direction with the cutter 14, and further cutting is performed between the forming portions of each container-like molded body 10 to form a peripheral edge portion as shown in FIGS. 3 and 4, for example. A lid 15 is obtained as a container-like molded body 10 having a hollow structure and having the lid 21 fused thereto. This lid body 15 has a locking projection 16 and a gripping portion 17. For example, as shown in the same figure, a locking piece 1 is placed at a position corresponding to the locking projection 16 and gripping portion I7 of the lid body 15.
The container body 20 is used in combination with a container body 20 having a locking piece 18 and a gripping part 19, and the lid of this container can be closed and opened by engaging and disengaging the locking piece 18 with the locking protrusion 16. When the lid is closed, the grip part 17 It is constructed so that it can be carried with a .19.

In the above embodiments, the container-like molded body is a lid, but in the present invention, the container-like molded body may be either a container lid or a container body. It can be applied to both the case of manufacturing only the container body and the case of manufacturing both the lid and the container body.

〔Effect of the invention〕

As explained above, in the method of the present invention, two upper and lower thermoplastic resin sheets are transferred to a heating area, and in the heating area, air is sent between the two sheets to heat them, softening the thermoplastic resin sheets, and By adopting a method of vacuum forming by enclosing air between two sheets to form an air-containing body, and then compressing the heated and softened air-containing body between upper and lower molds, it is possible to form multiple containers. The molded bodies can be molded at the same time, and hollow container-like molded bodies can be efficiently manufactured. Furthermore, according to the method of the present invention, it is possible to produce a molded article with a shape that could not be molded using conventional blow molding methods, and when a transparent sheet is used, its transparency is not reduced. It has effects such as being able to obtain a container-like molded article with excellent transparency.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, FIG. 1 is a process diagram showing the manufacturing method of the present invention, FIG. 2 is a perspective view showing an example of a mold used in the present invention, and FIG. 3 is a mold manufactured by the method of the present invention. An exploded perspective view of an example of a container using a lid body, FIG. 4 is the IV of FIG.
- It is a longitudinal cross-sectional view along the IV line. 2. Thermoplastic resin sheet 3. Heating area 4. Air 6. Molding mold 10. Container-like molded body

Claims (1)

[Claims] (1) Two upper and lower thermoplastic resin sheets are transferred to a heating area, where air is fed between the two sheets to heat them, soften the thermoplastic resin sheets, and ,
A container-like molded article characterized in that an air-containing body is formed by enclosing air between two sheets, and then the heated and softened air-containing body is compressed and vacuum-formed between upper and lower molds. Production method. (2) The method for producing a container-like molded object according to claim 1, wherein the container-like molded object is a container lid and/or a container body. (3) The method for producing a container-like molded body according to claim 1 or 2, wherein a plurality of container-like molded bodies are simultaneously molded using a mold having a plurality of container-like molded body molding recesses.