JPS58102721A - Molding method for plastic container - Google Patents

Abstract

PURPOSE:To form a reinforcing rib or an arbitrary shape, i.e., letters, patterns, in a container, by a method wherein a heat-flowing agent is applied to a plastic sheet surface, it is heat-foamed at a vacuum-molding time, and a shape, which is not provided in a mold, is formed by a foaming action. CONSTITUTION:A heat-flowing agent 2 is coated or printed on a plastic sheet 1 surface. The sheet 1 is then vacuum-molded so that the surface of the heat-flowing agent 2 is positioned at a mold side. The heat-flowing agent 2 is foamed by heat generated by heating at a molding time, the plastic sheet 1 is brought into such a condition that it escapes to an opposite side to the foamed side, a surface where the heat-flowing agent 2 appears, forms the very surface of the container, and a convex rib (b) is provided on the inner side of the container.

Description

DETAILED DESCRIPTION OF THE INVENTION When manufacturing a container by molding a plastic sheet by vacuum forming, the present invention forms a concave pattern on the surface of the container to perform auxiliary molding of the container. This invention relates to a method for molding plastic containers with characters, decorative patterns, or reinforcement patterns as shown in the following.

A typical example of molding containers using plastic sheets is the vacuum forming method, in which a heated plastic sheet is brought into close contact with a mold using a suction force generated from the difference between atmospheric pressure and the pressure of a vacuum device. The molds used in this vacuum forming method include female molds, male molds, and plugs used in combination with these molds, and have a shape that matches the shape of the molded product. Therefore, when the shape of the molded product is complex, such as when forming reinforcing ribs, or when the surface of the container has an uneven pattern,
The disadvantage is that the mold itself needs to be modified, and it takes a lot of time and money to make the mold. Furthermore, if the ribs or patterns are different, it is necessary to prepare a mold for each.

From this point of view, the present invention proposes a molding method that can perform auxiliary formation or pattern molding in an extremely simple method without relying on a mold other than the shape of a container. Apply heated foaming material to the surface of
Heat and vacuum form with this coated side facing the mold side,
This is a method of forming plastic containers in which a part of the container is auxiliary or patterned by the foaming action of a heated foaming material.

The present invention will be described in detail below based on embodiment figures.

First, as shown in Figure 1.2, a heated foaming material 2 is applied or printed on the surface of a plastic sheet 1. This heated foaming material foams when heated, and its attached area increases by 3 to 8 times. The type of paint or ink that can be printed with the printing layer is then the plastic sheet l coated with the heat foaming material 2 by the above method, as shown in Figure 3.4. Vacuum forming is performed so that the surface of 2 faces the mold 3 side.

When molding is performed in this manner, the heated foaming material 2 is foamed by the heat generated during molding, and the foamed plastic sheet 1 has a shape in which it escapes outward (111).

Figure 5.6 shows the shape of a container a molded by the above-mentioned molding method, in which the surface on which the heat-foamed material 2 appears is flush with the surface of the container, and there are convex ribs b on the inside of the container. It is formed.

When the heat-foamed material 2 is used as a character or pattern on a container, it is left as is, but when it is used simply to form ribs, it is removed.

As described above, the present invention prints the heat foaming material 2 on the surface of the plastic sheet 1 using a printing machine or the like, heats and foams it during vacuum forming, and uses this foaming action to form the plastic sheet 1.
Since it is used to mold shapes that are not available in molds, arbitrary shapes can be added to the container, such as for reinforcing the container, as letters or patterns, or for molding delicate shapes on the container.

Therefore, it is not necessary to spend time and money on making molds, and at the same time, the heat-foamed material 2 produces a texture (for example, velvet-like) that is not found in plastic sheets due to foaming, so this can be used as letters or patterns to create a texture on containers. It can give a sense of luxury.

[Brief explanation of the drawing]

Figure 1 is a plan view of the plastic sheet before being molded according to the present invention, Figure 2 is a side view of the plastic sheet shown in Figure 1, Figures 3.4 are explanatory views of the molding action, and Figure 5. 6 is a perspective view showing an example of a container molded according to the present invention, and FIG. 6 is a sectional view. 1... Plastic sheet, 2... Heat foaming material. 11''?1 Figure 4 Figure 5 Figure 6 Procedural amendment (method) % formula % 1. Indication of the case Patent application 1982-2019 2. Name of the invention Method for molding plastic containers 3. Person making the amendment Relationship to the case Applicant 6-15-12 Honkomagome, Bunkyo-ku, Tokyo Japan Patent Management Co., Ltd. Representative Akihiko Suzuki 4, attorney's specification 7, amendment details page 1, line 8 from the bottom "33 inventions""Name of the invention" should be corrected to "3. Detailed description of the invention."

Claims (1)

[Claims] 1. Applying a heating foaming material to the surface of a plastic sheet,
Heat and vacuum form with this coated side facing the mold side,
A plastic container molding method that applies auxiliary formation or pattern molding to a portion of the container using the foaming action of a heated foaming material. 2. The method for molding a plastic container according to claim 1, wherein the heat-foamed material comprises printing ink.