JPS6360727A - Manufacture of vessel made of foamed sheet and molding tool therefor - Google Patents

Abstract

PURPOSE:To prevent fouling of the inside of a vessel by controlling generation of slug, by a method wherein a part corresponding to a circumferential parting part of a molded vessel at the following trimming at the time of molding is cured by stronger smashing than the other part. CONSTITUTION:A stepped part 18 in a protruded state, which is ejected toward an upper male mold 2, is provided on a position corresponding to a circumferential parting part 17 of a molded vessel 1. The stepped part 18 crushed strongly further a part corresponding to the circumferential parting part 17 of the molded vessel 1 at the time of molding and a thickness of a part corresponding to the circumferential parting part 17 is cured by thinning the same. Then through a molded product (b) is trimmed and the molded vessel 1 is blanked after the circumferential parting part 17, as the circumferential parting part 17 is thin and comparatively hard, shearing is performed smooth and generation of slug is controlled.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a manufacturing method and a mold for forming containers made of foam sheets, such as packaging containers for various foods, and particularly for take-out products (take-out sales). This invention relates to a method for manufacturing a foam sheet container useful for packaging containers such as commercial products, and a mold for forming the container.

<Prior art> Conventionally, in the manufacture of this type of storage container, for example, a thermoplastic resin sheet such as a foamed polystyrene sheet is used, and compression molding is carried out using a molding die consisting of a male die and a female die. In order to achieve mass production, a large number of molded containers are connected to one foam sheet in order to achieve mass production. .

A single molded container is obtained by separating a large number of molded containers connected in this way from each other.

In the above manufacturing technology, it is necessary to trim the molded containers after forming the sheet, that is, to separate the molded containers from each other and to remove the excess parts (ears) around the molded containers. , and a holding mold that can be inserted through the inside of the frame mold are known.

This trimming device, for example, presses a molded container inside the molded product with a presser die while supporting the ear portion of the sheet molded product with a frame mold, and then presses the molded container inside the molded product and the ear portion of the sheet molded product. By punching along the boundary with the molded container, the molded container and the ear can be separated.

The boundary portion between the ear portion of the sheet molded product and the molded container inside thereof is the cutout portion for trimming. Note that a typical example of such a trimming device is one disclosed in Japanese Patent Application Laid-Open No. 58-219018.

<Problems to be Solved by the Invention> By the way, in the above-mentioned trimming device, the molded container is punched out along the boundary between the ear part of the sheet molded product and the molded container inside, that is, the punched-out part. So,
The molded container is, so to speak, sheared and separated from the foam sheet molded product.

In such a case, fibrous cutting waste (particles) is generated in the punching area of the molded product made of foam due to the above-mentioned punching, and this cutting waste falls off and enters the molded container, damaging the inside of the container. It can get dirty.

Further, the punched-out portion where scraps are produced becomes an unattractive cut surface, which may reduce the commercial value of the molded container.

Particularly when the molded container is a food packaging container, if the scraps get into the molded container, it will be unsatisfactory in terms of hygiene and credibility.

For this reason, conventionally, in the manufacturing process of foam sheet containers, in order to remove the scraps from trimming,
The process involved applying an air shower to the punched molded container to remove the punching residue, which was time-consuming.

<Purpose> This invention was made in view of the above-mentioned problems, and its main purpose is to suppress the generation of scraps during trimming, which is a subsequent process, to prevent staining of the inside of the container, and to prevent further trimming from occurring in the subsequent trimming process. It is an object of the present invention to provide a method for manufacturing a container made of a foamed sheet, which makes it possible to simplify the manufacturing process by omitting various steps of removing waste, and a mold for use in the method for manufacturing a container made of a foamed sheet. .

In addition, for other purposes, it can be suitably used in a method for manufacturing containers made of foamed sheets, which improves the appearance of the cut surface of the cut portion during trimming, and improves product value, and a method for manufacturing containers made from foamed sheets. The object of the present invention is to provide a mold for molding.

Means for Solving the Problems> The method for manufacturing the foam sheet container of the first invention to achieve the above object includes press-molding a thermoplastic resin foam sheet softened by heat into a predetermined shape. , in a method for manufacturing a foam sheet container in which a desired molded container is formed by trimming, during the molding, a portion corresponding to the cut-out portion of the molded container in subsequent trimming is crushed more forcefully than other portions. The mold for molding the container made of foamed sheet according to the second invention is composed of a male mold and a female mold, and is characterized by hardening the foamed sheet of thermoplastic resin that has been softened by heating into a predetermined shape. In a mold for forming a foam sheet container to be molded, at least one of the male mold and the female mold is provided with a protrusion that crushes and hardens a portion corresponding to the cut-out portion of the molded container more strongly than other portions during the molding. It is characterized by having a stepped portion.

Effect> According to the method for manufacturing a foamed sheet container having the configuration of the first aspect of the invention, prior to punching out the molded container in trimming, the portion corresponding to the punched-out portion of the molded container is crushed;
Since the portion corresponding to the punched portion is made thin and hardened, shearing at this portion is performed smoothly during punching, and generation of punched dregs can be suppressed.

Further, according to the mold for forming a container made of a foamed sheet having the configuration of the second aspect of the invention, the protruding stepped portion of at least one of the male mold and the female mold allows the portion corresponding to the cut-out portion of the molded container to be formed during molding. This is necessary in the method for manufacturing a foam sheet container having the configuration of the first invention, since the foam sheet container can be crushed more strongly than other parts, and the part corresponding to the punched-out part can be made thinner and harder. Molding can be performed accurately.

<Example> Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments.

First, with reference to FIGS. 1 to 3, a method for manufacturing a foamed sheet container of the present invention and a molded container (1) manufactured using the same mold will be described.

The molded container (1) is a packaging container suitably used for take-out sales of snack foods such as hamburgers, and is a sheet molded product made of expanded polystyrene. This molded container (1) includes a container body (goods) and a lid body (11) that are integrally connected at a hinge part (4) and can be fitted to each other, and a fitting engagement member is provided on the opening side of the container body. An engaging hole (12) for locking is formed on the lid (11) side, and when the container main body opening and the lid (11) are fitted, a locking hole (12) is inserted into the engaging hole (12) and locked. A tongue-shaped engagement piece (15) is provided in a protruding manner.

The engagement hole (12) is formed in a rising part (14) that extends upward from a step (13) formed at the front edge of the container body opening and becomes a vertical side surface. 14) in the horizontal direction.

Therefore, in order to use such a molded container (1) as a packaging container, the opening of the container body and the lid (11) must be connected to the hinge portion (
4) (see Figure 2), and as shown in Figure 3, insert and lock the engaging piece (15) into the engaging hole (12) to connect the container body opening and the lid (11). This is done by fitting and fixing the

Next, the characteristic components of this molded container (11) are as shown in FIG.
The thickness of the peripheral edge portion (16) is made thinner by, for example, being crushed from above and below. This peripheral edge portion (16) corresponds to the cut-out portion (17) (encircled by two chain lines) of the molded product (b) shown in FIG. 6, which will be described later. ) is a cut portion of a molded container (1) punched out using a known trimming device (not shown).

FIGS. 4 and 5 show the molding process for manufacturing the molded container (1). A pair of male and female molds (2).

(3) are an upper mold and a lower mold installed in a known press molding apparatus (not shown), and they are respectively used for the molded container (1) shown in FIG.
) is formed with an uneven shape corresponding to the outer shape.

First, as shown in Fig. 4, heat-softened expanded polystyrene sheet (a) is placed between the male mold (2) and the female mold (3), and then, as shown in Fig. 5, the male mold (2) and the female mold (3) are closed, the softened expanded polystyrene sheet (a) is press-molded, and a sheet molded product of a predetermined shape (
b) is molded (side view: see Figure 1, plan view: see Figure 6).

゛The molding process using the male mold [2] and female mold [3] is basically carried out in the same way as normal sheet molding, and other structures such as the sheet holding mechanism and heating mechanism are Since the molding apparatus is also implemented with the same structure as the conventional apparatus, detailed illustrations and descriptions of the molding process and the structure of the molding apparatus will be omitted.

On the other hand, the male die (
2. Of the female mold (3), for example, a fourth As can be seen from the figure, the protruding stepped portion (18
) is provided.

In this case, the protruding step portion (1B) is formed by further crushing the portion of the molded container (1) corresponding to the punched-out portion (17) during the above-mentioned molding. This is to make the wall thinner and harder.

Therefore, the part corresponding to the cut-out part (17) of the closed molded product (b) molded container] 1) (see Fig. 6) has a protrusion ( 18), the wall thickness becomes thinner and a hardened portion is formed.

In this way, when the molded product (b) is molded and at the same time a hard thin wall portion is formed at a location corresponding to the cut-out portion (17) of the molded container (1), the male mold (2) and the female mold ( After opening the mold and removing the molded product (b) from the mold, the molded product (b) shown in FIG. 6 is obtained.

Thereafter, the molded product (b) is transported to a trimming device in the post-process and trimmed, and the molded container (1) is punched out along the punched-out portion (17), but as described above, Since the punching portion 17) is thinner and relatively hard compared to the conventional case, shearing during punching is performed smoothly and generation of punched dregs is suppressed.

In addition, since shearing during punching is performed smoothly and generation of punching dregs is suppressed, the peripheral edge of the molded container (1) can be cut with good appearance.

In addition, the protruding step (18) makes the cut-out portion (17) of the molded container (1) thin, and an appropriate recess is formed here, so this recess is used for trimming of the molded product (b). It has the advantage that it can be used as a means for positioning the device.

In addition, in the above embodiment, the protrusion (18) is of the female type (3).
The case where the molded container [1] is provided at a location corresponding to the cut-out portion (17) has been described. however,
In addition, this protruding step part (18) may be provided at a location corresponding to the extraction part (17) of the molded container [1] of the male mold (2), and the male mold (2) and the female mold It may also be provided in both the same corresponding locations as in (3).

In addition, the protrusion (18) is of these male type (2) and female type (3).
The male mold [2] and female mold (3 ) is not limited to the above embodiments, and various design changes can be made without changing the gist of the invention.

<Effects of the Invention> As described above, according to the method for manufacturing a foam sheet container having the configuration of the first invention, when punching for trimming, shearing is performed smoothly in this part, and the punched waste is not removed. Since the occurrence can be reliably suppressed, it is possible to prevent the inside of the punched molded container from being contaminated and to omit the subsequent steps for removing punched dregs. For this reason, a unique effect is achieved in that the manufacturing process of the foam sheet container can be simplified.

Further, according to the mold for forming a container made of foamed sheet having the structure of the second aspect of the invention, a protruding step is formed in at least one of the male mold and the female mold at a location corresponding to the cutout portion during trimming of the molded container. During molding, the part corresponding to the recessed part of the molded container can be more strongly crushed, and the wall thickness of the part corresponding to the retracted part can be made thinner and harder. For this reason, the unique effect of being able to reliably carry out the molding required in the method for manufacturing a foam sheet container having the structure of the first aspect of the invention is achieved.

Specific Examples In order to demonstrate the effects of the invention described above, a molded product of foamed polystyrene sheet (a) was crushed using the protrusions 18). The condition settings are shown below.

Male Female Molding Mold 2 Normal hamburger container general-purpose mold, a protrusion is attached at the position corresponding to the removal of the female mold.Protrusion shape - Width 4 mm, height 1 mm Raw fabric sheet for molding 2 Foamed polystyrene sheet Tsubo Jl 14
0g4. Thickness 1.7 mm, width 960 mm Molding conditions: Furnace temperature 130°C, molding cycle 3
．． 5 seconds/shot, mold: H Under conditions of 80°C for the male mold and 30°C for the female mold, as shown in the table below, the results are extremely good compared to conventional molds that are not provided with these protrusions. It was confirmed that this was obtained.

In other words, the punching thickness decreased from the conventional 1.85 to 1.16, and the punching condition was greatly improved. The reason why the wall thickness of the protrusion is only about 0.7 mm is crushed when the projection is 1 mm is because the wall thickness is restored to a certain extent by the impact resilience of the foamed polystyrene sheet. In the table, skirt strength is a reference item.

In this invention, the sheet molded product may be used in addition to the illustrated packaging container for hamburgers, as well as packaging containers for storing various foods and other items, and furthermore, various conventionally used sheet molded products. It can be applied to

[Brief explanation of the drawing]

1 to 3 show a molded container manufactured by a foam sheet container manufacturing method and a mold according to an embodiment of the present invention, and FIG. Figure 2 is a partially cutaway side view with the lid closed, Figure 3 is an enlarged perspective view of the engagement mechanism, Figure 4 is a sectional view of the mold before closing, and Figure 5 is a sectional view after closing the mold. , Figure 6 is a plan view of the sheet molded product. (1)...Molded container (2)...Male mold (3
)...Female mold (goods)...Container body (1
1)...Lid 1B)...Peripheral edge (
17)...Extracted portion (18)...Protruding stepped portion (a)...Expanded polystyrene sheet (b)...Molded product patent applicant Sekisui Plastics Co., Ltd. Figure 2 Figure 3

Claims (1)

[Claims] 1. Foamed thermoplastic resin sheet softened by heating After press-forming the sheet into the specified shape, molding to form the desired molded container. In the method for manufacturing a foam sheet container, hand, During the above molding, the subsequent trimming Corresponds to the cut-out part of the molded container above. Squeeze some parts harder than other parts to make them hard. Made of foam sheet that is characterized by the ability to Method of manufacturing containers. 2. Consists of male and female types, softened by heating. Forming thermoplastic resin foam sheet into specified shape For molding of foam sheet containers. Leave it behind. At least one of the male type and female type, During the above molding, in the cutout part of the molded container. Squeeze the corresponding part harder than the other part This is equipped with a protruding step that hardens by Molding of foam sheet containers featuring Usage type.