JPH09301394A - Cap made up by insert injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adaptability in conveyance by means of vacuum system on a filling machine by a method wherein a cap constructed of a top plate made of a laminated board having paper as its base and a plastic cylindrical circumferential wall is provided with a top plate receiving part at the upper part at the inside extending all over its cylindrical circumferential wall so that the face of the top plate receiving part to be stuck to the top plate is formed in a slope looking upward in the direction heading toward the center. SOLUTION: A cap made up by insert injection molding suitably used for a container for dessert such as ice cream or yoghurt is constructed of a top plate 200 made of a laminated board having paper layer as its base and a plastic cylindrical circumferential wall 100 is provided with a top plate receiving part 110 at the upper part at the inside extending all over its cylindrical circumferential wall 100 so that the face 111 of the top plate receiving part to be stuck to the top plate is formed in a slope looking upward in the direction heading toward the center. An indented groove 112 may be provided at the surface of the top plate receiving part 110, running all round along the joint to the cylindrical circumferential wall 100. The cap is made up in a way wherein the cylindrical circumferential wall 100 is made of polystyrene by injection molding with the top plate 200 mounted on a cavity of a metal mold for the cylindrical circumferential wall 100 and the top plate 200 is stuck by heat sealing to the cylindrical circumferential wall 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insert injection molding lid used for a dessert container such as ice cream or yogurt or a paper container such as a powder container for detergent.

[0002]

2. Description of the Related Art Conventionally, a lid for covering a paper container for containing gel, powder, granules, viscous contents, etc. has been provided all around the inner surface of a peripheral wall cylinder made of polyethylene by injection molding. It has been widely used that a top plate of a laminated plate in which a polyethylene layer is provided on both sides of a paper layer on which letters and patterns are printed is heat-fused and bonded by ultrasonic waves to a top plate receiving portion.

[0003]

However, the above-mentioned conventional cover for a paper container is not fixed in shape because the top plate has a convex shape or a concave shape depending on how the top plate is adhered. , When carrying the vacuum method on the filling machine, an accident such as a poor transfer sometimes occurred. Further, the peripheral wall cylinder and the top plate are manufactured separately, and then the peripheral wall cylinder and the top plate are adhered to each other, resulting in a large number of manufacturing steps and a long manufacturing time and cost.

The present invention solves the above-mentioned problem of the conventional cover, in which the shape of the top plate is always slightly convex upward, and the vacuum system on the filling machine has good transportability. The present invention provides an insert injection molding lid having good stacking suitability and a small number of manufacturing steps.

[0005]

The first invention of the present invention is as follows:
As shown in FIG. 1, a top plate (2
00) and a plastic peripheral wall cylinder (100), the top plate having an adhesive surface (111) with the top plate that is upwardly inclined in the central direction on the entire circumference above the inner surface of the peripheral wall cylinder. The insert injection molding lid (10) is characterized in that a receiving portion (110) is provided.

[0006] The second invention, as shown in FIG.
A lid composed of a laminated top plate (200) having a paper layer as a base material and a plastic peripheral wall cylinder (100), wherein an adhesive surface ( 111)
Has an upward slope in the central direction, and is provided with a top plate receiving portion (110) having a groove (112) on the entire upper surface of the base of the peripheral wall cylinder. 10).

[0007]

In the insert injection-molding lid of the present invention, at the time of manufacturing, the peripheral wall cylinder is injection-molded, and at the same time, the top plate preliminarily mounted in the mold is attached to the peripheral wall cylinder whose bonding surface has an upward slope toward the center. Since it is heat-fused and adhered to the top plate receiving portion, the top plate after molding is always stably formed in a convex shape. Therefore, the vacuum system has good suitability for conveyance on the filling machine.

Further, the insert injection molding lid of the present invention in which the top plate receiving portion having the concave groove is provided on the entire upper surface of the base of the peripheral wall cylinder, the top plate receiving portion is centered by shrinkage in the cooling process after the molding. Although it is pulled downward, the upper end of the peripheral wall cylinder can be prevented from falling inward because of the concave groove, and the stacking suitability is good.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The insert injection-molding lid of the present invention comprises a top plate having a predetermined shape mounted in advance in an injection mold of a peripheral wall cylinder, injection molding the peripheral wall cylinder, and at the same time, receiving the top plate of the peripheral wall cylinder. The top plate is heat-sealed to the section. Therefore,
The manufacturing process can be reduced as compared with the conventional cover.

For the peripheral wall cylinder, a thermoplastic resin such as polystyrene having a relatively small molding shrinkage is selected and injection-molded to form an occlusal projection with the container below the inner surface of the peripheral wall cylinder, and the entire circumference above the inner surface. A top plate receiving portion is provided, the surface of which is adhered to the top plate having a predetermined upward gradient in the central direction.

The top plate is a paper layer on which letters and pictures are printed, and a layer which is heat-sealed to the material of the peripheral wall cylinder is provided on the lower surface of the paper layer. For example, (upper) polyethylene layer / paper layer / heat seal There is an agent layer (lower side) configuration and an (upper) polyethylene layer / paper layer / polyethylene layer / heat seal agent layer (lower side) configuration.

[0012]

EXAMPLE First, a top plate was mounted on a predetermined position of a cavity of an injection molding die of a peripheral wall cylinder attached to an injection molding machine, and then the peripheral wall cylinder was injection molded with polystyrene, and at the same time, the top plate was mounted on the peripheral wall cylinder. The insert injection molding lid of this example was produced by bonding by heat fusion. The lid of this example had fewer manufacturing steps than the conventional cover lid.

In the peripheral wall cylinder of this embodiment, the outer shape of the horizontal cross section is a square shape having rounded corners, and the bonding surface with the top plate is inclined upward by 2 ° toward the center all around the inner surface. The top plate receiving portion having the above is provided, and the occlusal protrusions that occlude the flange at the upper end of the container are provided at four locations below the inner surface. Further, stack ribs are vertically provided at four positions from the lower surface of the top plate receiving portion to a predetermined position of the peripheral wall cylinder.

The top plate of the present embodiment is a square plate having rounded corners after printing characters and patterns on a laminated plate having a (upper) polyethylene layer / paper layer / heat sealant layer (lower side) structure. Since it was cut to a predetermined size and adhered to the top plate receiving portion having an upward slope of 2 ° in the central direction of the peripheral wall tube, it was slightly convex upward.

Next, the insert injection molding lid of this embodiment was loaded into a filling machine, and the container was filled with the contents and sealed. The vacuum system had very good transportability. Further, the upper end of the peripheral wall cylinder did not fall inside and the stacking suitability was good.

[0016]

INDUSTRIAL APPLICABILITY The insert injection-molded lid of the present invention has a top plate that is always slightly convex, has good transportability by a vacuum system on a filling machine, and is superior to conventional lids. Therefore, the number of manufacturing processes is small, and the manufacturing time and manufacturing cost can be reduced. The insert injection molding lid of the present invention having the groove at the base of the top plate receiving portion with the peripheral wall cylinder does not fall into the inside of the upper end of the peripheral wall cylinder after molding, and thus has good stacking suitability.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an insert injection molding lid of the present invention.

[Explanation of symbols]

 10 ... Insert injection molding lid 100 ... Peripheral wall cylinder 110 ... Top plate receiving part 111 ... Adhesive surface 112 ... Recessed groove 120 ... Occlusal protrusion 130 ... Stack rib 200 ... Top plate

Claims (2)

[Claims] 1. A lid comprising a top plate of a laminated board having a paper layer as a base material and a peripheral wall cylinder made of plastic, wherein an adhesive surface to the top plate is centered on the entire circumference above the inner surface of the peripheral wall cylinder. An insert injection molding lid, characterized in that a top plate receiving portion having an upward slope in the direction is provided. 2. A lid comprising a top plate of a laminated plate having a paper layer as a base material and a peripheral wall cylinder made of plastic, wherein an adhesive surface to the top plate is centered on the entire circumference above the inner surface of the peripheral wall cylinder. An insert injection molding lid, characterized in that a top plate receiving portion having an upward slope in a direction and having a groove on the entire upper surface of the base of the peripheral wall cylinder is provided.