JPS5920540B2 - insulation cup - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper cup, and more particularly to a heat-insulating paper cup made of composite paper with a foamed plastic sheet laminated on at least one side of the paper.

It is generally known that foamed plastic sheets exhibit good heat insulation effects.

For this reason, various attempts have been made to make the subject heat-insulating cup using composite paper in which a foamed sheet of various plastic materials, such as polyethylene or polystyrene, is laminated on one or both sides of the paper in order to provide heat-insulating properties to the paper cup. When a cup is formed using the above-mentioned composite paper, inconveniences have conventionally occurred due to the presence of foam sheets at three locations: the top curl section, the side seam section, and the bottom curl section.

First, in the top curl part, the top curl returns due to the elasticity of the foam sheet.Second, in the side seam part, heat sealing cannot be performed satisfactorily due to the heat insulation effect of the foam sheet. Furthermore, the bulky volume of the foamed sheet caused molding defects at the bottom curl portion.

The object of the present invention is to pressurize and heat the foamed portions of the foamed sheet at the relevant locations, particularly at the side seam portions, to form a non-foamed film out of the three disadvantageous locations mentioned above. It is an object of the present invention to provide a heat insulating cup in which the elasticity of paper is reduced to improve moldability, and the heat sealing property is improved by reducing the heat insulating property.

Another object of the present invention is that the paper edge of the seam portion appearing on the inner surface of the heat insulating cup formed by the composite paper is heated during heat sealing by a bulky foam sheet laminated to the paper edge. The purpose is to provide a completely covered insulated cup.

The invention will now be explained with reference to the drawings.

Paper cups are generally formed by rolling up a side blank 1 as shown in FIG. The outermost edge of the blank 1 is a top curl part 5, and the innermost edge is a bottom curl part 4.

Both edges of the blank 1 in the circumferential direction constitute side seams. In the following description, the side edge that becomes the outer surface of the cup when it is overlapped during cup molding is referred to as the side seam part 6, and as shown in FIG. 3, an embodiment in which a foamed plastic sheet T is laminated on the inner surface of the cup I will explain about it. For those in which foamed plastic sheets are laminated on both sides of the paper 3, or those in which the foamed plastic sheets become the outer surface of the cup when forming the cup,
Since the configuration can be easily understood from the following explanation, the explanation thereof will be omitted. As shown in FIG. 1, the side blank 1 of this embodiment is made by punching out a substantially fan-shaped composite paper in which a foamed plastic sheet is laminated on at least one side of a paper 3.

Top car hole part 5, bottom car hole part 4 of blank 1
The foamed portion of the side seam portion 6 is heated under pressure to form a substantially non-foamed film as shown in FIG.

By forming the foamed portion of the top curl portion 5 into a non-foamed film, the top curl portion 5 can be easily formed and maintained as shown in FIG. That is, the foamed part of the top curl part 5 is
When the body part 7 shown in the figure is formed into a curl by remaining without becoming bubble-free, countless bubbles 1 in the curl part are formed when the curl is formed.
2 is distorted and the air in the bubble 12 is compressed or expanded, and as a result, pneumatic elasticity acts on the entire curled portion to cause it to uncurl, causing the top curled portion 5 to lose its curled shape over time. There is a drawback. Therefore, when making a heat insulating cup using the subject composite paper, it is desirable that the foamed portion of the top curl portion 5 be made into a non-foamed film as much as possible.

Next, by converting the foamed portion of the bottom curl portion 4 into a non-foamed film and molding it as shown in FIG. 2, the problem of poor molding of the bottom curl portion 4 can be solved.

If the foamed portion of the bottom curl portion 4 is curl-formed without being made foam-free, the thickness of the photol to curl portion 4 will become excessive, as is clear from the cross section in FIG. 3, and this excessive thickness and the aforementioned There is a drawback that molding defects in the bottom curl portion occur due to pneumatic elasticity caused by distortion of the foamed portion. However, curl formation troubles caused by foamed parts are generally more problematic in the top curl part 5 because the amount of deformation that occurs during curl formation is smaller, and the curl return phenomenon occurs significantly in the top curl part 5 when foam-free is not achieved. .

On the other hand, since the amount of deformation in the bottom curl part 4 is large, the uncurl phenomenon itself does not occur so markedly even if no foam is formed, but molding defects due to the bulky volume of the foamed part may occur. Occurs often. In view of the above, it is desirable to form the foamed portion of the bottom curl portion 4 into a non-foamed film.

Next, regarding the side seam portion 6 shown in FIG. 1, when conventional heat sealing was performed, it was not possible to perform satisfactory heat sealing within a desired time due to the heat insulating effect of the foamed portion.

As shown in FIG. 2, the present invention pressurizes and heats the foamed portion of the side seam portion 6 in advance to form a non-foamed film, thereby reducing the heat insulation effect of the heat-sealed portion, that is, the side seam portion 6. Thus, the purpose is to provide a side blank 1 that can be heat-sealed with sufficient strength within the required time.

As shown in the cross section of Fig. 4, the blank 1 has a cup-shaped core 11.
is wrapped in the circumferential direction around the circumferential direction, and the side seam portions 6, which are the opposite side edges in the circumferential direction, are overlapped.

The core 11 is mainly made of solid metal, and the blank 1
It has a Teflon (registered trademark) bond 9 extending along the side seam portion 6 of. The block 9 is usually made of Teflon (registered trademark) so that the cup can be easily removed from the core 11 after heat sealing. As shown in FIG. 4, a space 8 is provided between the other side end of the blank 1 overlaid on the side seam portion 6 and the end of the non-foamed film of the seam portion 6, that is, the tip of the foamed portion.

The space 8 is a clearance created when the blank 1 is wound around the core 11, and this is inevitably created when forming the cup. If this clearance is completely eliminated, there will be many cases where the foamed parts on both sides of the blank 1 overlap each other at the heat sealing part, and there is a risk that the heat sealing will be incomplete due to the heat insulating effect of the foamed parts. Fourth
The figure shows a radial section through a cup-shaped core 11, in which the prong 9 extends over the entire length of the heat-sealed body 7 of the blank 1.

After the blank 1 is wound around a core 11 and held as shown in FIG. 4, the side seam portion 6 is heated under pressure with a heated iron 10 and heat sealed. As shown in FIG. 5, the side seam 6 is
When the material is pressurized and heated in the direction of arrow A, the foamed portion of the body 7 plastically deforms and flows into the space 8 in FIG. 4, and after covering the paper edge 13 at the tip of the body 7, further It is squeezed out laterally and joined to the tip of the foamed portion of the side seam portion 6 at the abutment surface 14 . When further pressurized and heated, the foamed portion along the side seam portion 6 is squeezed and the abutting surface 14 disappears due to the fusion of the foamed portion, as shown in FIG. 6, and the paper edge 13 of the body portion 7 is completely closed. Covered by foam plastic. If the region of the body 7 where the above-described drawing process is performed is called the drawing area 18, then
As shown in FIG. 6, the foamed portion in the squeezing area 18 has been narrowed considerably compared to the state shown in FIG. Fully filled.

By filling the space 8 with foamed plastic,
The paper end 13 of the body 7 is completely covered by these plastics and is thereby isolated from the contents of the cup, for example liquids such as juices, colas, etc.

If the paper edge 13 comes into direct contact with the contents of the cup, such as cola, the cola, etc. will penetrate from the paper edge 13 into the paper 3 and moisten the paper 3, which will significantly reduce the rigidity of the cup. The disadvantage is that it cannot function. Generally, a method for isolating the paper edges 13 from the contents of the cup is to cover the paper edges 13 by applying wax or the like to the inner surface of the cup after forming the cup. This coating method has the disadvantage that separate coating equipment is required because it cannot be carried out at the same time as the cup forming process.

In the present invention, since the paper edge 13 can be covered at the same time as the cup is formed, there is an advantage that no complicated coating equipment is required.

Furthermore, in the heat insulating cup of the present invention, even if the foamed portion has a considerable thickness, the foamed portion at the required portions of the blank 1 is preheated under pressure to form a non-foamed film. This has the advantage that it can be carried out under almost the same conditions as when using composite paper laminated with ordinary plastic film. Therefore, the insulating cup of the present invention has the great advantage that it can be produced using conventional cup-forming machines almost unchanged. A boundary line 2 indicates the area between the foamed portion and the non-foamed film portion of the blank 1 in FIG.

A blank 1 as shown in a perspective view in FIG. 2 is referred to as a step crack 1 according to the present invention to distinguish it from a normal blank. Also, a blank 1 as shown in a perspective view in FIG. This method is distinguished from the usual heat seal method and is called the heat seal method.

As shown in FIG. 4, the step blank 1 of the present invention allows the bodies 7 of the foamed portions to face each other with a sufficient width so as to cover the paper edge 13 with both ends overlapped.

This method could not be carried out using a normal non-bubble laminate film because the film was extremely thin. By using foam and using the above-mentioned squeezing heat-sealing method during heat-sealing, paper edges 1
3 was completely covered with the plastic layer of the foamed part. The present invention is based on the idea that the paper edge 13 can be covered by the plastic of these foamed parts by taking advantage of the bulkiness of the foamed parts, which was a disadvantage when conventionally heat-sealing. It has been done.

As mentioned above, the heat insulating cup molded using the stepped blank 1 of the present invention has the following characteristics: firstly, the side seam part of the body is thin and the finished shape is beautiful; secondly, the contents of the cup are The paper edge 13 of the stepped blank 1 on the side that comes into contact with objects is completely covered with plastic, and thirdly, the heat insulation properties of the cup body 7, which is expected to have a heat insulation effect, are not impaired at all. Furthermore, it can be molded directly using a conventional cup molding machine.
It has the advantage of being able to be produced in large quantities at low cost.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the side blank, Fig. 2 is a perspective view of the side blank, Fig. 3 is a perspective view of the heat insulating cup of the present invention showing a part of the cup in cross section, Figs. and FIG. 6 is an explanatory diagram showing a partially enlarged cross-section of the seam portion of the cup during the squeezed heat sealing process. 1...Side blank, 2...Border line, 3...Paper, 4...Bottom curl part,
5... Top curl part, 6... Side seam part, 7... Body part, 8... Space,
9...Teflon (registered trademark) protection, 10.
... Iron, 11 ... Core, 12 ...
...Bubble, 13...Paper edge, 18...
Squeezing area.

Claims (1)

[Claims] 1 A foamed plastic sheet is laminated on one side of a fan-shaped paper, and the plastic at one side seam at both ends in the circumferential direction remains foamed, but the plastic at the other side seam is heated, The thin film part of the side blank, which is formed into a non-foamed thin film by applying pressure, is superimposed on the outside of the paper in the foamed side seam part and rolled up, and the overlapping part is heat-sealed by heating and pressurizing. The heated and pressurized plastic at the foamed side seam part during heat sealing extends to the other non-foamed thin film side and fuses together with the foamed plastic on the non-foamed thin film part side, and the foamed side seam part side An insulating cup in which the edge of the paper is molded with the fused plastic.