JPS60253532A - Method of forming bottom of paper cup - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a method for forming the bottom of a paper cup, and more particularly to a method for forming a bulge on the bottom.

(2) Prior Art In general, paper cups filled with liquid at a temperature of approximately 40°C or higher and lower than 100°C, as shown in Figs. Due to the volume reduction, the shape that initially had a normal shape as shown in Figure 1,
As shown in FIG. 2, a dent is created in the body portion 10 and the body portion 10 is deformed. This greatly reduces the value as a packaged product.

Therefore, in order to prevent this, the bottom part 12, which is hard to see by the human eye, is bulged outward in advance as shown in Fig. 3, and the contraction after filling and sealing is absorbed by the deformation of the bottom part as shown in Fig. 4. I am trying to do.

Conventionally, in order to form a paper cup having such a bottom part 12, first, a bottom member as shown in FIG. 3 is press-molded, and then it is fitted into a cylindrical body part as shown in FIG. 3 to integrate it. There is.

Therefore, since a press mold is used to mold the bottom member, the process of molding the paper cup is interrupted and becomes troublesome.

(3) Purpose The present invention was made for the purpose of solving the problems in the conventional art.Just by punching out and drawing the bottom member, it can be immediately fitted into the body, and the finished paper cup has a bottom part. Here, a method is provided in which the bulge of the material is directed outward.

(4) In the method for forming the bottom of the paper cup in which the bottom member of the paper cup is molded and then integrated into the cylindrical body of the paper cup, the bottom blank of the paper cup is formed using a male mold having a bulge at the tip. While pushing it into the female mold, it is drawn and formed into the bottom member, and then, using the male mold, the bottom member is fitted into the cylindrical body of the paper cup held by the winding mold, and then integrated. Compressed air is injected from the winding form to remove the integrated paper cup from the winding form and at the same time invert and bulge the bottom member of the paper cup so as to protrude outward from the paper cup. do.

(5) Effects In the present invention, the bottom blank of a paper cup is pressed into the female mold using a male mold having a bulging portion at the tip, and is drawn to form the bottom member, and then the bottom member is formed using the male mold. , the paper cup is fitted into the cylindrical body of the paper cup held by the winding form to be integrated, and then compressed air is injected from the winding form to remove the integrated paper cup from the winding form and at the same time Since the bottom member of the paper cup is inverted and bulged so as to protrude outward from the paper cup, part of the forming of the bottom member can be performed during the process of transporting the paper cup. Therefore, the conventional bottom member forming process can be simplified and the scale of the paper cup manufacturing line can be reduced.

(6) Examples Specific examples of the present invention will be described below with reference to the drawings.

After forming the bottom member of the paper cup, the ninth threshold from FIG.
Each step of the method for forming the bottom of the Gi cup that is fitted into and integrated with the cylindrical body of the Gi cup is shown.

In FIG. 5, reference numeral 14 denotes a winding former for holding the cylindrical body 10 of the paper cup, and a recess 16 having the same shape as the bulge to be provided on the bottom member 12 of the cup is formed at its tip.

Further, a hole 18 for blowing out compressed air is provided at the center. A plurality of winding forms 14 are provided, and they can be moved intermittently in the horizontal direction.

Reference numeral 20 denotes a male mold located above the winding form 14, and a bulging part 22 that can match with the recess 16 of the winding form is provided at the tip thereof.

Further, 24 is a male blade that surrounds the male mold 20, and 26 is a female blade, and when these two fit together, the material sheet 28 of the bottom member of the gi cup is punched out, and a bottom blank 30 is produced.

Note that the material sheet 28 can be a belt-shaped material made of laminated paper, aluminum, etc. and having a thickness of 0.1 to 0.5.

Reference numeral 32 denotes a female die that is combined with the male die 20, and is configured to sandwich the bottom blank 30 together with the tip of the male blade 24.

As shown in FIG. 5, the bottom blank 30 is punched out as the male blade 24 descends and is held between the male blade 24 and the female mold 32.

FIG. 6 shows the second step.

That is, the male die 20 descends and the bottom blank 30 is placed in the female die 3.
2, the bottom member 12 is formed by drawing and forming the bottom member 12. Immediately after the bottom blank 30 passes through the female mold 32, the first
As shown in Figure 0, wrinkles 34 are generated around the periphery.

FIG. 7 shows the third step.

In this step, the male mold 20 further descends while sucking and holding the bottom member 12 with its suction hole 36, and is fitted into the cylindrical body portion IO of the paper cup held by the winding form 14.

At this time, the bottom member 12 is attached to the winding form 14 at the bulging part 22 of the male die 20.
Since it is pressed against the recess 16, the wrinkles 34 generated during drawing are removed.

Next, the male die 20 injects compressed air from the hole 36, pushes the bottom member 12 downward, and rises to return inside the male blade 24, and the male blade 24, etc. and the winding form I4, etc. move relative to each other. and leave.

At this time, if a male die 38 and a winding die 40 as shown in FIG. 11 are used, a bead 42 can be formed on the bottom member 4\ as shown in FIG. It can increase strength.

In FIG. 11, 44 is an annular groove provided in the bulge 46, and 48 is an annular protrusion that matches the annular groove.

FIG. 8 shows the fourth step.

Here, a bottom tightening member (not shown) comes down, folds the end of the cylindrical body 10 inward, heats it to melt the resin applied to the blank in advance, and tightens the bottom member 12 and the cylindrical body 10.
and integrate them.

FIG. 9 shows the fifth step.

That is, compressed air is injected from the winding form 14 to remove the integrated paper cup from the winding form.

At this time, as shown in the figure, at the same time, the bottom member 12 of the paper cup
is inverted and bulged so as to protrude outward from the paper cup.

After that, the paper cup is filled with the heated contents as shown in Fig. 3 and sealed with the lid material 5o, and even if the contents cool down, the paper cup does not deform due to shrinkage as shown in Fig. 4. The upper wall, which is absorbed by reversing the bottom member 12 and is easily visible,
It does not reach the surrounding wall.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view immediately after hot filling of a paper cup of a general type. FIG. 2 is a similar cross-sectional view after cooling. FIG. 3 is a vertical sectional view immediately after hot filling of a paper cup having a bulged portion. FIG. 4 is a similar cross-sectional view after cooling. 5 to 9 are vertical sectional views showing each step of the method for forming the bottom of a paper cup according to the present invention, FIG. 5 is a step when punching out a blank for the bottom member, and FIG. During the drawing process, Figure 7 shows the bottom member being fitted into the cylindrical body, Figure 8 shows the bottom member and the cylindrical body being integrally molded, and Figure 9 shows the rolling process. Each represents the time when the paper cup is being ejected from the mold. FIG. 10 is a perspective view of the bottom member immediately after drawing forming of FIG. 6. FIG. 1I is a vertical sectional view of a different embodiment of the means for forming the bottom member, and FIG. 12 is a perspective view of the bottom member formed thereby. 10... Cylindrical body 12... Bottom member 14... Winding, mold 16... Recessed part 18... Hole 20... Male mold 22... Swelling part 30... Bottom blank 1st A Broom 2 Figure Chopsticks 3 7 Broom 4 Figure 5 Figure 6

Claims (1)

[Claims] In a method for forming the bottom of a paper cup, in which the bottom member (12) of the paper cup is formed and then integrated into the cylindrical body (10) of the paper cup, a male mold (20) having a bulge (22) at the tip thereof is used. ) to insert the bottom blank (30) of the paper cup into the female mold (3
2) Press the bottom member (12
), and then the male die (20) is used to attach the bottom member to the cylindrical body (10) of the Gi cup held by the winding die (14).
) to integrate it, and then the above winding form (14
) to remove the integrated paper cup from the winding form (14), and at the same time invert and bulge the bottom member (12) of the paper cup so as to protrude outward from the paper cup. The above-mentioned forming method is characterized in that: