JPS5933111A - Method of forming blister - Google Patents

Abstract

PURPOSE:To obtain a molded blister article without a bridge between the blisters, by using a mold table having movable molds that can be moved vertically through the mold table. CONSTITUTION:When a plastic sheet 4 is to be molded to have a plurality of relatively deep blisters 5 for housing items with a narrow space therebetween, the mold table 1 with the movable molds 2 that can be moved vertically through the mold table is used. First the movable molds 2 are lowered so that the tops of the movable molds may be flushed with the top surface of the mold table 1, then the heated and softened plastic sheet 4 is placed on the mold table 1, and then keeping the plastic sheet 4 in firm contact with the top surface of the mold table 1 by suction, the movable molds 2 are elevated to form the blisters 5 in the plastic sheet 4 for housing items. Accordingly, a bridge 10 between the adjacent blisters 5, 5 can be prevented from being formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blister forming method that prevents the occurrence of bridging.

In addition to blister molding, when molding small and deep storage recesses at narrow intervals, such as for mercury batteries, the thickness of plastic sheets is becoming thinner! ,
However, there is a tendency for wrinkles to form between the bridges, that is, the storage recesses. In addition, plastic sheets that can be stretched by heat are particularly prone to J-bridges due to sagging during heating during molding.

A blister molding method that is currently widely used uses a mold 8 having a shape similar to that shown in FIG. Figure 4 shows the mold (cross-sectional view) used in the conventional blister molding method and an explanatory diagram of the molding process using it.

Figure 4 is a perspective view of a vertical shape using a mold. E, Figure 6 shows the cross-section taken by the line ΩV+-W in Figure 5. As shown in Figures 5 and 6, it is easy for the bridge IO to remain at the gate in the receiving recess 5 due to the direction of forming the sheet 4. As a countermeasure for this, there is a method of pressing the auxiliary mold 9 (female mold) from above the metal 8 during suction, and stretching the sheet between the storage recesses using L6 while forming the mold, as shown in Figure 4. (It takes time and costs to produce it.Furthermore, the auxiliary type has drawbacks such as scratches on the sheet surface and the loss of outer edges.)

The present invention 1. , , ,H, which solves the above problems,
A, soi, l'l', II ,,,,l,',',
The main points of , 1° are: 1. The mold table is provided with a movable shaft that can move up and down through the mold table.First, the movable mold is lowered and the upper surface of the mold table is made flat. .

The molded plastic sheet is vacuum-suctioned and brought into close contact with the upper surface of the mold stand, and while the plastic sheet is softened, the movable mold is raised while vacuum is being applied, and the plastic sheet is molded along the movable mold. This is a method of forming and forming a blister.

Next, the blister forming method of the present invention will be explained with reference to the drawings.
The figure shows a mold (cross-sectional view) used in the present invention, . is the mold stand,
2 is a movable type, 3 is a suction hole, 4 is a plastic sheet, 5
6 is a storage recess, 6 is a sheet holding clamp, and 7 is a heater.

That is, as shown in FIGS. 1 to 3, the piston-shaped movable mold 2 is set so as to be movable in the direction of the arrow. First, as shown in FIG. Make sure the top surface is flat: and set aside. The sheet 4 is softened with the heater 7, and suction is applied through the cough suction hole 3 as shown in Fig. 2, and the sheet 4 is placed in the mold from the front side 1:1.・
□1゜□Mold along □ on the stand 1 and tightly adhere to the upper surface of the mold stand 1. Next Nisu: Guni Fang 3. As seen in the figure, the movable die 2 is pushed up to form a blister while the cough is being coughed through the suction hole 3 and the J-shinito 4 is in a softened state to form the four storage parts 5. Then take out one shot and trim it to an appropriate size. When using the blister molding method of the present invention, the movable mold 2 is raised while the sheet 4 is heated and softened and brought into close contact with the upper surface of the mold table l by suction, so that the middle part of the recess 5! Suction and recess formation can be carried out without any change, and bridges 10 do not occur between the blisters as in the molded product according to the conventional method (Figs. 5-6).・In addition, when using a mold base 1 having a convex or concave (not shown) overall shape as in this example, the sheet 4 is stretched and molded along the overall shape to try to shrink into the sheet 4. As a result, when the recessed portion 5 is formed in the movable mold 2, the sheet 4 adheres more tightly to the movable mold 2 and the upper surface of the mold table l, and a bridge occurs when heated to the molding temperature. This is preferred because it can be used even with sheets that tend to sag.

Furthermore, the effects of the present invention are as follows: (1) The process from primary molding to secondary molding (Fig. 3) is carried out instantaneously, thereby speeding up the molding process. ,■Defective,
rate is significantly reduced. ■It is possible to create molded products with good appearance.

[Brief explanation of the drawing]

Figure l-λ is a side cross-sectional view of the mold used in the blister molding method of the present invention) and a preliminary explanation of the blister molding process is shown in Figure 4. The kettle mold (cross-sectional view) used and a diagram illustrating the molding process are shown. No. 5- is a perspective view of a molded product made by the conventional method using No. 41 gold, and Figure 6 is a cross-sectional view taken along the Vt-W line of the 5-th hole. '1・:・Mold 42・!・Movable type 3...Suction hole 4・
...pu,'5 stick seat 5...storage recess 6...
Lunit presser clamp La... Minitor 8... Mold
9...Auxiliary type 10-...Bridge patent applicant Mitsubishi Plastics Co., Ltd. agent Patent attorney Yoshio Ohno

Claims (1)

[Claims] A movable mold that can penetrate the mold table and move up and down is installed in the mold table. First, with the movable mold lowered and the top surface of the mold table flattened, the heat-softened plastic sheet is vacuum-suctioned. 1. Place the plastic sheet on the top of the mold table and vacuum it while it is still softening. The blister molding method involves raising the movable mold and molding the plastic sheet along one axis.