JPS5848163B2 - Footwear stand mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a mold for inserting a sheet material such as leather, cloth, or a synthetic resin sheet of a different type or color onto the surface of a footwear stand such as a shoe or sandal during molding.

When a footwear stand is made of synthetic resin and a sheet material is inserted into its surface, manufacturing of the footwear stand is significantly simplified, and footwear stands with a wide variety of colorful designs can be manufactured.

However, in conventional molds, the sheet material to be inserted may be misaligned due to the injection pressure of the synthetic resin, or the resin may be press-fitted between the surface of the sheet material and the inside of the molding chamber. This method could not be put to practical use due to problems such as embedding in the resin.

When molten synthetic resin is injected into the molding chamber, the sheet material that is in close contact with the mold floats out of the mold, and the synthetic resin is press-fitted between the sheet material and the mold, which causes the sheet material to melt after molding. The reason for this is that the injection pressure of the synthetic resin is extremely high, over several hundred atmospheres, and the fluidity of the synthetic resin in the molding chamber during injection is extremely intense. This is because it cannot be temporarily fixed to the mold.

This is because, for example, when inserting a sheet material exposed on the top surface of a footwear stand, the height of the footwear stand is more than 5 cfrL even if it is low, and more than 5 cfrL for a high one, so when the mold is clamped, the height of the sheet material is as shown in Figure 1. As shown in FIG. In order to significantly reduce the strength and to press the peripheral edge of the sheet material 40 against the mold with the protrusions 3, it is necessary to significantly narrow the space between the protrusions 30, or to press with elongated protrusions instead of protrusions. Since the number of protrusions or protrusions becomes large or large, and these are continuous, the strength of the footwear stand is significantly reduced, making it impossible to manufacture a footwear stand that can withstand actual use.

As shown in FIG. 2, if the entire periphery of the sheet material 5 is extended outside the molding chamber 8 and the entire periphery of the sheet material 5 is clamped by the molds 6 and 7, the surface of the sheet material 5 and the molding chamber Although the resin is not press-fitted between the surfaces, products molded in this state cannot be used because the periphery of the sheet material protrudes from the footwear stand.

By the way, conventional molds have the disadvantage that in most cases the periphery of the sheet material is buried in the synthetic resin, but if conditions are bad, almost the entire sheet material may be buried in the synthetic resin. Also, the sheet material may even come out on the opposite side of the surface where it was temporarily fastened, which is even more troublesome.
Since the condition varies greatly from molded product to molded product, there is a lot of variation in the products, and there is a drawback that uniform products cannot be manufactured.

Therefore, the inventor of the present invention found that the method of temporarily fixing the sheet material by boiling it in the mold cannot prevent the sheet material from being lifted out of the mold and buried in the synthetic resin due to strong injection pressure. I came to the conclusion that this strong injection pressure could be used in some way to make the sheet material stick to the mold using this pressure, so I actually made a prototype mold.
After repeating various experiments, cutting the molded footwear platform in all directions, and carefully examining the inflow of the synthetic resin, we finally succeeded in sealing the sheet material into a certain shaped chamber using strong injection pressure. It was very successful.

Therefore, an important object of the present invention is that the high injection pressure of the synthetic resin allows the sheet material to be brought into close contact with the mold, so that the periphery of the sheet material is not buried in the synthetic resin, but even the periphery is exposed on the surface. Moreover, it is an object of the present invention to provide a mold in which a sheet material is always inserted in a fixed position, and a uniformly uniform footwear stand can be formed without unevenness in the product and with a low incidence of defective products.

An embodiment of the present invention will be described below with reference to the drawings.

The mold shown in FIG. 3 is a mold for molding a footwear stand, in which a recess 11 into which a sheet material 10 can be fitted is formed in a mold 9 located above a molding chamber 8. A synthetic resin injection port 13 is provided in the mold 12 facing the sheet material 10 at a location facing the center of the sheet material 10 .

As shown in FIG. 3, the recess 11 is formed by scraping the mold, or as shown in FIG. In some cases, depressions 16 are formed between the protrusions.

The inlet for the synthetic resin is located inside surrounded by the periphery of the sheet material, preferably at the center of the sheet material 6, so that the synthetic resin to be injected flows from the inside toward the periphery of the sheet material. It is provided on the surface facing the sheet material.

As described above, the mold for forming a footwear stand according to the present invention has a recess into which a sheet material is fitted, and the sheet material temporarily fixed in the recess has a molten state from the inside toward the periphery. Since an injection port is provided on the surface facing the recess in which the synthetic resin is press-fitted, the sheet material temporarily fixed in the molding chamber of the mold is simply pushed through the recess from its periphery to the surface of the sheet material. The synthetic resin is not prevented from entering between the inside of the molding chamber and the inside of the molding chamber, but the injection pressure of several hundred atmospheres or more causes the sheet material to adhere tightly to the inside of the molding chamber, and in this state. Since the synthetic resin is press-fitted into the certain shaped chamber, the resin does not enter between the sheet material and the inner surface of the certain shaped chamber, and the periphery or the entire sheet material is not buried in the synthetic resin.

The injection time for synthetic resin is a few seconds at most for a normal footwear stand, so it is not possible to directly see the flow state of the synthetic resin during injection, but when a shaped object is cut, the flow state of the resin can be seen at a glance. shall be.

Therefore, the inventor of the present invention found that by cutting the completed footwear stand, the synthetic resin was injected while pressing the sheet material against the inner surface of the shoe rack.

Therefore, in the present invention, the sheet material is not embedded in the synthetic resin,
The periphery is clearly exposed on the surface of the synthetic resin, and
The sheet material is inserted without misalignment, the unevenness of the product during molding is significantly reduced, the incidence of defective products is reduced, and footwear stands with high commercial value can be manufactured with uniformity.In addition, concave and concave surfaces are formed by the convex stripes. If so, around the periphery of the sheet material,
Since the synthetic resin is present through the groove, the edges of the sheet material can be treated with the synthetic resin on the periphery, making it possible, for example, to use uncut leather as is, which greatly simplifies the processing effort for the sheet material. have

[Brief explanation of drawings]

A cross-sectional view of the conventional footwear stand mold shown in Figures 1 and 2, and Figure 3.
FIG. 4 is a sectional view of a mold showing an embodiment of this invention. 1, 2...Mold, 3...Protrusion, 4,5
・・・・・・Sheet material, 6, 7・・・Mold, 8・
... Commandment room, 9 ... Mold, 10 ...
... Sheet material, 11 ... Concave, 12 ...
- Mold, 13...Injection port, 14...Mold, 15...Protrusion, 16...Concave.

Claims (1)

[Scope of Claims] 1. A mold having a recess into which a pre-shaped sheet material is fitted in order to temporarily fix the molding chamber of the mold, and the mold is fitted into the recess. A molding tool for a footwear stand, in which a synthetic resin injection port is provided on the surface facing the sheet material that is inserted into a recess so that the molten synthetic resin flows from the inside toward the periphery of the sheet material. Type. 2. A mold for forming a footwear stand according to claim 1, wherein a protruding strip is formed on the inner surface of the molding chamber of the mold, and a recess is formed by the protruding strip.