JPH0367618A - Manufacture of cushioning body - Google Patents

Abstract

PURPOSE:To strengthen boding power of foam parts whose foam magnifications are different from each other with simple facilities and a process and variable setting of strength of an arbitrary part is made easy further, by a method wherein a plurality of foaming materials whose foam magnifications are different from one another are filled into the same space at the same time through respective casting ports provided in the same mold and heating, foaming and cooling are performed at the same time. CONSTITUTION:Corner parts A of cushioning bodies 20 fitted to edge parts each of a product 10 to be packed up and the remaining part B are constituted respectively of foaming polyethylene (forty foam mangnifications) superior in shock resistance and durability and foaming polystyrene (fifty foam magnifications). The foaming polyethylene and foaming polystyrene are filled into confronted molds 30, 31 at the same time through material introducing pips 32, 33 piped respectively to casting ports provided in the molds 30, 31. Two kinds of foaming materials are dispersed freely in the same space in the molds 30, 31 and their contacting surface becomes a random uneven state where bonding power is strong. Steam is applied to the materials through a steam introducing pipe 34, they are heated and foamed at the same time, they are moved by cooling them at the same time through cooling of the molds 30, 31 and the above-mentioned cushioning body 20 is molded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a buffer body. Another object of the present invention is to provide a manufacturing method that can manufacture a shock absorber at low cost that will not be damaged even when subjected to shocks caused by falling products, etc. to be packaged.

(Prior art) Conventionally, when packaging various devices such as electronic devices such as television receivers, foamed polystyrene shock absorbers are attached to the corners and edges of the devices, and these are packed in cardboard boxes. It is well known that equipment is protected from external forces such as vibration and shock during transportation by storing it in packaging boxes such as .

FIG. 4 is a perspective view showing an example of a state in which a conventional packaging cushion is attached to an electronic device, and the illustrated electronic device is a television receiver.

In the figure, 1 is a television receiver which is a product to be packaged, and 2 is a cushioning body made of styrofoam.

By the way, when transporting the packaged product (television receiver) 1 to which the cushioning body 2 is attached as shown in FIG. 4 in a packaging box such as a cardboard box, for example, as shown in FIG. If a fall accident occurs from a corner or edge of the box 3, especially if the box 3 falls from a corner, concentrated stress may be applied to the corner or edge and the shock absorber 2 may be damaged. For this reason, when the product is delivered to the buyer,
Accidents have occurred in which the internal circuit boards of devices such as television receivers have been cracked, or the outer frames of devices have been damaged.

Conventionally, in order to prevent such accidents from occurring, the corners and edges were reinforced with adhesive tape, or the cushioning body 2 was made slightly thicker to increase its strength. Measures were taken, such as:

However, when such measures are taken, there are problems in that reinforcement costs are required and, furthermore, the cushioning body 2 is not of the minimum size, resulting in poor transportation efficiency.

Therefore, in recent years, various shock absorbers have been proposed in which the part to which concentrated stress is applied is made of a material stronger than other parts, instead of making the part to which concentrated stress is applied thicker.

For example, there is a cushioning body in which a portion to which concentrated stress is applied is made of a foam with a small expansion ratio, and other parts are made of a foam with a large expansion ratio.

As a method for producing such a cushioning body, there is a method in which a foam portion with a small expansion ratio and a foam portion with a high expansion ratio are separately molded, and then bonded together in a post-process to form a single cushioning body. However, in this method, since the molding is performed separately, two or more molds, two or more similar equipment systems, and a bonding process are required, which increases manufacturing costs.

Another manufacturing method is to first fill a mold with a foam material with a low expansion ratio, then move the mold, fill the same mold with a foam material with a high expansion ratio, and mold it into a cushioning body. There is. Although this method may require only one mold, the mold must be moved during molding, which increases the molding time. Furthermore, equipment for moving the mold during molding is required, which increases manufacturing costs.

Further, in both of the above two methods, sufficient bonding force between the foam portion with a small expansion ratio and the foam portion with a large expansion ratio could not be obtained.

(Problem to be Solved by the Invention) The problem to be solved by the present invention is that the bonding force between a foam part with a small expansion ratio and a foam part with a large expansion ratio is strong, and any part where concentrated stress is applied. The question is what measures should be taken to create a manufacturing method that can provide a shock absorber with increased strength and low manufacturing cost.

(Means for Solving the Problems) Therefore, in order to solve the above problems, the present invention provides a method for manufacturing a packaging cushion that is attached to a product to be packaged and stored in a packaging container, including a plurality of cushioning bodies having different foaming ratios. a filling step of simultaneously filling the same space in the mold from respective injection ports provided in the same mold; and a heating foaming step of simultaneously heating and foaming the plurality of filled foam materials. The present invention provides a method for manufacturing a cushioning body, comprising: a cooling step of simultaneously cooling the plurality of foamed materials that have been heated and foamed.

(Example) FIG. 1 is a diagram showing the basic structure of a cushioning body manufactured by the method for manufacturing a cushioning body of the present invention.

As shown in FIG. 1, the packaging buffer 12 attached to the packaged product 10 and stored in the packaging container 11 has a concentrated stress that is higher than the strength of the part B where the concentrated stress is not applied by the packaged product IO. The strength of the portion A is high, and the joining surfaces a and b of the portions having different strengths are uneven, so that the portions A and B are joined.

In the shock absorber 12 having the above-mentioned structure, the strength of the portion A to which concentrated applied force is applied is high, so that the shock absorber has excellent strength and functions effectively as a shock absorber.

In addition, since this part A and part B to which concentrated stress is not applied are joined at the complex uneven joint surfaces a and b,
The total joint area of image portions A and B becomes larger. As a result, the bonding strength between these image portions A and B is also high.

In addition, although the buffer body 12 of this type has excellent strength as described above, it is possible to downsize the buffer body 12, and furthermore, the buffer body 12
It is also possible to reduce the cost itself.

Hereinafter, preferred embodiments of the present invention will be described in detail using FIGS. 2 and 3.

FIG. 2 is a perspective view of an example of a cushioning body manufactured by the method for manufacturing a cushioning body of the present invention. This buffer 20 is
As shown in the figure, a cardboard box 1, which is a container to be packed, is attached to each edge of a television receiver 10, which is a product to be packed.
It is stored in 1.

The portion A1 of the shock absorber 20 that is subject to concentrated stress, that is, the corner portion, is made of foamed polyethylene (foaming ratio: 40 times) that has extremely excellent impact resistance and durability, and the remaining portion that is relatively free from concentrated stress. B1, that is, the middle part in the longitudinal direction of this buffer body 12, etc., is formed of conventionally known foamed polystyrene (expansion ratio: 50 times).

Here, the concentrated stress refers to a large stress that is concentrated on the portion of the buffer body 20 that comes into contact with the negative corner portion of the television receiver 10 when the television receiver 10 falls, for example, from a corner portion. This is stress applied to a relatively localized narrow area.

In addition, as mentioned above, the joint surface a of the image parts A and B with different strengths
, b have a complicated uneven shape as shown, and the image portions A and B are closely joined.

In this example, the volume ratio of the foamed polyethylene portion A to the total volume of the buffer body 20 is 3.
Similarly, the volume ratio occupied by the expanded polystyrene portion B is 70%.

The buffer body 20 configured as described above is manufactured by the following method.

As shown in FIG. 3, a pair of molds 30, 3 are butted against each other.
1 (a pair of molds 30 and 31 form one mold).The foamed polyethylene and foamed polystyrene are simultaneously introduced through material introduction pipes 32 and 33 respectively connected to injection ports provided at predetermined positions of a pair of molds 30 and 31. The mold 3031 is filled (filling step). The parts inside the mold 30.3+ that are filled with the above two types of foam materials are the same space without partition plates, etc., and the two types of foam materials can freely diffuse, and the contact surfaces of each are randomly distributed. It becomes uneven.

Next, steam is applied through the steam introduction pipe 34 to simultaneously heat and foam the two types of foaming materials (heating and foaming step).

Thereafter, by cooling the mold 3111.3+, the two types of foam materials are simultaneously cooled (cooling step), and the mold 31 on the cavity side is removed to mold the buffer body 20 as described above.

Note that the expansion ratios of the foamed polyethylene and foamed polystyrene in this example were 40 times and 50 times, respectively, and as a result of the experiment, the strength of the buffer body 20 in this case was the highest.

As described above, according to the manufacturing method of this embodiment, the buffer body 20 is made of a pair of molds 30. It can be manufactured using only one mold consisting of 31 and at the same time using materials with partially different strengths.

Furthermore, since foam materials with different expansion ratios can be filled at the same time, there is no need to move the mold during molding. Therefore, the molding time of the mold moving needle can be shortened, and there is no need for equipment to move the mold during molding, so the equipment can be simplified.

Therefore, by using the manufacturing method of this embodiment, the buffer body can be manufactured at extremely low cost.

Furthermore, by appropriately changing the connection position between the material introduction pipe 32, 33 and the stationary mold 30 (the position of the injection port), the strength of any desired part can be easily varied as appropriate. can do.

And, the bonding surface a of the portions having different strengths in the buffer body 20 manufactured by the method as described above.

b has an extremely complicated random irregularity shape. Therefore, the total joint area of image parts A and B is large,
The number of copolymerized portions between portions A and B increases, and as a result, a large bonding strength can be obtained at the bonded portion of image portions A and B.

Therefore, the joint portion between each portion A and B is extremely strong against various impacts such as tensile stress, bending stress, compressive stress, and torsional stress, and damage at this portion can be prevented.

Furthermore, compared to the case where the entire cushioning body 20 is made of foamed polyethylene, cost can be reduced by using foamed polyethylene only in necessary parts.

In addition, since the strength can be freely obtained in the necessary parts, the thickness of the buffer body 20 can be made thinner to some extent.
It is possible to improve cost benefits during transportation.

By the way, in the buffer body manufactured in the above-mentioned example,
Although two types of materials were used to vary the strength of each part, other cushioning materials may be used, for example, the same material may be used to vary the expansion ratio of each part to obtain the desired strength.

As a result of experiments, even with a cushioning material using only expanded polystyrene with a foaming ratio of 40 times in the areas where concentrated stress is applied and a foaming ratio of 50 times in areas where relatively no concentrated stress is applied,
Almost the same effect as the buffer body 2G mentioned above was obtained. In this case, the ratios of the portion to which concentrated stress was applied and the portion to which no concentrated stress was applied to the total volume were 30% and 70%, respectively.

Note that the foaming ratio or volume ratio of each part as described above is not limited to those mentioned above, and can be set as appropriate depending on the purpose of the cushioning body.

(Effects of the Invention) As described above, if the method for manufacturing a cushioning body according to the present invention is used, the bonding force between the foam part with a small expansion ratio and the foam part with a high expansion ratio can be increased, and the manufacturing cost may be reduced. A low-cost buffer can be obtained.

Furthermore, by using this manufacturing method, the strength of any part of the cushioning body can be easily and variably set as appropriate.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic structure of a cushioning body manufactured by the method for manufacturing a cushioning body of the present invention, and FIG. 2 is a perspective view of an example of a cushioning body manufactured by the method for manufacturing a cushioning body of the present invention. Figure 3 is a schematic diagram of an example of an acid forming machine used in this invention, Figure 4 is a perspective view of a general buffer, and Figure 5 is a schematic diagram of the relationship between the buffer, the product to be packaged, and the packaging container. FIG. DESCRIPTION OF SYMBOLS 10... Television receiver, 11... Packing container, 12, 20... Buffer body, 30, 31... Mold. 11th!1 0 l l8rXJ 211!1

Claims (1)

[Claims] In a method for manufacturing a cushioning material for packaging that is attached to a product to be packaged and stored in a packaging container, a plurality of foam materials having different expansion ratios are poured from respective injection ports provided in the same mold. a filling step of simultaneously filling the same space in the mold; a heating and foaming step of simultaneously heating and foaming the plurality of filled foam materials; and a cooling step of simultaneously cooling the plurality of foamed materials that have been heated and foamed. A method for manufacturing a cushioning body, comprising the steps of: