JPH05209082A - Production of reclaimed cushioning body - Google Patents

Abstract

PURPOSE:To provide a method for producing a reclaimed cushioning body of practical use readily in a short time from a waste unfoamed material, such as rubber chips, and a waste synthetic polyolefinic resin having a relatively poor adhesive force. CONSTITUTION:A cushioning material comprising a synthetic resin foam or its mixture with a different material such as rubber is crushed into small pieces of about 2-30mm in size. The crushed pieces 10 are mixed with a hot-melt resin 11, and the mixture is densely enclosed in a hermetically sealed container 12. The container 12 is then filled with a combustible gas 20, and the gas 20 is explosively burned to join the pieces 10 by bonding, thus giving the objective cushioning body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a regenerated buffer from waste synthetic resin foam.

[0002]

2. Description of the Related Art Since synthetic resin foams such as polyurethane foams and polyethylene foams are lightweight and have excellent heat insulating properties and shock absorbing properties, they are widely used as cushioning materials, packaging materials, heat insulating materials, heat insulating materials, etc. There is.

However, in recent years, due to the large amount of foam used, the amount of foam discharged as a waste also becomes enormous, and its treatment has become a problem. In particular, recently, the global environment has become a major social issue, and the reduction of waste and the effective use of resources have been called for, and the recycling of foam has been required.

The following methods have been proposed for treating foam waste. One of them is to pulverize soft polyurethane foam etc. as waste into small pieces, mix the foam strips with an adhesive and heat the mixture under pressure to bond the foam strips and regenerate them. It is a method of manufacturing a buffer. The other method is a method in which a thermoplastic resin foam as waste is finely crushed and the foam pieces are pressed against a heater heated to a temperature below the ignition point of the foam to perform a melting treatment. (Described in JP-A-62-205138)

However, in the former method using an adhesive, when a regenerated buffer is produced from a thermoplastic resin foam, particularly a polyolefin foam waste such as polyethylene foam or polypropylene foam,
Since these foams are poor in adhesiveness, the regenerated buffer obtained is easy to separate into the original foam pieces, and there is a problem that it is difficult to obtain a practical regenerated buffer.

Further, in the latter method, since the foam strip must be pressed against the heater to melt it, the pores of the foam strip are easily crushed and a uniform regenerating buffer cannot be obtained. There is a problem that the processing such as the melting takes time. Further, the foam strip must be pushed out of the melting furnace while being pressed against the heater, which causes a problem that the device becomes complicated.

The inventors of the present invention previously stored the thermoplastic resin foam strips in a container tightly, filled the container with a combustible gas, and explosively burned the thermoplastic resin foam strips. Provided is a method for producing a regenerated foam by fusing the surfaces together to form a single foam. (Japanese Patent Application No. 3-29584)

According to this method, a practical recycled foam can be easily obtained from the waste of the thermoplastic resin foam.

However, in this method, when the thermoplastic resin foam is the above-mentioned polyolefin-based foam, the adhesive strength between the strips is poor, and the shape of the regenerated foam obtained may be lost. was there. In addition, it cannot be applied to non-foamed materials such as rubber chips and resins other than thermoplastic resins.

[0010]

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above problems,
A method for manufacturing a regenerating buffer, which can easily obtain a practical regenerating buffer in a short time from waste of non-foam such as rubber chips or polyolefin-based synthetic resin with relatively poor adhesive strength It is what

[0011]

That is, the present invention is
The synthetic resin foam or the synthetic resin foam and a cushioning material made of a different material such as rubber are crushed into small pieces having a size of about 2 to 30 mm, and the small pieces and the hot melt resin are mixed, and the mixture is mixed. Characterized by tightly accommodating in a hermetic container, then filling the combustible gas in the hermetic container, explosively burning the combustible gas, and joining the buffer material strips integrally to obtain a buffer body The present invention relates to a method for manufacturing a regeneration buffer.

[0012]

The mixture of the buffer strips and the hot-melt resin contained in the container causes the surface of the thermoplastic resin foam in the hot-melt resin and the buffer due to the explosive combustion heat of the combustible gas filled in the container. Even if it is an olefin-based resin or rubber that melts and is difficult to adhere, adjacent strips are joined and integrated into one regenerative buffer. At that time, if the mixture is densely housed in a container in a compressed state, adjacent strips are pressed against each other by the restoring force and are welded to each other, so that the welding is sure and strong. Moreover, since the bonding force is larger in welding than in bonding, there is no fear that the shape of the obtained cushioning body will collapse. In addition, the explosive combustion of flammable gas occurs instantly, and the generated pressure is evenly applied to the strip inside the container.Therefore, the time required to manufacture the regenerative buffer is extremely short, and the pores of the regenerative buffer are obtained. Is also uniform.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a container at the time of containing a cushioning material mixture in an embodiment of a method for manufacturing a regenerated cushioning body of the present invention, FIG.
Is a perspective view showing an example of a closed container used in the production method of the present invention, FIG. 3 is a perspective view showing an example of a mesh basket, FIG. 4 is a sectional view showing another example of the production method of the present invention, and FIG. 5 shows a pressed state. 6 is a cross-sectional view showing when the press is released, and FIG. 7 is a perspective view showing when the regeneration buffer is taken out.

First, a buffer material made of synthetic resin foam or the like is finely crushed in advance by a crusher to form a buffer material strip 1.
Get 0. In this embodiment, polyethylene foam waste is used as the cushioning material.

As the cushioning material used in the present invention, one kind or two or more kinds of thermoplastic resin foams such as polyethylene, polypropylene, polyvinyl chloride and polystyrene and thermosetting resin foams such as polyurethane are mixed. Used. Butyl rubber, SBR,
It is also possible to mix different materials such as NBR.

The size of the buffer material strip 10 is about 2 to 30.
mm is suitable. If the size of the strip is smaller than 2 mm, the strip may be melted and lost due to explosive combustion. On the other hand, if it is larger than 30 mm, not only the gap between the strips becomes large and the adhesion becomes incomplete, but also the amount of the hot melt resin for adhering the strips increases and the cost may increase. The size of the strips 10 does not have to be uniform, but rather the strips are preferably formed in a non-uniform manner so that they can be densely housed in a container.

Hot-melt resin 1 is added to the cushioning material strip 10.
1 to mix to obtain a buffer mixture. As the hot melt resin 11, a known low melting point hot melt adhesive in the form of pellets, flakes or powder is used. In this embodiment, the mixing ratio of the buffer strip 10 and the hot melt resin 11 is 7: 3 (volume ratio). In addition,
The mixing amount of the hot melt resin 11 is appropriately set according to the type and amount of the cushioning material strip to be joined, and when the cushioning material strip is a thermosetting resin or a rubber chip, the amount is increased to a practical level. It is preferable to impart an adhesive force. At this time, the hot melt resin 11 can be effectively attached to the buffer material strip 10 by generating static electricity in the buffer material strip 10.

The resulting mixture of 1.5 cubic meters is housed in an iron plate hermetic container 12 having a thickness of 20 mm and having an internal size of 1005 × 2005 × 505 mm and an internal volume of about 1.0 cubic meter as shown in FIG. Seal it.

An example of the closed container 12 is shown in FIG. The closed container 12 has a strength sufficient to withstand explosive combustion of combustible gas such as iron, has a lid 13 formed on one side so as to be openable and closable, and has one end connected to a vacuum pump (not shown). A suction pipe 14, a gas filling pipe 15, an ignition plug 16 connected to a power source (not shown), and a pressure gauge (not shown) are provided. The spark plug 16 used is for an automobile.

The cushioning material mixture may be prepared in advance by
The net cage 17 as shown in FIG. 3 is packed tightly, and the net cage 17 is housed in the closed container 12. An upper portion of the net cage 17 is a lid 18 that can be opened and closed. Further, the mesh of the mesh cage 17 is formed in a size such that the cushioning material strip does not protrude. As a result, the cushioning material mixture is easily accommodated in the closed container 12, and the regenerated cushioning body does not stick to the wall surface of the closed container 12 during explosive combustion.

Next, the vacuum pump is actuated to suck out the air in the closed container 12 through the suction pipe 14, and when the internal pressure reaches 20 mmHg, the operation of the vacuum pump is stopped and the suction pipe 14 is provided. Close the valve (not shown) provided. The reason for sucking the air in the airtight container 12 to the outside is that if a large amount of air is present in the airtight container 12, not only is it difficult to fill the flammable gas described below, but the explosive combustion power of the flammable gas is This is because it will decrease.

Then, the volume ratio of hydrogen to oxygen is 2:
The flammable gas 20 mixed with 1.1 is filled into the closed container 12 through the gas filling pipe 15 at a rate of 0.5 cubic meters / minute. The pressure in the closed container 12 is 760 mm
At the time of reaching Hg, the valve (not shown) of the gas filling pipe 15 is closed. Filling time for flammable gas is about 2
It was a minute. The flammable gas is pressurized (for example, at a pressure of ² kg / cm ² ) to be filled in the closed container 12, so that energy at the time of explosive combustion can be increased and welding can be performed more efficiently.

As the combustible gas 20 in the method of the present invention, a mixture of various oxidants and oxidants is used. Hydrogen is most suitable as the oxidizable agent, but methane, ethane, propane, ethylene, propylene, acetylene and the like can also be used. On the other hand, oxygen is most suitable as the oxidant, but air, ozone, etc. can also be used. The optimum mixing ratio of the oxidizer and the oxidizer varies depending on the kind of the oxidizer and the oxidizer or the material of the synthetic resin foam used, but for example, hydrogen and oxygen are 2: 1 in volume ratio, Alternatively, the volume ratio of acetylene and oxygen is 2: 5. The explosive combustion of the combustible gas is performed by igniting the combustible gas 20 by the ignition plug 16 in the closed container.

The valve of the gas filling pipe 15 is left for 1 minute with the valve closed so that the combustible gas is evenly distributed in the closed container 12 and between the buffer material strips 10.
After that, the ignition plug 16 is ignited, and the combustible gas in the closed container 12 is exploded and burned. Immediately after that, the pressure in the closed container is adjusted to 760 by using the gas filling pipe 15.
Carbon dioxide is introduced into the closed container 12 until it returns to mmHg. This is because the explosive combustion of the combustible gas 20 is ended in an instant, and the buffer material strips 10 are prevented from entirely melting.

The pressure in the closed container, which has been reduced by the explosive combustion of the combustible gas, is set to the atmospheric pressure of 760 mmH.
The reason for returning to g is to make it easier to open the lid 13 of the closed container when the regeneration buffer is subsequently taken out.

1 was introduced by introducing carbon dioxide into the closed container 12.
After a lapse of minutes, the lid 13 of the closed container 12 is opened to open the net cage 17
Take out and then 500 × 100 from the mesh basket 17
One regeneration buffer consisting of a 0 × 2000 mm rectangular parallelepiped was taken out. The regenerated buffer body obtained was one in which the mixed hot-melt resin was melted and the adjacent buffer material strips were bonded to each other to be firmly integrated, and the pores were hardly collapsed and were uniform.

4 to 7 show another embodiment of the present invention. First, as shown in FIG. 4, 1.47 cubic meters of the cushioning material mixture used in the previous example is accommodated in an iron net cage 41 having an internal size of 1000 × 2000 × 700 mm and an internal volume of 1.4 cubic meters. did. The same reference numerals as those in FIG. 1 denote the same members in the drawings. The amount of the cushioning material mixture accommodated was determined such that the strips were not excessively dense in the container and the contact area with the flammable gas described below was sufficient. In addition, the net cage 41 is
The upper part is opened, and a part of the side surface is formed so as to be openable and closable by the lid 48, and the mesh has a size that does not cause the buffer material mixture to be contained to pop out.

Then, the mesh basket 41 was housed in a closed container 42. The closed container 42 is made of an iron plate having a thickness of 70 mm, has an inner size of 1050 × 2050 × 780 mm, and can be opened / closed by a lid 43. In the figure, reference numeral 44 is a suction pipe whose one end is connected to a vacuum pump (not shown), 45 is a gas filling pipe, and 49
Is a spark plug connected to a power source (not shown).

A press plate 46 connected to an external hydraulic cylinder 47 is provided on the top of the closed container 42.
2 and the net cage 41 are arranged so as to be vertically movable.
A silicon mold release agent is applied to the lower surface of the press plate 46, and the hermetically sealed container 42 is used until the explosive combustion of combustible gas described later.
It is arranged at the top. The press plate 46 has a size of 980 ×
It is 1980 x 20 mm.

Then, by operating the vacuum pump, the air in the closed container 42 is sucked out through the suction pipe 44, and when the internal pressure reaches 20 mmHg, the operation of the vacuum pump is stopped and the suction pipe 44 is provided on the way. Close the valve (not shown) provided.

Then, the combustible gas 20 used in the previous embodiment, in which the volume ratio of hydrogen and oxygen was adjusted to 2: 1.1.
Is filled into the closed container 42 through the gas filling pipe 45 at a rate of 0.5 cubic meters / minute. Closed container 42
When the internal pressure reaches 760 mmHg, the valve (not shown) of the gas filling pipe 45 is closed. The filling time of the flammable gas was about 2 minutes.

The valve of the gas filling pipe 45 is left closed for 1 minute so that the combustible gas is evenly distributed in the closed container 42 and between the buffer material strips 10. After that, the ignition plug 49 is ignited, and the flammable gas in the closed container 42 is exploded and burned.

Immediately after the explosive combustion of the combustible gas, as shown in FIG. 5, the hydraulic cylinder 47 is operated to lower the press plate 46, and the buffer body is pressed to a height of 40 mm. The time required for pressing was about 20 seconds.

After the buffer material mixture has been pressed by the press plate 46 for 3 minutes and 30 seconds, the pressure inside the container is 760 mmHg through the gas filling pipe 45 while maintaining the pressed state. The carbon dioxide is introduced into the closed container 42 until the process returns to step 1, the hydraulic cylinder 47 is operated, and the press plate 46 is returned to the upper part of the closed container 42 to release the press, as shown in FIG.

Then, as shown in FIG. 7, the closed container 4
The lid 43 of No. 2 was opened, the net-like basket 41 was taken out, the lid 48 was opened, and one regeneration buffer 50 was taken out. The size of the obtained cushioning body 50 is a rectangular parallelepiped of 1000 × 2000 × 400 mm, and the neighboring cushioning material strips are joined together by a mixed hot melt resin and are firmly integrated by pressing. It was a uniform one with almost no collapse.

[0036]

As shown and described above, according to the method for manufacturing a regenerative cushioning body of the present invention, a synthetic resin foam or a synthetic resin foam and a cushioning material made of a different material such as rubber are used in an amount of about 2 or less.
Crush into small pieces having a size of ˜30 mm, mix the small pieces and the hot-melt resin, tightly store the mixture in a closed container, and then fill the closed container with a flammable gas, Since the flammable gas is explosively burned and the cushioning material strips are integrally joined to obtain a cushioning body, it is a waste product of a non-foamed material such as a rubber chip or a polyolefin-based synthetic resin having a relatively poor adhesive strength. However, it is possible to easily obtain a practical regeneration buffer in a short time, and it has great advantages in terms of reduction of industrial waste and effective use of resources.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a container at the time of containing a cushioning material mixture in an embodiment of a method for manufacturing a regenerative cushioning body of the present invention.

FIG. 2 is a perspective view showing an example of a container used in the manufacturing method of the present invention.

FIG. 3 is a perspective view showing an example of a net cage.

FIG. 4 is a sectional view showing another example of the manufacturing method of the present invention.

FIG. 5 is a cross-sectional view showing a pressed state.

FIG. 6 is a cross-sectional view showing when the press is released.

FIG. 7 is a perspective view showing the time when the reproduction buffer is taken out.

[Explanation of symbols] 10 buffer material strips 11 hot melt resin 12 closed container 17 reticulated basket 20 flammable gas

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display B29K 105: 26

Claims (2)

[Claims] 1. A synthetic resin foam or a cushioning material made of a different material such as synthetic resin foam and rubber is crushed into strips having a size of about 2 to 30 mm, and the strips and the hot melt resin are mixed. Together, the mixture is tightly housed in a closed container, then the closed container is filled with a flammable gas, and the flammable gas is explosively burned to integrally join the buffer material strips to a buffer body. A method for producing a regeneration buffer, which comprises: 2. The method for manufacturing a regenerated buffer body according to claim 1, wherein after the explosive combustion of the combustible gas, the buffer material strip in the container is pressed.