JPS6194705A - Treatment for regeneration and recovery of polystyrene resin from polystyrene foaming body - Google Patents

Abstract

PURPOSE:To regenerate and recover granular etc. polystyrene resin easily from used polystyrene foaming body by a method wherein polystyrene foaming body is heated to such an extent that it is not completely melted, shrunk to a specified volume, densified to a high grade and then crushed in a crusher. CONSTITUTION:Polystyrene is heated to such an extent that it is not completely melted, shrunk down to 1/5-1/30 in volume and densified to a high grade. Then, it is crushed in a crusher. Modifier composed of inorganic material such as clay or aluminium hydroxide, etc. wood chips, rubber, plastics is mixed with granular or powdered polystyrene resin obtained. This mixture is pelletized by an extruder etc.s to recover the polystyrene resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for treating polystyrene foam;
The present invention relates to a processing method for recycling and recovering resin materials from the waste.

[Technical background of the invention]

Polystyrene resin foams are used in large quantities for containers such as fish boxes and fruit packaging boxes, or as cushioning materials. Traditionally, these used polystyrene foam products are disposed of as is, but since they are not decomposed by microorganisms, most of them have no choice but to be incinerated, and the cost of incineration equipment and work has become a social issue. It has come to be debated.

Although some experimental methods have been carried out to separate and recover styrene resin by heating and gasifying polystyrene foam, it is difficult to put it into practical use because it requires expensive equipment, running costs, and energy consumption. The reality is that this is far from the case.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and provides a processing method that can process polystyrene foam at low cost without requiring large-scale and expensive equipment, and recover polystyrene resin that can be used as a resin material. This is what we provide.

[Summary of the invention]

The first treatment method according to the present invention is to heat the polystyrene foam without completely melting it to a volume of 115 to 100 liters.
The method is characterized in that after shrinking the resin to a size of 1/30 to increase the density, it is passed through a suitable pulverizer to recover granular or powdered polystyrene resin.

In addition, the second treatment method according to the present invention is to heat the polystyrene foam without completely melting it to reduce the volume to 17.
It is characterized in that it is shrunk to 5 to 1/30 times, densified, and then passed through a suitable pulverizer to obtain a granular or powdered polystyrene resin.1 It is then pelletized using an extruder or the like.

As described above, the main feature of the present invention is that the polystyrene foam is densified by heating and shrinking, and then pulverized. In this case, if the polystyrene foam is completely melted, it will become a hard 8M@ lump that cannot be crushed with a normal crusher, so it is necessary to control the degree of heating so that it does not completely melt. be. - To give an example, when waste polystyrene foam is placed in an oven heated to a temperature of approximately 150°C to 250°C, the gas in the foam is released in a few seconds to several tens of seconds, and the volume decreases to approximately 175°C. Shrinks to ~l/30. If we express this shrinkage in density, 0.02 g/am' is 0,
The beak is densified to about 2-0.8 g/cm'.

Since the material densified to this extent is relatively hard and brittle, it can be easily ground into granules or powder using a kneader, Henschel mixer, or other conventional grinder.

Note that when heat-shrinking the polystyrene foam, the foam may be cut into pieces in advance to radiate heat;
As a heater, a normal dryer, other infrared heaters, gas burners, etc. may be used.On the other hand, when the polystyrene foam shrinks due to heating, flammable gas is released, so this flammable gas should be removed from the duct. It is preferable to remove it from the thread by means such as the following.

The granular or powdered polystyrene resin thus recovered can be used as a molding material for boards and the like in the same way as ordinary polystyrene resin. In order to facilitate handling at that time and to make the quality of the molded product uniform, it is preferable that the particle size of the pulverized particles be approximately 5 mm or less.

As mentioned above, the granular or powdered polystyrene resin obtained in the first invention of the present application can be directly used as a molding material.
It is also possible to use clay or aluminum hydroxide for the granular or powdered polystyrene resin. A composite resin material can be easily obtained by mixing inorganic substances such as, wood flour, rubber, and other modifying materials such as plastics, and pelletizing this mixture.

In addition, in both the first invention and the second invention, the recycling and recovery steps are extremely 11! It is easy to carry out and can be carried out without using any special equipment, and the recovered polystyrene resin hardly deteriorates.

[Embodiments of the invention]

The present invention will be explained in detail below.

Example 1 Used Styrofoam fish box 1: degree 0.015g/
When the carbon dioxide 3) was placed on a belt conveyor and heated for 640 seconds at 190° C., it contracted in volume and became a thin plate with a density of 0.35 g/am 3 .

When this thin plate-shaped contracted body was crushed in a Henschel mixer for 5 minutes, one grain of polystyrene resin was recovered.

In addition, a gas vent hole was provided in the upper part of the oven to remove the gas released from the styrofoam (1), and the used fish box was heated.

Example 2 Used Styrofoam fish box (density 0.015g/
c3) was crushed into approximately 20 to 50 l, washed with water to remove dirt and foreign matter, and introduced into an open chamber at 180°C by a belt conveyor. When heated for 40 seconds, it shrunk to a density of 0.35 g/C1. When this was pulverized for 3 minutes using a Henschel mixer, one grain or powdered polystyrene resin was recovered.

Example 3 The a-form and 11-powder polystyrene resins recovered in Examples 1 and 2 were heated at 190°C.
After extrusion into a diameter of 31 cm using an extruder, the pellets were further pelletized using a pelletizer to obtain polystyrene resin pellets with a length of 3 to 5 cm.

〔Effect of the invention〕

As detailed above, 1. According to the present invention, used polystyrene foam, which was previously discarded as is, can be processed simply and at low cost, and polystyrene resin as a useful resin material can be recovered, etc. is obtained.

Claims (3)

[Claims] (1) After heating the polystyrene foam without completely melting it to shrink its volume to 1/5 to 1/30 and making it highly densified, it is crushed into a suitable pulverizer to form granular or powdered polystyrene resin. A processing method for regenerating and recovering polystyrene resin from polystyrene foam, characterized by recovering polystyrene resin. (2) After heating the polystyrene foam without completely melting it to shrink its volume to 1/5 to 1/30 and making it highly densified, it is crushed into a suitable pulverizer to form granular or powdered polystyrene resin. A processing method for recycling and recovering polystyrene resin from a polystyrene foam, characterized by further pelletizing it using an extruder or the like. (3) One or more modifiers selected from the group consisting of inorganic substances such as clay or aluminum hydroxide, wood flour, rubber, and other plastics are mixed with the granular or powdered polystyrene resin. A processing method for regenerating polystyrene resin from a polystyrene foam according to claim 2, characterized in that this mixture is pelletized using an extruder or the like.