JPS6210164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for pre-foaming expandable thermoplastic resin particles, and more specifically, is characterized in that pre-foaming can be easily performed even in places without boiler equipment. There is.

Conventionally, in order to pre-foam expandable thermoplastic resin particles such as expandable polystyrene particles (polystyrene beads), steam is generated in a boiler, and this steam is introduced into a foaming tank, foaming kettle, etc., and the resin particles are Pre-foaming was carried out by steam heating.

However, in order to mold expandable thermoplastic resin particles by installing a boiler, molding machine, etc. in a factory, pre-foaming by introducing steam generated in a conventional boiler is optimal. However, if only the resin particles were to be used at a construction site or other intended use site, there was no boiler equipment and it was impossible to pre-foam the resin particles.

Therefore, the present invention has been devised for the purpose of allowing the resin particles to be pre-foamed even in places where boiler equipment as described above is not available, and the method has the following characteristics.

That is, in a batch pre-foaming method in which expandable thermoplastic resin particles are supplied in a fixed amount in batches to a foaming tank, foaming pot, etc., the particles are pre-foamed, and then taken out from the foaming tank, foaming pot, etc. in batches. This is a method in which the resin particles are pre-foamed using steam generated by heating water in a water tank directly connected to a foaming pot or the like.

Next, the method of the present invention will be illustrated below with reference to the drawings together with a pre-foaming device used for carrying out the method.

Reference numeral 1 denotes a main body of a pre-foaming device having a foaming tank 10, a foaming pot, etc. A stirring motor 11 is attached to the upper part, and the foaming tank 10 is directly connected to the motor 11.
A stirring shaft portion 12 is introduced inside, and a plurality of stirring blades 13 are attached to the shaft portion 12. A raw material input hopper 14 is also connected to the upper part of the main body, so that foamable thermoplastic resin particles (beads) as a raw material can be supplied into the foaming tank 10.

Further, an opening 15 for taking out the foamed resin particles is provided on the side surface of the lower end of the main body 1, and a hinged opening/closing lid 16 is attached to the opening 15.

Furthermore, a flange portion 20 is provided at the lower end of the main body portion 1, and a hot plate 20 is arranged so as to match the flange portion 20.
1 is attached to form the lower part of the foaming tank 10. This hot plate 21 has pores 22 for steam passage.
(Core vents can also be used) are perforated,
A bearing portion 23 for the stirring shaft portion 12 is attached to the central portion.

A water tank 3 is placed below the hot plate 21 in the foaming tank 10.
0 are directly connected to each other, and the upper edge of the water tank 30 is fixed to the flange portion 20 with bolts or the like, so that the foaming tank 10, the hot plate 21 at the lower part thereof, and the water tank 30 are joined together.

The aquarium 30 is equipped with means for heating the water in the aquarium 30 either externally or internally, and in the case shown, a propane gas burner 40 is provided below the aquarium 30 to heat the aquarium 30. There is. 41 is a propane gas cylinder, which is connected to the burner 40 through a rubber hose 42 or the like.

In addition, 17 in the figure is a viewing window made of heat-resistant glass, 1
Reference numeral 8 indicates a window holder secured with bolts or the like, 50 a pedestal for supporting the foaming device, 31 a liquid level gauge, and 32 a water supply stop valve.

In practice, as shown in the figure, the shape of the hot plate 21 is such that the center portion with the pores 22 is formed high so that the top surface of the hot plate 21 and the top of the openings 15 for taking out the foamed resin particles are high. This is because it is easier to take out the foamed resin particles if the lower part is on the same plane or if the hot plate 21 is on the top, and it is okay if some foamed resin particles remain in the foaming tank 10. The hot plate 21 may also have a flat shape.

Using the pre-foaming device constructed as described above, water is first supplied into the water tank 30 by opening the water supply stop valve 32 while observing the liquid level gauge 31.

Next, the gas burner 40 is ignited to heat the water tank 30, and when the water has boiled, the stirring blades 13 are rotated and raw resin particles are fed into the foaming tank 10 in a fixed amount from the raw material input hopper 14.

The raw material resin particles that have entered the foaming tank 10 are caused by the steam generated by heating the water tank 30 entering the foaming tank 10 through the pores 22 of the hot plate 21, and the heated hot plate 21 and the steam. After foaming is completed, the opening/closing lid 16 is opened through the removal opening 15 and the foam is taken out to the outside.

When the water tank 30 was heated with the gas burner 40 as described above, the foamed resin particles became slightly moist and difficult to form into blocks, and the pre-foaming was performed well. However, in place of the gas burner 40, For example, it is practically possible to heat the water in the aquarium 30 by installing an electric rod heater underwater, and various heating means for the aquarium 30 are possible.

Further, in practice, by adjusting the stop valve 32 while observing the liquid level gauge 31, the liquid level can be stabilized to some extent in relation to the amount of evaporation. Also, liquid level gauge 3
1 and the stop valve 32 automatically electrically controlling it is also practical and convenient.

Furthermore, if a shutter (not shown) is provided between the foaming tank 10 and the raw material input hopper 14, the foaming speed can be further increased without dissipating steam, which is convenient. Although the bubbling state is controlled by marking the glass surface while looking through the viewing window 17, it is also possible to control the level by attaching a level meter.

As described above, in the method of this invention, water in a water tank directly connected to a foaming tank, foaming kettle, etc. for pre-foaming raw resin particles in fixed quantities in batches is heated. Since the raw material resin particles are pre-foamed by the resulting steam, sufficient foaming can be achieved even in places without steam boiler equipment, and pre-foaming can be easily carried out at the site of use. Therefore, it is possible to transport raw resin particles with a small volume, contributing to a reduction in transportation costs, and it has the advantage of being able to foam only the amount that will be used at construction sites and other intended use locations, and is extremely effective in terms of management and storage of foamed resin particles. This is a convenient method.

Furthermore, in addition to being newly installed as a device used to carry out the method of the invention, it is also possible to configure a conventional batch-type pre-foaming device with improvements.
It is simple in structure and extremely economical in terms of installation cost, and is highly effective in use, and can greatly contribute to implementing the method of the invention at low cost.

[Brief explanation of the drawing]

The figure is a schematic sectional view showing an apparatus for implementing the present invention. 1... Main body part, 10... Foaming tank, 21... Hot plate, 22
... Pores for passing steam, 30... Water tank, 40... Gas burner serving as heating means.

Claims (1)

[Claims] 1. Supplying foamable thermoplastic resin particles to a foaming tank, foaming pot, etc. in a fixed amount in batches, and pre-foaming them;
In a batch-type pre-foaming method in which the resin particles are taken out from a foaming tank, foaming pot, etc. in batches, the resin particles are pre-foamed by steam generated by heating water in a water tank directly connected to the foaming tank, foaming pot, etc. A method for pre-foaming expandable thermoplastic resin particles, characterized in that: 2. Supply the expandable thermoplastic resin particles in a batchwise manner to a foaming tank, foaming pot, etc. in a fixed amount, and pre-foam the particles.
In a batch-type pre-foaming device that extracts foam from a foaming tank, foaming pot, etc. in a batch manner, a water tank is directly connected to the bottom of the foaming tank, foaming pot, etc., and a means for heating the water in the water tank is provided outside or inside the water tank. A pre-foaming device for expandable thermoplastic resin particles, characterized in that: 3. The pre-foaming device according to claim 2, wherein the means for heating the water in the water tank comprises a gas burner provided outside the water tank. 4. The pre-foaming device according to claim 2, wherein the means for heating the water in the water tank comprises a heater provided inside the water tank.