WO1999067471A2

WO1999067471A2 - Method and apparatus for molding continuously a foamed plastic board

Info

Publication number: WO1999067471A2
Application number: PCT/KR1999/000323
Authority: WO
Inventors: Kyu-Tae Yoon
Original assignee: Mipo Chemicals Co., Ltd.
Priority date: 1998-06-20
Filing date: 1999-06-19
Publication date: 1999-12-29
Also published as: WO1999067471A3; AU4654999A; KR19980065058A

Abstract

The present invention relates to a method and apparatus for molding continuously a foamed plastic board (100). For molding continuously a foamed plastic board (100) using preliminary granular foam, the present invention provides an apparatus for molding continuously foamed plastic board (100) comprising: a filling and transferring means (10) for filling continuously preliminary granular foam in the form of sheet to mold a foamed plastic board (100) while the preliminary granular foam is foamed by dry vapor, and transferring the foamed plastic board (100); a maturing means (20) for maturing the foamed plastic board (100) molded by the filling and transferring means (10); and a cutting means (30), such as a cutter, for cutting the foamed plastic board (100) matured by the maturing means (20) by the fixed size.

Description

TITLE

METHOD AND APPARATUS FOR MOLDING CONTINUOUSLY FOAMED PLASTIC BOARD

TECHNICAL FIELD

The present invention relates to a method and apparatus for molding continuously a foamed plastic board, and more particularly to a method and apparatus for molding continuously a foamed plastic board using preliminary granular foam.

BACKGROUND ART

Generally, a foamed plastic board, i.e., a polystyrene board manufactured by the beading process (referred to as what is called "styrofoam" ) , is made of preliminary granular foam obtained from a first foaming of foamable plastic granules, such as EPS (expandable polystyrene), said preliminary granular foam being matured in a mold having a fixed shape by steam of high temperature, and cut by the fixed thickness, thereby the finished board being obtained.

The foamed plastic board manufactured by the beading process as mentioned above, which is generally used as a heat insulating member for bulidings, is lightweight and low-cost, and provides excellent heat insualting efficiency compared to concrete. Therefore, the foamed plastic board is widely used in all kinds of construction of buildings or as packing members and shock-absorbing members .

Since such a foamed plastic board is cut by the fixed size after foaming and maturing of the preliminary granular foam, however, the finished granular foam in the cut section is broken and therefore it can not preserve the complete shape. As a result, binding force is weakened between the cut granular foam and the inner granular foam, surface strength is weakened, and water-proofing is weaken as water is liable to be penetrated into the cut granular foam.

Also, the method for manufacturing a board according to the conventional beading process is not carried out successively, thus the method has problems that productivity is low, that the board must be cut by additional process and apparatus, and that it is essential to provide additional mold in conformity with standards of the foamed plastic board.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to solve the problems as mentioned above.

It is another object of the present invention to mold continuously foamed plastic board and to enlarge combining strength between the granular foams at the upper surface and the ones at the lower surface. To accomplish the objects of the present invention, there is provided a method for molding continuously foamed plastic board comprising: filling the preliminary granular foam into a foaming chamber by virtue of negative pressure to mold continuously the foamed plastic foam in the form of sheet while the preliminary granular foam is foamed by dry vapor of temperature ranged between 110 °C to 140 °C, and transferring the foamed plastic board which is molded continuously; maturing the foamed plastic board molded at the filling and transferring step at the temperature of 70 °C to 120 °C for a prescribed time period; and cutting the foamed plastic board matured at the maturing step by the fixed size.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the present invention will be described in connection with the accompanying drawings, in which

Fig. 1 is a side sectional view showing an preferred embodiment according to the present invention;

Fig. 2 is a perspective view showing an preferred embodiment of a filling and transferring means according to the present invention;

Fig. 3 is a side sectional view showing another preferred embodiment of a filling and transferring means and maturing means according to the present invention;

Fig. 4 is a side sectional view showing an preferred embodiment of a coating means according to the present invention;

Fig. 5 is a side sectional view showing an preferred embodiment of a cooling means according to the present invention; Fig. 6 is a side sectional view showing another preferred embodiment of a cooling means according to the present invention;

Fig. 7 is a perspective view showing an preferred embodiment of a forming means for forming a concavo-convex portion according to the present invention;

Fig. 8 is a perspective view showing another preferred embodiment of a forming means for forming a concavo-convex portion according to the present invention; and

Fig. 9 is a perspective view showing an preferred embodiment of a printing means according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention will be described in detail with reference to the accompanying drawings .

Fig. 1 is a side sectional view showing an preferred embodiment according to the present invention, and Fig. 2 is a perspective view showing an preferred embodiment of a filling and ^' transferring means according to the present invention. As shown in Fig. 1 and Fig. 2, an apparatus for molding continuously foamed plastic board according to the present invention comprises: a filling and transferring means 10 for filling continuously preliminary granular foam in the form of sheet to mold a foamed plastic board 100 while the preliminary granular foam is foamed by dry vapor of temperature ranged between 110 °C to 140 °C, and transferring the foamed plastic board 100; a maturing means 20 for maturing the foamed plastic board 100 molded by the filling and transferring means 10 at the temperature of 70 °C to 120 °C; and a cutting means 30, such as a cutter, for cutting the foamed plastic board 100 matured by the maturing means 20 by the fixed size.

The filling and transferring means 10 comprises a supply tube 11 for supplying preliminary granular foam 100a from a hopper; a supply tube 12 for supplying dry vapor of the temperature ranged between 110 °C to 140 °C such that foamed is the preliminary granular foam 100a supplied through the supply tube 11 for preliminary granular foam; a molding chamber 13 for forming a filling space in which the preliminary granular foam 100a foamed by virtue of the dry vapor as described above is molded into the foamed plastic board 100 in the form of sheet; and a transferring means 14 for transferring the foamed plastic board 100 molded in the molding chamber 13 so that the molding of the foamed plastic board is carried out successively. The molding chamber 13 comprises a upper molding plate 13a with an exhausting unit 15 for exhausting air to create negative pressure, and left and right side plate 13b. The transferring means 14 comprises a driving roller 14a driven by an ordinary driving means, a transferring belt 14b arranged over the driving roller 14a and having a plurality of exhausting holes 14b' for exhausting air formed on the surface thereof, and a supporting plate 14c for supporting the transferring belt 14b such that the transferring belt 14b does not droop and having a exhausting unit 15 for exhausting air to create negative pressure.

The maturing means 20 includes a passage through which passed is the foamed plastic board 100 obtained from the foaming of the preliminary granular foam 100a, and a maturing chamber 21 heated at the temperature of 70 °C to 120 °C by means of a heating means. The heating means is obtained by providing the maturing chamber with a passage 21a through which a fluidic heat medium is circulated or by constituting the maturing chamber 21 and the heater as a single body.

Other preferred embodiments of the present invention will be described below.

According to another preferred embodiment of the present invention as shown in Fig. 3, at the upper side is also arranged a transferring means 14 constituted in the same structure as the transferring means 14 at the lower side, which is provided to transfer smoothly the foamed plastic board 100 obtained from foaming and filling of the preliminary granular foam 100a.

And at the upper and lower sides of the maturing means 20 is arranged a transferring means 24 comprising a transferring belt driven by an ordinary driving means, which is provided to transfer easily the foamed plastic board 100 foamed at the maturing step. Preferably, the molding chamber 13 is made of aluminium materials having superior heat transfer efficiency. Meanwhile, as shown in Fig. 2, the left and right side plates 13b are attached to the filling and transferring means 10 and the maturing means 20 detachably, and movable from side to side. Accordingly, the left and right side plates 13b are replaced with new ones corresponding to the size of the foamed plastic board 100 to be manufactured in case that it is required to mold a foamed plastic board thicker than the products to be manufactured. The left and right side plates 13b are retreated to make sure that they correspond to width of the products to be manufactures in case that it is required to mold a foamed plastic board wider than the products to be manufactured.

Furthermore, the transferring means 14, which are arranged at the filling and transferring means 10 and the maturing means 20, is provided with a cleaner 14d contacting the transferring belt 14b. The cleaner 14b is constituted in the form of a scraper of a brush for removing any granular foam which remains on the transferring belt 14b.

According to still another preferred embodiment of the present invention as shown in Fig. 4, at the rear of the maturing means 20 is provided a coating means 80 for spraying and coating combining materials to the upper and lower surfaces of the foamed plastic board 100 to improve combining force between the upper and lower surfaces of the foamed plastic board 100. With the coating means 80, combining force is enlarged between the granular foam at the upper and lower surfaces of the foamed plastic board, and the penetration of water is prevented, thus water-proofing is improved.

According to still another preferred embodiment of the present invention as shown in Fig. 1, between the maturing means 20 and the cutting means 30 is provided a attaching means 40 for attaching deposit film, synthetic resin film, synthetic resin sheet, aluminium film, fabric sheet, etc. to the upper and lower surfaces of the foamed plastic board 100 in compliance with the purpose of the use. By means of the attaching means 40, the foamed plastic board 100 can be used for various use.

According to still another preferred embodiment of the present invention as shown in Fig. 5 and Fig. 6, at the rear of the maturing means 20 is arranged a cooling means 50 for cooling the upper and lower surfaces of the foamed plastic board 100. The cooling means 50 comprises a cooling chamber 51 having a passage 51a through which the cooling water is circulated, and an air nozzle 52 arranged at the upper and lower surfaces of the foamed plastic board 100 for cooling the foamed plastic board 100 by air. With the cooling means 50, cooled rapidly is the upper and lower surfaces of the foamed plastic board 100 passed through the maturing chamber 21 of the maturing means 20, thus construction of the upper and lower of the surfaces become fine. According to another preferred embodiment of the present invention as shown in Fig. 7 and Fig. 8, at the front of the cutting means 30 is provided a means for forming a concavo- convex portion 60 on the upper and lower surfaces of the foamed plastic board 100. The means for forming a concavo- convex portion 60 includes various kinds of rollers in accordance with the purpose of the use. For example, the means for forming a concavo-convex portion 60 includes a rib roller 61 in case that it is required to form ribs on the upper and lower surfaces of the foamed plastic board 100. The means for forming a concavo-convex portion 60 includes a concavo-convex roller 62 in case that it is required to form simple concavo- convex portions on the upper and lower surfaces of the foamed plastic board 100. The means for forming a concavo-convex portion 60 includes a pattern roller in case that it is required to form special patterns on the upper and lower surfaces of the foamed plastic board 100. The rollers as described above are heated at the constant temperature by means of the heating means, such as vapor, fluidic heat medium, heater, etc. Since the various kinds of rollers are provided, various kinds of products can be manufactured in accordance with the purpose of the use. Preferably, there is provided an additional cooling roller for stabilizing the surfaces of the foamed plastic board 100 after patterning work is carried our by means of the special roller. According to another preferred embodiment of the present invention as shown in Fig. 9, at the front of the cutting means 30 is provided a printing means 70 comprising a printing roller 71 and a ink supply unit 72 by which pictures or characters may be printed on the upper and lower surfaces of the foamed plastic board 100. With the printing means 70, the trademark of the manufacturing company may be advertized as the trademark can be printed on the upper and lower surfaces of the foamed plastic board 100, and the quality of the goods is improved as various pictures or patterns can be printed on the upper and lower surfaces of the foamed plastic board 100.

Now, detailed description will be made of the process for manufacturing the foamed plastic board according to the present invention.

Before manufacturing process is carried out with the apparatus for manufacturing the foamed plastic board according to the present invention comprising the filling and transferring means 10, the maturing means 20, and the cutting means 30, the inlet of the molding chamber 13 is closed by the closing member of the same size in cross section as the molding chamber 13 such that the negative pressure created by exhausting the air from the exhausting unit 15 is applied to the inlet of the molding chamber 13, that is, the supply tube 11 for supplying preliminary granular foam.

If the apparatus is operated after the preparation as mentioned above is completed, the preliminary granular foam 100a is supplied through the supply tube 11 for supplying preliminary granular foam, exhaustion is performed through the exhausting unit 15, and the closing member moves to the inner side of the molding chamber 13 by means of the transferring belt 14b. The negative pressure is created in the molding chamber 13 as the closing member pass through the exhausting unit 15. By virtue of the negative pressure, the preliminary granular foam 100a supplied through the supply tube 11 is molded into the foamed plastic board 100 in the form of sheet in the vicinity of the exhausting unit 15. At this time, the filled preliminary granular foam 100a is foamed and filled by the dry vapor of the temperature ranged between 110 °C to 140

°C, supplied from the supply tube 12 for supplying dry vapor.

And the.foamed plastic board 100, which is molded in the form of the sheet by the preliminary granular foam foamed in the vicinity of the exhausting unit 15, is transferred by means of the transferring belt 14b. Consequently, the foamed plastic board 100 is molded successively in the vicinity of the exhausting unit 15. The foamed plastic board 100, which is molded in the molding chamber 13 of the filling and transferring means 10, is passed through the maturing chamber 21 having a heating means comprising the passage 21a through which the fluidic heat medium is circulated, a heating means operated by vapor, or a heating means such as a heater. As a result, the foamed plastic board 100 is matured at the temperature of 70 °C to 140 °C.

The foamed plastic board 100, which is matured in the maturing chamber 21 of the maturing means 20 and discharged, is cut by the fixed length by means of the cutting means such as a cutter.

On the other hand, as described above in connection with other preferred embodiments, the apparatus according to the present invention provides the coating means 80 for coating combining materials to the upper and lower surfaces of the foamed plastic board 100, the attaching means 40 for attaching deposit film, synthetic resin film, synthetic resin sheet, aluminium film, fabric sheet, etc. to the upper and lower surfaces of the foamed plastic board 100, the means for forming a concavo-convex portion 60, and the printing means 70. By means of these means, the foamed plastic board having many uses is manufactured.

INDUSTRIAL APPLICABILITY According to the present invention, the foamed plastic board can be manufactured successively, combining strength is remarkable between the granular foams as the granular foams on the upper and lower surfaces are maintained in whole granular condition, not in cut granular condition. Furthermore, the method and apparatus according to the present invention provides much more flexibility as thickness and width thereof can be adjusted easily in accordance with the purpose of the use.

It is to be understood that the forms of the invention herewith shown and described are to be taken as illustrative embodiments of the same, and that various changes in the shape, size and arrangement of parts, as well as various procedural changes, may be resorted to without departing from the spirit of the invention.

Claims

WHAT IS CLAIMED IS:

1. A method for molding continuously foamed plastic board comprising: filling the preliminary granular foam into a foaming chamber by virtue of negative pressure to mold continuously the foamed plastic foam in the form of sheet while the preliminary granular foam is foamed by dry vapor of temperature ranged between 110 °C to 140 °C, and transferring the foamed plastic board which is molded continuously; maturing the foamed plastic board molded at the filling and transferring step at the temperature of 70 °C to 120 °C for a prescribed time period; and cutting the foamed plastic board matured at the maturing step by the fixed size.

2. An apparatus for molding continuously foamed plastic board comprising: a filling and transferring means 10 for filling continuously preliminary granular foam in the form of sheet to mold a foamed plastic board 100 while the preliminary granular foam is foamed by dry vapor of temperature ranged between 110 °C to 140 °C, and transferring the foamed plastic board 100; a maturing means 20 for maturing the foamed plastic board 100 molded by the filling and transferring means 10 at the temperature of 70 °C to 120 °C; and a cutting means 30, such as a cutter, for cutting the foamed plastic board 100 matured by the maturing means 20 by the fixed size, said maturing means 20 including a passage through which passed is the foamed plastic board 100 obtained from the foaming of the preliminary granular foam 100a, and a maturing chamber 21 heated at the temperature of 70 °C to 120 °C by means of a heating means .

3. The apparatus for molding continuously foamed plastic board as claimed in claim 2, wherein said filling and transferring means 10 comprises a supply tube 11 for supplying preliminary granular foam 100a from a hopper; a supply tube 12 for supplying dry vapor of the temperature ranged between 110 °C to 140 °C such that foamed is the preliminary granular foam 100a supplied through the supply tube 11 for preliminary granular foam; a molding chamber 13 for forming a filling space in which the preliminary granular foam 100a foamed by virtue of the dry vapor as described above is molded into the foamed plastic board 100 in the form of sheet; and a transferring means 14 for transferring the foamed plastic board 100 molded in the molding chamber 13 so that the molding of the foamed plastic board is carried out successively, wherein said molding chamber 13 comprises a upper molding plate 13a with an exhausting unit 15 for exhausting air to create negative pressure, and left and right side plate 13b, and wherein said transferring means 14 comprises a driving roller 14a driven by an ordinary driving means, a transferring belt 14b arranged over the driving roller 14a and having a plurality of exhausting holes 14b' for exhausting air formed on the surface thereof, and a supporting plate 14c for supporting the transferring belt 14b such that the transferring belt 14b does not droop and having a exhausting unit 15 for exhausting air to create negative pressure.

4. The apparatus for molding continuously foamed plastic board as claimed in claim 3, wherein at the upper side is also arranged a transferring means 14 constituted in the same structure as the one at the lower side, and wherein at the upper and lower sides of the maturing means 20 is arranged a transferring means 24 comprising a transferring belt driven by an ordinary driving means .

5. The apparatus for molding continuously foamed plastic board as claimed in claim 3, wherein the left and right side plates 13b are attached to the filling and transferring means 10 and the maturing means 20 detachably, and movable from side to side.

6. The apparatus for molding continuously foamed plastic board as claimed in any one of claims 2 - 5, wherein at the rear of the maturing means 20 is provided a coating means 80 for coating combining materials to the upper and lower surfaces of the foamed plastic board 100 to improve combining force between the upper and lower surfaces of the foamed plastic board 100.

7. The apparatus for molding continuously foamed plastic board as claimed in any one of claims 2 - 6, wherein between the maturing means 20 and the cutting means 30 is provided a attaching means 40 for attaching deposit film, aluminium film, fabric sheet to the upper and lower surfaces of the foamed plastic board 100.

8. The apparatus for molding continuously foamed plastic board as claimed in any one of claims 2 - 7, wherein at the rear of the maturing means 20 is arranged a cooling means 50 for cooling the upper and lower surfaces of the foamed plastic board 100.

9. The apparatus for molding continuously foamed plastic board as claimed in any one of claims 2 - 8, wherein at the front of the cutting means 30 is provided a means for forming a concavo-convex portion 60 on the upper and lower surfaces of the foamed plastic board 100.

10. The apparatus for molding continuously foamed plastic board as claimed in any one of claims 2 - 8 , wherein at the front of the cutting means 30 is provided a printing means 70 by which pictures or characters may be printed on the upper and lower surfaces of the foamed plastic board 100.