GB2084069A

GB2084069A - Mould for producing a plastics foam body

Info

Publication number: GB2084069A
Application number: GB8124208A
Authority: GB
Original assignee: Mirabed AG
Current assignee: Mirabed AG
Priority date: 1980-09-26
Filing date: 1981-08-07
Publication date: 1982-04-07
Also published as: AU7446381A; NO812938L; ES267178Y; DE3128718A1; GB2084069B; ES267178U

Abstract

The mould comprises side walls (5, 6) which can be swung away or removed and is provided with a floating cover (7). Provided on the cover are upwardly projecting bars (9) which are displaceably mounted in guides (10) on a beam 11 spanning the mould. The bottom of the mould is designed as a tiltable base (3) so that they still tacky but stable plastics foam body can be removed from the mould shortly after it has been formed. The mould thus becomes available for use in the production process after a short time and does not lie around unused but can be employed for the intermediate storage of tacky plastics foam bodies. <IMAGE>

Description

SPECIFICATION Mould for producing a plastics foam body The invention relates to a mould for producing foam bodies and comprising side walls, which can be swung away or removed, and a floating cover.

For the discontinuous production of plastics foam bodies, e.g. made of polyurethane, use is made of closed or open moulds into which the plastics foam mixture, which is capable of reacting, is charged.

After the material has foamed and fully hardened, the resultant plastics foam bodies are removed from the mould. Since these plastics foam bodies remain tacky for a relatively long time, they usually have to remain in the mould until they can be transported.

For this reason, a plurality of moulds are required, and for most of the time these stand around without being involved in the production process. Where production capacity is great, these moulds, immobilized in an intermediate position, represent a considerable capital outlay.

Nor has it been possible hitherto to solve the problem of contamination of the moulds in a satisfactory way. AT-PS 351,242, for example, discloses a mould, the cover of which comprises an insert part which passes through the side walls of the mould; The materials involved in the reaction are able to penetrate between the insert and the side walls and to cause these walls to become tacky and dirty. Still greater difficulties in this connection occur with the mould in accordance with AT-PS 353,473, wherein a device for lowering the bottom is provided. Since the side edges of the bottom can never be completely sealed to the side walls of the mould, contamination and clogging of the internal lifting mechanism must inevitably be reckoned with.

The object of the present invention is to provide a mould which is affected as little as possible by contamination and which is easy to clean. In addition, the intention is to design the mould in such a way that the plastics foam body can be removed from it shortly after completion of the foaming reaction, so that the mould can continue to be used for the intermediate storage of tacky plastics foam bodies and does not lie around unused.

According to the invention, these objects are achieved in that the bottom of the mould is designed as a tiltable base, and in that means for guiding the cover are arranged therabove.

An example of the construction of the mould of the invention will now be described in greater detail by reference to the drawing, in which: Figure 1 is a perspective view of a movable mould and its cover; Figure 2 shows a cross-section through the mould of Figure 1 into which the not yet foamed mixture involved in the reaction is charged; Figure 3 shows the Figure 1 mould with the cover fitted, and the foamed material; and Figure 4 illustrates how a still tacky plastics foam body is tipped out of the mould by means of the tiltable bottom.

The mould, illustrated in the drawing, for producing plastics foam bodies comprises a frame 1 with wheels for ease of movement of the mould. A base-plate 3 is secured at the side of the frame 1 by means of a hinge 4 in such a way that the base-plate 3 can be swung upwardly. The mould also comprises four side walls 5, 6 which are likewise swingably mounted on the frame 1 or are detachably connected thereto so that they can be removed.

Afloating cover7 having reinforcing members 8 is provided with two upwardly projecting bars 9. These are displaceably mounted in two lengths of tubing 10 which in turn are secured to a beam 11 which is mounted on and spans the mould.

Before the mould is charged with the liquid foam-forming plastics composition, the side walls 5, 6 of the mould are swung up and are secured to each other at the edges in a manner not illustrated. The plastics composition is then introduced into the mould (Figure 2), and the cover 7 is fitted at the top of the mould. The cover 7 centred and guided by the length of tubing 20 is lifted by the action of the expanding foam material. Because of the weight of the cover 7, slight pressure is applied to the foaming composition, so that its surface cannot become curved.

The foam-forming reaction is completed in a few minutes, and a short while later the plastics foamed body will have acquired sufficient inherent stability to enable it to be removed from the mould although, in this condition, it is still tacky and cannot be touched. The side walls 5, 6 are then swung away or removed, the mould is conveyed to a storage area and the base-plate 3 is swung up to enable the plastics foam body to be tipped out (Figure 4). The mould then becomes availableforfurther use in the production process.

1. A mould for producing plastics foam bodies and comprising side walls, which can be swung away or removed, and a floating cover, in which the bottom of the mould is designed as a tiltable base, and means for guiding the cover are arranged thereabove.

2. A mould according to claim 1, in which the tiltable base comprises a flat base-plate which is linked at the side to a movable frame of the mould by means of a hinge.

3. A mould according to claim 1 or claim 2, in which the cover comprises two upwardly-projecting bars which are displaceably mounted in two guides.

4. A mould according to claim 3, in which the guides are secured to a beam which is mounted on the top of the mould and spans it.

5. A mould according to claim 1 substantially as described herein with reference to the accompanying drawing.

6. A process for the production of a plastics foam body by means of a mould in accordance with claim 1, wherein a plastics foam mixture capable of reacting is charged into the mould open at the top whereupon the cover is then fitted, the cover being removed on completion of the reaction and the side parts being swung away or removed, after which the bottom is swung up and the still tacky but stable

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Mould for producing a plastics foam body The invention relates to a mould for producing foam bodies and comprising side walls, which can be swung away or removed, and a floating cover. For the discontinuous production of plastics foam bodies, e.g. made of polyurethane, use is made of closed or open moulds into which the plastics foam mixture, which is capable of reacting, is charged. After the material has foamed and fully hardened, the resultant plastics foam bodies are removed from the mould. Since these plastics foam bodies remain tacky for a relatively long time, they usually have to remain in the mould until they can be transported. For this reason, a plurality of moulds are required, and for most of the time these stand around without being involved in the production process. Where production capacity is great, these moulds, immobilized in an intermediate position, represent a considerable capital outlay. Nor has it been possible hitherto to solve the problem of contamination of the moulds in a satisfactory way. AT-PS 351,242, for example, discloses a mould, the cover of which comprises an insert part which passes through the side walls of the mould; The materials involved in the reaction are able to penetrate between the insert and the side walls and to cause these walls to become tacky and dirty. Still greater difficulties in this connection occur with the mould in accordance with AT-PS 353,473, wherein a device for lowering the bottom is provided. Since the side edges of the bottom can never be completely sealed to the side walls of the mould, contamination and clogging of the internal lifting mechanism must inevitably be reckoned with. The object of the present invention is to provide a mould which is affected as little as possible by contamination and which is easy to clean. In addition, the intention is to design the mould in such a way that the plastics foam body can be removed from it shortly after completion of the foaming reaction, so that the mould can continue to be used for the intermediate storage of tacky plastics foam bodies and does not lie around unused. According to the invention, these objects are achieved in that the bottom of the mould is designed as a tiltable base, and in that means for guiding the cover are arranged therabove. An example of the construction of the mould of the invention will now be described in greater detail by reference to the drawing, in which: Figure 1 is a perspective view of a movable mould and its cover; Figure 2 shows a cross-section through the mould of Figure 1 into which the not yet foamed mixture involved in the reaction is charged; Figure 3 shows the Figure 1 mould with the cover fitted, and the foamed material; and Figure 4 illustrates how a still tacky plastics foam body is tipped out of the mould by means of the tiltable bottom. The mould, illustrated in the drawing, for producing plastics foam bodies comprises a frame 1 with wheels for ease of movement of the mould. A base-plate 3 is secured at the side of the frame 1 by means of a hinge 4 in such a way that the base-plate 3 can be swung upwardly. The mould also comprises four side walls 5, 6 which are likewise swingably mounted on the frame 1 or are detachably connected thereto so that they can be removed. Afloating cover7 having reinforcing members 8 is provided with two upwardly projecting bars 9. These are displaceably mounted in two lengths of tubing 10 which in turn are secured to a beam 11 which is mounted on and spans the mould. Before the mould is charged with the liquid foam-forming plastics composition, the side walls 5, 6 of the mould are swung up and are secured to each other at the edges in a manner not illustrated. The plastics composition is then introduced into the mould (Figure 2), and the cover 7 is fitted at the top of the mould. The cover 7 centred and guided by the length of tubing 20 is lifted by the action of the expanding foam material. Because of the weight of the cover 7, slight pressure is applied to the foaming composition, so that its surface cannot become curved. The foam-forming reaction is completed in a few minutes, and a short while later the plastics foamed body will have acquired sufficient inherent stability to enable it to be removed from the mould although, in this condition, it is still tacky and cannot be touched. The side walls 5, 6 are then swung away or removed, the mould is conveyed to a storage area and the base-plate 3 is swung up to enable the plastics foam body to be tipped out (Figure 4). The mould then becomes availableforfurther use in the production process. CLAIMS

6. A process for the production of a plastics foam body by means of a mould in accordance with claim 1, wherein a plastics foam mixture capable of reacting is charged into the mould open at the top whereupon the cover is then fitted, the cover being removed on completion of the reaction and the side parts being swung away or removed, after which the bottom is swung up and the still tacky but stable plastics foam body is tipped out.