SE430967B - CONTINUOUS PROCEDURE FOR ASTAD COMMUNICATION OF A SHEET OF FOAMED THERMOPLAST HEART - Google Patents

Description

10 15 20 25 30 35 7908575-9 2 The method of the invention also eliminates the need for the ability to dry the sheets produced, thereby costs are reduced and production speed increases.

The invention will be described in more detail below. vase with reference to the accompanying drawing, which shows an embodiment. Fig. 1 shows schematically from si- an apparatus according to the present invention. Fig. 2 vi- shows the apparatus in cross section and Fig. 3 illustrates in cross section a resulting laminated product.

The drawing shows an oven, which was used for early heating of two or more sheets 2 of expanded thermoplastic materials to be joined each other, a calibration and cooling station 3 for the sheets after connecting to each other and a station 4 for subsequent printing and cutting of the product to discs.

The furnace 1 consists of a chamber 5, in which the carrier and transport means for each sheet are mounted, the transport the door means allow continuous displacement of each single sheet 2 through the oven. These transport means can, so as shown, have the shape of rollers 6, which form webs for the sheets. Alternatively, the transport means may have the shape of endless bands or chains or of others suitable devices, which can transport sheet 2 in individually and separately. s The support and transport means 6 are aligned with the corresponding inlet openings 7 in one wall of the oven. Arken 2 is sprayed and dried and then wound on rolls R. Arken is drawn from the rollers R and enters the oven by opening As shown in the drawing, these openings 7 formed in one of the end walls of the oven 1. 7 It should be noted, however, that the sheets of expanded material can be fed either horizontally or vertically without adverse effect thereof. Guide means 6 for the sheets are therefore mounted in a corresponding manner.f In both cases, in the wall, which is located mid- 10 15 20 25 30 35 79085 75-9 3 against the wall in which the inlet openings 7 are formed, a single outlet opening 8 provided for all sheets 2.

In the oven 2 there are at least a pair of adjustable guide rollers 9 mounted next to the outlet opening 8 to bring the ken 2 to converge and approach each other to placed on top of each other.

For heating the sheets of sprayed, expanded material 2 as they pass the furnace 1 are heating means 10, such as electric heating elements, placed between and the transport means 6 for the sheets 2, which heating elements keeps the oven chamber at a predetermined temperature, for thus achieving a predetermined expansion of each individual sheet. It will be appreciated that the expansion of the sheets entails a reduction in their density.

In the area next to the outlet 8 of the oven 1, where the sheets 2 ' converges towards the pair of guide rollers 9 is further heating elements ll arranged for heating the opposite_ the surface portions of adjacent sheets to theirs melting temperature. By such melting is brought next stacked sheets to adhere to each other or to melt, as they pass between the rollers 9. This is done regardless of whether the surfaces of the sheets are smooth or exposed a previous, mechanical pretreatment.

During its passage through the oven 1, the sheets 2 can be traded at any suitable, desired temperature for one predetermined time period. During such treatment, they can further expanded, thereby reducing labor costs. density to a desired value is made possible. After the further expansion they are subjected to fastening intended surfaces for the action of the heating elements ll, so that at least their surface areas are heated to their melting point. peratur. The sheets are thus welded together as they pass between the guide rollers 9 and form a single laminate 20 with one number of layers, corresponding to the number of sheets used, whereby the thickness of the sheet is equal to the sum of the sheets used thickness and density of the laminate depend on the turn the density of the sheets. 10 15 20 25 30 35 7908575-9 4 Depending on the nature of the thermoplastic material, av which sheets are made, the temperature in the oven can vary between 100 ° C and 200 ° C and the speed at which the sheets are transported through the oven, can be between 4 and 15 m. By using these parameters it is possible to achieve a density reduction from 60-70 gr / l in the starting sheets to 22 gr / 1 in the finished one the product.

The method and apparatus of the invention allow thus a considerable increase in the volume of the starting sheet without that some major technical difficulties arise.

The laminate thus prepared is transported then to and through a calibration and cooling station tion 3, in which the physical product of the finished product properties are fixed. This station 3 includes as Fig. 2 shows two sets of adjustable rollers 12, which are facing each other to form a guide therebetween. path along which the laminate 20 must pass. During this passage between the rollers is cooled by the laminate by for example air entering through openings 13, which are arranged above and below the rollers 12, and by means water. IN After cooling, the product is ready to be exposed for subsequent printing and cutting to desired size. This takes place in station 4.

Using the procedure described above is it is possible to form sheets of each injected, expanded thermoplastic material, the sheets, of which the disc is prepared, may include desired additives such as against fire resistant materials and dyes. If ar- are made of fibrous material can the fibers be oriented or arbitrarily distributed.

During the procedure, it is also possible to on it one or both surfaces of the finished product apply plastic laminate or plain or bituminous paper to of the finished product to achieve the desired structure and desired properties. 7908575-9 5 Thus, according to the invention, in a simple and cheaply produced a laminated product, which has desired density, thermal insulation capacity, mechanical firmness, low moisture absorption, considerable resistance to diffusion of water vapor thereby and dimensional stability small, which is equivalent to similar products, ka obtained directly by spraying a structure with a layer.

Claims (1)

7158575-9 PATENT CLAIM Continuous process for producing a sheet (20) of foamed thermoplastic resin by joining two or more continuous webs (2 ') of the foamed thermoplastic resin under pressure, characterized in that continuous webs of partially foamed thermoplastic resin (2) is passed through a heating zone (5), in which the individual webs are homogeneously heated to a temperature which is below the melting temperature of the material but is sufficient to effect a further foaming to a final one, predetermined material density value, and that subsequently the webs foamed in this way are heated to the melting temperature of the material beyond the surface on the sides to be joined together and therefore not beyond the surfaces which, due to the connection of the webs, will form the disc. exteriors, and that the webs heated in this way are placed on top of each other and compressed to provide a complete weld. ing the individual sheets and producing a sheet (20) having a homogeneous structure.