DE1235566B - Device for extrusion of foam profiles - Google Patents

Description

FEDERAL BEPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

DESIGN SCREEN

Ie *. CU

B29d

German KL:} 9a3-27 / 00

Number: 1235566

File number: 'C26872X / 39t3

Aamekktng: April 30, 1962
Acknowledged:

Device for extrusion of
Foam profiles

Register

Chemical works KUt Aktk

It is known that foamable masses can be processed on strand machines; the foaming takes place either immediately when it exits the nozzle of the extrusion machine or by subsequent heating. Aacu $ have already been described for the. Production of KabdJsolaticnen, Blasfolkn etc. are suitable. However, it has not yet been possible to use screw presses to manufacture Schaurmloffplatcen bits to a thickness of a few centimeters directly ία an endless a »strand.

It has been shown that the for manufacturing where ■ Flat nozzle commonly used with plastic sheets «a 2

regulated Kumtsfoffverschäumung, ie "egg or im-

indirectly behind the nozzle take place soO, not allow, is edge or a corresponding decrease in height in one In particular, because of the rectangular cross-section starting at 4, the propellant can be

with the side parts, as usual, to improve the flow, the sides are designed as fillets 5,6.

Named as inventor:
Rudolf Schumacher,
Dr. Fritz Baxmann, Mari

Nozzle prevailing pressure only after the plastic Compose the nozzle lather; As a result, the disc cannot ensure a uniform, even formation of the surfaces of the foam strand, but these surfaces appear very uneven and irregular. This also promotes outgassing from the surface, creating the cavities collapse in the outer layers, aod reduce the usable cross-section of the strand.

The simple enlargement of the generally insufficient opening of these doths does not lead to the Z * el. Also the frequent union of several smaller ones

Schautasfoffzcltcn to undesired larger hollow p> with the attached displacement bodies 8 crriumen BQt ilch so tightly fix. follows through IMm of the screw series 11, 12 and

It has been found that one can use foam profiles, in particular plates, avoiding the aforementioned Disadvantages of thermoplastics

bi excellent u MaterialverdJchlung greeted by means of a slot die. The can be extruded between the connecting pieces if in the part of the displacement body 8 and the brackets 9, 10 a parallel cross-section is replaced by means of the necessary free cross-section at this point.

It is arranged that the Plaitcnstrang in parallel DJc strong compression causes a short-term Orbits divided, at the same time by the displacer- «« complete homogeneity of the mass, whereby also through body 8 and, if necessary, additionally through their thermal decomposition of the blowing agent or the holding of solvents 9. IO strongly compressed and immediate evaporation of an oasis that has already become free or behind it by cmc extension of the Dtiscaqucr- dump completely in the optattiichen measure unier fichnilts is relaxed in a predetermined manner. Pressure can be released so that only one phase is present.

For the production of foam board, «S When exceeding the point greatest compression ifa'e in Λ b b. As shown in Fig. 1, the slot nozzle 1 has proven its worth, the nozzle cross-section initially widens rapidly, which in its external structure resembles its use! The warm plastic, drifting formation of many small cells occurs. From point 15 high-grade plastic becomes from a sea corner to the nozzle end 16, the w * <i press expands through the cylindrical attachment! promoted. * e slower and reaches there for pressure equalization. From the end of 3 of this approach, the circular opening towards the atmosphere gives lire the largest opening. The cross-section isochoric with a square-shaped widening.

are bikkt. Between the UnJen4 and 7, the inner surfaces ν are performed in parallel within this Rnu- - -MES starting, the plastic material parallel to each other by cmc number of arranged, suitably shaped strömungsglinstig Vcrdrünge is / divided körpcr 8 and compresses the compression can comparable except K by the vertically take place at the Dliscninncnilächcn 13, 14 stationary in Fig.3 Vcrdrängcrkörpcr8 also in parallel by the support formed as the displacement body 8 interchangeable supports 9, 10th Replacing the brackets

Open dta expediently second dBg trained BrdtschQtzdQse 1. Ok middle of the in A b b. 3 m section shown brackets 9, 10 is also the location of the

level, as the displacement bodies 8 taper and taper to a point on the disc 16. The hot foam strips weld together at the end of the nozzle and thus form a single sheet of panels that is uninterrupted by a suitable take-off device can be discharged.

The displacement bodies 8 can, as in A b b. 1 shown, be attached at equal intervals; but you can also keep the distances different in order to control the flow of material in addition. ao

Special effects can be achieved in that the displacement body 8 can be heated or designed coolable; this can be done, for example, by installing electrical heating elements or by using hollow ones Execution of the displacement body and its mountings 9,10 for the purpose of passage of heat or Reach coolants. Heating can be advantageous, for example, for the subsequent welding to favor a compensation for the relaxation heat converted into work to »0 create etc. With sufficient cooling of the displacement body 8, however, it is possible to make the individual strands, if desired, in a non-welded manner To maintain shape, so that a subsequent separation is not necessary. In particular through appropriate Profiling of the displacement body 8 can be made in this way already finished foam profile strands obtain.

It is also possible, for example, to use a ring nozzle instead of the slot nozzle, in which the displacement bodies 8 are expediently arranged radially.

The new type of device allows the processing of all known foams that can be foamed as a result of the addition of fluid thermoplastics; beispiclswcisc can be polystyrene, polyolefins such as Polyethylene or polypropylene, hard and soft gcmachtcs Polyvinyl chloride, polyamides, acrylonitrile-butadicn-styrene copolymers insert.

As a result of the different properties of these different plastics, which are still characterized by type and Amount of propellant can be further changed, leaving the sieve extremely uniform, fine-pored Products are especially preserved if you consider the compression ratio as well as speed and The degree of relaxation, i.e. the control of foam formation, is adapted to the material to be processed. For example, it is often expedient to compress hard polyvinyl chloride less than plastic polyvinyl chloride; In contrast, hard polyvinyl chloride can be expanded more in many cases. the The most favorable operating conditions can be determined through appropriate preliminary tests; to make things easier In these attempts, it is useful to have several types of displacers 8 and brackets 9, 10 interchangeable to design.

With the help of the new device it is possible in particular, the heat and sound-absorbing foam panels in very uniform, easier to manufacture mold.

Claims (2)

Patent claims: 1. Device for extrusion of foam profiles, in particular panels made of thermoplastic Plastics by means of a slot nozzle, characterized in that in the part of the greatest nozzle width a parallel set of exchangeable, heatable or coolable displacement body (8) is arranged so that the plate strand divided into parallel tracks, simultaneously by the displacement body (8) and if desired additionally strongly compressed by their brackets (9, 10) and immediately behind them is relaxed in a predetermined manner by widening the nozzle cross-section. 2. Apparatus according to claim I _1, characterized in that the extent of compression and relaxation of the plastic is changed by using different distances and shapes of the displacement body (8) and / or the exchangeable brackets (9,10). References considered: U.S. Patent No. 2,734,224. 1 sheet of drawings 709 517/522 2.67 Q Bundesdruckerei Berlin