Particle foam component and method for production thereof

Abstract

A particle foam component has a foam body, which is provided with a cover layer made of a plastic material at least in partial areas of its outer surface. The foam body has a compressed surface structure in its areas supporting the cover layer. The cover layer is bonded in substance to the compressed surface structure of the foam body. For producing the particle foam component, the foam body is foamed in a mold and the cover layer is foamed or molded integrally in a subsequent method step. A compressed surface structure is formed in the surface areas supporting the cover layer before applying the cover layer, and the cover layer is bonded in substance to the compressed surface structure.

Claims

1. A method for producing a particle foam component, the method comprising: providing a foam body comprising an outer surface, said foam body being provided with a cover layer made of a plastic material at least in partial areas of said outer surface, wherein the foam body is foamed in a mold and the cover layer is foamed or molded integrally in a subsequent method step, wherein a compressed surface structure is formed in said partial areas of the foam body supporting the cover layer before applying the cover layer, and the cover layer is bonded in substance to the compressed surface structure, wherein the compressed surface structure of the foam body is formed by an external force of pressure on the foam body, the compressed surface structure of the foam body being formed after the foaming of the foam body.

2. A method in accordance with claim 1, wherein at least one of: surface areas of the foam body, on which the external force of pressure acts, are melted at least in some areas one or more of before applying the external force of pressure; and said surface areas of the foam body are melted at least in said some areas during application of the external force of pressure.

3. A method in accordance with claim 1, wherein the external force of pressure is applied by means of a punch.

4. A method in accordance with claim 3, wherein the punch is formed by means of an adjustable mold part of the mold.

5. A method in accordance with claim 1, wherein the plastic material forming the cover layer is a thermoplastic elastomer.

6. A method in accordance with claim 1, wherein at least one of: the compressed surface structure is melted in some areas before applying the cover layer; and the compressed surface structure is melted in said some areas during application of the cover layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 is a sectional view of a mold for foaming a foam body;

(3) FIG. 2 is a sectional view of the mold according to FIG. 1 with a foamed foam body;

(4) FIG. 3 is a sectional view of the mold according to FIG. 2 after formation of the compressed surface structure;

(5) FIG. 4 is a sectional view of the mold according to FIG. 3 after opening the mold;

(6) FIG. 5 is a sectional view of the mold according to FIG. 4 upon removal of the foam body;

(7) FIG. 6 is a sectional view of the foam body with compressed surface structure;

(8) FIG. 7 is a sectional view of an injection mold with inserted foam body;

(9) FIG. 8 is a sectional view of an injection mold according to FIG. 7 upon closing;

(10) FIG. 9 is a sectional view of the closed injection mold with inserted foam body;

(11) FIG. 10 is a sectional view of the injection mold according to FIG. 9 with molded integrally cover layer;

(12) FIG. 11 is a sectional view of the opened injection mold upon removal of the particle foam component, and

(13) FIG. 12 is a sectional view of the finished particle foam component.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(14) FIG. 12 shows a schematic view of a particle foam component 10, which consists of a foam body 11 made of EPP or EPS and is provided on one side with a cover layer 13 made of a thermoplastic elastomer, wherein the foam body 11 has a compressed surface structure 12 in its areas supporting the cover layer 13.

(15) The method for producing a corresponding particle foam component 10 shall be explained below in detail on the basis of FIGS. 1 through 11.

(16) FIG. 1 shows a schematic view of a mold 20 with a container-like lower mold part 21, in which an only schematically suggested filling nozzle 22 for inserting foamable plastic particles and two steam nozzles 23 for introducing hot steam into a mold cavity 25 defined by the lower mold part 21 are provided. The mold cavity 25 is closed by a cover-like second mold part 24, which can be inserted into the mold cavity 25 with a punch-like attachment 24a. The cover-like second mold part 24 can be adjusted in relation to the first mold part 21, as it is suggested by the double arrow A. Further, the second mold part 24 may be heated up to a desired temperature by means of a heating device 26, which is shown as an example.

(17) In its starting position, the second mold part 24 is retracted from the mold cavity 25 with its punch-like attachment 24a, as it is shown in FIG. 1.

(18) The punch-like second mold part 24 is preheated to a predetermined temperature by activating the heating device 26 and particles made of foamable plastic, especially of EPP or EPS are inserted into the mold cavity 25 by the filling nozzle 22. Hot steam is introduced into the mold cavity 25 by the steam nozzles 23 (arrows D in FIG. 2), as a result of which the particles foam and form a mold cavity 25 forming the entire foam body 11.

(19) After a predetermined residence time of the foam body 11 in the mold cavity 25, the adjustable second mold part 24 is moved, such that it enters the mold cavity 25 with its punch-like attachment 24a and compresses the foam body 11 and melts on the surface facing the punch-like attachment 24a because of its high wall temperature. Due to the melting-on boundary layer of the foam body 11 and the compression resulting from the punch-like attachment 24a of the second mold part 24, a compressed, closed-pore surface structure 12 forms in the surface areas of the foam body 11 coming into contact with the second mold part 24, as it is suggested in FIG. 3.

(20) After a predetermined cooling-off phase, the cover-like second mold part 24 is removed and thus the mold 20 is opened (see FIG. 4) and the foam body 11 with compressed surface structure 12 on the top side can be removed from the mold 20 (see FIG. 5).

(21) The cover layer 13 made of a thermoplastic plastic is subsequently sprayed onto the foam body 11 with compressed surface structure 12 shown in FIG. 6 in a further method step, which is explained below on the basis of FIGS. 7 through 11.

(22) FIG. 7 shows a schematically shown injection mold 30 with a container-like lower first mold part 31, which defines a cavity 34. The foam body 11 with compressed surface structure 12 can be inserted into the cavity 34, as it is shown in FIG. 7.

(23) The injection mold 30 is subsequently closed by a cover-like, upper second mold part 32, in which a spray nozzle 33 is formed, as it is suggested by arrow V in FIG. 8.

(24) FIG. 9 shows the closed injection mold 30 with inserted foam body 11, wherein the cavity 34 is somewhat larger than the foam body 11, so that a cavity 35 is formed between the top side of the foam body 11, i.e., between the compressed surface structure 12 of the foam body 11 and the second mold part 32.

(25) A thermoplastic elastomer can be injected into this cavity 35 by the spray nozzle 33, which forms the cover layer 13 and forms a positive-locking bonding to the compressed surface structure 12 of the foam body 11.

(26) After a predetermined cooling-off phase, the injection mold 30 is opened and the particle foam component 10 with the foam body 11 and the thermoplastic cover layer 13, which is bonded to the foam body 11 via the compressed surface structure 12, can be removed from the injection mold (see FIG. 11).

(27) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.