Method for fusing particle foams by means of porous sleeves
A process for producing a molded article involves providing a thin-walled, gas-permeable shell; filling the shell with a foamed pelletized material composed of a polymer; and welding the foamed pelletized material to obtain the molded article. Molded articles are obtainable or obtained by such a process, and can be used as a footwear sole, part of a footwear sole, a mattress, a seat cushion, an underlay, a grip, a protective film, a component in automobile interiors and exteriors, a gymnastics mat, a body protector, a trim element in automobile construction, a sound insulator, a vibration damper, a cushion, a bicycle saddle, a toy, a tire or part of a tire, a covering for a track and field surface, a covering for a sports hall or a pathway, a damping layer or a damping core in a sandwich element, or a packaging.
1. A process for producing a molded article (M), comprising: (i) filling a thin-walled, gas permeable shell with a foamed pelletized material made of a polymer (P1); and (ii) welding the foamed pelletized material to obtain the molded article (M); wherein the shell is configured such that it has a shape that simulates the shape of the molded article (M) and wherein the shell conforms to the shape of a mold.
2. The process according to claim 1 , wherein the welding is steam welding.
3. The process according to claim 1 , wherein the shell is porous.
4. The process according to claim 1 , wherein the shell is a film, a weave, a knit, a mesh or a perforated metal.
5. The process according to claim 1 , wherein the shell consists of a flexible porous material.
6. The process according to claim 1 , wherein the shell is closed after the filling in (i).
7. The process according to claim 1 , wherein the shell consists of a material which is weldable with the foamed pelletized material.
8. The process according to claim 1 , wherein the shell is removed from the molded article (M) after the welding.
9. The process according to claim 1 , wherein the polymer (P1) is selected from the group consisting of polystyrene, polypropylene, polyethylene, ethylene-propylene-diene rubbers (EPDM), ethylene-vinyl acetate (EVA), ethylene-vinyl acetate copolymers, thermoplastic polyurethanes, polyamides, polyesters, polyvinylidene fluoride, polyetheramides, polyethylene terephthalates, polybutylene terephthalates, and mixtures and blends thereof.
10. The process according to claim 1 , wherein in (i), the shell is filled with the foamed pelletized material and at least one further foamed pelletized material.
11. The process according to claim 1 , wherein in (i), shell is filled with the foamed pelletized material and at least one further foamed pelletized material of a different color or at least one further foamed pelletized material having different particles.
12. The process according to claim 1 , wherein in (i), the shell is filled with the foamed pelletized material and at least one further foamed pelletized material of a different color, wherein the foamed pelletized material and the at least one further foamed pelletized material are arranged in the shell in such a way that graphic elements become visible after the welding.
13. The process according to claim 1 , wherein the shell is filled by layering, pushing, pressing, robot positioning, spinning or suction.
14. The process according to claim 1 , wherein particles of the foamed pelletized material are positioned in the shell in a controlled manner.
15. The process according to claim 1 , wherein a controlled introduction of particles of the foamed pelletized material into the shell is accomplished using a computer simulation.
16. The process according to claim 1 , wherein at least one further element is introduced into the shell in the course of filling in (i).
17. The process according to claim 16 , wherein the at least one further element is selected from the group consisting of inserts, securing elements, struts, reinforcing elements, metal plates, meshes, grids, electrical or electronic components, hollow bodies, foams, pastes, adhesives, lubricants, and processing auxiliaries.
18. The process according to claim 1 , wherein an average diameter of particles of the foamed pelletized material is in the range from 0.5 to 20 mm.
19. A molded article obtained by the process according to claim 1 .
20. The molded article according to claim 19 , wherein the molded article is a footwear sole, a part of a footwear sole, a mattress, a seat cushion, an underlay, a grip, a protective film, a component in automobile interiors and exteriors, a gymnastics mat, a body protector, a trim element in automobile construction, a sound insulator, a vibration damper, a cushion, a bicycle saddle, a toy, a tire or part of a tire, a covering for a track and field surface, a covering for a sports hall or a pathway, a damping layer or a damping core in a sandwich element, or a packaging.