US 4,925,508 AGranted

Moldless process for manufacturing foamed articles

AssigneeNamba Press Works Co., Ltd.

InventorsFumio Goto, Taro Ogawa

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Abstract

Moldless process for manufacturing foamed articles is disclosed wherein a trim cover is first prepared as having a composite structure of an outer facing material such as fabric and an inner backing material of low melting point such as a thin foam of polystyrene and having a shape substantially corresponding to a final contour of the finished article; the trim cover is heated and forced to form a pre-shaped cover conforming to the final contour of the finished article preferably by means of a restraining frame such as basket or plastic cage configured to the final contour of the finished article; highly reactive polyurethane composition foamable at low internal pressure is poured inside the pre-shaped cover and allowed to foam and expand to fill substantially an entire volume within the pre-shaped cover; and then the pre-shaped cover is externally heated to around the melting temperature of the backing material so as to significantly shrink and virtually dissipate the backing material interposed between the facing material and the foaming polyurethane at the same time allowing the polyurethane to further expand to adhere to and become integral with the inner surface of the facing material, thereby an integral foamed article is produced without the use of any molds.

Claims18

Dependent claims

A process for manufacturing a foamed article without use of a mold, comprising the steps of:

(a) preparing a cover composed of a facing material and a foamed backing material having a low melting point applied to the inner surface of said facing material, said cover having a shape substantially corresponding to a desired final contour of the article;
(b) heating said backing material to its softening temperature or its vicinities to plasticize said backing material;
(c) blowing air to the inside of said plasticized backing material, for pressing outwardly and inflating said backing material so as to conform said inflated cover to the final contour of the article and for hardening the backing material of the final contour to obtain a pre-shaped cover;
(d) placing a desired insert inside said pre-shaped cover and sealing an open end thereof;
(e) inserting a pouring nozzle having a predetermined length of residential passage into said sealed pre-shaped cover, and pouring a predetermined amount of reactive polyurethane composition through said nozzle to the inside of said cover;
(f) allowing the poured composition to foam and expand to fill substantially an entire space within the cover, and then externally heating said cover up to around the melting point of said backing material to significantly shrink the backing material;
and
(g) allowing the foaming polyurethane composition to further expand to adhere to the inner surface of the facing material thereby to obtain a foamed article with the pre-shaped cover integrally enveloping the polyurethane foam.

5 more elements

Dependencies are inferred from the claim text.