FR2520291A1 - Closed tubular cushions with integral foam filling - using lightweight mould with separate sides - Google Patents

Abstract

Process for the mfr. of upholstered items having a closed volume and integral stuffing involves forming a pouch by bonding two blanks of the cover material and an intermediate layer. The pouch is turned inside out, secured in a mould, and filled with foamed polymer. The mould consists of a tube with end-pieces secured by the intermediate layer. The cover material consists of a foam covered on one side with a textile or plastics material and on the other with a barrier film. Blanks of the material are placed with their textile faces together and a layer of material with an affinity for the barrier film, or with similar properties, is interposed. The blanks are bonded along the seam lines, leaving only a gap large enough to permit turning inside out and filling. Prod. is esp. for tubular items, e.g. automobile head-rests. The mould may be simple and light weight.

Description

 We have described, in French patent 74 0472fez a method of manufacturing a padding in integrated lining of closed volume whose outer envelope is made of a material having a barrier-forming face and a textile or plastic face, according to which a practically closed pocket is formed, reserving as openings only those necessary for filling the foam before expansion in a mold, pocket obtained by welding two blanks presented face to face with the barrier film directed towards the outside and between which an intermediate sheet of material having an affinity for the two barrier films # was interposed, then inverting this pocket "as a thermowell" before placing it in the foaming mold.

 In this patent, which essentially targeted padding with a single joint plane, it was intended to cut the central part of the intermediate sheet by reserving external tabs which were folded and pressed at the periphery of the joint plane in order to locate the pocket in the mold.

 The present invention aims to apply this process to the production of parts of more complicated shapes, for example having several joint planes and in particular to parts of tubular shape, such as the head restraints of automobiles.

To do this, one can use a conventional mold, having hinged covers on the planes
Joint and apply the measures defined in French patent 74 04723, that is to say, fold the tabs of the intermediate sheet on the periphery of the joint surfaces provided with pins on which the sheet is fixed thus ensuring good maintenance of the cap in the foaming mold.

 But it is also possible, using a simplified mold, to use the intermediate sheet by turning it over to retain rigid parts or cheeks which replace the cover walls of the mold.

 The cap is perfectly maintained during expansion and the attached cheeks can, after demolding, be recovered to be put back on another cap.

 This process is particularly advantageous when the barrier films of the flanks constituting the bag are semi-permeable and allow degassing of the expanding foam through the coating.

 The foam then exerts only a slight push on the mold which can be of very light structure.

By way of non-limiting example, there are shown in the accompanying drawing two examples of implementation of the method described in French patent 74 04725, for the manufacture of an automobile headrest, the first using a conventional mold and the second an added cheek mold according to the present invention, in which
Fig. 1 is a schematic perspective view of the mold used for the first example, in the open position
Fig. 2 is a partial view, in section, of the mold of FIG. 1, closed after foaming.

Fig. 3 is a perspective view of the mold used for the second example, closed, after foaming, and
Fig. 4 is a partial view, in section, of the mold of FIG. 3.

 The two examples shown aim at the manufacture of a support ## e, that is to say of a part in tubular form, with two planes of joints.

 As described in French patent 74 Q4725, it is accomplished by making a closed pocket, from blanks having a textile face, covered with foam, itself covered with a barrier film. To assemble the blanks by welding, a plastic sheet is interposed between the textile faces having an affinity with the barrier films, or of the same nature as them. Once the welding has been carried out on the contours of the pocket, in which an opening is reserved, the pocket is turned over as a "thermowell", and the intermediate sheet is then outside. The pocket is then ready to be filled with foam. For this filling operation, the bag is placed in a foaming mold.

 In the example of figs. 1 and 2, the mold comprises a tubular body 1 and two covers 2, 2 'pivotally mounted on hinges 3, 3'. The edges of the lateral faces of the body 1 are provided with pins 4 to which correspond recesses 3, 5, in the covers 2, 2 '.

The inverted pocket being introduced into the body 1, the intermediate sheet 6 is turned over on the rim of the body 1 and folded over the pins 4. The pocket is then positioned precisely.

 The covers 2, 22 being applied to the body 1, the foaming completes the application of the pocket on the walls of the mold.

 In the example of fig2.3 and 4, the mold comprises, as in the previous example, a tubular body 7, but no cover.

 After the pocket is introduced into the body 7, the lateral openings of the body are closed by two rigid cheeks 8, and the intermediate sheet 9 is turned over on this cheek. These therefore replace the cover walls of the previous example.

 The intermediate sheet must be semi-permeable to allow degassing of the expanding foam. The mold body can be of very light structure. The cap is well maintained during expansion.

 After release of the part, the intermediate sheet is cut out, by tearing, and the added cheeks can be recovered to be put back on another pocket, or cap.

Claims (2)

 1 - Method for manufacturing a padding in integrated closed volume packing, the outer envelope of which is made of a material having a barrier film face and a textile or plastic face, according to which a practically closed pocket is formed, by not reserving as openings only those necessary for filling the foam before expansion in a mold, pocket obtained by welding two blanks presented face to face with the barrier film directed towards the outside and between which an intermediate sheet of material having been interposed affinities with the two barrier films and then inversion of this pocket "glove finger" before placing it in the foaming mold, characterized in that a simplified mold is used consisting of a body (7) having openings corresponding to the parting surfaces of the part to be manufactured, the pocket is placed inside said body (7), the body openings are closed off by rigid cheeks (8) on which they return the edge of the, or, intermediate sheet (9) so as to retain said cheeks which thus replace the mold cover walls.  g -A method according to claim lsdans the barrier films of the blanks constituting the pocket are semi-permeable and allow degassing of the foam expanding through the coating.  3 - Foaming mold for the implementation of the method according to one of claims 1 and 2, characterized in that it is constituted by a simple tubular body, with which are associated rigid cheeks dlobtura- tion of the openings of said body.