| 摘要 |
1,224,211. Laminate. COMPAGNIE DE SAINT-GOBAIN. 27 March, 1968 [11 Dec., 1967], No. 14759/68. Addition to 1,224,028. Heading B5N. The process of the parent invention is modified in that the first thermosetting resin is located between two webs of the second thermosetting resin and adjacent longitudinal edges of the webs are joined to enclose the first resin before foaming of the latter begins. As shown, the resin 3a for the foam core is spread from a device 6 over a web 2 and is then covered by the other web 1, rolls 8 and 9 being positioned so that no air is entrapped between the webs. Alternatively, Fig. 9 (not shown), a single roll (7) may be used for this purpose. Subsequent expansion of the resin 3a to form the foamed core 3 is limited by endless belts 12, 13, between which the laminate passes. Grippers 10, mounted on conveyers (11), Figs. 12, 13 (not shown), hold adjacent edges of webs 1 and 2 in contact during foaming of the core. The heat liberated by core resin 3a during its conversion to core 3 may be sufficient to heat-set both webs 1 and 2 and the core 3 and to bond the core to the covering webs. Alternatively, heat may be supplied by heating belts 12, 13 and grippers 10 to accelerate the heat-setting. The contact between adjacent edges of webs 1 and 2 may be reinforced by cords, e.g. of resin - impregnated glass fibres (5), Figs. 5-8 (not shown), one of which may be glued to each longitudinal edge of web 2. The width of the laminate, comprising the enveloped core, may be decreased during foaming, Fig. 12 (not shown). The web on to which the resin to be foamed is spread may be pre-formed into a trough and the edges of the panel including the overlapped bonded web edges may be formed into various configurations, Figs. 1-4 (not shown). Each of the grippers 10 may comprise two jaws which are urged into the gripping position by a spring and forced apart by mechanical means which coacts with a projection located at the downstream end of the conveyers carrying the grippers Figs. 16, 17 (not shown). Alternatively, the grippers may normally be open and mechanical means may be provided which coact with rails running alongside the conveyers to urge the gripper jaws into gripping position, Figs. 14, 15 (not shown). A further alternative, Fig. 18 (not shown), includes on each side of the panel two chains which move on two respective sets of sprockets, which sets are inclined to each other. The chains of each pair are close together when gripping the side edges of the webs and then move apart to release the same. |
