Abstract: The invention relates to a structural element that has a layer containing cells bordered by stiff lamellas (4) with a cover plate (6) at least on one side attached with adhesive to the edges of the lamellas (4), and which is characterised by that the cover plate (6) is a fibre-reinforced composite plate, and the edges of the lamellas (4) extend into it keeping a certain distance (a), and they are connected to the cover plate (6) via a chemical bond realised between its synthetic resin matrix and the adhesive.

Abstract: The invention is a process for monitored cross-linking of unsaturated polyester resins in the presence of a metal-ion-containing accelerator and an organic peroxide initiator, complemented by promotor in some cases. According to this process, the cross-linking is carried out in the presence of one of the compounds from the group consisting of alizarin, sodium alizarinesulfonate, 3-nitroalizarin, chinizarine, or purpurin, where the substituents are H atoms or OH, NO.sub.2, SO.sub.3 H, or SO.sub.3 Na groups with the restriction that at least one of them should be other than H, which is present in a ratio of from 0.005 to 0.5, preferably 0.01 to 0.1 percent (mass/mass), compared to the mass of the polyester resin, and cross-linking is trailed by the color change in the system. The invention permits all of the chemical-technological processes involved in the processing of unsaturated polyester resins to be monitored visually.

Abstract: Method and apparatus for dispensing material from a hand-held gun connected by a flexible conduit to a source of the material under pressure. The control of material flow is effected by a valve in series between the flexible conduit and the source of material, and hence remote from the gun, thereby to reduce the weight of the gun and to provide a gun that has no moving parts for controlling material flow. One or more orifices is provided in the handle of the gun for the continuous discharge of low pressure control air that actuates the valve or valves; and the selective opening or closing of the orifice or orifices by the hand or fingers of the operator, thus controls the valve or valves and hence the flow of material for materials to the gun.

Abstract: In a batcher plant at least one pair of reciprocable pressure cylinders are provided one of which as a first pressure cylinder is connected to a source of pressure medium while the other one as a further pressure cylinder is supplied with pressure medium in dependence on the number of strokes per minute of the first pressure cylinder. Both pressure cylinders drive delivery pumps. The total amount of delivered material is controlled by the speed and the number of cycles of the piston of the first pressure cylinder while the mutual proportions of delivered material are controlled by varying the length of stroke of the further pressure cylinder. Thus, on the one hand, mutual proportions of delivered substances can be finely adjusted within very wide limits and, on the other hand, the pressure cylinders of the various batcher units may be located in considerable distances from one another so that the plant is suitable to perform the most various functions.

Abstract: The invention relates to a process and an apparatus for the production of wound sandwich structures, wherein the inner shell, made of a galss-reinforced plastic, is prepared in a known way, then solid core elements are wound onto the inner shell, and finally an outer shell, made of a glass-reinforced plastic, is formed on the wound core. Thus rigid articles (e.g. containers), consisting of inner and outer shells of glass-reinforced plastic and a core of wound core elements, are obtained. The core elements are wound up by forwarding the individual elements directly one after another onto a thread which carries the core elements, presses them onto the rotating mandrel, and is also wound up, or by forming a flexible band by adhesion, from the core elements and the carrier thread or band, and this flexible band is wound up. The inner and outer shells, and the surface of the core material are prepared preferably on a conventional winding machine, provided with auxiliary equipments according to the invention.