Abstract: Gasket used in a fabrication method, wherein a methylmethacrylate prepolymer or a mixture of unsaturated monomers, whose main constituent is methylmethacrylate, or the unsaturated monomer or monomers themselves is (are) introduced into a mold comprised of two parallel plates separated by said gasket, and the mold is brought to a temperature sufficient to complete or carry out the polymerization. The gasket consists of a core of plasticized poly(vinylchloride), said core being sheathed by a thin layer of thermoplastic polymers chosen from among propylene polymers and saturated polymers, said thermoplastic polymer being capable of retaining its elasticity at temperatures ranging from 20.degree. to 120.degree. C. and having a melting or softening point higher than 115.degree. C.

Abstract: Article produced from a laminate comprising at least one thermoplastic resin layer (A), at least one fibre-reinforced heat-cured resin layer (B) and at least one adhesive layer (C) intermediate between layers (A) and (B).It is of complex shape and the ratio of the thickness of layer (B) to the thickness of layer (A) in the said article is at least equal to 1.5.The process of manufacture consists in that, in a first step, a thermoplastic resin layer (A) is coated hot with at least one adhesive layer (C) and then, in a second step, the said adhesive-coated layer (A) is subjected to a skeleton forming operation using a complex-shaped layer (B) of fibre-reinforced heat-cured resin as a forming mould, the skeleton forming conditions being such that the ratio of the thickness of layer (B) to the thickness of layer (A) in the complex-shaped article produced is at least equal to 1.5.

Abstract: Acrylic prepolymer comprising:from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms,from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, andfrom 10 to 40% by weight of units derived from methyl acrylate.The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10.degree. and 70.degree. C. and for a sufficient time to solidify the polymeric resin at the temperature selected.

Abstract: Acrylic prepolymer comprising:from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms,from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, andfrom 10 to 40% by weight of units derived from methyl acrylate.The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10.degree. and 70.degree. C. and for a sufficient time to solidify the polymeric resin at the temperature selected.

Abstract: The rheometer is located in a non-return branch of a molten polymer line and includes, in succession, a fixed-speed pump, a first capillary tube, and a second capillary tube in series with the first tube. The second tube has a diameter less than or equal to that of the first tube, and emerges into a fluid medium at regulated pressure. Pressure-sensors at the inlet of each tube determine the pressure loss between the inlet of each tube and the fluid medium at regulated pressure. The temperature is monitored by means that are at least party external to the body of the rheometer.