摘要:
An in-mold coating composition is disclosed which includes (a) an isocyanate-terminated material containing an excess of reactive isocyanate groups and (b) a material selected from the group consisting of a composition containing reactive hydrogen atoms, generally hydroxyl groups, and a catalyst capable of trimerizing the terminal isocyanate groups. The coating composition is applied to a molded substrate, such as an FRP part, by placing a charge of the composition in the mold on the substrate, the charge being sufficient to provide a coating having a thickness less than about 20 mils. Appropriate pressure is then applied to the charge, such as by closing the mold, so that the coating composition is forced to cover substantially the entire surface area of the substrate, filling any surface defects. The composition is cured to yield a crosslinked, isocyanate-based coating which adheres tightly to the substrate.
摘要:
An SMC (FRP) molding is coated with a minimum amount of an IMC composition by skewing one of the mold halves during the initial IMC molding cycle to effect a scissoring action, the fulcrum being at or about the IMC injection point or placement to spread or wipe the IMC over the surface of the SMC part and then effecting at least substantial parallelism of the mold halves during the remaining IMC cycle of coating and curing the IMC.
摘要:
A method is disclosed comprising in-mold coating a structural foam part made from a thermoplastic aromatic polycarbonate resin or a thermoplastic ABS polymer resin with a thermosetting in-mold coating composition at a pressure of from about 25 to 50 p.s.i. and at a temperature not in excess of about 200.degree. F. for from about 1 to 10 minutes, preferably for from about 1 to 3 minutes, to provide hard, smooth and adherent coatings, said thermosetting in-mold coating composition comprising an ethylenically unsaturated polyester resin and an ethylenically unsaturated monomer(s) catalyzed with an organic perioxide initiator including an accelerator for the initiator.
摘要:
A method of producing an extrudate is disclosed in which on-line adjustments are made to size and shape deviations by varying the temperature conditions in the extruder and by varying the relative speeds along the extrusion line. The temperature conditions can be adjusted by varying the temperature of the stock while maintaining a fixed relationship of the die temperature to the stock temperature to produce deviations in the thickness of the extrudate with respect to the width of the extrudate, and by varying the temperature of the die with respect to the temperature in the stock to produce variations in different thicknesses of the extrudate. The relative speeds along the extrusion line can be varied by changing the speed of the screw in a cold-feed extruder, by changing the feed rate for a hot-feed extruder, or by changing the speed of the take-away device which regulates the speed by which the extrudate is taken away from the extruder.
摘要:
A rotatable accumulator roll which may move substantially horizontally or vertically is disposed between the die of an extruder and a take-away conveyor to minimize the effects of output surging of the extrudate from the die of the extruder in order to maintain substantially the dimension of the extrudate as delivered to a constant speed take-away conveyor. Variable force is applied to the roll to maintain tension on the extrudate.
摘要:
A puncture sealant package for incorporation into a pneumatic tire is formed by coextruding a puncture sealant, and a skin forming material. The ribs are formed in an initially circular package profile as chords. After flow in a sheet die, the chords form divider ribs making small angles with the encapulating skin. The compartments formed by the ribs prevent flow of the sealant toward the center of a tire.