摘要:
An inventive solid phase forming process, and related structure, using conventional pelletized thermoplastic compositions to form the elements of a non-textile fabric by coining a single pellet or briquette of the polymer into an individual element in a single forming step. The steps of the process generally include: a) positioning a pellet (78A) in or adjacent to a mold cavity, and b) forcing the pellet into contact with the mold surfaces of the mold cavity to plastically deform the pellet to cause the pellet to adapt the shape of the mold cavity (102, 104). The mold cavity has a shape to form the desired element, and its volume is substantially the same as the volume of the pellet (78A). The forcing step or act preferably uses an energy and speed wherein the pellet superplastically deforms to substantially fill the volume of the mold cavity. This process is repeated with the particular element being formed in the appropriate order to form interconnected plates (40) and rivets (42), as an example, with the final result being a non-textile fabric. The elements formed by the inventive process can have any of a variety of shapes, and can form base units for the formation of the non textile fabric of two, three or more elements. This inventive process elimininates the need to first form the pelletized polymer into a sheet or other type of preform prior to the forming of the final product.
摘要:
Partially cured gel coats are prepared in a manner for subsequent application to a substrate, e.g. a reinforcing polymer matrix, by a process comprising the steps of :A. Applying a gel coat, e.g., an unsaturated polyester resin, to a nonporous mold, e.g., a polyester film, which is at least partially transparent to actinic radiation, e.g. UV light; andB. Exposing the surface of the gel coat that is in contact with the film, i.e., the bottom surface, to actinic radiation that has first passed through the mold. In certain embodiments of the invention, the surface of the gel coat opposite the bottom surface, i.e., the top surface, is exposed to actinic radiation shortly after the bottom surface is exposed to the actinic radiation to effect a bi-directional cure of the gel coat. The gel coat produced by the process of the invention is nonporous and essentially defect-free.
摘要:
The present invention is directed to biaxially oriented polymeric films. Specifically, the present invention is directed to biaxially oriented polyethylene films having unidirectional tear characteristics in machine direction and method thereof. The film of the present invention comprises (1) a core layer of medium density polyethylene (MDPE) and optionally a cavitating agent; and (2) at least one skin layer on at least one surface of the core layer. The skin layer is also made from a polyethylene. The core and skin layers coextensively adhere to one another and are biaxially oriented in both machine and traverse directions.