摘要:
A method for the production of a lamellar reflective polymeric body is provided and includes the steps of providing a first stream of a first heat plastified polymeric material and a second stream of a second heat plastified polymeric material, and encapsulating discrete portions of the first polymeric material in the second polymeric material by coextruding the polymeric materials to form a plurality of ribbon-like layers of the first polymeric material within a matrix of the second polymeric material to form the reflective polymeric body. The layers of the first polymeric material are arranged to have their major interfaces aligned substantially parallel to the major surfaces of the body such that at least 30% of light incident on the body is reflected. The ribbon-like layers may be further divided into a series of platelet-like layers to produce layers which are discontinuous in all major planar dimensions by passing the ribbon-like layers through a reciprocating feed plate or valve.
摘要:
A method of molding polysilazane which includes heating a liquid sheet composed of liquid polysilazane alone or containing not more than 30 wt. % of a ceramic powder or a ceramic precursor to form a highly viscous sheet having a viscosity coefficient of 10.sup.4 to 10.sup.6 poise, fitting the highly viscous sheet to a forming mold, and heating to set the sheet. According to the method of the invention, molded bodies are easily obtained which have relatively uniform thickness, and are excellent in transferability, homogeneous and show less defects.
摘要:
A method of making thermal insulating products comprising porous, lightweight, high temperature resistant inorganic particles in a polyimide foam matrix and the product thereof. A polyimide precursor powdered is mixed with about equal weight of flake-like porous inorganic particles to substantially uniformly coat the particles with powder. The mixture is placed in a mold and compressed slightly. The assembly is heated to the foaming temperature of the polyimide precursor for a period suitable to produce uniform foaming. Then the temperature is raised to the curing and crosslinking temperature of the precursor for a time period sufficient to produce complete cure. A high temperature and flame resistant, light weight, highly insulating product results. If desired, protective sheets of material may be bonded to selected product surfaces during or after the molding operation.
摘要:
The invention relates to a thermoplastic composite material for the preparation of moulded objects, particularly of injection-moulded objects, and to a process for making same. The material according to the invention has the following composition by weight:______________________________________ polypropylene between 50 and 60% and preferably 55% glass spheres from 5 to 15% and preferably 11% polyvinylic alcohol from 25 to 40% and preferably 33% ______________________________________ The invention is more particularly applicable to making moulded objects such as containers or medical syringes adapted to be subjected to sterilization.
摘要:
A method is provided for compacting viscous polymeric molding compositions preparatory to compression molding to substantially improve the physical properties of articles molded therefrom. Suitable compositions include those filled with a geometric reinforcing particulate filler that are flowable and thermosettable when compression molded. The method comprises forming a slab of a said filler composition and thereafter reducing its thickness by passing it between spaced-apart pairs of compression means. The pair members of the means are spaced apart to ultimately substantially reduce its thickness. The method yields unexpected improvements in the tensile strength, isotropy and surface characteristics of articles compression molded from the compounds.
摘要:
Composite materials reinforced by flakes of glass are made by applying a powdered, partially polymerised epoxy resin to fresh surfaces of a ribbon of film glass, e.g. by electrostatically spraying the powdered resin on to both surfaces of the glass ribbon as it is taken from a float bath, subsequently cutting or breaking the glass ribbon to form glass flakes most of which have an aspect ratio of between 100 and 200, assembling the flakes together, possibly with a further addition of resin, to form an assemblage with a glass content of between 20% and 70% by weight, and completing the polymerisation of the resin, e.g., under heat and pressure, to bond the assemblage together.
摘要:
1. A METHOD OF IMPARTING OR IMPROVING PEARLESCENCE AND INCREASING OPACITY WHICH COMPRISES COLD DRAWING A PLASTIC AT A TEMPERATURE AT LEAST 10*C BELOQW ITS GLASS TRANSITION TEMPERATURE AT LEAST 10*C BELOW ITS GLASS ANCE HAS BEEN ACHEIVED, WHEREIN THE PLASTIC IS A THERMOPLASTIC POLYMER OF AN UNSATURATED ALIPHATIC HYDROCARBON OF 2 TO ABOUT 10 CARBON ATOMS WHICH NECKS DOWN UPON COLD DRAWING AND HAS CRYSTALLINITY OR CONTAINS A PLATY SUBSTANCE.
摘要:
A monolayered plastic casting means for substantially enveloping and interlocking a substantially rigid core formed means utilizing an isotropic producing principle by providing a cavity space making element means, said element means utilized to permit substantially equal quantities of curable material to be formed on the front and back face sides of said core means, and wherein said curable material has at least one side that has a deep dimensional decorative surface appearance.