Abstract: A leather-like thermoplastic polyester series resin sheet is disclosed, including a uniformly and finely foamed sheet comprising a thermoplastic polyester series resin, wherein said foamed sheet has cells having a diameter of substantially not longer than 1 mm, the cell walls thereof have a thickness of substantially not thicker than 100 .mu.m, and the cell wall constructing each cell extends with irregular bending so as to make a flexibility of not more than 20,000 mg in the Gurley flexibility test. A process for production of the leather-like thermoplastic polyester series resin sheet is also disclosed.

Abstract: A method of forming a thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm.sup.3, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.

Abstract: A thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm.sup.3 is diclosed, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.

Abstract: A polypropylene resin foamed sheet for thermoforming having compounded therein an inorganic fine powder is disclosed. The sheet contains 10 to 50% by weight of the inorganic fine powder, has a density of 0.2 to 1.2 g/cm and a thickness of 0.2 to 3 mm and having a percent shrinkage of 5 to 30% in each of the longitudinal and crosswise directions on heating at 190.degree. C. for 30 minutes, with the ratio of a residual rate in the longitudinal direction to that in the crosswise direction being from 1:0.7 to 1:1.1. The sheet is produced by extruding and foaming a compounded resin from a ring die of an extruder, and taking off the extruded tubular foamed sheet along a cylindrical drum whose diameter is 2.0 to 3.0 times that of said ring die.

Abstract: A thermoplastic polyester series foamed material having a thickness of at least 3 mm and an apparent density of from 0.05 to 0.7 g/cm.sup.3 is disclosed, wherein the crystallinity of the resin in the surface portion within 0.5 mm from the surface of the foamed material is not more than 30% and at least 1% lower than the crystallinity of the resin in the central portion of the foamed material.

Abstract: A leather-like thermoplastic polyester series resin sheet is disclosed, comprising a uniformly and finely formed sheet comprising a thermoplastic polyester series resin, wherein said foamed sheet has cells having a diameter of substantially not longer than 1 mm, the cell walls thereof have a thickness of substantially not thicker than 100 .mu.m, and the cell wall constructing each cell extends with irregular bending so as to make a flexibility of not more than 20,000 mg in the Gurley flexibility test. A process for production of the leather-like thermoplastic polyester series resin sheet is also disclosed.

Abstract: A process for producing a thermoplastic polyester resin foam comprising melting a thermoplastic polyester resin, mixing the molten resin with a blowing agent and extruding the mixture into a low-pressure zone to carry out expansion molding, characterized in that a compound having two or more acid anhydride groups per molecule, optionally together with a compound of a metal of Group I, II or III elements of the Periodic Table is added to the thermoplastic polyester resin. There is also disclosed a process for producing a thermoplastic polyester resin foam comprising cooling a high-temperature foam immediately after expansion and then re-heating the foam. Further, a thermoplastic polyester resin foam sheet and a food container prepared from the foam sheet are also disclosed.

Abstract: A method and apparatus for the production of a foamed thermoplastic material. A cavity transfer mixer is provided between a screw extruder which melts, or fuses, the thermoplastic material, and a cooler. The cavity transfer mixer enables the formation of uniform and well mixed admixtures of a foaming agent and a thermoplastic material and, optionally, other desired additives.

Abstract: A method of producing thermoplastic resin foams is disclosed. The method comprising extruding an expandable resin through a plurality of holes bored in a die in the inside of a frame fitted to the extrusion end surface of the die in an adjacent relation therewith and fusing together the thus-extruded materials while they are expanded and still softened, wherein the inner surfaces of the frame are inclined at an angle of inclination ranging between 5.degree. and 30.degree., so that the cross-sectional area of the frame is increased toward the outer end thereof, and the extruded materials are fused together while kept in contact with the inner surfaces of the frame.

Abstract: A method for preparing a multi-cellular foamed board of thermoplastic resin which comprises forming under pressure in a die a thermoplastic resin melt containing a foaming agent to give the resin melt a shape of a flat board having a broad width compared with a thickness thereof, extruding the resin melt from the die having the convex forward end with a middle portion in the width direction thereof protruding the greatest toward the extruding direction, introducing thus extruded resin melt immediately into a moulding passage having a concave end engaging with the said convex forward end of the die, allowing the resin melt to expand in the thickness direction at the portion adjacent to and extending along the concave end of the passage, and thereafter allowing the resin melt to expand in both the thickness and width directions of the board in the passage.

Abstract: A granular flame retardant additive is provided comprising from 70 to 99.5% by weight of an organohalide flame retardant and from 0.5 to 30% by weight of thermoplastic synthetic resin as a binder. The additive is easy to handle and resistant to disintegration during transportation and mixing with fabricating resin pellets. Uniform distribution thereof in fabricated thermoplastic articles is achieved by simply co-feeding the granules and the fabricating resin to a fabricating machine.

Abstract: A method and apparatus for preparing a substantially uniform thermoplastic foam extruded from an extruder, the molten thermoplastic resin having uniformly distributed therein a foaming agent. A cooling-mixer continuously receives the extruded mass of resin and foaming agent from the extruder and intimately mixes and substantially cools the mass. A substantially adiabatic zigzag mixer is connected to the cooling-mixer and divides the mass into a plurality of separate streams which are at least partially separated and recombined. A die is connected to the zigzag mixer and extrudes the uniformly cooled mass into a lower pressure zone to produce a substantially uniform thermoplastic foam.

Abstract: A process and die are disclosed for preparing a foamed article of thermoplastic resin having a particular cross section configuration. The die of the invention is provided with a plurality of apertures in its face through which the resin is discharged. The apertures in the face of the die are distributed in a shape corresponding to the cross section of the foamed article which is produced. The apertures are further divided into a plurality of groups in which there is at least one zone which is void of apertures so that the apertures in the same group are actually restricted to a narrow band. The zone on the surface of the die which is void of apertures has a thickness more than twice the average distance between two adjacent apertures belonging to the same group.

Abstract: A process for producing an expanded article of a thermoplastic resin by extruding and expanding a foamable resin using an extruder equipped, on a resin channel in a die, with a nozzle having a number of apertures, which comprises flowing a resin mixture stream through an expansion zone while maintaining the resin mixture at a temperature above the melting point thereof, dividing the resin mixture stream into a plurality of separate streams, exiting these streams from the extrusion zone directly into a confined zone, thereby forming a plurality of soft expanded resin strands corresponding in number to the number of strands, bringing the strands into surface contact with each other to fuse and bond them together to form a bonded expanded resin mass while simultaneously removing gases generated in the course of extrusion and expansion, passing the bonded mass into an unconfined zone to permit the mass to further expand while still in a softened condition, passing the further expanded mass into a confined receivi

Abstract: An improved process for preparing foamed articles of thermoplastic resin having a hard, mar-resistant surface that is flat and smooth and resembles natural wood, and an extrusion die therefor. In the process a softened thermoplastic is extruded through apertures of the extrusion die of the invention which is a fiered die having a resin discharge plate having a peripheral recessing portion and a protruding interior portion which are formed on the resin discharge plate by one or more step-ups. Each of the peripheral and interior portions of the resin discharge plate is provided with a plurality of apertures, the aperture density of the peripheral portion being greater than that of the interior portion. A longitudinally extending cooling frame is mounted adjacent the resin discharge plate and extends in the direction of extrusion to at least the forward face of the interior portion of the plate.

Abstract: An improvement in a process for preparing a foamed thermoplastic article in which a foamable thermoplastic resin is passed through an orifice of a die and is permitted to expand after passing through said orifice. The improvement includesA. passing the foamable thermoplastic resin through an orifice, the outer periphery of which contains a plurality of recesses,B. allowing the resin to expand to form a soft-surfaced porous shaped article having peaks and valleys corresponding to the recesses of the orifice, andC. pressing the surface of said article so as to level the peaks.A smooth-surfaced shaped article is produced having a surface structure characterized by high density portions corresponding to the peaks and low density portions corresponding to the valleys and resembling natural wood.