Abstract: A process and an apparatus for the direct, continuous and flexible modification of polymer melts by branching off a brand melt stream from the main melt stream to be modified, dispersing the initially introduced additive in the melt in a specially designed twin-screw extruder, and subsequent recycling of the additive melt concentrate to the melt stream to be modified.

Abstract: A diaphragm- and spring-less check valve for gaseous media comprising an inlet housing (41) having a sealing edge (51), an outlet housing (11) and a closure body (30) disposed in between the housings, which is guided so as to be axially (14) movable and capable of being impressed bilaterally in any desired position and/or state of the valve, wherein the closure body (30) is moveable exclusively on the basis of a differential pressure between inlet (41) and outlet housing (11) in the blocking position against the sealing edge (51) and in the through-put position the sealing edge (51).

Abstract: A reusable blasting medium of a thermoplastically processable polymer granulate filled with finely divided metal, the metal particles being coated with an adhesion promoter. The medium is suitable for the deflashing of cast metal parts, in particular ground, die-cast metal parts. The invention further relates to a process for the production of the blasting medium, including intimately mixing a polymer granulate of a commercial thermoplast, such as polyamide and/or polycarbonate, with a metal such as iron, copper, tin, stainless steel, brass, and/or bronze. The particles are coated with an adhesion promoter, the metal particles are in finely divided spherical form or a powder and the particle sizes are 0.01 to 0.5 mm. This mixture is extruded in the usual manner, preferably as a ribbon, and thereafter is reduced to the desired form and size. The blasting medium has the form of cubic particles of an edge length of 0.75 to 2.0 mm.

Abstract: Water-resistant, thermoplastic starch materials which are processable into environmentally safe, thermoplastically produced products and cast sheets. They consist of starch acyl compounds, obtainable from high amylose starches and their derivatives (being sparingly soluble in water), and of plasticizers (like citric acid ethyl ester, glycerol acetate and lactic acid ester), which have a gelatinizing effect, and preferably, a dissolution property resulting in brilliant transparence and, as can be proved, are biodegradable.

Abstract: A biodegradable, single-phase starch/polymer mixture comprising(a) 10 to 99 parts of a starch molding composition comprising(i) 95 to 45 parts of at least one chemically modified starch, and(ii) 5 to 55 parts of at least one emulsifier, plasticizer or destructurizing agent, the parts of (i) and (ii) adding up to 100; and(b) 90 to 1 parts of at least one linear polymer, the parts by weight of components (a) and (b) adding up to 100. In addition, 0 to 20 parts of additives which are customary in this area are included. A method of preparation, and the use thereof for thermoplastically molded parts, in particular films, is also disclosed.

Abstract: Thermoplastically processable elastomeric block copolyetheresteretheramides from recurring units of the formula ##STR1## in which ##STR2## represents a polyamide segment containing terminal carboxyl groups and having an average molar mass of 700 to 10 000, --O--E--O-- is a poly-(oxytetramethylene)-segment having an average molar mass of 600 to 3 500, --NH--F--NH-- represents a poly-(oxy-1,2-propylene)-segment containing terminal amino groups and having an average molar mass of 350 to 2 500, x and y are integers from 3 to 35 and indicate the number of the respective, randomly arranged, recurring units, the ratio x:y of components A and B varying between 5:1 and 1:5.The ether amides of the present invention can optionally be mixed with additives, fillers, modifiers, or other compatible polymers normally used in the processing of polyamides and which are suitable for the production of molded articles, for example by injection molding, coinjection, extrusion, blow molding, etc.

Abstract: A thermoplastic polyamide comprising a copolyamide which is the reaction product of a hexamethylene diamine unsubstituted or substituted with at least one alkyl group, and a bis(4-aminocyclohexyl) alkane which is substituted adjacent to the amino groups, and a dicarboxylic acid. Molded bodies made therefrom have high rigidity and tensile strength over a broad temperature range, low water uptake, high dimensional stability, low permeability to oxygen, and high distortion temperatures. They are particularly suitable for injection molding and extrusion particularly when they are modified to improved impact strength, especially for the preparation of thin walled or large surface area shapes.

Abstract: A thermoplastic polyamide comprising a copolyamide and a modified copolyolefin. The copolyamide is the reaction product of a hexamethylene diamine, which may be substituted with one or more alkyl groups, and a his (4-aminocyclohexyl) alkane which is substituted adjacent to the amino groups, and a dicarboxylic acid.Molded bodies made therefrom have high rigidity, excellent impact resistance over a broad temperature range, low water uptake, high dimensional stability, low permeability to oxygen, and high shape retention on heating. They are particularly suitable for injection molding and extrusion, especially for the preparation of thin walled or large surface area shapes.

Abstract: A process for the production of a homogeneous, thermoplastically processible melt. The process includes a. introduction of chemically modified starch into an intake zone of an extruder and conveyance thereof to a receiving zone, b. addition of a prehomogenized liquid mixture of plasticizer, emulsifier, and additives, followed by mixing and further conveyance of the starch liquid mixture through the receiving zone at elevated temperature, c. destructurization of the modified starch without adding any water and conveyance of the starch and mixture at elevated temperature to form a homogeneous, thermoplastically processible melt, d. degassing of the melt at elevated temperature and under reduced pressure, and e. extrusion thereof through a die at elevated temperature and pressure.

Abstract: Thermoplastic molding compositions including a semicrystalline polyamide a) and an amorphous copolyamide b), the latter containing dimerized fatty acid as one monomer building block. Optionally, a compatibility agent and other additives are also included.The molding compounds having high stiffness up to at least 100.degree. C. are produced by melt-mixing components a) and b), and optionally a compatibilizer, and are used for making molded parts which are outstanding in their thermal properties, high solvent resistance, and resistance to stress corrosion.

Abstract: A process for producing ultra-high molecular weight polyamide fibers by thermal post condensation in the solid phase in the presence of catalysts of normally viscous polyamide fibers below their melting point in the absence of oxygen wherein the fibers have extremely high relative solution viscosities.

Abstract: Cold impact-resistant tubing especially useful as a fuel line for motor vehicles which is stable in length, has a brief thermal overload capacity, and consists of at least three layers of at least two different mutually compatible polyamides. The tubing also preferably has an internal and an external layer of impact resistance-modified polyamide, with or without a plasticizer, and a barrier between the layers of impact resistance modifier-free homopolyamide, copolyamide or blends thereof.

Abstract: A process for catalytic oxidation of organic materials in waste water by hydrogen peroxide in the presence of iron (III) salts at temperatures below 80.degree. in the presence of titanium dioxide and with exposure to light.

Abstract: A pack for spinning core/sheath fibers from a plurality of fiber-forming materials including a distributor, a spinneret plate, and a separating plate therebetween. The distributor has a first conduit adapted to convey one of the first materials in a stream in a downstream direction, and a second conduit adapted to convey another material in a second stream in the same direction. The separating plate includes a core cavity, an annulus surrounding it, a sheath channel fluidly connecting the first conduit and the annulus, and a core channel fluidly connecting the second conduit and the cavity. The spinneret plate includes an exit channel with a die capillary at its downstream end fluidly connected to the annulus and the core cavity at its upstream end. The exit channel has an entry with diameter at least equal to the annular diameter, the entry being located at or adjacent the upstream end. As a result, the first stream surounds the second stream and both are extruded through the die capillary to form the fiber.

Abstract: A molding composition including a thermoplastic processable polyamide, an elastomer, and an epoxy having a plurality of epoxide groups.

Abstract: Rigid, amorphous copolyamides which can be produced in a single-stage polycondensation reaction with a high glass transition temperature and low water absorption capacity, based on cycloaliphatic diamines, dimerized fatty acids and aromatic dicarboxylic acids.

Abstract: Rigid, amorphous copolyamides, which can be produced in a single-stage polycondensation reaction, having a high glass transition temperature and low water absorption capacity, consisting essentially of cycloaliphatic diamines, dimerized fatty acids, and aromatic dicarboxylic acids, and a method for the manufacture thereof.

Abstract: In a method and apparatus for the production of thermoplastic, caprolactam containing molding compositions by hydrolytic polymerization of caprolactam in stirrer autoclaves in which a molten mass is polymerized at pressures of 5 to 20 bar and temperatures of 220.degree. to 280.degree. C., the molten mass is transferred into an intermediate vessel to which vacuum is applied for continued polymerization and removal of volatile portions. Subsequently, the mass is continuously fed into a multi-screw extruder, in order to attain at increased temperatures and vacuum the desired polymerization degree and the desired monomer and oligomer contents. In a subsequent zone of the extruder, when desired, additional agents are worked in, whereafter a further degasification occurs in the end zone of the extruder, whereafter the mass is extruded, quenched, subdivided and dried. The method and apparatus use relatively little energy as compared with the prior art.

Abstract: An article consisting of a base and one or more attachments thereto. The base is made of one thermoplastic polymer and the attachment is made of a second thermoplastic polymer which is at least partially incompatible with the first polymer. Either the first or second polymer contains 5 to 75% by weight of a third polymer which is an olefinic polymer having functional groups thereon. Either of the first two polymers may contain up to 90% of the usual additives. This enables the production of such articles with high interface strength.

Abstract: 4-component thermoplastic molding compositions which are easily processed on injection molding or extrusion machinery consisting essentially of amorphous copolyamides which can be produced from inexpensive raw materials, inexpensive elastomeric block polyetherpolyamides and block polyetheresterpolyamides as well as commercially available modified copolyolefins and are distinguished by high cold impact resistance, good ductility, variably adjustable rigidity which is independent of the degree of humidity and excellent pigment compatibility as well as by good stress crack resistance, thermal and dimensional stability.