The present invention relates to an extruded expanded thermoplastic polyurethane elastomer bead and a preparation method therefor. The bead consists of components of the following parts by weight: 100 parts by weight of a thermoplastic polyurethane elastomer, 0.01-0.5 parts of a foaming nucleating agent, and 0.01-0.2 parts by weight of an antioxidant. The preparation method comprises: mixing materials, then putting the mixture into an extruder for granulation to produce a particle raw material suitable for foaming, finally, putting the particle into a foam extruder, and die foaming then underwater pelletizing, thus obtaining a product bead. The present invention utilizes an extrusion method to prepare expanded thermoplastic polyurethane beads. Control of the working conditions of the foaming process could lead to acquiring an expanded=bead of a controllable density, the cell density evenly distribute. The overall production process is easy to operate. Without any special limit or requirement placed on the equipment, this method is suitable for industrial continuous production.

A shim stack foaming die for making foam slabs comprises a plurality of shims that are layered together under pressure to form a shim stack, wherein the shims combine to collectively define a plurality of die orifices in a working face, to define a main body of the shim stack foaming die, and also to define a plurality of die cavity that is fluidly connected to the plurality of die orifices. And articles foamed from the shim stack foaming die have found wide use in various applications, thermal or acoustic insulation, reinforcing layers and/or space-filling layers, and so on.

The invention provides devices that are attached to an extruder making the operation thereof more efficient and convenient and allowing for a quick change over of parts used to make various products prepared in the extrusion process. A high pressure relief assembly is attached to the extruder that allows for the rapid release of pressure from the extruder at the end of the process by venting product under pressure from the extruder and the extruder also has attached thereto a quick assembly locking device that allows for the exchange of assemblies, such as a density control assembly and other assembles, without the removal of nuts, bolts, and clamps by attaching the assembly to an arm that can be moved in and out of place in front of the extruder and wherein the device has a locking mechanism that seals and releases the assembly from the extruder.

The present invention relates to a plastic based high density wood fiber composite (HDWFC) product and a method for manufacturing said composite product. The invention also relates to an apparatus for manufacturing said composite product.

A plastic film of a thermoplastic synthetic resin is made in a film-making system by extrusion from a die of an extruder. First the plastic is melted and extruded from the die as a tube or web that is, typically after cooling and stretching, formed into a package. At least one reference parameter is provided, and, during continuous operation of the system, two input parameters different from the reference parameter are measured by respective measuring devices An output is determined from these reference parameters and is compared with the reference parameter.

Method for determining at least one layer property of a layer to be determined, in particular a foam layer, in an extrusion process, where a supply material is at least partially foamed and an extrusion product with the foam layer is put out (in other words, is output). The method has at least the steps of irradiating the extrusion product using electro-magnetic radiation, and electro-magnetically measuring at least one radiation having travelled through the foam layer. Measuring at least one feed-in rate or feed-in volume of the supply material, and determining the at least one material property of the layer to be determined from the measured feed-in volume and the electro-magnetic measurement.

A multilayer film having coextruded layers comprising a znLLDPE-based core layer, and mLLDPE-based outer layers on each side of the core layer comprising, wherein the znLLDPE of the core layer has a density which is less than 0.005 g/cc different from a density of the mLLDPE of the outer layers, and wherein the znLLDPE of the core layer has a melting temperature which is less than 15° C. different from a melting temperature of the mLLDPE of the outer layers.

An apparatus (1) for optical inspection of a mass of polymeric material (2) passing through an extruder (3) having a hollow extrusion cylinder (4) extending elongately in a longitudinal direction comprises an optical sensor (8) which can be operatively coupled to the extrusion cylinder (4) and having an infrared light emitter (8a) and a receiver (8b) configured to measure a measurement parameter representing an optical property of the polymeric material (2) inside the extrusion cylinder (4) and is characterized in that it comprises a plurality of the optical sensors (8) which can be operatively coupled to the extrusion cylinder (4) in a plurality of measurement sites located in succession and spaced from each other along the longitudinal direction and a processor (9) programmed to acquire a plurality of measurement signals containing the measurement parameters measured by the corresponding optical sensors (8) and programmed to process the plurality of measurement signals in order to calculate a corresponding plurality of values of a control parameter indicating a physical state of the polymeric material (2) as a function of a longitudinal position.

A multilayer film having coextruded layers comprising a znLLDPE-based core layer, and mLLDPE-based outer layers on each side of the core layer comprising, wherein the znLLDPE of the core layer has a density which is less than 0.005 g/cc different from a density of the mLLDPE of the outer layers, and wherein the znLLDPE of the core layer has a melting temperature which is less than 15 C. different from a melting temperature of the mLLDPE of the outer layers.

Poly(ethylene tetrafluoroethylene) (ETFE) polymers having an average molecular weight of at least 300,000 g/mol and a melt enthalpy of at least 57 J/g are provided. The ETFE polymer may include at least one additional comonomer. The ETFE polymer is used to form a porous tape or membrane that has a node and fibril structure. A porous ETFE tape may be formed by lubricating the ETFE polymer and subjecting the lubricated polymer to pressure at a temperature below the melting point of the ETFE polymer. Optionally, the ETFE tape may be expanded at a temperature below the melting temperature of the ETFE polymer to form an expanded ETFE membrane. Alternatively, the ETFE polymer may subjected to heat and pressure without the addition of a lubricant to form a dense preform. The dense preform may be subsequently slit in a length direction and stretched to form a dense ETFE fiber.