It is disclosed a process and an apparatus for manufacturing a figure of eight cable. An extrusion head has separate extrusion dies extruding in parallel a first and second outer sheath around a first and second core, respectively, so as to provide two separate cable elements having respective longitudinal axes laying in a first plane. While the outer sheaths are in a softened state, the cable elements are passed in parallel through a twisting die which causes their longitudinal axes to lay in a second plane forming a predetermined twisting angle with respect to the first plane. This twisting causes the outer sheaths to join together, thereby forming a figure of eight cable.

A method for directly preparing a foamed polylactic acid (PLA) product from a PLA melt includes PLA melt preparation, feeding, and two-stage extrusion. In the two-stage extrusion, a pressure at an outlet of a first-stage twin-screw extruder is 15 MPa to 17 MPa, a PLA melt is fed at a rate of 250 kg/h, a foaming additive is fed at a rate of 7.5 kg/h to 10 kg/h, and a foaming gas is fed at a rate of 2.8 L/h to 7.5 L/h. The method can ensure both foamability and quality of a material and reduce more than ⅓ of energy consumption; and an obtained product has an adjustable foaming rate of 3 to 25, a crystallinity of 40.3% to 48.5%, a tensile strength of 8.7 MPa to 19.6 MPa, and an apparent density of 0.05 g/cm.sup.3 to 0.4 g/cm.sup.3.

Mold blocks of a pipe molding corrugator are provided with enhanced cooling capability due to the provision of cooling fins on the side portions of each mold block. Air can be forced between the fins and some exhaustion of the air can occur at the base of the fins adjacent the mold block cavity. With this arrangement, enhanced cooling of mold blocks is possible.

An extrusion process for creating a roof ditch molding including forming a main body from a plastic material in a first stage extrusion, conveying the main body through a stacked array of die plates and into a first stage cooling tank, and communicating the main body from an outlet of the first stage cooling tank to a second stage extruder with crosshead die for applying a skim film bonding layer to the main body. Additional steps include applying a decorative layer over the skim bonding layer, communicating the main body to a third stage extruder with cross head die for applying wing portions in partially overlapping fashion along opposite side edges of the decorative layer and drawing the completed ditch molding through a second stage cooling tank prior to conducting one or more finishing operations.

A method of forming a three-dimensional object by extrusion of a highly viscous pseudoplastic flame retardant material having a first viscosity and agitating the material to shear the pseudoplastic flame retardant material thereby decreasing the first viscosity to a second viscosity and to cause the pseudoplastic flame retardant material to flow. Adjacent layers of the extruded material are offset to form a cantilevered 3D object.

A process and related assembly for creating an extrusion molded article with a chemically applied outer film. An extruded base material is formed during a first extrusion operation, following which a multi-layer film is bonded to the base material while the base material still at an above ambient temperature. The multi-layer film further includes successive layers of each of a polypropylene (PP), an adhesive, a polyethylene terephthalate (PET), a coating and s subsequent surface PET. The step of bonding of the film further occurs during an intermediate step between the first extrusion operation for forming the base material according to a given profile section and a subsequent extrusion operation for applying additional material along an edge of the film, the additional material including profile wings as required for a given design.

The aspects of the disclosed embodiments provide unique extrusion methods and apparatus to create a multi-component product made from various streams of molten plastic. The method for creating multicomponent multilayered products includes merging multiple streams containing individualized component and layer designs into a single stream to form a rod, tube, pipe, filament, or profile shape.

A method of extruding filament comprises the steps of cutting a bulk source material into pieces having size S.sub.1, performing a first extrusion pass comprising the steps of melting the pieces in an extruding device at a temperature T.sub.1 and extruding a first filament at an extrusion speed V.sub.1, and performing at least one additional extrusion pass k comprising the steps of cutting the first filament into pieces having size S.sub.k, melting the pieces in an extruding device at temperature T.sub.k, and extruding a final filament at an extrusion speed V.sub.k. A system for extruding filament is also described.

An improved composition for use in the manufacture of building materials having improved mechanical properties, including bending strength and creep recovery. Compositions and methods are disclosed for producing a polymer composite material containing reinforcing additives/additive blend, which is useful in the manufacture of composite building materials, including decking boards, rails, posts and the like. The present composite building materials have improved flexural and impact properties over similar composite building materials known in the industry, providing a viable alternative to wood, and other composites in the building industry.

The aspects of the disclosed embodiments provide unique extrusion methods and apparatus to create a multi-component product made from various streams of molten plastic. The method for creating multicomponent multilayered products includes merging multiple streams containing individualized component and layer designs into a single stream to form a rod, tube, pipe, filament, or profile shape.