The plastic formwork includes a main member made of polypropylene, stone powder, flame retardant, and reinforcing agent mixed together, where the main member has a number of channels inside and the channels are sealed by caps. To produce the plastic formwork, polypropylene, stone powder, flame retardant, and reinforcing agent are stirred, heated, and melted together, and the mixture is driven through a mesh forming machine to produce the main member. Finally, caps are attached to the main member to seal the channels. The manufacturing process allows convenient, precise, and uniform addition of materials, thereby improving production efficiency and product stability. The formwork provides fire retardation, heat isolation, sound proof, water tightness, and reusability. Additionally, cement paste is prevented from flowing into the main member, thereby avoiding the breeding of bugs and molds.

Methods of manufacturing bulked continuous carpet filament which, in various embodiments, comprise: (A) grinding recycled PET bottles into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) adding one or more color concentrates to the flakes; (E) passing the group of flakes through an MRS extruder (400) while maintaining the pressure within the MRS portion (420) of the MRS extruder (400) below about 25 millibars; (F) passing the resulting polymer melt through at least one filter (450) having a micron rating of less than about 50 microns; and (G) forming the recycled polymer into bulked continuous carpet filament that consists essentially of recycled PET.

This application is directed to polymer blends of polyethylene naphthalate, polytrimethylene terephthalate, and polyethylene naphthalate, for use in fibers, such as carpet fibers, and other applications. This application is also directed to methods of producing such polymer blends and fibers.

A process for producing a polypropylene composition using a compounding extruder includes a) a melting section having a first elongated cylindrical tube with a first inlet port to receive a propylene-based polymer and additives containing an elastomer of ethylene and α-olefin comonomer having 4 to 8 carbon atoms and a first outlet port to discharge a first melt composition containing a melt of the propylene-based polymer and the additives and a first screw arranged in the first elongated cylindrical tube, convey the propylene-based polymer and the additives to the first outlet port, and a mixing section including a second elongated cylindrical tube having a second inlet port to receive the first melt composition, and a second outlet port to discharge a second melt composition containing the first melt composition and the optional further component and a second screw arranged in the second elongated cylindrical tube to convey the first melt composition to the second outlet, wherein the first screw and the second screw areoperable at different screw speeds. The process includes: A) feeding the propylene-based polymer and the additives to the first inlet and discharging the first melt composition from the first outlet, wherein the first screw is operated at a first screw speed and B) feeding the first melt composition from the first outlet to the second inlet, and discharging the second melt composition from the second outlet, wherein the second screw is operated at a second screw speed smaller than the first screw speed.

A kneading method includes conveying a raw material along a conveyance path; and increasing the raw material in pressure by restricting a conveyer from conveying the raw material by a barrier, causing the raw material with an increased pressure to flow into a passage from an inlet located at the conveyer, circulating the raw material having flowed into the passage to an outlet in the same direction as the conveying direction of the conveyer, and causing the raw material having circulated in the passage to flow out from the outlet to the outer circumference of a screw body. The raw material includes a polypropylene-based resin composition containing polypropylene and olefin rubber.

An extruder screw conveying raw materials while kneading them includes a screw main body, conveyance portions, barrier portions, and paths. The conveyance portions convey the raw materials in an axial direction. The paths each include an entrance and an exit. The raw materials, the conveyance of which is limited by the barrier portions, flow in from the entrance. The raw materials flowing in from the entrance flow through the paths in the same direction as a conveyance direction of the conveyance portions. The exit is opened in the outer circumferential surface of the screw main body at a position outside the conveyance portions in which the entrance is opened.

The present invention refers to the to the reuse of waste materials based on synthetic resins and, more specifically refers to the reuse of disposable diapers, plastic packaging (PVC, PP, PET, and so on), for the production of raw material for extrusion, lamination, injection and rotational molding processes, among others. The invention consists of a system comprising a chopper, a mill for homogenization of particle size, a disk compactor employing frictional heating between a fixed disk and a rotating disk and cooling means by circulation of cold water inside said discs.

An extruding system includes a mixing unit configured to mix a polymeric material with a blowing agent and to form a mixture, and an injection unit coupled to the mixing unit and configured to inject the mixture. The mixing unit includes a mixing cartridge, a first mixing screw and a second mixing screw, the first and second mixing screws are disposed in the mixing cartridge. A method of extruding a mixture includes mixing a polymeric material and a blowing agent in a mixing cartridge of a mixing unit by at least one of a first and second mixing screws to form the mixture; conveying the mixture from the mixing unit to an injection unit; and discharging the mixture from the injection unit into a molding device. The mixture is sequentially in contact with the first mixing screw and the second mixing screw.

An extruder screw conveying raw materials while kneading them includes a screw main body, conveyance portions, barrier portions, and paths. The conveyance portions convey the raw materials in an axial direction. The paths each include an entrance and an exit. The raw materials, the conveyance of which is limited by the barrier portions, flow in from the entrance. The raw materials flowing in from the entrance flow through the paths in an opposite direction to a conveyance direction. The exit is opened in the outer circumferential surface of the screw main body at a position outside the conveyance portions in which the entrance is opened.

Method for manufacturing a composite material, comprising the following steps: a) plasticizing a binder in an extruder, wherein the binder comprises a polymer; b) providing a mixture of a cellulosic material and a hydrophobic agent dissolved and/or dispersed in a liquid carrier; c) mechanically shearing and drying the mixture in an extruder whereby liquid is at least partly extracted from the mixture or is not present in liquid form anymore; and d) blending the dried mixture with the plasticized binder.