The materials used in the wood plastic profile production are low & high density PE / PP / PVC and 20%-60% wood contents. The polymers used in the wood plastic profile production must have melting temperature that is below than thermal decomposition of wood (approximately 225 degrees C). The wood used to manufacture wood plastic profile is mostly in the form of wood flour. The unit operations for wood plastic profile production include: wood processing and feeding equipment, polymer feeding, an extruder(s), die, cooling tank, cut-off saw and drop table.

The first step in wood plastic profile production is the drying wood flour. To obtain maximum extruder output rate, less than 1% moisture content is recommended to facilitate adequate mixing of wood flour with polymer. Now this dry wood flour is ready for extrusion process. In wood plastic profile production, extruder is used to melting and mixing the polymer, wood and additives as well as conveying the wood-polymer mixture through the die. As per need, user can select any one extrusion method to process wood plastic profile production. These extrusion process include: 1) Single Screw, 2) Co-Rotating twin screw, 3) Counter-Rotating twin screw and 4) Woodtruder.

A single screw extruder is the simplest extrusion for producing wood plastic profiles. Advantage of using single screw extruder is lowest capital acquisition cost. Disadvantages of using single screw extruder include lower output rates, high raw material cost, polymer is melted with the fiber with greater risk of fiber thermal decomposition, drying system is required, and high screw speed (rpm) with greater risk of burning at the screw tip.

A counter-rotating twin screw extruder is suitable where heat-sensitive polymers (PVC) are utilized. These extruders may have parallel or conical screw configuration. Advantages of using counter-rotating twin screw extruder include its low shear mixing and low screw speed. Disadvantages of using counter-rotating screw extruder include that a drying system is required and a pre-blending system is required.

With combination of hot melt single screw, a co-rotating twin screw can be used in wood plastic profile production. In this case, no need to prepare material in terms of pre-blending components. By using atmospheric and vacuum vents, moisture removal is achieved. Disadvantages include high screw speed (rpm) and greater risk of burning as no screw cooling.

The woodtruder includes a counter-rotating twin screw extruder with single screw extruder, a blending unit, die, spray cooling tank, cut-off saw. In this process, the separation of wood conveying and plastic melting ensures that fibers will not be burned during plastic melting and that melted plastic encapsulate the fibers completely. Further advantages include efficient fiber/polymer mixing and the ability to maintain a low melt temperature with a high head pressure.

Hi TECH Machinery General Trading L.L.C offers wood-plastic extrusion production line specially designed screw barrel, mold and extruder processing production technology to produce wood-plastic products. The equipment has strong adaptability and can process PP, PE, ABS, PS, etc. at the same time. JINHU product series: Wood-plastic one-step thick plate equipment; Wood-plastic one-step profile equipment; Wood-plastic one-step decorative material equipment; Wood molding granule equipment; Various wood-plastic molds.