Palltrusion the Process for the Preparation of Raw Materials
in the Wood Plastic Composite Industry Production of Wood Plastic Composite (WPC) Products is booming. To achieve the best possible process parameters and to get the highest output for the production of WPC products the treatment of the individual raw materials is very important. The preparation of raw materials and the Palltrusion process are the key factors for a successful production of high quality products. Different production processes in the WPC industry There are three (3) major production processes involved in manufacturing of WPC parts with using granules made of thermoplastic and natural fibers. These granules (Pallwood ® ) are produced on the Palltruder ® Installation.  The Thermofix ® process is using Pallwood ® regularly scattered and with a nearly no-pressure process fed in the intererior of the installation between two conveyor belts and heated up. Sheet thickness’ of 1-20 mm can be produced.
 The Extrusion process uses Pallwood ® as infeed material as well. Hollow profiles for almost any shape can be produced at any lengths.
 The Injection Moulding process produces smaller parts like caps but even more complicated parts can be produced out of Pallwood ® .
Palltrusion  The Palltruder ® was developed to produce continuously dry, homogeneous granules (the Pallwood ® ) with a high bulk density made out of thermoplastics, natural raw materials and, if necessary, additives.
A dosing system allows the adjustment of the Wood Plastic Additive ratio. The type of plastic, the type of wood flour and its moisture content (not exceed 8 %) are the limiting factors for the ratio. The produced Pallwood ® itself has a humidity below 1 % and is well suited for high quality parts produced in the further processes. Palltrusion Process The feed materials are continuously dosed by a gravimetrical dosing system into the Palltruder ® . With frictional heat and mechanical pressing power the material mixture is evenly sintered and pressed through the holes of a special die.
Steam released during the pulltrusion process, resulting from water in the wood fibers, is discharged via a vacuum exhaust system.
The palltruded material is pneumatically discharged and conveyed to a Granulator to achieve a homogenous and even granule.
Depending on the requirement the Pallwood ® can be conveyed into a intermediate silo in front of the production machine.  Palltruder®
Throughput capacity depends on feed materials, humidity and mixing proportion. Palltruder ® with capacities between 200 and 2.000 kg/h are available. The Palltrusion is an important preparation step in order to produce a perfect feed material for the further Production processes. The agglomerate is homogeneous, free flowing and with high bulk density. It is dry, therefore a 20 – 50 % higher capacity on the extruder can be achieved. Preparation using friction heat only leads to minimum thermal degradation of the Pallwood ® . Besides the Palltruder ® Pallmann supplies all machinery and installations for the preparation of wood and plastic, as well as the size reduction machines for the recycling of production waste. During the K- Show 2004 on booth A 22 in hall 9 Pallmann will present the new Palltruder model for capacities up to 2.000 kg/h, equipped with a Colortronic gravimetrical dosing unit. | 
The PALLMANN pulverizing systems, type PKM, are high capacity systems for the profitable pulverizing of thermoplastic and other heat sensitive materials such as LDPE, LLDPE, MDPE and HDPE, as well as other heat sensitive thermoplastics such as PP and EVA without the added cooling of nitrogen. PALLMANN pulverizing systems produce quality powders with excellent flow properties and bulk densities. PALLMANN pulverizing systems are mainly used for the following applications: 
