Home >> Resources/Information >> Extrusion, Wood
New technology in plastic composite lumber
New technology in plastic composite lumber
Recycled plastic composite lumber has been in manufactured for over twenty years, most commonly from relatively pure post-consumer plastics such as high density polyethylene (HDPE). Until now there was no way to produce a consistently high quality product from mixed feedstock. However, new technology from Cierra Industries Inc enables processing of mixed environmental wastes and plastic material into extruded composite lumber which can be used for building materials such as: window and door trim, outdoor flooring materials, complete panels for structural buildings, outdoor furniture, marine application and other.
Click here to go to the recommended retailer of used plastic machinery.
Years of research and trial and error development have finally resulted in a reliable system that yields a quality assured product from low end materials. Third generation Cierra lines are now producing up to 65% recycled Cellulostics materials and 30% recycled plastic materials.
This technology can be separated into several categories.
1. Material Preperation: Uniform melt blending of plastic and cellulostics is a difficult and exacting process. The cellulosic is a porous powder which will absorb the plastic. This absorption is the characteristic which binds the materials together and gives the finish product greater strength, however it also increases molten viscosity and restricts ability to flow in the extrusion prosess. Cellulostics also usually contain moisture and are more sensitive to processing heat than plastic polymers. The Cierra system addresses these problems by careful use of additives such as curing, coupling agents, lubricants and processing aids. The end product can then become sufficiently strong to be used as construction material.
2. Extruder Design: A standard extruder is not properly designed to blend and compound composites. Proper gear boxes, thrust bearings, length to diameter ratio, all must be engineered into the design in order to insure adequate mixing and drying of the cellulosic material. Cierra remanufactured machines incorporate all these features into the design.
3. Screw Design: The screw design is configured to uniformly mix and control temperature of recycled plastic and cellulosic material while compressing sufficently to obtain uniform strength.
4. Cooling Technology: Standard cooling tanks limit production rate. Cierra designs speed the cooling rate by use of proprietary techniques and enable higher speed production.
5. Die technology: It has long been known that pressure forming increases strength. Cierra's dies apply uniformly controlled die pressure to assist in forming the part as it is being extruded. The pressure is monitored and is increased or decreased to main constant within a predetermined varient. This permits a higher loading of non plastic material without loss of strength and it also produces a precise board by eliminating product surging.
6. Fillers: Cierra formulations are specific to the customer requirements and are designed to produce a high quality product from the materials which are available to the customer. Cierra has developed a low density inorganic filler to be incorporated for the purpose of reducing product weight.
If you have further questions please address them to pvan123@aol.com. Questions concerning equipment for plastic recycling equipment or plastic lumber will be answered as soon as possible.
