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Wood-Plastic Composites process

Sep 12, 2019

Wood-plastic composite (Wood-Plastic Composites,WPC) is a new type of composite material which has sprung up at home and abroad in recent years. It refers to the use of polyethylene, polypropylene and polyvinyl chloride to replace the usual resin adhesive. With more than 50% of wood flour, rice husk, straw and other waste plant fibers mixed into new wood materials, and then extrusion, molding, injection molding and other plastic processing technology to produce plates or profiles. With the properties and characteristics of wood and plastics, it can replace new environmental protection high-tech materials of wood and plastics.
Mainly used in building materials, furniture, logistics packaging and other industries. The sheet formed by hot extrusion after mixing plastic and wood powder in a certain proportion is called extruded wood-plastic composite plate.
1.Technological advantages.
1.1 waterproof and moistureproof. It fundamentally solves the problem that wood products are easy to rot, expand and deform after absorbing water and moisture in wet and multi-water environment, and can be used in the environment where traditional wood products can not be used.
1.2 to prevent insects and termites, effectively eliminate insect disturbance and prolong the service life.
1.3 colorful, there are many colors to choose from. It not only has natural wood texture and wood texture, but also can customize the color according to its own personality.
1.4 strong plasticity, can be very simple to achieve personalized modeling, fully reflect the personality style.
1.5 High environmental protection, no pollution, no public pollution, and can be recycled. The product does not contain benzene and the content of formaldehyde is 0.2, which is lower than the EO standard. It is the European grading environmental protection standard, and can be recycled to greatly save the amount of wood used.
1.6 High fire resistance. Can effectively flame retardant, fire grade up to B1, fire self-extinguishing, do not produce any toxic gases.
1.7good processability, can be ordered, planable, sawing, drillable, surface can be painted.
1.8 the installation is simple, the construction is convenient, does not need the complicated construction technology, saves the installation time and the cost.
1.9 does not crack, does not expand, does not deform, does not need the repair and the maintenance, facilitates the cleaning, saves the later stage repair and the maintenance cost.

The wood-plastic board was obtained by hot extrusion after the plastic and wood powder were mixed in a certain proportion.
Process classification.
1. Mixing process:
Add wood powder and light calcium to 110 degrees and open the top of the high mixer for about 1 minute, add pa-02 and HD3304//HD3303 to 125-135 degrees and put in the cold cylinder to cool down to 40 degrees to make granules.
2. Granulation process:
2.1. It is best to use cone double or flat double granulation with good mixing and plasticizing effect.
2.2. The basic temperature of granulation is as follows:
(160-170 degrees)-(160-170 degrees)-(165-175 degrees)-(175-185 degrees)-(190-200 degrees)-(200-220 degrees) the temperature setting order is from head to stock, depending on the mass of the equipment and particles. The colloidal particles must be smooth, non-sticky, strong, the size and length of the colloidal particles are the same, and there is no dust.
3. Injection Molding:
3.1 The injection molding machine does not need to make a big change, but the nozzle is about 20%-30% larger than the injection molding non-wood plastic products. .
3.2 If the gate of the mold varies in thickness, it is best to set it in the thickest place.
3.3 WPC wood injection molding product thickness must be above 1.5-2mm, the product is too thin is not conducive to production and affect the quality of products.

 

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