PVC is durable, cheap, and easily worked. Before PVC can be made into finished products, it always requires conversion into a compound by the incorporation of additives (but not necessarily all of the following) such as heat stabilizers, UV stabilizers, plasticizers, processing aids, impact modifiers, thermal modifiers, fillers, flame retardants, biocides, blowing agents and smoke suppressors, and, optionally, pigments.
A variety of processes are used to form PVC Compounds viz: extrusion, injection molding, blow molding, calendaring, spreading and coating.
Specially Extruder for PVC Compounding
PVC is very easy degrade at high temperature (more than 170℃). Our Tandem Compounder is specially designed for PVC compounding.
- The first stage is co-rotating parallel twin screw extruder with modular structure for screw and barrels. You can change the screw sequence easily for different formula. Due to high screw speed (about 300-500rpm), it will get the better dispersion and more output, but high melt temperature.
- The second stage is single screw extruder. It is used to cooling down the melt material from twin screw extruder, and extrude it for pelletizing.
Technical Specifications of Extruder:
Experience for Special Applications
USEON has delivered more than 105 sets of high performance machines for PVC Compounding. We would like to share the experience for the following special application:
a) Rigid PVC for Pipe Fitting/Connections
- For pipe fitting injection process, it is always better to use the PVC compounding pellets. You can add more percentage of CaCO3. Some customer only use premix powder for injection machine, the dispersion and shape quality is less
- No filter, need eccentric pelletizer
- Need strong cooling on single screw extruder
PVC + 5-15% CaCO3 + Heat Stabilizer + Impact Modifier + Lubricant Wax + Color Pigment
b) PVC Compounding for Cable
Polyvinyl chloride is the third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. It is produced by polymerization of the vinyl chloride monomer (VCM) .
PVC’s relatively low cost, biological and chemical resistance and workability have resulted in it being used for a wide variety of applications. Plasticized PVC is commonly used as insulation & sheathing on electrical cables.
PVC 60% + DOP 20% + Calcined Clay 10-20% + CaCO3 0-10% + Heating Stabilizer + Additives
c) Medical Grade Transparent PVC Compound
Medical Grade PVC Compound is highly preferred in medical industry. There are lots of PVC compound suppliers and importers but medical industry only demands the best quality PVC. Medical Grade PVC is preferred for the purpose of manufacturing flanges for Copper-T, Disposable tubes, IV- Tubes, oxygen mask, regulators, urine bags, blood bags, glucose bags etc.
d) PVC Recycle for Window Profile
The waste from window profile can be recycled. Premixing all kind of profile scrap with few percentage of virgin PVC powder, components providing impact resistance, color pigments, stabilizer, then feed it into the first barrel. Feeding other filling materials (wood fiber or CaCO3). into the barrel by side feeder.
No need make into pellets, Just cooling down on the conveyor, then crushing into powder.
PVC Scrap 40% + Virgin PVC Powder 10% + Wood Fiber 20% + CaCO3 20% + Additives