GSmach has delivered over 100 extruders for PVC compounding.
PVC is durable, cheap and easy to process. Before PVC can be made into a finished product, it always needs to be converted into a compound by adding additives (but not necessarily all of the following) such as heat stabilisers, UV stabilisers, plasticisers, processing aids, impact modifiers, thermal modifiers, fillers, flame retardants, fungicides, foaming agents and smoke suppressants and, optionally, pigments.
Various processes are used to form PVC compounds: extrusion, injection moulding, blow moulding, calendering, spreading and coating.
Specially Extruder for PVC Compounding
PVC very easily degrades at high temperatures (more than 170℃). Our Two stage Compounder is specially designed for PVC compounding.
1.The first stage involves using co-rotating parallel twin screw extruder with modular structure for screw and barrels. You can change the screw sequence easily for different formulae. Due to high screw speed (about 300-500rpm), dispersion will become greater, and more output is generated, but it holds a high melting temperature.
2.The second stage involves using the single screw extruder. It is used to cool down the melted material from twin screw extruder and extrude it for pelletizing.
Experience for Special Applications
GSmach 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
Rigid PVC for fittings/connections
It is best to use PVC composite granules in the injection moulding process of fittings. You can add a higher proportion of CaCO3. some customers only use pre-mixed powders on the injection moulding machine, which have poor dispersion and shape quality.
There is no filter and an eccentric pelletizer is required.
Powerful cooling required on single screw extruders
Basic formulation:
PVC + 5-15% CaCO3 + heat stabiliser + impact modifier + lubricating wax + 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 polymerising vinyl chloride monomer (VCM).
The relatively low cost of PVC, its biological and chemical resistance and its processability make it widely used in a variety of applications. Plasticised PVC is commonly used as insulation and sheathing for cables.
Basic formulation:
PVC 60% + DOP 20% + Calcined clay 10-20% + CaCO3 0-10% + Heat stabiliser + Additives
c) Medical Grade Transparent PVC Compound
Medical grade PVC compounds are the first choice for the medical industry. There are many PVC compound suppliers and importers, but the medical industry demands only the best quality PVC.
Medical grade PVC is the first choice for the manufacture of copper tubing, disposable tubing, intravenous tubing, oxygen masks, regulators, urine bags, blood bags, glucose bags and other flanges.
d) PVC Recycle for Window Profile
Window profile scrap can be recycled. The various profile scraps are pre-mixed with a small amount of virgin PVC powder, components to provide impact resistance, colours and stabilisers and fed into the first drum. Subsequently, the other filling materials (wood fibre or CaCO3) are fed into the barrel via a side feeder.
The granules do not have to be made, they are cooled on a conveyor and then crushed into powder.
Basic recipe:
PVC scrap 40% + virgin PVC powder 10% + wood fibre 20% + CaCO3 20% + additive