●What is Polyvinyl Chloride?
Polyvinyl Chloride is a thermoplastic polymer, which is white, and brittle. As compared to the other plastic materials, PVC has been around for longer period. There are two basic types of PVC, namely, unplasticized or rigid polymer (uPVC or RPVC) and flexible polyvinyl chloride. Also referred to as regular or plasticized PVC, the flexible polyvinyl chloride is widely used in construction as insulation for electrical wires in hospitals, homes, etc. The rigid polyvinyl chloride material is also used in construction as pipe for plumbing.
●What Characteristics of PVC material Make it Suitable for
Injection Moldat?
What makes this material suitable for the
injection molding are its characteristics. The following are some significant properties of the PVC material:
Strength: The rigid polyvinyl chloride is known for its excellent tensile strength, which makes it durable.
Density: The specific gravity of the PVC material is 1.4, and is denser as compared to the other types of plastics.
Hardness: This is yet another property of the material, which makes it popular. The rigid PVC material has an outstanding hardness.
Easily Available: Last, but not the least, the PVC material can be availed easily, and that too at cheaper prices as compared to other plastic materials.
●What Are the Ideal Conditions for Using PVC Compounds in Injection Molding?
All the characteristics explained above are the reasons behind increasing use of polyvinyl chloride in
injection molding. However, there are certain necessary conditions for their use. What are they? Read below:
Injection Speed: In order to achieve an optimal consistency, it is necessary to have the injection pressure 20% to 40% of the maximum value.
Heater Band Setting: You are required to set the nozzle temperature to 10 degrees lower than the suggested stock temperature. Similarly, the barrel temperature should be set 20 degrees lower than recommended stock temperature.
Stock Temperature: You will get the exact value of the recommended stock temperature by referring to the technical data sheet. This temperature is controlled by adjusting the screw back pressure, screw rpm, and heater band settings.
Mold Temperature: The temperature of the inlet water should be within the range 70 to 100 degrees Fahrenheit. However, the temperature on the ejector side should be colder by around 10% to 20%.
Rotation Speed: The machine, which is responsible for carrying out
injection molding, should have the screw rotation speed of 35 to 50 rpm.
Screw Back Pressure: Generally, the screw back pressure is 60 to 100 PSIG. However, it can vary depending on the machine used.
Holding Pressure: The holding pressure should be maintained at 50% of the injection pressure.
Injection Pressure: For achieving an optimal consistency, it is necessary to around 20% to 40 % of the maximum pressure.
With the knowledge of PVC
injection molding, you can now make more informed decisions about
injection molding process design. ABBYLEE has extensive expertise in all
injection mold design techniques. We are ready to work with you to determine the most effective design to achieve production efficiency and quality.