Injection Moulding Polyvinyl Chloride (PVC)

Material Description

Polyvinyl Chloride (PVC) is a versatile thermoplastic polymer known for its excellent material properties, making it widely used in various applications. PVC is composed of repeating vinyl chloride monomer units, which are polymerized to form a linear, high molecular weight structure. This polymer exhibits several key characteristics: it is durable, lightweight, and cost-effective, making it a popular choice for construction materials, piping, and electrical insulation. PVC is also inherently flame-resistant due to its chlorine content, and it has good electrical insulation properties. Its high chemical resistance ensures it can withstand exposure to a wide range of acids, bases, and other corrosive substances, making it ideal for piping and storage applications in chemical industries. Additionally, PVC is highly customizable, as it can be modified with plasticizers, stabilizers, and other additives to achieve specific properties, such as flexibility or rigidity. However, it should be noted that PVC can release toxic chlorine gas when burned, and there are environmental concerns related to its production and disposal, leading to increased interest in recycling and sustainable alternatives.

Tensile Yield
Modulus (MPa)
Point (°C)
Coefficient of
(x 10^-6 /°C)
Absorption (%)
1350 - 148045 - 601.0 - 3.0100-2000.14 - 0.190.9 - 1.250 - 800.1 - 2.0

Design Recommendation

PVC presents unique challenges due to its chlorine content. When designing molds for PVC, it’s essential to use materials that are corrosion-resistant, as the chlorine can be corrosive. Proper venting and ventilation within the mold are critical to prevent the release of harmful chlorine gas during processing. Adequate cooling is also essential, as PVC tends to generate more heat during the molding process, which can lead to part distortion and reduced dimensional stability.

Cost Saving Tip

A key strategy for cost savings in PVC injection molding involves optimizing both material selection and processing parameters. This entails selecting the most suitable PVC resin and additives that align with the specific application needs, effectively reducing material expenses without sacrificing necessary performance attributes. Furthermore, meticulous adjustment of injection molding process variables, including temperature, pressure, and cycle duration, can curtail material wastage and energy consumption. By enhancing cooling methods and mold designs, manufacturers can accelerate production, lower cycle times, and minimize energy expenditure. Combining these approaches ensures significant cost reductions in PVC injection molding, all while maintaining product quality and functionality.