Injection Moulding Polyethylene Terephthalate (PET)

Material Description

Polyethylene Terephthalate (PET) is a versatile thermoplastic polymer with a wide range of applications due to its exceptional material properties. PET is characterized by its high tensile strength, making it a durable material that can withstand significant mechanical stress. It exhibits excellent chemical resistance, which makes it resistant to various solvents, acids, and bases. PET is also highly transparent, making it ideal for packaging applications where product visibility is crucial. Its low water absorption and moisture resistance contribute to its excellent dimensional stability and suitability for outdoor use. Furthermore, PET is a lightweight material with good electrical insulating properties, making it an excellent choice for electrical and electronic components. Additionally, PET is recyclable, further enhancing its appeal in an environmentally conscious world. Overall, PET’s combination of strength, chemical resistance, transparency, and recyclability makes it a widely used material in industries such as packaging, textiles, electronics, and more.

Tensile Yield
Modulus (MPa)
Point (°C)
Coefficient of
(x 10^-6 /°C)
Absorption (%)
1350 - 145050 - 802.5 - 4.0250-2600.25 - 0.321.3 - 1.560 - 700.1 - 0.8

Design Recommendation

When designing for injection molding with Polyethylene Terephthalate (PET) material, it is crucial to pay special attention to key parameters to ensure a successful and cost-effective manufacturing process. First and foremost, it’s essential to maintain a uniform wall thickness in the design to prevent issues like warping and sink marks. Additionally, the use of generous fillets and radii at corners and transitions can help distribute stress more evenly and improve part strength. To prevent voids and reduce cooling time, it’s advisable to incorporate a proper gate and runner system, along with cooling channels strategically placed to facilitate efficient heat dissipation. Finally, incorporating draft angles on vertical walls and textured finishes on mating surfaces can aid in easy part ejection and minimize surface imperfections, thus optimizing the quality and manufacturability of PET injection-molded parts.

Cost Saving Tip

Cost-saving in the injection molding of Polyethylene Terephthalate (PET) involves several critical considerations. Firstly, optimizing the design of PET parts for injection molding is paramount, as it directly affects material consumption and cycle times. Utilizing efficient gating and runner systems, minimizing undercuts, and ensuring uniform wall thickness can significantly reduce scrap rates and material waste. Secondly, process parameters like temperature, pressure, and injection speed should be fine-tuned to minimize energy consumption while maintaining product quality. Implementing a robust regrind program, where post-consumer or post-industrial PET scrap is recycled and reintroduced into the process, not only reduces raw material costs but also promotes sustainability. Additionally, employing advanced simulation and mold flow analysis software can help in designing molds that reduce cycle times, enhance cooling efficiency, and improve part quality. Lastly, preventive maintenance and regular inspection of molds and machinery are essential to extend their lifespan and prevent unexpected downtime. By integrating these cost-saving measures, manufacturers can optimize their PET injection molding operations for both economic and environmental benefits.