Injection Moulding Polyphenylene Oxide (PPO)

Material Description

Polyphenylene Oxide (PPO), also known as poly(2,6-dimethyl-1,4-phenylene) oxide, is a high-performance thermoplastic polymer renowned for its exceptional combination of material properties. PPO exhibits a high glass transition temperature (Tg) in the range of 205-210°C, imparting excellent dimensional stability and resistance to deformation at elevated temperatures. Its amorphous structure contributes to transparency and ease of processing. PPO possesses outstanding electrical insulating properties, making it suitable for a wide range of electrical and electronic applications. Moreover, it is inherently flame retardant due to its self-extinguishing nature, ensuring safety in various applications. PPO also demonstrates excellent chemical resistance to a variety of solvents, acids, and bases, which makes it ideal for use in aggressive environments. Its low moisture absorption, dimensional stability, and resistance to creep make it an excellent choice for structural components. Additionally, PPO can be easily blended with other polymers to modify its properties further, such as increasing impact resistance or reducing cost. This versatility, combined with its inherent strength and heat resistance, makes PPO a highly desirable material for various engineering and industrial applications.

Tensile Yield
Modulus (MPa)
Point (°C)
Coefficient of
(x 10^-6 /°C)
Absorption (%)
1030 - 108060 - 802.3 - 3.1215-2400.22 - 0.251.0 - 1.290 - 1100.05 - 0.2

Design Recommendation

When designing for the injection molding of Polyphenylene Oxide (PPO), several key recommendations must be considered. Firstly, due to PPO’s high melt temperature, it is essential to employ a robust mold with efficient cooling channels to dissipate the heat generated during the injection process. This will help prevent thermal degradation of the material and ensure consistent part quality. Additionally, PPO exhibits low shrinkage, so precise control of mold temperature is crucial to avoid warping or dimensional inaccuracies. Moreover, using a mold release agent or surface finish treatments can aid in ejection and prevent sticking issues. Finally, to mitigate the risk of part defects such as sink marks and voids, it is advisable to employ proper gate design and placement, as well as consistent and controlled injection pressure and speed settings, ensuring that PPO’s unique properties are harnessed to achieve high-quality, durable components.

Cost Saving Tip

Cost-saving in Polyphenylene Oxide (PPO) injection molding processes can be achieved through a combination of material optimization, process efficiency, and waste reduction strategies. To begin with, selecting PPO with appropriate additives, such as glass fibers or mineral fillers, can enhance the material’s mechanical properties while reducing the required resin volume, resulting in cost savings. Moreover, fine-tuning the injection molding parameters, including temperature, pressure, and cooling time, can lead to reduced cycle times and energy consumption. Implementing hot-runner systems for mold designs can minimize material waste during startup and shutdown phases. Additionally, employing scientific molding techniques, like Design of Experiments (DOE), can enhance part quality and repeatability, reducing the need for costly rework or scrapped components. Proper maintenance of injection molding equipment ensures longer service life and minimizes downtime for repairs. Finally, adopting a systematic approach to regrind and recycle PPO scrap material can cut down on raw material costs and contribute to environmental sustainability. By effectively integrating these strategies, manufacturers can optimize their PPO injection molding processes, realizing significant cost savings while maintaining product quality and consistency.