Injection molding

⭐How to solve the problem of poor filling during the injection molding of high-temperature resin PEEK?

The poor filling (lack of material/underfilled) in PEEK materials is mainly caused by its high melting point (about 343℃) and high melt viscosity, resulting in poor fluidity. To solve this problem, systematic optimization needs to be carried out from three aspects: process parameters, mold design, and material handling.

Specific solutions for different stages:

Optimization Area	Key Measures	Core Function & Parameter Reference
1. Process Parameters	Increase injection speed and injection pressure	Overcome high viscosity flow resistance; PEEK requires high pressure and high speed for filling.
	Increase mold temperature	Critical control point. Prevents premature solidification of the melt; recommended 170°C-200°C (338°F-392°F).
	Increase barrel/melt temperature	Reduce melt viscosity; do not exceed 430°C (806°F) to avoid degradation.
2. Mold Design	Enlarge gate and runner sizes	Reduce filling resistance. Experience reference: minimum gate size should be 2/3 of the maximum wall thickness.
	Add mold vents	Prevent high-pressure air from hindering melt flow.
	Optimize gate location and number	Improve melt flow balance; suitable for thin-walled or complex structures.
3. Material & Equipment	Thoroughly dry the material	Eliminate moisture. Dry at 150°C (302°F) for at least 3 hours; control moisture content ≤ 0.02%.
	Check injection molding machine performance	Ensure the machine can deliver high pressure and high speed.
	Select the appropriate material grade	For precision small parts, choose high-flowability PEEK grades.

💡 Key Points and Advanced Suggestions

• Key Points: Addressing poor PEEK filling. If the mold temperature and injection speed cannot be effectively controlled, merely increasing the material temperature often yields limited results and may even lead to material degradation. Therefore, it is essential to ensure high temperature and high speed.

• Advanced Suggestions: If the above conventional adjustments still do not yield satisfactory results, more specialized solutions may need to be considered. For instance, for ultra-thin-walled or micro-precision parts, using a dedicated injection molding machine with extremely high injection pressure (e.g., >340 MPa) and extremely high injection speed (e.g., >1000 mm/s) can solve the problem of insufficient filling power at the hardware level.

If necessary, you can provide the approximate dimensions of the specific product (such as wall thickness, flow length), and we can conduct a more targeted analysis for you.

Email: ciky@hainamould.com

Jun 04, 2026 at 10:55