Microcellular Foam Mould
Bumper Mould Specifications
Microcellular Foam Mould Cycle Time | 40s – 50s |
Manufacturing Lead Time | 45 – 55 days |
Microcellular Foam Mould Quality Essentials
SINOMOULD strictly controls the design and manufacturing quality of microcellular foam moulds. Addressing the special requirements of the microcellular foaming process for mould sealing, runner systems, and surface quality, we implement the following quality essentials:
- High‑pressure sealing design of the microcellular foam mould: The microcellular foaming process requires injection of supercritical fluid (SCF). Multiple sealing structures are applied to the mould parting line, ejector pin holes, and slider mating surfaces. An air‑tightness test at ≥30 bar with no pressure drop ensures that the foaming gas does not escape.
- Hot runner system quality of the microcellular foam mould: A dedicated valve‑gated hot runner is used, with valve pin response time ≤0.05 seconds and gate diameter accuracy of ±0.01 mm. This ensures that the melt and SCF are uniformly mixed before precise injection into the cavity, preventing premature foaming.
- Cavity surface quality of the microcellular foam mould: The moulded surface roughness Ra ≤0.2 μm prevents surface defects caused by bubble rupture. For appearance parts, mirror polishing or precision texturing processes ensure that the microcellular foamed part is free from flow marks and silver streaks.
- Venting system optimisation of the microcellular foam mould: The microcellular foaming process requires controlled gas escape. Venting slot depth is precisely controlled to 0.01–0.02 mm, allowing excess gas to be expelled while maintaining sufficient back pressure to promote uniform bubble nucleation.
Microcellular Foam Mould Machining Essentials
Relying on high‑precision 5‑axis machining centres and extensive experience in microcellular foam mould manufacturing, SINOMOULD achieves high‑precision, high‑sealing machining of microcellular foam moulds. The core machining essentials are as follows:
- Precision machining of sealing structures for the microcellular foam mould: Sealing slots are machined using 5‑axis milling combined with wire‑cut EDM. Slot width tolerance ±0.005 mm, slot bottom roughness Ra ≤0.8 μm. After installation, the sealing ring compression is controlled to 20%–25% to ensure long‑term sealing performance.
- Precision assembly of the hot runner nozzle for the microcellular foam mould: The fit clearance between the nozzle and the mould is controlled to 0.005–0.01 mm, with end face contact ≤0.005 mm. Red dye spotting is used to check mating surfaces, preventing melt leakage that could cause gate blockage.
- Micro‑machining of venting slots for the microcellular foam mould: Fine venting slots are machined using precision surface grinders or laser processing. Slot depth accuracy ±0.001 mm, slot width 0.5–1.0 mm. The distribution density of vents is determined by mould flow analysis results to ensure uniform venting.
