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Automotive Parts
Structural parts such as handles, door handles, guards — weight reduction while ensuring rigidity and appearance.
MICROCELLULAR FOAMING · SCF
Based on supercritical fluid (SCF) technology, it instantly forms numerous microcells in the melt (cell diameter 1–100μm, cell density 10⁶–10¹² /cm³). Parts are lightweight, sound-insulating, high in specific strength, with improved dimensional accuracy and reduced warpage.
Cell diameter 1–100μm, cell density 10⁶–10¹² /cm³; compared with traditional foams (cell diameter 250μm–1mm), the microcellular structure is more uniform and fine.
A "third fluid" above the critical point with both gas and liquid properties. Considering processability, cost and environmental impact, supercritical inert gases — especially nitrogen (N₂) or carbon dioxide (CO₂) — are preferred as blowing agents.
Typical sandwich structure: a non-foamed skin layer and a foamed core layer, with an ideally uniform cell distribution in the core.
Matrix materials are thermoplastic resins (PP, ABS, PC, PA, etc.), thermoplastic elastomers and mineral-filled / fiber-reinforced materials; the blowing agent is supercritical inert gas.
Resin is plasticized under a preset back-pressure while SCF (N₂ or CO₂) is metered into the melt; after further mixing/diffusion a homogeneous solution is formed and maintained until entering the mold cavity. After injection into the cavity, thermodynamic instability instantly creates numerous bubble nuclei; during filling and cooling, bubbles grow and are fixed, yielding microcellular foamed parts.
Key Points of SCF Foaming Process
Improves dimensional accuracy and stability (flatness, roundness ≥50% improvement); reduces residual stress, less warpage; no sink marks on part surface; shorter molding cycle (≥5% for thin-wall parts).
Reduces part weight 5%–30%; lowers machine clamp tonnage; increases design freedom (thinner, differential-wall structures); reduces mold development/validation time; better low-pressure in-mold decoration.
Cannot achieve Class-A appearance: foam marks and higher roughness exist, requiring cavity back-pressure and other techniques to improve surface effect.
Internal microcellular structure may vary with fill distance; existing functional structures limit weight-reduction magnitude; glass-fiber orientation limits warpage improvement.
By building pressure inside the mold cavity, the melt flow front cannot foam during injection, significantly improving part surface effect.
Process Flow
Structural parts such as handles, door handles, guards — weight reduction while ensuring rigidity and appearance.
Printer/copier structural parts — improved dimensional stability and reduced warpage.
Thin-wall, high-precision parts — eliminating sink marks, improving flatness.
Filter caps (15% lighter, sink marks eliminated, warpage solved), gears (improved roundness), Mingrui handles (uniform cells, 10% lighter, quality surface), etc.
Technology Development Status
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