Plastic Part Post-Processing: Polishing, Chemical Smoothing, Painting & Texture Spraying for Industrial Use
Created on 05.21
Meta Description: A comprehensive guide to plastic part post-processing, including polishing, chemical smoothing, painting and texture spraying, suitable for injection molding, 3D printing and vacuum casting plastic parts. #plastic post processing #chemical smoothing plastic #plastic texture spraying #3D printed plastic polishing
Plastic parts (PU, ABS, PA, PC, TPU) are widely used in consumer electronics, automotive interiors, medical non-implant components, and industrial prototypes. Raw plastic parts (injection molding, 3D printing, vacuum casting) often have surface defects such as burrs, layer lines, micro-pinholes, and uneven gloss, which cannot meet industrial appearance and functional requirements. Reasonable post-processing not only improves surface quality but also enhances wear resistance, waterproof performance, and assembly compatibility. We classify four core plastic post-processing methods, their technical parameters, applicable scenarios, and practical operation tips.
1. Polishing (Manual & Mechanical)
Technical Parameters: Polishing grit 400-2000 mesh (coarse: 400-800, fine: 1000-2000); polishing speed 1000-3000 rpm; surface roughness after processing: Ra ≤0.8μm (fine polishing).
Applicable Materials: All plastic materials (PU, ABS, PA, PC, TPU); suitable for injection molding, 3D printing (SLA/FDM/SLS), vacuum casting parts.
Core Application: Prototype appearance improvement, small-batch functional parts; removing burrs, layer lines, and micro-pinholes.
Advantages: Flexible operation (suitable for complex-shaped parts); low equipment cost; no chemical pollution.
Limitations: Low efficiency for mass production; manual polishing quality depends on operator skill; easy to produce polishing marks.
Practical Tips: Adopt step-by-step coarse-to-fine polishing; use non-toxic polishing paste for medical-grade plastic parts.
2. Chemical Smoothing
Technical Parameters: Smoothing agent (PU/ABS special); processing temperature 20-30℃; processing time 10-60s; surface roughness after processing: Ra ≤0.4μm.
Applicable Materials: PU (vacuum casting), ABS (injection molding/3D printing), PA (SLS 3D printing); not suitable for PLA/FDM parts.
Core Application: High-gloss appearance parts (consumer electronics casings, automotive interior parts); 3D printed parts with obvious layer lines.
Advantages: High efficiency (compatible with mass production); uniform surface effect; no dimensional loss (±0.01mm); improves waterproof performance.
Limitations: Chemical agents are volatile (needs ventilation); not suitable for heat-sensitive plastics; high cost of smoothing agents.
Compliance Note: Use medical-grade smoothing agents (ISO 10993 compliant) for biocompatible plastic parts.
3. Painting & Spraying
Technical Parameters: Paint type (acrylic, polyurethane); coating thickness 10-30μm; color difference ΔE ≤2; adhesion (cross-cut test ≥4B).
Applicable Materials: All plastic materials; suitable for injection molding, vacuum casting, 3D printing parts.
Common Types & Applications:
• Solid-color matte/gloss painting: Consumer electronics casings, household appliance parts; uniform color, wear-resistant.
• Soft-touch painting: Wearable devices, handheld industrial equipment; anti-slip, anti-fingerprint.
• High-gloss painting: High-end decorative parts; requires post-polishing before painting.
Advantages: Customizable color and gloss; improves surface wear resistance and corrosion resistance; suitable for mass production.
Limitations: Requires pre-treatment (degreasing, priming); easy to produce bubbles and orange peel if parameters are improper.
4. Texture Spraying
Technical Parameters: Texture type (sand texture, leather texture, grain texture); particle size 50-150 mesh; coating thickness 15-40μm.
Applicable Materials: ABS, PU, PC; suitable for automotive interior parts, injection molding plastic parts.
Core Application: Simulate injection-molded grain effect; hide surface defects (scratches, flow lines); improve tactile feel.
Advantages: High industrial realism; covers surface defects; suitable for batch production; low cost.
Limitations: Cannot achieve high-gloss effect; texture uniformity depends on spraying skills.
Quick Selection Guide:
① Prototype parts: Manual polishing;
② High-gloss appearance parts: Chemical smoothing + high-gloss painting;
③ Automotive interior parts: Texture spraying;
④ Mass plastic parts: Mechanical polishing + spray painting.
Our post-processing workshop provides one-stop solutions for plastic parts of all processes.
Contact Us
Contact Us
Address: 303, 3rd floor, building A, No. 80 ChangJiang Road, Dong District, ZhongShan City, GuangDong Province, China 528403
Email: selina@marigold-rapid.com
Mobile: +86 18718750572
Industries
Services
Company