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Vacuum Casting Post-Processing Solutions: Polishing, Painting & Coating for Industrial Parts

Created on 05.21

Meta Description: Compare vacuum casting post-processing methods including polishing, painting and coating, select optimal industrial-grade solutions for appearance, corrosion resistance, wear resistance, and compliance requirements. #vacuum casting post processing #PU part polishing #PU painting coating #vacuum casting surface finishing

Raw vacuum-cast PU parts commonly have surface defects including fine burrs, flow lines, micro-bubble pinholes, and uneven gloss, which cannot meet industrial standards for automotive interior components, consumer electronics casings, and ISO-compliant non-implant medical parts. Standardized post-processing effectively improves surface smoothness, appearance texture, wear resistance, corrosion resistance, and assembly performance. We classify mainstream post-processing methods, standardized technical parameters, and industry-specific application scenarios for different PU grades and functional requirements.

1. Manual & Mechanical Polishing (Basic Appearance Improvement)

• Standard Process Parameters: Polishing grit 400–2000 mesh, step-by-step coarse-to-fine progressive polishing

• Core Application: Remove burrs, flow lines, and micro-pinholes; form matte or semi-gloss surface finishes

• Features: Flexible for complex irregular structures, low processing cost, suitable for prototype and small-batch parts

• Limitations: Low efficiency for mass production; manual polishing quality varies by operator skill

• Compliance Note: Adopt non-toxic medical-grade polishing paste for biocompatible PU medical parts

2. Surface Sealing & Primer Treatment (Pre-Coating Base Process)

• Standard Process: Apply dedicated PU sealing primer to fill micro-pinholes and surface pores, improving subsequent coating adhesion

• Core Application: Mandatory pre-treatment before painting for all painted vacuum-cast industrial parts

• Core Function: Solves paint bubbling, peeling, and discoloration caused by internal air voids and surface porosity

3. Painting & Spraying (Core Industrial Appearance Process)

1. Solid-Color Matte/Gloss Painting

• Application: Consumer electronics casings, household appliance structural parts, automotive non-exterior components

• Features: Uniform color, stable gloss, wear-resistant and scratch-resistant surface

2. Texture/Grain Spraying

• Application: Automotive interior plastic-simulated texture parts

• Features: Simulates injection-molded grain effects with high industrial realism

3. Soft-Touch Rubber-Feel Painting

• Application: Wearable device housings, handheld industrial equipment casings

• Features: Anti-slip, anti-fingerprint, soft tactile surface performance

4. Functional Industrial-Grade Coating for Special-Requirement Parts

• UV Curing Coating: High-gloss, scratch-resistant, anti-yellowing finish for high-end consumer electronics appearance parts

• Waterproof & Anti-Corrosion Coating: For new-energy and outdoor industrial PU structural components

• Medical-Grade Antibacterial Coating: ISO 10993 compliant for non-implant medical devices

Quick Industrial-Oriented Post-Processing Selection Guide

• Prototype appearance parts: Fine polishing + clear sealing primer

• Automotive interior parts: Texture grain spraying or soft-touch painting

• Consumer electronics casings: Solid-color high-gloss painting + UV top coating

• Medical non-implant parts: Fine polishing + medical-grade antibacterial coating

Our dedicated post-processing workshop provides customized polishing, painting, and coating solutions, strictly controlling surface roughness, color difference, and coating thickness to meet batch industrial quality standards.