The carrier resin in a masterbatch significantly affects dispersion quality, mechanical properties, and processing performance. Selecting the right carrier is essential for optimal results.
1. Carrier Types & Compatibility
PE (Polyethylene) Carrier - Compatible with: PE, PP (polyolefin family) - Not compatible with: ABS, PA, PC, engineering plastics - Best for: Film, injection molding of PE/PP parts - Market share: ~60% of all masterbatch
PP (Polypropylene) Carrier - Compatible with: PP specifically - Limited compatibility with: PE (may affect properties) - Not compatible with: ABS, PA, PC - Best for: PP injection molding, PP woven bags
ABS Carrier - Compatible with: ABS, SAN, PMMA (styrenic family) - Limited compatibility with: PC/ABS blend - Not compatible with: PP, PE, PA - Best for: ABS housings, appliances
PA (Polyamide) Carrier - Compatible with: PA6, PA66 - Not compatible with: Other polymer families - Best for: Engineering parts, gears, connectors
Universal Carrier - Based on: EVA, special copolymer, or wax-based - Compatible with: Broad range (but with trade-offs) - Trade-off: Lower compatibility at molecular level - Best for: Multi-material production, small batches
2. Incompatibility Issues
Delamination - Occurs when carrier and base resin don't mix - Visible as layer separation at part surface - Most common with PE carrier in ABS base
Poor Dispersion - Pigments not properly distributed - Visible streaks, spots, or color variation - Results from carrier viscosity mismatch
Mechanical Property Loss - Impact strength reduction (up to 30%) - Tensile strength reduction - More pronounced at higher addition rates
Surface Defects - Silver streaks (splay marks) - Flow marks - Haze or cloudiness - Reduced gloss
Prevention: - Always match carrier to base resin - Use compatibility test before production - Keep addition rate within recommended range - Consider pre-colored compound for critical applications
3. Selection Decision Tree
Step 1: Identify Base Resin - Polyolefin (PP, PE) β PE or PP carrier - Styrenic (ABS, SAN) β ABS carrier - Engineering (PA6, PC) β Specific carrier - Multiple resins β Universal carrier (with testing)
Step 2: Determine Application Priority - Color accuracy critical β Matched carrier - Cost priority β PE carrier (if compatible) - Multi-product line β Universal carrier - High addition rate β Matched carrier (avoid property loss)
Step 3: Verify Compatibility - Trial molding with actual production conditions - Check: dispersion, surface quality, mechanical properties - Test at minimum and maximum addition rates
Step 4: Optimize Addition Rate - Injection molding: 1-4% typical - Extrusion: 2-6% typical - Film: 3-8% typical - Higher rate = more carrier influence on properties
Quick Reference: | Base Resin | Best Carrier | Alternative | |-----------|-------------|-------------| | PP | PP carrier | PE carrier | | PE | PE carrier | β | | ABS | ABS carrier | Universal | | PA6 | PA carrier | Universal | | PC | PC carrier | Universal | | Multi | Universal | Per-product |