W13-A-003 — Calcium Carbonate vs Talc
1. What decision is the buyer trying to make?
Which mineral filler to specify for cost reduction, stiffness, or dimensional performance in a polyolefin or PVC formulation.
2. Which variables actually matter?
- Target property: cost dilution, stiffness (flexural modulus), HDT, dimensional stability, surface finish
- Polymer (PP, PE, PVC) and process (injection, film, sheet, pipe)
- Loading level and its effect on impact / elongation
- Particle geometry (CaCO₃ ~cubic/rhombic vs talc ~platelet)
- Coating and surface treatment
- Regulatory (food contact, toy)
3. Which variables are commonly misunderstood?
- "Talc is stronger" is context-dependent — platelet orientation only helps in flow-oriented parts.
- Interchanging CaCO₃ and talc at equal loading changes shrinkage, warpage and impact simultaneously.
- Colour shift: talc typically reduces brightness compared to high-brightness CaCO₃.
4. What additional information is required before deciding?
- Application and part geometry
- Target properties (with tolerances)
- Current formulation and its known weakness
- Process window constraints
- Regulatory scope
5. What should be included in the RFQ?
- Polymer + process
- Target property to improve (single primary target)
- Loading window
- Coating requirement
- Colour / brightness constraint
- Regulatory scope
- Volume and packaging
So what should the buyer investigate next?
Whether the primary property they want (cost dilution, stiffness, shrinkage) actually maps to CaCO₃ or to talc — and to validate on the target process, not on a datasheet.
Bridges
- W1–W2 — CaCO₃ pillar and masterbatch
- Discovery Backlog — Talc (Priority A)
- W10 — Application × Masterbatch (Injection, Sheet)