Pilling Issue in Sunscreen Formulation with Added Powders and High Oil Content

Based on the discussion in the forum thread you linked, the most likely reason your sunscreen formulation is pilling is the high speed of your blender.

Here's a breakdown of the points:

• High Blending Speed: The staff indicated that Light Cream Maker, an emulsifier in your formula, is sensitive to high shear force. Blending at speeds exceeding approximately 2500 RPM can damage its polymer structure, leading to pilling. You mentioned using a blender at over 5000 RPM, which is significantly higher than the recommended limit.
• Added Powders: You asked if adding MatteSilica (1%) and Silk Sericite Powder (0.5%) could cause pilling. The staff confirmed that while excessive amounts of some powders can cause pilling, the low percentages you used for these specific powders are unlikely to be the cause.
• Oil Percentage: You also inquired if the total oil percentage (27.5%) might be an issue, given that Light Cream Maker is stated to handle up to 20% oil. The staff explained that an oil phase exceeding the emulsifier's capacity typically results in an unstable or separating emulsion over time, rather than immediate pilling. They reiterated that the amount of Light Cream Maker you used (1%) is generally not problematic for pilling.

Therefore, the primary recommendation to resolve the pilling issue is to reduce the blending speed when making your formulation, keeping it below 2500 RPM as advised by the staff.