Sunscreen Formulation Issues: Pilling, White Residue, and Texture

Subject: Sunscreen Formulation Issues (Pilling, White Residue, Texture)

Thank you for your question regarding your homemade sunscreen formulation. Based on the issues you described (pilling and white powder in pores) and the advice from the forum, here's a summary and some suggestions:

1. Pilling (เกิดขุย):

   • This can happen when ingredients don't fully emulsify or disperse properly. As suggested, if you used "Light Cream Maker" (Product ID 141) and mixed manually by stirring, it might not have been sufficient to fully incorporate all ingredients, leading to small particles or clumps that cause pilling when rubbed on the skin.
   • Another possibility, especially with physical sunscreens, is that the powder particles are not fully dispersed or bound within the cream matrix, causing them to roll up or separate on the skin.

2. White powder in pores (มีเม็ดแป้งสีขาวติดที่รูขุมขน):

   • This is likely related to the physical sunscreen powder settling into pores or fine lines, as mentioned. This can be more noticeable if the powder isn't finely milled or well-dispersed.
   • Insufficient blending of ingredients like "Light Cream Maker" (Product ID 141) can also contribute, as unmixed particles can appear as white spots.

How to address these issues:

• Improve Blending: As suggested, if using "Light Cream Maker" (Product ID 141), try blending more vigorously and for a longer time to ensure everything is fully emulsified and dispersed. Using a high-shear mixer (like a small electric whisk or homogenizer) is often necessary for achieving a smooth, stable emulsion, especially with ingredients like emulsifiers and powders. Manual stirring might not be enough.
• Consider Emulsifier: If you are using "Light Cream Maker" (Product ID 141) and manual mixing, switching to an emulsifier that is easier to work with or more tolerant of manual mixing might help. "Satin Cream Maker" (Product ID 247) was suggested as an alternative that might handle ingredients better.
• Consider Formulation Type: As suggested, if the issue is the physical sunscreen powder settling, a Water-in-Oil (W/O) formulation (like using "Water in Oil Serum" - Product ID 726) can sometimes provide better dispersion and feel for physical sunscreens compared to Oil-in-Water (O/W) emulsions (which "Light Cream Maker" typically creates). Switching to a chemical sunscreen is another option, as they don't involve solid powder particles.

3. Improving Spreadability/Smoothness (อยากให้เกลี่ยง่ายขึ้น/ลื่นกว่านี้):
   • Yes, you can add ingredients like Silicones (e.g., Cyclomethicone - Product ID 171, Dimethicone - Product ID 508), Silicone Gel (Product ID 201), or emollients/oils (e.g., Isododecane - Product ID 228, LipidSoft types) to improve the slip and feel of the cream.
   • Important Note: As mentioned, "Light Cream Maker" (Product ID 141) has a limited capacity for oil/silicone (typically up to 20%). Adding too much can destabilize the emulsion and cause separation. If you need to add a significant amount of these ingredients for texture, consider switching to an emulsifier that can handle a higher oil phase, such as "Satin Cream Maker" (Product ID 247), as it generally has a higher oil tolerance.

In summary, the issues likely stem from insufficient blending with the chosen emulsifier ("Light Cream Maker") and potentially the nature of physical sunscreen powder. Improving blending technique or switching emulsifiers/formulation types are key solutions. Adding silicones or oils can improve texture, but be mindful of the emulsifier's oil tolerance.