Functional & Processing FAQ

When the powder has to survive a system it was not born to live in — a silicone phase, a W/O emulsion, a high-humidity wear claim, or a compact that has to press hard.

Untreated mineral powder is hydrophilic: it wets with water, disperses poorly in oil and silicone, and takes up moisture from the air. A treatment makes the surface lipophilic, which improves dispersion, reduces viscosity at the same loading, and makes the finished film more water-resistant.

If your formula is a simple O/W cream and the powder disperses without trouble, you probably do not need it. If you are fighting viscosity, dispersion time, or wear, a treatment usually fixes all three at once.

ZnO for UVA coverage and TiO2 for UVB and the higher refractive efficiency; many serious formulas use both.

ZnO has a wider absorption band that extends further into UVA, which is why it appears in products making a broad-spectrum claim on an inorganic-only basis. TiO2 scatters more efficiently per unit mass and gives better SPF for the same loading, but its coverage falls off in the UVA region. Blending them lets you hit both ends without pushing either to a loading that ruins the texture.

In practice, an inorganic-only broad-spectrum formula is usually a blend. A single-filter formula is usually ZnO for UVA or TiO2 for SPF.

Yes, within the limits of the production line. Particle size classification and surface treatment are both adjustable, and a custom combination is a normal request rather than an exception.

What is realistic: a different cut from an existing size ladder, a standard treatment applied to a different base grade, or a custom carrier for a dispersion. What is not: a new chemistry or a size outside the mill's range.

Custom work starts at 100–200 kg and typically adds 2–4 weeks to the lead time. Send the target specification and the application and we will tell you whether it is a cut, a treatment, or a new development.

By what you are trying to fix — that is what separates them.

Dimethicone (SI) is the general-purpose choice: chemically bonded, shear-resistant, works over a wide temperature range, gives strong water repellency and disperses well in silicone oil, which suits W/Si systems. Triethoxycaprylylsilane is the standard for UV filters and pigments where you need a very hydrophobic surface without adding silicone feel. ITT (isopropyl titanium triisostearate) is for dispersion and a rich feel in anhydrous systems. DSG (disodium stearoyl glutamate) is for wear and water resistance. Lauroyl lysine, hydrogenated lecithin and magnesium myristate are for skin-feel effects more than for dispersion.

Start from the problem, not from the treatment name. If the problem is 'it will not disperse', SI or ITT. If it is 'it does not wear', DSG. If it is 'it feels dry', lauroyl lysine or lecithin.

It is the single most consequential decision in an inorganic sunscreen, because nano status changes the notification route, the labelling and the safety dossier.

Most markets define nano by primary particle size below 100 nm. Above that threshold the material is treated as a conventional pigment; below it, additional requirements usually apply — a specific notification, a safety assessment on the nano form, and in some markets specific labelling. The definitions are not identical between markets, and a material that is non-nano in one may be nano in another.

Our sunscreen range is nano by design (15–160 nm), and our pigment TiO2 range is non-nano. Tell us the destination market at enquiry and we will identify which documents that market requires for the nano form.

1 kg of powder or 5 kg of a dispersion, with COA, TDS and SDS. Samples are free; you cover the freight.

For a first evaluation, ask for two grades rather than one — the comparison is what tells you whether the material is right. If you are testing a treatment, ask for the treated and untreated version of the same base so the only variable is the treatment.

Tell us the application when you request the sample. Sending the right grade the first time saves a round trip, and we can include application notes for your system.

Yes — to all series and particle sizes. That is stated on the page and it is the practical advantage of the range.

So Kingbornit 3002 SI, Kingsica 3028 SI, Kingruti 0205 SI, Kingtalfer LS-800 SI and Kingcovite 51 SI are the same base powders you already use, with the same particle size, carrying a dimethicone surface. You can move a formula from untreated to treated by changing the grade code, without re-optimising the particle size.

That matters more than it sounds: it means the treated version is a drop-in, and any difference you measure comes from the treatment rather than from a size change.

Smaller particles give more transparency and better SPF per unit mass; larger ones give less whitening but require more loading, and above a certain size the UV performance starts to drop.

15 nm (N15E, 4015) is the transparency grade — the film is nearly invisible on skin, which is what makes a high-SPF mineral sunscreen cosmetically acceptable. 30 nm (23M, N30E, S30W, S25W) is the balance point most formulas use. 50 nm (N20E, 4513, 4528) and 80 nm (N80E AS) trade a little transparency for lower viscosity and easier dispersion. 160 nm (Kingruti 160 AS) is at the edge of the UV absorption range and is used where feel matters more than SPF efficiency.

One caveat: the optimum for UV attenuation is around half the wavelength being blocked, so the smallest particle is not automatically the most efficient performer. It is the most transparent, which is a different thing.

COA per lot, TDS per grade, and SDS. Beyond that, the regulatory statements a market requires — heavy metal declarations, non-nano or nano statements, allergen declarations, REACH status, BSE/TSE statements — are issued on request against the specific grade and lot.

The distinction that matters: the TDS describes the grade, the COA describes the lot. For release testing and for a customer questionnaire, the COA is usually what is being asked for, and a generic datasheet will not satisfy it.

If your questionnaire is long, send it at enquiry rather than after the order. Most of it can be answered once and reused.

Very little, and what does change is the dispersion, which can look like a colour change until you know why.

The treatment is a molecular layer on the surface, so it does not alter the refractive index or the pigment's intrinsic colour. What it does change is how the particles sit in the film: a treated powder disperses more evenly, which usually reads as slightly stronger and more uniform colour at the same loading. In a TiO2 system this can show as a small increase in opacity.

So if your shade shifts after switching to a treated grade, it is usually an improvement in dispersion rather than a change in the pigment — re-check the loading before you re-tint.

Pre-dispersion if you can — it solves the hardest problem in the formula, which is wetting a nano powder completely.

Nano powders have enormous surface area and agglomerate readily; getting them fully dispersed in your own process usually needs specialist equipment and a lot of time, and any agglomerate left is both a whitening defect and an SPF loss. A pre-dispersion arrives already dispersed at a known solids content, so you are adding a liquid rather than a powder.

Choose powder only if your process already handles nano dispersion well, or if the carrier of the available dispersions is incompatible with your system.

MOQ 25 kg for a stock grade, 100–200 kg for a custom grade or a custom carrier. Lead time 7–15 working days for stock, longer for custom. Payment terms are confirmed at quotation and depend on the market and the order value.

Standard packing is 25 kg paper-plastic composite bags; 500 kg and 1000 kg jumbo bags are available for most grades. Dispersions ship in 5, 20 or 200 kg containers.

Give us the destination port and the mode of transport at enquiry. Packing and documentation both depend on the route, and it is easier to get right at quotation than to fix later.

Both make the surface hydrophobic; the silane does it without adding a silicone feel, which is why it dominates in UV filters.

Triethoxycaprylylsilane bonds directly to the surface hydroxyls and gives a very hydrophobic, relatively thin layer. In a sunscreen that means better dispersion in the oil phase at high solids loading, and less interaction with the organic filters. Dimethicone gives a thicker, more lubricious layer, which is better for skin feel and for press behaviour in a compact.

In practice: silane for sunscreen and pigment dispersions, dimethicone for powders where feel and pressing matter.

Match it to your emollient system and to the feel you want — the carrier becomes part of the formula.

C12-15 alkyl benzoate (4015, 4513, 4560, Z-6060) is the general-purpose choice: light, dry, widely compatible. Dimethicone (2355, Z-6050) suits silicone-heavy and W/Si systems. Dicaprylyl carbonate (4528) gives a slightly drier, more elegant feel. Water and glycerin (5030) is for aqueous systems and gels.

The solids content also varies by carrier — 40% for the finer 15 nm material, up to 65% for the 30 nm grades in a light ester. Check the delivered solids against your target loading before you fix the percentage in the formula.

Yes, within limits — we can tell you what has worked in comparable systems and what the common failure modes are, and we can review a formula for obvious incompatibilities.

What we cannot do is take responsibility for your finished formula or its claims. That stays with you, and it should: the base, the process and the testing are yours, and the interactions that matter usually come from those rather than from the powder.

The most useful thing to send is the system (O/W, W/O, anhydrous, W/Si), the target feel, and the problem you are trying to solve. With those three we can usually shortlist two or three grades rather than asking you to test the whole range.