Liquid Film Surface Finish
Safety. Halogenation uses corrosive oxidizers. The numbers below are industrial vocabulary, not a home recipe. Process detail lives in Chlorination for Tack Control.
Executive summary
On dipped or cast film, gloss and matte usually come from the surface the film dried against. A glazed former gives a shiny face and vivid color. A bisque or sandblasted former gives a dull, flat face. Tack can be cut for a while with talc, or permanently by halogenation. Bloom is wax moving to the surface.
Use this when you are forming film and reading the face you got, or when stored film looks powdery. Storage sits in Aging, Storage and Care.
Former finish sets the face
What is a glazed vs bisque former?
A glazed former has a smooth, polished porcelain surface. Film that dries against it comes off shiny, with vibrant color. A bisque or sandblasted former has a micro-rough face. Film comes off dull and flat. The finish is set while the film forms.
On a flat cast or spread, the bed does the same job as the former: the contacting face copies the tool. A polished bed reads glossier than a rough one. Forming geometry is in Former Dip vs Mould Cast vs Flat Spread.
Bulk color in the compound is a different lever than this face finish. See Pigment and Filler Decks.
Tack: talc or halogenation
Fresh cured film is often tacky. Plants dust with talc for handling. That dusting is temporary.
Permanent de-tack on dipped goods is aqueous halogenation: chlorine water, sodium hypochlorite, or bromine water, usually in a tumbler, then neutralize, rinse, and dry warm. Handbook example: about 0.15% chlorine, 4.5–7.5 minutes at room temperature. No copper or brass in contact with the chlorine liquor.
That process belongs in Chlorination for Tack Control. Chlorinated glove surfaces show a chemically modified, chlorine-bearing skin.
Bloom after storage
What is wax bloom?
Wax bloom is antidegradant wax moving to the rubber surface. Industrial compounds use microcrystalline wax at 0.5–1.0 phr to build a surface film that protects against static ozone. Flexing and stretching crack that film. The powder can look like chalk. Peer work on NR bloom treats it as a migrating layer, not leftover talc.
What does phr mean?
phr is parts per hundred rubber. 1.0 phr means one part of that ingredient for every 100 parts rubber in the compound.
Wiping the powder off can bring tack back if the bloom was the only ozone shield. Wax bloom is for film that sits still. Compounding choices for antidegradants sit in Antidegradants in DIY Compounds.
Reading cues
| What you see | Think first |
|---|---|
| Shiny face, vivid color | Glazed or smooth tool. |
| Dull, flat color | Bisque, sandblast, or rough bed. |
| Powder after storage | Wax bloom. |
| Still tacky after talc | Halogenation is the permanent class. |
| Texture but poor wet grip | Embossing alone is not enough. Halogenation is the industrial wet-grip class. |
Deep dives (optional)
Deep dive: Chlorination window (pointer)
Saturated chlorine water is about 0.56% chlorine, diluted to about 0.15% for treatment. Typical tumble is 4.5–7.5 minutes at room temperature, then neutralize, triple rinse, and dry at 40–46°C. Full solution choice and rinse discipline: Chlorination for Tack Control.
Deep dive: Wax bloom timing
Industrial guidance allows bloom time before ozone exposure. One handbook example: weeks at 23°C and 50% relative humidity in kraft wrapping. Dynamic wear defeats the wax barrier. PPD antiozonants are a different class; they can stain dark goods.