As water-based paint increasingly enters everyday life, people are no longer strangers to it. Here we share some practical tips for using water-based paint, hoping to help you.
1. Types and application technology of water-based wood coatings
Analyzing water-based wood paint products on the market by binder type, the application technologies fall into the following categories:
(1) Acrylate type: including styrene-acrylic and (modified) acrylate emulsions, suitable for primers and matte topcoats. Relatively low cost, average hardness, less prone to craters, but poorer film formation and gloss - not ideal for high-gloss; poor abrasion resistance and difficult defoaming, usually blended.
(2) Polyurethane dispersion (PUD): including aromatic and aliphatic PUDs; the latter has excellent yellowing resistance and suits outdoor use. Good film formation, self-crosslinking with higher gloss and abrasion resistance, fewer bubbles and craters. Moderate hardness, higher price - suited to glossy topcoats and floor paints.
(3) Acrylic-modified PUD: a blend of aromatic/aliphatic PUD and acrylate dispersion, combining both advantages; moderate cost, self-crosslinking or two-component, good hardness, fast drying, chemical resistance, low/no yellowing - suited to semi-matte, primers and outdoor paints.
(4) Water-based urethane oil: single-component, like oil-based urethane oil, oxidative-reductive drying; needs driers; fast drying, good gloss/hardness/abrasion/water resistance - suited to glossy finishes and floor paints.
(5) Water-based two-component PU: component A is a -OH-bearing PU dispersion; component B is a water-based (mainly aliphatic) curing agent. Mixed and applied, crosslinking significantly improves water resistance, hardness, fullness and gloss; overall good performance, low yellowing - especially suited to outdoor coating.
2. Current product technology
Packaging: single- and two-component, with single-component dominant. Sourcing: imported, foreign brands produced domestically, and domestically developed - mostly the first two. Tested performance:
(1) Appearance: milky white, slightly yellow, or slightly red viscous liquid.
(2) Solid content: generally 30%-45%, much lower than solvent-based.
(3) Water resistance: aliphatic PUD and water-based urethane oil far better than aromatic/acrylic emulsion types.
(4) Alcohol resistance: similar trend to water resistance.
(5) Hardness: acrylic emulsion lowest; aromatic PU medium; aliphatic PUD, two-component PU and urethane oil highest, increasing over time (especially two-component crosslinked), but slower/lower than solvent-based; pencil hardness reaching H is rare.
(6) Gloss: glossy hard to match solvent-based wood coatings, generally ~20% lower; two-component highest, then urethane oil/PUD, acrylic emulsion lowest.
(7) Fullness: affected by solid content; higher solid content gives better fullness; two-component crosslinked better than single-component, acrylic emulsion poorer.
(8) Abrasion resistance: urethane oil and two-component crosslinked best, then PUD, then acrylic emulsion.
3. Application technology of water-based PU paint
As a new green product entering China only in recent years, water-based PU paint's greatest strength is solving domestic consumers' focus on film fullness, feel and hardness, plus heat, scald, alcohol, water and stain resistance; it overcomes water-based wood paint's weaknesses, produces few bubbles during application, is easy to sand, and is little affected by temperature and humidity - laying a solid foundation for full market adoption.
Changzhou Lihe Xu Chemical Technology Co., Ltd. specializes in eco-friendly water-based industrial paints and coatings. For product details, technical data and consultation, please contact us at 13809076780.
