Heavy-Build Epoxy Floor Systems: Gloss Control at 60–150 µm DFT
Floor coatings operate at dramatically higher dry film thicknesses than architectural topcoats — epoxy floor systems typically apply at 60–150 µm DFT, polyaspartic at 50–100 µm, and PU floor coatings at 40–80 µm. At these build levels, conventional fine-particle matting agents (d50 3–5 µm) are fully embedded within the coating matrix, providing minimal matting effect. GMATT 300 Series with d50 values of 5.5–9 µm (sub-grades 285 and 290) is engineered for heavy-build floor systems — the larger particle size provides sufficient surface protrusion at 60–150 µm DFT to achieve gloss targets of 10–35 GU at 60°.
Formulation for two-component epoxy floor coatings: add GMATT 300 at 2–4% by weight to the resin (Part A) and disperse with a Cowles blade at 1,200–1,500 rpm for 10–15 minutes before adding the amine hardener. Loading above 5% in epoxy reduces elongation at break (ASTM D638) and can initiate cracking at concrete substrate joints subjected to thermal movement. Target loading within the 2–4% window and adjust sub-grade d50 to hit the specific gloss specification.
Polyaspartic Floor Coatings: Fast-Cure Matting Challenges
Polyaspartic floor coatings have gained market share in commercial flooring due to their 1–4 hour return-to-service time (versus 12–24 hours for epoxy). The matting challenge is driven by the fast cure rate: once the aliphatic diamine activator is mixed with the polyaspartic ester, viscosity increases rapidly, and film leveling must be complete before the coating gels. GMATT 300 Series at d50 5–8 µm must be pre-dispersed in the polyaspartic resin component for a minimum of 15 minutes at 1,200 rpm before activator addition. Pre-blended single-component packs with factory-dispersed GMATT 300 are available for high-volume applicators.
The rapid film formation of polyaspartic coatings also means the silica particle has less time to orient at the surface by gravitational settling. At DFT 50–75 µm, GMATT 300 at 3–4% loading targets 15–25 GU. Surface texture contribution from GMATT 300 in polyaspartic (Ra 10–20 µm) is suitable for commercial flooring but requires supplementary aggregate for industrial anti-slip specification.
Anti-Slip Performance: Matting Agents vs. Aggregate Systems
Industrial floor coatings in manufacturing, food processing, and chemical plant environments must meet anti-slip requirements per EN 13036-4 (pendulum friction) or DIN 51130 (ramp test, R9–R13 classification). GMATT 300 Series at 3–5% loading contributes micro-roughness of Ra 15–25 µm — sufficient for R9 classification (pendulum value >36). For R10 (PV >45) and R11–R13 requirements, combine with coarser aggregate systems.
The most effective floor coating anti-slip system uses GMATT 300 as the base matting agent (for gloss control and micro-roughness) plus 1–3% aluminum oxide or silicon carbide aggregate at 40–80 mesh grit for macro-roughness. This two-component texture approach achieves R11 classification while maintaining the visual appearance of a matte floor coating at 15–25 GU rather than the heavily textured appearance of aggregate-only systems.
Sedimentation Control and Shelf Life in Part A Components
Floor coating Part A components (epoxy or polyaspartic resin) are stored 6–18 months before application. Coarser matting agent grades (d50 5–9 µm) have higher settling velocities than fine-particle architectural grades — a GMATT 300 d50 8 µm particle settles approximately 4× faster in a low-viscosity epoxy resin than a d50 4 µm particle, per Stokes' law. Two strategies prevent settling: (1) combine GMATT 300 with 0.3–0.5% SEMISIL H100 fumed silica to create a thixotropic network that counteracts gravitational settling; (2) use pre-gelled matting agent dispersions (50% solids in compatible resin) that have inherently lower settling velocity due to higher initial dispersion viscosity.
Anti-settling formulations must pass ASTM D869 (10 mL sediment volume maximum) at both 25°C and 40°C accelerated aging (4 weeks) to qualify for commercial product release.
Floor Coatings Matting Agent Specification Guide
DFT and cure chemistry determine optimal GMATT 300 sub-grade selection.
| Parameter | Epoxy Floor (Industrial) | Polyaspartic (Commercial) | PU Floor | Clean Room (Ultra-Matte) |
|---|---|---|---|---|
| Target gloss (60°) | 10–25 GU | 20–35 GU | 15–30 GU | 5–15 GU |
| Recommended d50 | 6–9 µm | 5–8 µm | 5–7 µm | 8–10 µm |
| Loading (% by wt) | 2–4% | 3–4% | 3–5% | 4–6% |
| Surface treatment | Wax-treated | Wax-treated | Wax-treated | Wax-treated |
| DFT range | 80–150 µm | 50–100 µm | 40–80 µm | 60–120 µm |
| Anti-settle aid | SEMISIL H100 0.3–0.5% | SEMISIL H100 0.3% | SEMISIL H100 0.3% | SEMISIL H100 0.5% |
| Recommended grade | GMATT 300 Series | GMATT 300 Series | GMATT 300 Series | GMATT 300 Series |
Frequently Asked Questions
Common questions about floor coatings matting agent applications.
+What matting agent loading is recommended for epoxy floor coatings at 100 µm DFT?
At 100 µm DFT in two-component epoxy floor coatings, load GMATT 300 Series at 2–4% by weight in the resin component (Part A). This range achieves 15–35 GU at 60°. Loading above 5% in epoxy floor coatings reduces flexibility and can cause stress cracking at thermal joints. Always disperse into Part A before adding the amine hardener (Part B).
+How do silica matting agents affect the anti-slip performance of floor coatings?
GMATT 300 Series at d50 5–9 µm contributes Ra values of approximately 15–25 µm — sufficient for R9 anti-slip classification per EN 13036-4 pendulum test. For R10 and above, combine with 1–3% coarse aluminum oxide or silicon carbide aggregate at 40–80 mesh grit for macro-roughness.
+What is the correct matting agent selection for polyaspartic floor coatings?
GMATT 300 Series at d50 5–8 µm is suitable for polyaspartic systems when pre-dispersed in the resin for at least 15 minutes before activator addition. The rapid cure window means film leveling is critical — use a slow-flow resin variant or add a flow agent when matting above 3%.
+Can I use the same matting agent in both waterborne and solvent-borne floor coatings?
Not always. Solvent-borne systems work well with wax-treated GMATT 300 Series. Waterborne floor coatings require hydrophilic grades (GMATT 600 Series) that maintain stable dispersion in aqueous media. Using wax-treated grades in waterborne systems causes floating and gloss streaking.
+How do I prevent sedimentation of matting agents in floor coating Part A?
Combine GMATT 300 with 0.3–0.5% SEMISIL H100 fumed silica to create a thixotropic anti-settling network. Alternatively, use pre-gelled GMATT concentrates. Validate anti-settling per ASTM D869 at 25°C and 40°C over 4 weeks.
+What gloss range do commercial and industrial floor coatings specify?
Commercial floor coatings target 20–50 GU at 60°. Industrial floor coatings specify 10–30 GU for functional matte appearance. Clean room floors, where particle visibility is critical, often require 5–15 GU ultra-matte.
For industrial epoxy floor coatings at 60–150 µm DFT, specify GMATT 300 Series (d50 6–9 µm) at 2–4% in Part A with 0.3–0.5% SEMISIL H100 as anti-settling aid; add coarse aggregate for R10+ anti-slip requirements.