Industrial Applications

Kaolin for Fiberglass

A functional mineral filler for GRP/FRP composite resin systems.

Home / Applications / Fiberglass
Previous: Construction Next: Ceramics

Kaolin for Fiberglass

Fiberglass-reinforced polymer (FRP/GRP) composites — used in boat hulls, building panels, pipes, and automotive parts — require mineral fillers in the resin system to reduce material cost, improve stiffness, and enhance surface properties.

UT-WHITE works as an inorganic mineral filler in unsaturated polyester and vinyl ester resins used in GRP/FRP composite manufacturing. Its D50 4.571 µm and low oil absorption (0.468 g/g) allow high filler loading while keeping resin viscosity workable. The platey particle structure reduces resin shrinkage during cure and improves barrier properties in composite laminates.

  • Mineral filler in unsaturated polyester resins for GRP/FRP composites
  • Reduces resin cost at high filler loading with low oil absorption (0.468 g/g)
  • Improves Melt Flow

From Powder to Fiber

Kaolin Input 1500°C MELT Alumina + Silica Fusion Platinum Bushing Continuous Strand

UT-WHITE provides mineral filler loading in composite resin systems

Performance Characteristics

Low Oil Absorption (0.468 g/g)

Allows high filler loading in unsaturated polyester and vinyl ester resin systems while keeping viscosity workable for hand lay-up and spray-up processes.

Platey Barrier Structure

UT-WHITE's platey particles improve barrier properties in composite laminates, reducing resin permeability and surface cracking during cure.

Resin Compatible

Chemically inert and compatible with unsaturated polyester, vinyl ester, and epoxy resin systems used in GRP boat hulls, panels, and piping.

Recommended Grades

Grades for fiberglass and composite applications, providing the controlled chemistry and low iron content essential for high-transmission glass fibres.

UT-WHITE High Brightness Kaolin

UT-WHITE

UT-WHITE is a natural hydrous kaolin with 96.6% ISO brightness, ground to D50 4.571 µm using alumina ball milling to prevent iron contamination. Acts as a low-cost extender and surface-smoothing filler in unsaturated polyester resin and fiberglass composite systems.

Brightness96.6%
SiO272.2%
Al2O313.7%
pH Value8.0
Oil Adsorption (g/g)0.468
Median Size (D50)4.571 μm
Particle Size400-1200 Mesh
Download Spec Sheet
UT-WASH Precision Kaolin
Coming Soon

UT-WASH

A washed, low-grit grade for composite resin applications requiring reduced iron content and tighter particle size control for surface-finish critical GRP/FRP laminates. Consistent particle distribution, meeting the strict purity demands of electronics and structural composites.

ProcessPrecision Washing
Target GritZero (0.000% on 400 Mesh)
Target WhitenessHigh (94%+)
Purity LevelLess Contamination
Primary UseCeramics & Precision Coatings
Request Early Access
UT-ULTRA Calcined Kaolin
Coming Soon

UT-ULTRA

Our upcoming ultra-pure calcined grade targeting optical and specialty glass fibre applications where iron content must be near-zero. Designed for solar glass, high-transmission optical fibres, and advanced aerospace composites.

ProcessFull Calcination
Target WhitenessExtremely High
Target QualityMedical Grade Sterile
Impurity LevelZero Contamination
Primary UseOptical & Specialty Glass Fibre
Request Early Access

Start Your Inquiry

Factory direct pricing for local and international orders. Darson exports kaolin FOB Bangkok to buyers across Thailand, Bangladesh, Malaysia, India, and Southeast Asia.

We will contact you back as soon as possible.

Inquire: sales@darson.co.th
Have a chat: +66 65 393 2426
Come visit: Nakhon Pathom, Thailand
Darson
<