Interaction of Resin, Glass, and ATH in FR Laminate by Mike Mathews, Hexion Specialty Chemicals

Variables Investigated : Different Mean Diameter Particle Size Alumina Tri-Hydrate (ATH) ATH loading levels Glass fiber content

Laminating Technique Low glass with high ATH percentage High glass with low ATH percentage

ATH Particle Packing Variables "Standard" : mean particle diameter of 15.5 micron 60/40 "Efficient" : ratio between 15.5 and 2 microns 60/40 "Coarse" : ratio between 18.5 and 3.5 microns 80/20 "Coarse" : ratio between 18.5 and 3.5 microns

Laminate Construction Materials (Wt.%) Standard Mix Efficient 60/40 Coarse 60/40 Coarse 80/20 FR Resin 48 E-Glass 20 40 ATH, (18.5 µ)   19.2 25.6 7.2 9.6 ATH, (3.5 µ) 12.8 6.4 4.8 2.4 ATH, (15.5 µ) 32 12 ATH, (2 µ)

Property Testing Viscosity / Wet Out Mechanical Flame

Mechanical Testing ASTM D 638 Tensile Peak tensile strength at break Tensile modulus for determining stiffness Elongation at break ASTM D 790 Flexural Peak Flexural strength at break Flexural modulus for determining stiffness

Flame Testing ASTM D 2863 Limited Oxygen Index (LOI) Measures the minimum amount of oxygen in a mixture of oxygen and nitrogen that will just support combustion. Oxygen Index = O2 O2 + N2

Smoke Testing ASTM E 662 (NBS) Measures the specific optical density of smoke (Ds) generated Ds at 1.5 minutes Ds at 4 minutes

Results / Discussion

Brookfield Viscosity (LVT#3 at 50rpm) 20% Glass / 32% Filler / 48% Resin Standard Mix : 604 cps Efficient 60/40 : 580 cps Coarse 60/40 : 616 cps Coarse 80/20 : 562 cps

Brookfield Viscosity (LVT#3 at 50rpm) 40% Glass / 12% Filler / 48% Resin Standard Mix : 309 cps Efficient 60/40 : 294 cps Coarse 60/40 : 306 cps Coarse 80/20 : 291 cps

20% Glass Peak Strengths

40% Glass Peak Strength

Typical Smoke Criteria for Surface Mass Transit Vehicles Ds (1.5 minute) less than or equal to 100 Ds (4.0 minute) less than or equal to 200

20% Glass Fire Properties

40% Glass Fire Properties

Combined Ratings (20% Glass) Smaller the value the better the results   Standard Efficient Coarse (100/0) (60/40) (80/20) Viscosity 2 4 3 1 LOI Smoke (1.5 Ds) Smoke (4.0 Ds) Tensile Flexural Total 11 14 19 10

Combined Ratings (40% Glass) Smaller the value the better the results   Standard Efficient Coarse (100/0) (60/40) (80/20) Viscosity 2 3 1 LOI N/A Smoke (1.5 Ds) Smoke (4.0 Ds) Tensile Flexural Total 11 9

Conclusion Particle Sizing Viscosity , Larger Size Particles Glass % , Small Size Particles Smoke , Larger Size Particles

Conclusion ATH Loading The higher concentration of ATH yields greater resistance to flaming. LOI is not affected by particle sizing but by the amount of ATH and resin in the laminate.

Conclusion Glass Loading Does not effect flame properties Increases mechanical properties