ISO-PUR® K350
Tough elastomer for surface coating
ISO-PUR® K350 is an elastic, cold-curing and slightly-filled 2-component polyurethane elastomer. The compound is used for coating pre-treated rolls of metal, ceramics and various plastics. The product is RoHS compliant according to EU Directives 2011/65/EU (“RoHS”) and 2015/863/EU (“RoHS III”).
Technical data
Resin
Colour
Viscosity (25°C; rot.; 1 s-1)
Viscosity (25°C; rot.; 10 s-1)
Density (23oC)
Blue
Approx. 1100 mPas
Approx. 650 mPas
Approx. 1,12 g/cm³
Hardener
Colour
Viscosity (25°C; rot.; 1 s-1)
Viscosity (25°C; rot.; 10 s-1)
Density (23oC)
Yellow
Approx. 160 mPas
Approx. 140 mPas
Approx. 1,22 g/cm³
Mixture
Mixing ratio resin : hardener
Colour
2,3 : 1 parts by weight
Blue
Density (23oC)
Approx. 1,14 g/cm³
Pot life (23°C)
Gel time (23°C)
Approx. 11 min
Approx. 15 min
Mixed viscosity (25°C; rot.; 1 s-1)
Mixed viscosity (25°C; rot.; 10 s-1)
Approx. 1000 mPas
Approx. 500 mPas
Cured product
Mixing ratio resin : hardener
under standard curing conditions
2,3 : 1 parts by weight
(14 days 23°C / 50% rel. Lf.) unless otherwise stated
Hardness Shore A
(23°C; 14d RT 50% rel. h.)
Hardness Shore A
(23°C; oven curing: 4hRT + 24h80°C)
Approx. 76
Approx. 25
Hardness Shore D
(23°C; 14d RT 50% rel. h.)
Hardness Shore D
(23°C; oven curing: 4hRT + 24h80°C)
Approx. 80
Approx. 30
Long-term temperature resistance
Short-term temperature resistance
Approx. 120°C
Approx. 140°C
Glass transition temperature (midset)
Approx. 6°C
Tensile strength (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23°C)
Elongation at break (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23°C)
Approx. 5,50 N/mm2
Approx. 250%
Tear resistance
(W-specimen; incision; speed: 10 mm/min; 23°C)
Approx. 6,20 N/mm
Water absorption after 28 days
in water (immersion; 23°C)
Approx. 1,40%
Water vapour permeability
(75% relative humidity; 23°C; 1 mm thickness)
Approx. 2,10×10-6 g/(day×mm2)
Storage and transport
Store resin containers dry and airtight at 10 – 35°C. Store hardener containers at 20 – 35°C. Can be stored for at least 12 months in originally sealed containers under the above conditions. Short-term deviations during transport and storage are acceptable.
Cleaning
To ensure good adhesion of the cast resin the customer should individually test the suitability of the involved surfaces. Possible pre-treatments like cleaning, activation processes (plasma process) etc. should also be taken into account. The contact surfaces should be free of dirt such as dust, grease or water. For cleaning we recommend ISO-RC® Degreaser for wipe degreasing or ISO-RC® Flux-Off + ISO-RC® Spraywash for spray degreasing (available in 400 ml spray cans).
Processing
Stir up the resin container thoroughly before use to remove any possible sedimentation. Weigh the resin and hardener in the desired mixing ratio and mix for 1 – 3 minutes (depending on mixed quantity and processing time). Apply suitable mixing speed in order to ensure complete homogeneous mixing without introducing too many air bubbles into the reaction mass. The ideal processing temperature is 20 – 25°C. In general, curing is delayed at lower temperatures and accelerated at higher temperatures. When using a double chamber bag, empty the corners well and knead for 3 minutes. Before casting a homogeneous mass, free of streaks, must be obtained. Then pour immediately and do not scrape the mixing pot. Air bubbles in the reaction mass can be removed before the end of the potlife by evacuating the material or carefully fanning the surface with a hot air gun. Machine casting is also possible.
The EC safety data sheet provides information on safety-relevant product properties.
Hardener component (containing diisocyanate): As of August 24, 2023, appropriate training must be provided before industrial or commercial use.