Polyester Resins
WEP Casting Resin (Water Extended Polyester)
WEP Resin is a unique polyester resin system which forms an emulsion with water to extend the polyester and improve physical properties.
General Information:
Extending the resin with water is an important feature of this resin. As a filler, water is low cost and reduces the overall production cost of the finished part. Water also acts as a heat sink (absorbs heat) making it easy to cast parts without exotherm problems. In addition, the viscosity of the emulsion is low enough that it will pick up minute details in the mold, and the emulsion gels and cures quickly providing rapid mold turnover. A variety of mold materials can be used successfully with WEP resins: Latex, Urethane, and Silicone rubbers are common types--each has its advantages. Casted parts can easily be stained or painted with oil or water based systems.
Casting with WEP Resin Emulsions
WEP resins can be pumped through a continuous mixing machine with catalyzed water, producing a fluid emulsion with a gel time of approximately 5 to 6 minutes. The cast part can be demolded within 8 to 15 minutes, depending upon configuration of the part, the water content and the resin employed. For normal applications, 50% water content is recommended, although WEP resins can be used at higher water levels. Increasing water content from 50% toward 60% produces the following:
• REDUCED STRENGTH
• REDUCED PEAK EXOTHERM TEMPERATURE
• REDUCED COST
• INCREASED EMULSION VISCOSITY
• NCREASED GEL TIME
• INCREASED WATER LOSS RATE
***Water content is shown as a percentage and refers to the amount of water in the finished casting.
Catalyst:
WEP requires NOROX W-60 catalyst. Add 1% of W-60 calculated on the combined weight of both resin and water. Avoid excessive exotherm by reducing catalyst ratio when casting large pieces or when weather is hot.
Typical Properties of WEP Resin:
Color: PURPLE, HAZY
LB/Gal @77F: 8.6
Viscosity, cps: 130
Flash Point PM F: 86
Caution:
Above Mixture must be high speed mixed with a preferable exposion proof motor. Contact Technical Support for more information.