FILCO® 389 represents a highly unsaturated polyester resin meticulously dispersed within a non-ionic water dispersion, specifically employed as a film former in glass fiber sizings. Notably, FILCO® 389 does not contain DAP (diallyl phthalate) and is suitable for applications involving food contact. Its appearance is that of a milky liquid. Key product characteristics include high unsaturation, integration of a non-ionic emulsifier within the polymer, stability against hydrolysis and sedimentation, a narrow particle size distribution, and remarkable high mechanical shear stability, even in diluted emulsions.

Functions: Film Former

Chemical Family: Polyesters, Unsaturated Polyester (UPE)

Technical Data Sheet

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Identification & Functionality

Composite Materials Functions

Features & Benefits

  • Highly unsaturated
  • Non-ionic emulsifier built in the polymer
  • Hydrolysis and sedimentation stability from pH 1 to 6 = min. 48 hours
  • Narrow particle size distribution
  • High mechanical shear stability of diluted emulsion
Characteristics of Film
  • Clear
  • Not tacky
  • Fully crosslinked
  • Low solubility in styrene

Applications & Uses

Compatible Reinforcements
Processing Information

FILCO® 389 is suggested as film former for glass fiber sizes for:

  • SMC roving
  • BMC roving


Physical Form
Milky liquid
Typical Properties
ValueUnitsTest Method / Conditions
Solid Content42 - 46%MA145LFE
pH1 - 4-MA148LFE
Viscositymax. 5000mPa.sMA143LFE

Packaging & Availability

Regional Availability
  • Canada
  • Mexico
  • USA

Storage & Handling

Shelf Life
6 months
Storage and Shelf Life Conditions

FILCO® 389 should be stored in closed containers away from direct sun rays, at temperature between +5 and +30°C. In these conditions maximum suggested storage time is 6 months from production, in the original package. After that date product must be rechecked. Prevent from freezing.