FILCO® 358 is an easily dispersible unsaturated polyester resin in water, presenting as a yellow-amber, viscous liquid. Specifically recommended as a film-former for continuous filament mat (CFM), FILCO® 358 is typically applied as a water micro-colloidal emulsion to glass fibers. Benzoyl peroxide can be introduced as an initiator in its application.

Functions: Film Former

Chemical Family: Polyesters, Unsaturated Polyester (UPE)

Compatible Polymers & Resins: Unsaturated Polyester (UPE)

Technical Data Sheet

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Enhanced TDS

Identification & Functionality

Features & Benefits

Materials Features
Characteristics of Film
  • Clear
  • Compatible with unsaturated polyesters and other thermosets
  • Highly crosslinked
  • Low yellowing at high temperature
  • Insoluble in styrene

Applications & Uses

Compatible Polymers & Resins
Compatible Reinforcements

FILCO® 358 is suggested as film-former for continuous filament mat (CFM)

FILCO® 358 is normally applied as water micro-colloidal emulsion to glass fiber. Benzoyl peroxide can be added as initiator. Emulsion of FILCO® 358 is made as follows:

  • FILCO 358 5 pbw
  • Benzoyl peroxide paste 50% 0,1 pbw
  • Water 94,9 pbw

Add benzoyl peroxide to FILCO® 358 and mix thoroughly; Pour water slowly into FILCO® 358 while stirring at room temperature. The very fine and stable emulsion formed is ready to be applied to glass fiber. Glass treated with FILCO® 358 is stoved at minimum temperature of 150°C to evaporate water and cure FILCO® 358


Physical Form
Yellow - amber viscous liquid
Typical Properties
ValueUnitsTest Method / Conditions
Viscosity (at 25°C)15000mPa.sMA041LCP
Acid Number10mg KOH/gMA018LCP
Gel time (at 80°C)8minutesMA130LCP

Packaging & Availability

Packaging Type
Regional Availability
  • Canada
  • Mexico
  • USA
Packaging Information

FILCO® 358 is supplied in steel drums with polyethylene liner, net weight kg 200.

Storage & Handling

Shelf Life
12 months
Storage and Shelf Life Conditions

FILCO® 358 should be stored in closed containers away from direct sun rays, at a temperature between +5 and +30°C. In these conditions, maximum suggested storage time is 12 months from production, in the original package. After that date product must be rechecked.