FILCO® 657 is an unsaturated polyester resin in powder form that includes a catalyst and an antiblocking agent. Available in various formulations such as FILCO® 657 (approximately 1% catalyst) and FILCO® 657 (around 2% catalyst), it's recommended as an insoluble binder specifically tailored for producing Continuous Filament Mat (CFM). Its versatile applications encompass suitability for hot or cold pressing, vacuum and injection molding, as well as pultrusion processes.

Polymer Name: Thermoset Polyester

Chemical Family: Polyesters

Processing Methods: Injection Molding, Pultrusion

Technical Data Sheet

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Identification & Functionality

Chemical Family
Composite Materials Functions

Applications & Uses

Composites Processing Methods
Processing Information
  • FILCO® 657 is recommended as unsoluble binder for the production of Continuous Filament Mat (CFM), for application in hot or cold press, vacuum and injection molding, pultrusion.
  • 4-10% on weight of the mat is normally used. The tensile strength of the mat obtained depends on the binder content and the curing rate of FILCO® 657.
  • Curing cycle depends on the oven conditions; the mat shall remain in a hot air circulating oven at 200-220°C for at least 90 seconds.
  • Temperatures below 200 or above 240°C are not advised: below 200°C because of risk of lack ofcuring, above 240°C as yellowing might occur.


Physical Form
Off - white powder
Typical Properties
ValueUnitsTest Method / Conditions
Glass Transition Temperature (Tg)104°F-
Catalyst Content0.5 - 2%-
Acid Number40mg KOH/gMA018LCP
Particle Size Distribution
ValueUnitsTest Method / Conditions
Particle Size (>425 μm)max. 4%MA123LFE
Particle Size (>250 μm)41%MA123LFE
Particle Size (>150 μm)32%MA123LFE
Particle Size (>75 μm)20%MA123LFE
Particle Size (>45 μm)max. 6%MA123LFE
Particle Size (Passing Through)max. 3%MA123LFE

Packaging & Availability

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

FILCO® 657 is supplied in 125 kg fiber drums.

Storage & Handling

Shelf Life
6 months
Storage and Shelf Life Conditions

FILCO® 656-1 should be stored in closed containers away from direct sun rays and source of heat, at temperature below 25°C. In these conditions, maximum suggested storage time is 6 months from production, in the original package. After that date the product must be rechecked.