HS-940 Mold Tool Release Coat

HS-940  is a high temperature-resistant solvent-based Polysilazane, wipe-on application, ambient air cured product that create a covalent bond to the substrate giving it an intrinsic bond to the mold tool surface.  It’s chemical resistant surface allows for multiple pulls with little to no cleaning of the mold unit or components need.  It will not contaminate the finished parts surface as it has “no free silicones,” leaving the part ready for paint or adhesive application.  It’s high temperature operating range of 900+ degrees F makes it the perfect release material for thermal curing resin systems.  It apples thin at 2-3 microns, so multiple application will not measurably change too tolerances.

This is a high-performance, single component, wipe-on, ambient air cured product.  It is an inert (benign) material containing “no free silicones.”  HS-940 has excellent release properties with all the curing temperature resins.

  • Holds pre-preg materials well on vertical layups
  • Lay-up can start with 25-30 minutes after completion of the HS-940 application
  • Multiple pulls are normal and possible with the HS-940 material
  • Multiple applications will not measurably change tool tolerances
  • Works on all metal, graphite, and composite mold tool surfaces

It is a VOC-exempt solvent-based thin film nano-ceramic mold tool release that has “no free silicones”.  Thus it will not contaminate to face side of the composite piece that is in contact with the mold tool.

This coating is applied at approximately 2-3 microns dry film thickness, thus does not alter mold tool tolerances even after repeated applications.  It can operate at elevated temperatures beyond 900 degrees F with no change it its release properties, making it excellent to use with polyimides and similar HT resin formulations.

Cost-effective advantages:

  • Being applied at 2-3 micron and only needing a single coat, allows this material to cover up to 4800+ sq ft/gallon, helps it to be cost effective.
  • Mold tools need little to no cleaning before being returned back to productions, as the surface will retain little or no residue or flashing and is easily cleaned off without the use of scrapers or other tools that may damage the face of the tooling.
  • Ambient cure and fast dry time allows for multiple pulls.
  • Greatly reducing labor costs and tool downtime while allowing for more production turnaround per shift.

Guide >>

HS-940 Properties


Color Clear
Viscosity 12 sec. #2 Zahn
Percent of Solids 12%
Odor (liquid) Slight Solvent
Odor (cured) None
V.O.C. Exempt per CFR 51.100/regulation 8
RoHS Compliant
REACH Compliant
Halogens None
Thermal Stability (cured) 1200+ degrees F (648.8 degrees C)
Conical Bond (1/8 inch mandrel) Passed (ASTM D522-93a)
Cross cut adhesion 5B (ASTM D3359)
Coefficient of Friction 0.03 microns (ASTM D2047)
Specific Gravity 0.889 (ASTM D891-09)
Pencil Hardness 8h (ASTM D3363)
Average applied dry film thickness 2 to 3 microns
Est. Coverage Rate @ 3 microns 4500 sq ft / gal
Transfer to surrounding material Zero (0)
Dry to Touch (time @ ambient) 15-25 minutes