G-781 is a silicone 1K gap filler (heat cure) from Shin-Etsu, rated 2.60 W/m·K. Typical uses: Electronics requiring thermal dissipation. Short answer: we dispense it with a PCP progressive cavity pump.
Material at a glance
| Manufacturer | Shin-Etsu |
|---|---|
| Type | 1K gap filler (heat cure) |
| Chemistry | Silicone |
| Thermal conductivity | 2.60 W/m·K |
| Viscosity | 99 Pa·s |
| Cure | 1 h at 105 °C |
From the manufacturer's published data (source). Always work from the current technical data sheet.
How we dispense it
For a single-component gap filler we start with a PCP progressive cavity pump, fed from a cartridge for lab and low volume, or from a pail with a follower-plate pail pump for production. A progressive cavity pump meters by volume, so dot and bead size stay consistent. Pump size depends on your dot or bead size and cycle time.
- Abrasion: the ceramic filler that carries the heat wears pumps out. We use tungsten carbide rotors and wear-resistant stators and run the pump slowly, at 8 to 12 rpm, for long wear life.
- Dispense pattern: gap fillers are squeezed between the part and the housing, so the pattern (dots, lines or a star) decides coverage and whether air gets trapped.
- Heat cure: the material is stable at room temperature in the pump and cures in the oven after assembly.
See our PCP progressive cavity pumps, or use the pump configurator.
Frequently asked questions
What pump should I use to dispense G-781?
For a single-component gap filler we start with a PCP progressive cavity pump, fed from a cartridge for lab and low volume, or from a pail with a follower-plate pail pump for production. Pump size depends on your shot or bead size and cycle time; send us those and we will size it.
Can G-781 be fed from pails instead of cartridges?
Cartridges suit lab and low volume. Above that, a follower-plate pail pump feeds the metering pump directly, which cuts container changes and waste.
Does G-781 need mixing?
No. It is a single-component material, so there is no mixer and no ratio to hold. The job is accurate, repeatable volumetric metering, which is what a progressive cavity pump does.
Will G-781 wear out the pump?
Thermally conductive fillers are abrasive. With tungsten carbide rotors, wear-resistant stators and pump speeds of 8 to 12 rpm, stators typically last 6 to 12 months and rotors up to 24 months, and a pump rebuild takes under an hour.
Talk it through with us
Running G-781, or about to? Send us the technical data sheet, your bead or shot size and your cycle time, and we'll recommend a pump and feed system. We can run an application test on your material before you buy. Contact us
Related materials
- SDP-5040 A/B · Shin-Etsu, 2K gap filler
- G-1000 · Shin-Etsu, 1K gap filler (moisture cure)
- BERGQUIST GAP FILLER TGF 4000 · Henkel Bergquist, 2K gap filler
- BERGQUIST GAP FILLER TGF 3600 · Henkel Bergquist, 2K gap filler
- BERGQUIST GAP FILLER TGF 4400LVO · Henkel Bergquist, 2K gap filler (low volatility)
- BERGQUIST GAP FILLER TGF 4500CVO · Henkel Bergquist, 2K gap filler (controlled volatility)
All thermal interface materials · Materials we've dispensed
G-781 is a trademark of Shin-Etsu or its affiliates. Dispense Robotics is not affiliated with the manufacturer; the name is used to describe the material our equipment dispenses.