SEMICOSIL 961 TC A/B is a silicone 2K gap filler from Wacker, rated 2.3 W/m·K. Typical uses: Automotive electronics, EV/HEV battery assembly, power electronics, consumer electronics. Short answer: we dispense it with a PDP two-component progressive cavity metering pump with a static mixer.
Material at a glance
| Manufacturer | Wacker |
|---|---|
| Type | 2K gap filler |
| Chemistry | Silicone |
| Thermal conductivity | 2.3 W/m·K |
| Mix ratio | 1:1 by weight |
| Viscosity | Part A 130,000 mPa·s, Part B 130,000 mPa·s, mixed 130,000 mPa·s |
| Cure | 300 min at 25 °C or 5 min at 100 °C; pot life 60 min |
| Packages | 30 kg pail/hobbock, 900 g / 300 cc EURO cartridge, 20 oz & 6 oz SEMCO cartridges (sampling only) |
From the manufacturer's published data (source). Always work from the current technical data sheet.
How we dispense it
For a two-component gap filler we start with a PDP two-component progressive cavity metering pump and a disposable static mixer, fed from dual cartridges for lab and low volume, or from pails with a follower-plate pail pump for production. Pump size depends on your shot 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.
- Ratio: each side is metered by its own progressive cavity pump to within ±1%. Check ratio by weighing a shot from each side every week, because filled materials vary from batch to batch.
- Mixing: a disposable static mixer does the mixing. Purge or change it before the material's working life runs out.
- 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.
See our PDP two-component metering pumps, or use the pump configurator.
Frequently asked questions
What pump should I use to dispense SEMICOSIL 961 TC A/B?
For a two-component gap filler we start with a PDP two-component progressive cavity metering pump and a disposable static mixer, fed from dual cartridges for lab and low volume, or from pails 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 SEMICOSIL 961 TC A/B be fed from pails instead of cartridges?
Wacker lists these packages: 30 kg pail/hobbock, 900 g / 300 cc EURO cartridge, 20 oz & 6 oz SEMCO cartridges (sampling only). Cartridges suit lab and low volume. Above that, a follower-plate pail pump feeds the metering pump directly, which cuts container changes and waste.
How do you keep SEMICOSIL 961 TC A/B on ratio?
Each side is metered by its own progressive cavity pump, held to within ±1% per side. We recommend a weekly check: weigh a shot from each side and adjust, because filled materials vary from batch to batch.
Will SEMICOSIL 961 TC A/B 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 SEMICOSIL 961 TC A/B, 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
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SEMICOSIL 961 TC A/B is a trademark of Wacker or its affiliates. Dispense Robotics is not affiliated with the manufacturer; the name is used to describe the material our equipment dispenses.