Dispensing DOWSIL TC-4025 Dispensable Thermal Pad

Dow · 2K gap filler (dispensable thermal pad) · 2.5 W/m·K

DOWSIL TC-4025 Dispensable Thermal Pad is a silicone 2K gap filler (dispensable thermal pad) from Dow, rated 2.5 W/m·K. Typical uses: Thermal interface in LED lamps; electrical/electronic protection. Short answer: we dispense it with a PDP two-component progressive cavity metering pump with a static mixer.

Material at a glance

ManufacturerDow
Type2K gap filler (dispensable thermal pad)
ChemistrySilicone
Thermal conductivity2.5 W/m·K
Mix ratio1:1
Cure24 h at 25 °C or 145 min at 40 °C; work time >3 h at 25 °C
Packages2 kg kit

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 DOWSIL TC-4025 Dispensable Thermal Pad?

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 DOWSIL TC-4025 Dispensable Thermal Pad be fed from pails instead of cartridges?

Dow lists these packages: 2 kg kit. 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 DOWSIL TC-4025 Dispensable Thermal Pad 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 DOWSIL TC-4025 Dispensable Thermal Pad 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 DOWSIL TC-4025 Dispensable Thermal Pad, 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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DOWSIL TC-4025 Dispensable Thermal Pad is a trademark of Dow or its affiliates. Dispense Robotics is not affiliated with the manufacturer; the name is used to describe the material our equipment dispenses.