For accurate dispensing from a cartridge based system it is important to keep the cartridge under pressure and have some sort of outlet valve control the shot. Without the valve, the cartridge will balloon and shrink each time it is pressurized which may cause the shot being dispensed to be off-ratio. If both sides balloon at different rates the flow from each cavity will not be synchronized and the ratio will be inconsistent. For small shots this can be very significant.

An outlet valve overcomes this issue. The cartridge is pressurized once so it is fully expanded, and the outlet valve opens and closes as required to make the deposit, ensuring an accurate ratio. A controller with a timer can be used to open and close the valve for a preset time to determine shot size. Traditionally, single component pinch-tube valves have been used for the valve function. These are fitted on the end of special static mixers with luer-locking devices. The tube that runs through the pinch-tube valve is continuous so that the valve is not contaminated with reactive resin. At the end of the run the static mixer and pinch tube are removed and discarded.

Concern about the environment has made minimizing waste a top priority. This is where DTV technology comes in. Our "DTValve" is a very small dual component valve that receives liquids from dual cartridges and keeps them apart until presented to the mixer. The mixer is the only disposable component. This is a very simple valve with one moving part and two O Ring seals. Fluid paths through the valve are disposable and can be changed quickly should they become contaminated with mixed resin.