For the filling of white LEDs two alternative systems mts/led/* are available. The system mts/led/w is composed of a modular dispensing valve and a media tank with a pneumatic pressure booster, the system mts/led/svwa contains a slider valve instead of the modular valve (see image). Adhesive with filler, usually a two component (2K) adhesive, is conveyed to the dispensing valve and applied to the LED.
To make full use of the pot life of the 2K adhesive, it is filled into 30 ccm cartridges which can easily be replaced once they are past their pot life. The cartridge is mounted horizontally and rotatable in order to avoid the sedimentation of the filler material in the cartridge. The mechanically generated pressure in the media tank, which provides up to 18 bar feed pressure, ensures there is no contact with air so that no gas is absorbed by the medium.
marco uses a special piston to optimise pressure transfer to the fluid. A static mixer homogenises the medium once again as it passes through the fluid body, shortly before it is dispensed, ensuring sufficient mixing in the finished product to avoid light scattering and maintain constant and equal converter content. The mts/led/* system was specially developed by marco for use with highly abrasive media. The modular valve (system mts/led/w) does not close completely during the dispensing process. As a further advantage the slider valve system (system mts/led/svwa) is less vulnerable for abrasion due to the principle of the slider valve.
The advantages of both systems are twofold: the product life increases due to less friction on the sealing seat and the filler particles are not destroyed.