In order to get the good adhesion force of substrates, we have to do the polarization processing. We need to make bottle surface tension not lower than 3.8 x 10-2N/M.
Polarization treatment method is mainly flame treating. Through high temperature makes plastic surface decontaminate, and melt surface membrane layer, thus can improve the surface of the plastic bottles, then improve the surface adhesion performance of ink.
Flame treating is made up of conveyor belt, tapered column, flame nozzle and tank, etc.
Put the plastic bottle into a tapered column, Conveyor belt will move at a constant speed forward. Tapered column begins to turn before running to the front of the flame spray nozzle, , also turns the bottle at the same time, the blue flames will burn the bottlesurface, so that improves the surface of the plastic bottles and the adhesion strength of the ink.
