Dai An Trading & Technical Service Company Limited is a distributor of BAK manufacturer in Switzerland. It is one of the leading manufacturers of plastic welding equipment such as handheld plastic welding machine, extrusion machine, heaters – heaters, air blowers, folding tables and bending. Dai An Trading & Technical Service Company Limited is a distributor of BAK manufacturer in Switzerland. It is one of the leading manufacturers of plastic welding equipment such as handheld plastic welding machine, extrusion machine, heaters – heaters, air blowers, folding tables and bending.