... machine. 3.High quality Ultrasonic Plastic Welding Machine Used on Three-side Sealing Machine 1. Usage: PE, PP, PVC, OPP ... material such as plastic bag machine,can be equipped with three-side sealing machine, ziplock bag machine, etc.2. Features:( ... without preheating, convenient to produce quickly.(5) Time control using three-digit dial code switch, adjustable 1 / 100 seconds precision, easy ...