Investigation of Plastic Film Welding for Packaging Applications

Plastic welding is critical in the production of flexible packaging, where strong seals are required under diverse material and geometric constraints. This study explores two industrially relevant welding processes: port welding, in which a rigid plastic port is thermally bonded to a flexible IV bag film, and bag sealing, where two identical thermoplastic layers are impulse welded to form a pouch. Each process presents distinct fluid-thermal challenges and different approaches were taken. Port welding involves joining dissimilar materials via heated die pressing, requiring sustained conduction and mechanical compliance. Bag sealing instead uses a resistive nichrome wire to induce rapid, localized melting and fusion under pressure. We conducted experimental trials to optimize parameters such as time, temperature, and force for each method, and developed simplified thermal models to predict interface heat transfer. This comparative analysis supports the design of plastic welding systems.