Blow molding

TPE blow molding is a mainstream processing technology for producing hollow soft products, relying on the unique melt extensibility and elasticity of thermoplastic elastomers. It is mainly suitable for TPE materials with excellent rheological properties such as SEBS and TPU, and is often used to process irregular hollow products like soft hollow bottles, airbags, hoses, and protective hollow sleeves. This process compensates for the shortcomings of traditional rigid plastic blow molding, which feels hard and lacks elasticity, combining the convenience of plastic molding with the flexibility of rubber, resulting in a wide range of application scenarios.

The TPE blow molding process is mainly divided into five stages: plasticizing and parison extrusion, mold closing and parison clamping, air blowing and expansion, cooling and solidification, and trimming and finishing. First, the dried TPE raw material is melted and plasticized in an extruder to extrude a tubular parison. Once the parison reaches the preset length, the mold closes quickly to clamp the parison, and compressed air is introduced into the parison through a blowing needle, using air pressure to uniformly inflate the melt so that it conforms to the inner wall of the mold for forming. Compared with injection molding and extrusion processes, TPE blow molding requires higher melt strength and viscosity stability, and strict control of processing temperature and screw speed is necessary to avoid defects such as parison sagging, parison rupture, and uneven wall thickness.

TPE products formed by blow molding have uniform wall thickness, good sealing, and are resilient and flexible, with excellent tensile resistance, bending resistance, and shock absorption and cushioning properties. Additionally, the products are seamless and have a complete appearance. Moreover, TPE materials can be recycled and reprocessed without vulcanization, making the production process simple and environmentally friendly. With excellent molding effects and performance, TPE blow-molded products are widely used in daily protective items, medical soft hollow accessories, industrial cushioning airbags, and small soft hollow tubes.