Production Process Of Electrofusion Tees

As a key component in piping systems for multi-directional branching, the performance and reliability of electrofusion tees highly depend on a rigorous production process. This process encompasses multiple stages, including raw material preparation, mold design, injection molding, heating element embedding, quality inspection, and packaging. Each step requires strict control to ensure precise product dimensions, uniform material composition, and stable heating parameters, meeting the high standards required for engineering applications.

 

Production begins with raw material preparation. High-density polyethylene (HDPE), polypropylene (PP), or modified engineering plastic granules are selected, meeting the requirements for melt flow index, density, and environmental resistance. Upon arrival at the factory, raw materials are screened and dried to remove moisture and impurities, preventing bubbles or strength defects during molding.

 

Mold design and manufacturing are fundamental to molding quality. High-precision steel molds are fabricated based on product specifications and structural forms (such as T-shapes, Y-shapes, and branch pipe angles) to ensure smooth transitions between the main pipe and branch pipe flow channels, uniform wall thickness, and pre-set positioning grooves and wire channels at the heating element embedding locations to prevent deviations in subsequent processing.

 

The injection molding process uses a specialized injection molding machine to heat pre-treated plastic granules to a molten state and inject them into a closed mold cavity under high pressure. Process parameters such as injection pressure, holding time, and cooling rate need to be optimized based on material properties and product structure to ensure a smooth surface, dense internal structure, and dimensional tolerances that meet standards.

 

The heating element is embedded immediately after molding. Pre-formed spiral or mesh-like resistance wires are placed in the mold at predetermined positions or embedded into the inner wall of the pre-formed tube using specialized equipment. The resistance wires are mostly made of nickel-chromium alloy, requiring stable resistivity and high-temperature resistance. After embedding, they are fixed with high-temperature insulating resin or a plastic skeleton to ensure accurate positioning and electrical safety.

 

Subsequent heat treatment and cooling are performed to ensure a strong bond between the plastic and the heating element and to eliminate internal stress. The cooling process must be uniform and slow to prevent warping or cracking due to temperature differences.

 

Quality inspection is conducted throughout the entire process, including visual inspection, dimensional measurement, resistance value determination, pressure resistance testing, and melt bonding simulation tests to ensure the product meets industry standards. Qualified products are labeled, packaged, and protected before being stored to ensure they are not damaged during transportation and storage.

 

The overall process relies heavily on precision molding and reliable embedding of heating elements. Through standardized operations and strict quality control, electrofusion tees achieve stable connection performance and a long service life, providing a solid guarantee for pipeline projects.