Braid tube reinforced hollow fiber membrane spinneret 2 holes

When MEM-TEK purchased this spinneret, they were focused on R&D and pilot scale trials of "braid tube reinforced hollow fiber membranes," primarily aimed at treating high salinity industrial wastewater and advanced purification of municipal drinking water.  Previously, with standard spinnerets, they frequently experienced issues such as non uniform PVDF flow, corrosion inside the spinneret cavity, and breakage of the braid guide needle.  These problems severely affected the stability of membrane performance data and delayed project timelines.  Therefore, when procuring Trustech 2 hole braid tube reinforced hollow fiber membrane spinneret, MEM-TEK specified four core technical requirements tailored to their application:

First, corrosion resistance of spinneret materials: Because PVDF dopes and solvent formulations are highly corrosive, MEM-TEK required long term corrosion resistance with no rusting or wear inside the cavity.  (With their previous standard stainless steel spinneret, noticeable internal wear appeared after only three months, causing membrane diameter deviations up to 15%.)  Trustech spinneret, made of brand stainless steel and treated with heat processing, effectively solved this issue—after one year of use, the internal surface remained smooth, and membrane diameter deviation was controlled within 4%.

Second, strength and reliability of the braid guide needle: The braid tube acts as the reinforcement skeleton of the hollow fiber membrane and must pass through the central guide needle during spinning.  Previously, after about 500 hours of continuous use, the needle tended to bend or break, requiring frequent replacement;  each replacement caused 2–3 hours of downtime.  Through structural optimization and refined manufacturing, Trustech achieved zero instances of bending or breakage over one year of operation, improving equipment uptime by nearly 7%.

Third, uniform PVDF flow between the two holes: The 2 hole design enables simultaneous production of two fibers to improve pilot efficiency.  MEM-TEK required the inter hole PVDF flow rate difference to be no more than 5%—exceeding this threshold would cause significant differences in flux and rejection between the two fibers, compromising the validity of test data.  Trustech fluid dynamics team optimized the spinneret flow channels via simulation and precision machining on a 5 axis CNC, keeping the actual inter hole PVDF flow rate difference within 2%, thereby ensuring data accuracy.

Fourth, meeting hollow fiber concentricity standards: Concentricity (alignment between the braid tube and the outer PVDF layer) directly affects pressure resistance and service life—poor concentricity creates thin spots that can fail under pressure.  MEM-TEK required spinneret concentricity within 0.005 mm.  Leveraging Trustech precision assembly (as reflected in the manufacturing accuracy: assembly concentricity up to 0.003 mm), all fibers produced with this spinneret consistently met the required concentricity, earning strong approval from the R&D team.

After one year of continuous operation (total runtime exceeding 3,000 hours), the spinneret maintained excellent performance: produced fibers showed stable water flux and high rejection, and the spinneret exhibited no abnormal wear or corrosion.  To acknowledge the product quality, MEM-TEK photographed the spinneret in normal operation and the qualified fibers, stating that Trustech "spinneret has become a key piece of equipment enabling the smooth progress of MEM-TEK’s membrane material R&D program."

In March 2017, MEM-TEK indicated that, as the project advanced, the 2 hole spinneret could no longer meet larger pilot scale needs.  Based on the trust established with the 2 hole unit, they immediately ordered a higher efficiency 4 hole braid tube reinforced hollow fiber membrane spinneret, requiring compatibility with existing PVDF processing equipment and the same high precision as the 2 hole spinneret.  Trustech customized a 4 hole spinneret with a symmetric flow channel design;  it was successfully delivered in April 2017 and has operated stably to date.