Waterproof Gland

Waterproof Cable Gland (IPX7/IPX8) for Submersible Enclosures

Project Role: Consultant Mechanical Design and CAD Engineer

Project Goal: Developed a robust, reusable cable gland achieving IPX7 and IPX8 waterproof ratings for integration with TPU enclosures. Target applications included VHF radios, microphones, and insulin pumps, requiring reliable submersion protection.

Design Description:

The three-component system comprised:

  1. TPU Base: Injection-molded with a 5mm wide, 1.5mm thick flange for HF/RF welding directly onto the enclosure's exterior. This improved upon a previous seam-welded prototype, enhancing manufacturing efficiency and robustness. A modified buttress thread was designed for easy mold release.
  2. TPU Cap: Injection-molded, engaging with the base's threading to compress the internal seal.
  3. Silicone Sealing Bung: Precision-molded, providing the primary waterproof seal. A central aperture accommodated cables from 2.5mm to 5mm. Different bung sizes were achievable from a single tool. Nominal dimensions were 19mm diameter and 10mm length.

Manufacturing Process:

  • Prototyping: Initial prototypes and low-volume runs (up to 1500 units) utilised a Manumold process for rapid iteration and validation.
  • Production Tooling: A plan existed for a hardened steel injection mold for mass production after successful testing and market validation.

Key Design Innovations:

  • Flange-Based Welding: Improved integration and structural integrity compared to seam welding.
  • Optimized Thread Design: Enabled easy part removal from the mold.
  • Modular Bung System: Accommodated various cable diameters, increasing versatility.
  • Material Selection: Facilitated HF/RF welding to existing products.