PTFE membrane heat sealing quality testing method

The quality of heat-sealing welding of PTFE membrane materials directly affects the safety and durability of engineering projects. This article discusses methods for inspecting the quality of heat-sealing welding of PTFE membrane materials.

**Visual Inspection:** Observe the weld surface visually or with a magnifying glass, ensuring there are no defects such as bubbles, cracks, or burrs. For transparent PTFE membranes, also check the uniformity of light transmittance at the joint.

**Physical Property Testing:**
**Tensile Test:** Cut weld samples according to standards and test their tensile strength and elongation at break. The tensile strength of a high-quality weld should not be less than 80% of that of the base material.

**Peel Test:** Apply a vertical force to one side of the weld and record the peel force and peel length. The peel strength should reach at least 1.5 MPa.

**Sealing Inspection:**
**Electrical Spark Test:** Suitable for detecting micropore defects in welds. Scan the weld surface with a high-voltage electric spark; if a discharge phenomenon occurs, it indicates a leak.

**Steam-Water Circulation Test:** Apply a pressure of 0.2 MPa to the weldment, alternately introduce steam and water for 10 minutes each, repeat 500 times, and then check for leaks.