Method of testing the strength of seams in plastic sheets

Abstract From the Canadian patent

Current state-of-the-art requires welded seams between adjacent sheets of material, e.g. polyethylene to be tested for leaks using vacuum, ultrasonic or low pressure air techniques. In general, the devices used are somewhat complicated and consequently expensive. A relatively simple method of determining the strength and integrity of a welded seam between layers of plastic which are, interconnected by welding to form a sealed passage including the step of injecting air or another gas into the passage under sufficient pressure that any weakness in the seam results in visible distortion or total separation of the plastic in the area of such weakness.