The coated fabric used by ORTLIEB – including all welded seams – continues to resist leaking when exposed to a 100,000 mm column of water! This extreme degree of waterproofing is achieved using a process known as high frequency welding (HFW). Instead of applying heat from the outside, HFW involves the application of high frequency voltage to the objects that need to be welded. The voltage causes the molecules within the various materials to vibrate and, essentially, to generate heat. Softened from within by the heat, the materials are then bonded under high pressure, leaving the welded seam at least as strong as the surrounding material.
The 2-D-welding process is used for flat products like mapcases and document bags, consisting of an upper and a lower side, these are then welded together along the edges. The 3-D-welding process is used for producing three-dimensional products like bike panniers, panniers and drybags.
ORTLIEB bike panniers consist of 3 sections of material that are welded together: the front (1) and rear section (2) are connected / welded to each other by means of a “circumference piece” (3) with an approx. 10mm wide overlapping seam. This is how a three-dimensional product with height, width and depth is created (e.g. Back-Roller Classic).
ORTLIEB drybags consist of one piece cut out of fabric. This piece is welded along a seam into a tube; later the bottom is welded into the bag; this is how a three-dimensional product is created in the case of a drybag.