Prior art seaming elements (e.g. WO 2010/121360 to Manninen) include nonwoven seaming elements which are formed from an oriented polymer film. One of a pair of such seaming elements can be attached at each end or edge of a textile to be joined, and looped portions at the free edge regions of the two elements can be interdigitated to provide a channel suitable for receiving a securing means such as a pintle. The dimensions for the seaming elements are selected so as to be compatible with the textile to be seamed, in particular as to thickness so as to minimize or avoid any discontinuity at the seaming area.
It has now been found that a seaming element can be constructed so as to provide two or more looped regions, thereby creating at least two channels across the seam, which allows for improved distribution of the tensile load across the element. The element can be constructed from two or more layers of an oriented polymer film, so that the same total element thickness can be obtained using thinner film, which allows for significantly improved biaxial orientation and thus maximization of the physical properties, in particular tensile strength. In addition, thinner films can better accommodate tight (smaller) bending radii and are thus better able to successfully wrap smaller diameter pintle pins without suffering mechanical failures such as cracking or other fatigue related issues. Alternatively the element can be constructed as an extruded body having two or more looped regions and a total body thickness suitable for the intended end use.
The seaming elements of the invention can be secured to the seamable end or edge of the textile by any suitable means, including bonding, either to compressed yarn ends of a woven textile, or to appropriate selected surfaces of a non-woven textile, including a textile comprising one or more layers of film.
It has further been found that the channels can be dimensioned so as to provide sufficient space in which the free ends of pintles can be turned back into the channel to secure the ends.