Polyamide spiral seam for seamed papermakers' fabrics

An on-machine-seamable papermakers' fabric, closable into endless form with a pin seam, comprising:

• a system of machine-direction (MD) yarns and a system of cross-machine direction (CD) yarns, said yarns of said system of MD yarns being interwoven with said yarns of said system of CD yarns by a modified endless weaving technique to form said papermakers' fabric in a rectangular shape with a length, a width, two lengthwise edges, and two widthwise edges, said MD yarns extending back-and-forth continuously for said length of said papermakers' fabric between said two widthwise edges, said MD yarns further forming seaming loops along each of said two widthwise edges, said MD yarns being plied/twisted yarns, said plied/twisted yarns therefore forming said seaming loops;
• a first seaming spiral interdigitated with said seaming loops at one of said two widthwise edges of said papermakers' fabric and attached thereto by at least one connecting yarn extending in a cross-machine direction;
• and a second seaming spiral interdigitated with said seaming loops at the other of said two widthwise edges of said papermakers' fabric and attached thereto by at least one connecting yarn extending in a cross-machine direction,
• whereby said papermakers' fabric is joined into endless form by interdigitating said first and second seaming spirals and by directing a pintle through the passage defined by the interdigitated seaming spirals to form a pin seam.