The fabric is united with the mineral wool insulating core prior to passage through the curing oven which cures the resin applied to the mineral wool in the spinning chamber.

The multifilament yarn is made from no-set, textured, no oil, polyester and first pretensioned (42) before entering a spinning chamber (56, 58) where it is co-spun with the staple fibers (14) which is made from pima cotton.

The tension is relaxed after passing through the spinning chamber (56, 58) to allow the filaments (50) of the yarn to expand and form a matrix to which the staple fibers (14) can adhere.