Process for the manufacture of a non-woven product having high shear strength and dimensional stability

摘要

Spunlaid products are provided especially for the manufacture of substrates for polyvinyl chloride coated structured floor coverings. These products consist of crimpfree polyester filaments which are laid down and bonded. Bonding is carried out first by needling at 80 to 300 stitches/cm2 to a stitch depth of 11 to 20 mm. After needling, impregnation is carried out using a binder liquor consisting of an aqueous dispersion of a copolymer containing from 47 to 59 weight % of styrene from 33 to 45 weight % of butadiene from 3 to 4 weight % of acrylic acid from 3 to 4 weight % of acrylic acid amide and small amounts of emulsifiers. The binder liquor may also contain the said copolymer and, in addition, from 0.5 to 2 weight % (relative to the copolymer) of a melamine/formaldehyde precondensate etherified with methanol which was prepared using at least one acidic catalyst.