Air permeable flexible web carrying active particles fixed by adhesive dots - obtd. by applying active particles to wet adhesive dot pattern onto the support in extended state and then shrinking the coated web

摘要

Flexible sheet material has air-permeable web shaped carrier onto which active particles which act upon or react with harmful and/or odorous substances are attached, separately from each other, esp. by adhesive printed in a pattern of dots. The carrier web is made of material which is extendable or which can be shrunk by physical and/or chemical treatment, and the carrier is either stretched before application of the adhesive dots and then released, or is shrunk by the appropriate treatment after application of the adhesive dots. USE/ADVANTAGE - The process allows the adhesive to be applied at the max. rate possible by rotary screen printing (ca. 0.6 mm aperture dia., ca 30 dots per 2.54 x 2.54 cm2) without the adhesive dots running together and reducing the air permeability of the support. After application of the active substance (eg an adsorbent material or catalytic material) to the still wet adhesive, the adhesive is dried and the carrier is either allowed to contract or is shrunk to give a material with a larger number of active substance particles per unit of area whilst retaining good air permeability. The prods. are useful e.g. in the prodn. of protective clothing for protection against gaseous and liq. harmful and/or odorous substances (claimed)