Coating roll surface configuration for applying liquid sterilant to a moving web

摘要

An apparatus for coating a plastics coated paperboard web with a sterilizing liquid such as hydrogen peroxide, the web adapted to be folded and cut to form aseptic packages for filling with foodstuffs such as fruit juices and milk. The apparatus includes a pair of rolls between which the web is moved and is coated. The lower (applicator) roll of the pair is provided with continuous helical grooves and is partially immersed in a bath of sterilizing liquid. The configuration of the grooved surface of the applicator roll has been found to be critical in meeting coating standards in the field of aseptic packaging. The grooves make a pitch angle of from 5 DEG to 12 DEG with the longitudinal axis of the applicator roll, with a preferred angle of 9 DEG . Either single grooves or crossed grooves may be used, with the land area of this roll being from 60 to 80%. The applicator roll is manufactured from stainless steel (#316). The silicon elastomer of 60 Durometer hardness is bonded to its diameter, the outer cylindrical surface carrying the configuration or pattern of grooves.