Wrapping pulp bales - by automatically folding and sticking plastic film wrappers to avoid using wire ties

摘要

Bales of paper pulp are wrapped between >=2 layers of film fed over and under the bale(s), using adhesives to secure the flaps under a pressure of >0.7, pref. 2.1-4.2, kg./cm2 maintained or >5, pref. 10-20, secs. Pref. the upper surface of the bale is compressed by 1, pref. 0.21-0.7 kg./cm2 to prevent it bulging while the glaps on the sides and ends are under pressure. Pref. the adhesive used is ultimately compatible with paper processing and use, is pref. a protein type gum, esp. collagen, or based on PVAc or a low mol. wt. melt adhesive. Pref. the platens are coated or covered with 'Teflon' (RTM) or a PTFE impregnated fabric to ensure release.