主权项 |
1. The method of producing a non-flammable synthetic wicker, that includes:
a) providing pellets incorporating polyethylene and flame retardant material, b) providing a screw conveyor means, introducing said pellets into the conveyor means and operating the conveyor means while heating the pellets, thereby forming a fluidized mixture and dispersing the flame retardant material throughout the mixture, c) extruding the fluidized and heated mixture in coherent strand form, d) cooling the extruded strand to partly solidify the strand, e) the following materials being also incorporated in the pellets introduced into the conveyor means:
i) foaming agent,ii) anti-oxidant,iii) pigment, f) the pellets consisting essentially of
about 95 weight percent polyethyleneabout 2 to 4 weight percent flame retardantabout 0.1 to 0.2 weight percent foaming agentabout 1 to 2 weight percent pigmentabout 1 to 2 weight percent anti-oxidant, g) and including initially forming said pellets by extrusion of a mixture of powder form materials defined in f) above, h) and including providing a heated barrel having successive interior zones at successively higher temperature, and a screw conveyor rotating in said zones to convey said materials under pressure to an extrusion die at high temperature, and via which a coherent strand is extruded, and subsequently cooled in a coolant bath prior to pellet formation, i) and wherein said zones are maintained at temperatures within the range about 170° C. to about 190° C., j) and wherein three said strands are simultaneously extruded in local linear side-by-side adherent relation with longitudinally linearly elongated wicker appearance, lateral spacing being maintained the same between outer two said strands at opposite sides of a medial strand, along the longitudinal length of the three strands, each of said three strands provided to be rectangular in cross section with flat sides and four right angles at corners so that substantially the entireties of opposite flat sides of a medial strand cohere flatly to sides of the remaining two strands in conjunction with said extruding. |