Apparatus and method of the production of flexible packaging bag

Abstract

Antislip, heat sealable plastic packaging bag (16), formed from an antislip flexible packaging material (35) whose wall (45) has an average surface weight of at most 500 g / m2. The packaging material (35) comprises a multiplicity of randomly distributed, separate antislip protrusions (7) of a first substance. The protrusion height (11) is between 50 microinetres and 10000 micrometres, with an average of top-plan-view aspect ratios of the antislip protrusions (7) being at most 5.0. Some antislip protrusions (7) have a hidden surface portion (12) being a portion of a free surface of the antislip protrusion (7) which the antislip protrusion (7) covers from a viewer in a top plan view of the wall (45). The first substance is a thermoplastic polymer, and the wall's outer surface (46) is of a substance at least somewhat different from the first substance. It is an important feature that the first substance has a melt mass flow rate of at least 0.6 g / 10 min.. An apparatus, for producing the packaging material (35), includes a film blowing die head (24), a cooling air ring (1), and a particle dispersing unit (38) therebetween, for dispersing polymer particles (36) on the bubble neck (21) at a place in, or closely under, an expanding area (25) where the bubble (19) has a divergent shape.