Apparatus and methods for producing shrink wrap packaging

摘要

An apparatus (10) is disclosed including a web of film (20) extending between first and second pairs of pinch rollers (12-15) and onto a vacuum table (18). A rotary cutter (46) positioned before the first pair of pinch rollers (12, 13) includes laterally extending and spaced knives (52) for creating cuts (54, 58) in the film (20) which expand into vent openings (54') positioned over the sides (68) of the product (72) when the film (20) is wrapped around and shrunk upon the product (72). A further rotary cutter (30) positioned between the pairs of pinch rollers (12-15) includes a cut-off knife (36) and first and second blades (44). The cut-off knife (36) creates a cut (60) in the film (20) to form a single sheet of film (20) and includes notches (38) in its cutting edge to form tie strips (62) connecting the single sheet to the web of film (20). The tie strips (62) are broken after the cut (60) leaves the second pair of pinch rollers (14, 15) since the speed of the film (20) on the vacuum table (18) is greater than the peripheral speed of the first pair of pinch rollers (12, 13) at their abutment. The blades (44) cut perforations (56) in the film (20) which extend between the bullseye openings (78) in the shrink wrapping and are positioned over the top (66) of the product (72). Thus, the shrink wrapping can be torn by pulling the film (20) between the perforations (56) to allow ease of removal of the product (72) from the shrink wrapping.