GB1419581A - Wrapping of products - Google Patents

Abstract

1419581 Wrapping articles D A NORR and R C NORR 22 Jan 1973 3092/73 Heading B8C [Also in Divisions F2 and B5] An article to be wrapped is placed on a heat shrinkable sheet 252 moving along a conveyer 212, one half of the sheet is folded over the article and over the other half of the sheet, and the edges of the sheet are sealed together and the sheet shrunk about the article in a hot air chamber. The article may be a frozen meal slice which is fed from a dispenser to a conditioner which removes the frost from the slice and adds a film of water which, when the package is refrozen, binds the sheet to the slice. The article dispenser comprises an inclined supporting surface 10, 15, 11 (Fig. 5) having slots 16, 17 through each of which a pusher plate 45, (44) extends. Each plate is mounted on a slide (34) or 35 movable along a rectangular bar 31 or 33 by a pin on a chain 24, 25. The meat slices are stacked against the plates. When a slice falls off the top of surface 10, 15, 11 down an apron into the conditioner a switch is actuated to stop the motor driving the chains and to brake the chains. When one plate is exhausted it is pushed back down its bar and a new supply of slices inserted, while the other plate takes over supplying the slices. In the conditioner each slice is pushed by bars 321 (Fig. 11) on chains 320 through a curtain 322 into a chamber 323 where water or hot air is sprayed thereon. The curtains 322 may be slit. A web of wrapping material 229 (Fig. 17) is unwound by a driven roller 231 which has an anti reverse mechanism (Fig. 22, not shown) on to a conveyer belt 212 and is transversely severed by a rotating electrically heated blade 257 coated with P.T.F.E. When a slice falls on to a cut wrapper and passes an electric eye 415 a blast of air issues from a manifold 406 to fold half of the wrapper over an arm 403 and over the top of the slice. In the hot air chamber 504 the slices are sandwiched between a lower belt 502 and an upper belt (505) while hot air from units 541, 542 blow diagonally across the belts to the inlets of the opposite units to shrink and seal the wrappers and form a tear rib where the opposing edges meet. The two belts may be formed of a fibre-glass mat dipped or coated on each side with a layer of silicone rubber. The upper belt may have an inside layer of polyethylene terephthalate bounded to the silicone rubber by a silastic adhesive. Each unit comprises a fan 545, electric elements A, B, supplementary elements C, thermostatic switches TH1-TH4 and a nozzle 547. The upper run of the upper belt passes through a chamber where it is cooled by passage over a platen having fins cooled by a flow of air. Control circuits for the apparatus are described.