Method and apparatus for wrapping a product, particularly wrapping a bundle of newspapers or magazines in plastic film

A method of wrapping a product, the product being carried on a conveyor system through a plane towards a curtain of film formed in the plane by an upper and a lower film, the curtain accompanying the product and then being auto-sealed behind the product, a film wrapper being produced around the product which, after shearing in the sealing region, is separated from the curtain;

• wherein a deflection member for the upper film is displaced in conjunction with the wrapping operation so that film is supplied to the top of the curtain quickly and substantially without tensile force;
• the method further comprising sensing the height of the approaching product and, in response to the sensing of the height of the approaching product, (1) initiating the displacement of the deflection member at the start of the wrapping operation if the height of the product is less than a certain predetermined value and (2) initiating the displacement of the deflection member at the end of the wrapping operation if the height of the product exceeds the certain predetermined value.

An apparatus for wrapping a product, the product being a stack of newspapers or magazines or a single newspaper or magazine, the apparatus comprising a generally horizontal conveyor (1, 2) with a gap (3), an upper stock (5) for an upper film (6), a lower stock (15) for a lower film (16), first and second deflection members (9, 19) to establish a curtain of film (26) running through the gap (3), the first deflection member (9) being for the upper film (6), the curtain being formed by the upper film (6) and the lower film (16), a sensor (32) for sensing the product, and sealing and shearing means (20, 21) to form a film wrapper around each product and separate it from the curtain, the first deflection member (9) being supported by a displacement member (30) to achieve displacement of the first deflection member (9) in response to the sensing of the product as the product approaches the curtain, the upper part of the curtain thereby being quickly supplied with film while its tensile force is reduced, the first deflection member (9) substantially defining the upper edge of the curtain (26).

An apparatus for wrapping a product, comprising a generally horizontal conveyor (1, 2) with a gap (3), an upper stock (5) for an upper film (6), a lower stock (15) for a lower film (16), first and second deflection members (9, 19) to establish a curtain of film (26) running through the gap (3), the first deflection member (9) being for the upper film (6), and sealing and shearing means (20, 21) to form a film wrapper around each product and separate it from the curtain, the first deflection member (9) being supported by a displacement member (30) for displacing the first deflection member in conjunction with the wrapping operation, the upper part of the curtain thereby being quickly supplied with film while its tensile force is reduced;

• and
• means (33) for sensing the height of a product approaching on the conveyor, the displacement member being responsive to the sensing means (33) and arranged to initiate displacement of the first deflection member at the start of the wrapping operation if the height of the product is less than a certain predetermined value and to initiate displacement of the deflection member (9) at the end of the wrapping operation if the height of the product exceeds the certain predetermined value.