Flow wrapping is one of the most widely used methods of packaging, particularly for products such as biscuits, tissues, chocolate bars and tea bags. Flow wrapping is a low cost, economical solution that can handle high volumes of product. For any item that can be pushed along a conveyor belt, flow wrapping offers one of the best packaging methods available.
Flow wrapping is considered to be a hygienic packaging option, as products are well-protected from outside contamination from dust, moisture or UV rays. Products that are flow wrapped avoid direct handling.
A flow wrap machine pushes solid product along a conveyor belt. The packaging material, with a longitudinal seal on the underside, forms a tube to catch the product as it approaches on the conveyor. The film ‘bag’ is then sealed at either end with the product inside.
The end product has a seal at each end and a seam running along the middle of one side. The film should sit tightly around the product, which prevents the product from shifting - and potentially breaking - within the packaging. The ‘tails’ at each sealed end should also be cut to a minimal length by the flow pack machine, to allow more product to be boxed together.
A flow wrap machine operates horizontally, with product passing along a conveyor belt. The packaging material is (usually) mounted above the operating level and lowered to meet the product as it approaches.
Flow wrapping differs from the similar process of overwrapping in one critical way. Flow wrapping needs only seal to itself, whereas overwrapped products must seal both to themselves and to the other side of the film. Products for flow wrapping do not need to be of a minimum height, nor have a flat bottom or sides, which are requirements for overwrapping.
Lower reel flow wrap machines mount the packaging material below, with the lengthways seal on the packaging ‘tube’ facing upwards. Lower reel flow wrap machines are preferable for delicate products, whereas standard flow wrap machines are suitable for more robust items.
Though vertical form fill seal packaging is, in many ways, similar to flow wrapping. However, rather than product being fed horizontally into the pack, with vertical form fill the product falls vertically into the packaging. It is a flexible way to package loose, dry product, such as powder, seeds, beads and some confectionery.
A heat sealable film is taken from a roll and folded around a product. The folded film is then closed using a heat sealing device. Overwrapping is a packaging option that is both attractive and amenable to a wide variety of uses, requiring low energy and low material costs.
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