Flow wrapping is used extensively throughout a number of industries, especially confectionery. Flow wrapping is when the product to be packaged is run continuously into its packaging.
The packaging material, usually a plastic film, is pulled off a reel into a folding station. The folding station converts the flat sheet into a tube, though this tube can be square or rectangular and of different sizes. The packaging material has a lightweight contact adhesive on its underside, so that when it is formed into the tube, the adhesive holds the tube shape together.
After the product is feed into the tube, the open end is crimp sealed with the help of the adhesive already on the underside of the packaging material. The now fully packaged product continues flowing along the line to be collated and packaged into larger containers or boxes whilst the next product piece moves into its tube ready for crimp sealing.
The very nature of the flow wrapper means that the whole operation is quite fast. It lends itself to products such as chocolate bars, where the item to be packaged is uniform in size and shape and is a discrete piece.
The areas where Impreglon can improve the performance and reduce the maintenance cost of flow wrappers are as follows:
Application:
Guide/idle rolls used to transport and guide the packaging material from the unwind reel to the folding station.
Problem:
The adhesive used on flow wrappers is called cold seal. It will seal itself to itself with just light crimping pressure. Although the adhesive is lightweight and is only applied by the packaging material manufacturer where it is needed, it does come off onto the guide/idle rolls. In a manufacturing environment where the temperature is not kept below approximately 18*C, then over a period of a several weeks with continuous operation, the glue build up on the rolls is sufficient to warrant them being cleaned. Obviously this means the flow wrapper has to be stopped.
Solution:
PC40511/4001F. Experience has shown this coating to last at least three years in a continuous operation with no cleaning. Furthermore its traction properties ensure there are no tracking problems. It can be applied to both metallic and glass fibre rolls.
Application:
Folding station components used to create the tube into which the product is placed. These components will vary by machine design and according to the shape and size of product being packaged.
Problem:
The main issue is one of friction. Modern packaging materials are printed films and an effect the marketing people like to achieve is that of metallised film. Metallised film can be a high friction material and so having a low friction coating on the folding station components would give an obvious advantage. Wear also needs to be considered.
Solution:
PC60321/XP1240 has been proven time and again where low friction and hard wearing properties are required. The lifespan will vary according to the film being used but one to two years should be expected.
Application:
Folding station components that see the product being packed. Problem:
Products such as chocolate will build up on the inside surfaces of folding station components. The issue here is one of uniform flow. If the product is not flowing correctly into the packaging material tube, then the flow rate is slowed and rejects are created which in turn cause a product back log in the line feeding the flow wrapper.
Solution:
The coating solution depends upon the product being packaged. In the case of chocolate PC30302/2018 has been proven to be successful. There may be instances where both this solution and PC60321/XP1240 need to be applied onto reverse sides of the same component.
Application:
Date stamping carried out by high speed ink printing.
Problem:
Ink build up can occur on nearby components which can be seen as a health and quality issue. It has also been known for ink build up to transfer back onto the packaged product, which is clearly a quality problem.
Solution:
TC1501F is well proven for its ink non-stick properties. Depending upon the amount of wear taking place, one may wish to use PC30302/1501F. Lifespan is usually long unless there is direct contact with the moving product in which case wear will shorten the coating life.
Application:
Creation of the final box using hot melt adhesive.
Problem:
The hot melt misfires or dribbles onto the folding arm or block used to create the box. Over time the hot melt builds up to the point where the boxes are not properly seated on their track or are not folded correctly.
Solution:
PC60521/4001F. Although this is a high friction coating, the area of contact on the folding arm or block is very small. Experience has shown this coating to last over three years in continuous operation.
Application:
Final box transfer to the warehouse.
Problem:
The hot melt will usually leave traces of itself on the outside surfaces of the final box. These traces can prevent the final box from flowing along the conveyor system used to take these boxes to the warehouse. In a worst case scenario, the line could stop.
Solution:
PC40511/2009F. The hot melt wont stick and the coating is low friction so box flow is improved. It is also quite hard wearing. A lifespan of over a year with no cleaning has been experienced.
To summarise. Impreglon has a great deal of experience in solving flow wrapping problems and can point to a number of high profile customers who have saved money and time by using Impreglon coatings.
