- I’VE GOT WRINKLES
Wrinkles- One of the most common problems found with companies new to shrink wrapping. Wrinkles in the shrink film after heat is applied means more heat should be applied to the film or the air velocity is too low If using a heat tunnel either slow down the belt speed or increase the heat on a Chamber machine increase the heat and the fan running time. Another cause is if the bag is made too big in the first place.
- I’VE GOT DOG EARS
Dog Ears are Shrink film bunched up in the of the package. Another very common problem when shrink wrapping. Dog ears will happen in almost any shrink wrapped package, but excessive dog ears can be prevented by applying more heat to the shrink film. The worst ones appear on circular product, you are in effect putting it round product in to a square bag so theres lots of excess film to shrink the corners down to the circumference.
The sixe of bag and the height of the product also effects the forming of dog ears as does the micron thickness of the film, so the least dog ears would be on a square, thin product using the thinnest presentation film.
- I’M BALLOONING
Ballooning- Excess air trapped inside the sealed shrink film. Ballooning happens after the seals have been made and heat is applied. It is hard to determine which products will balloon, generally the larger the surface area and the better the seals the more chance there is of ballooning. If ballooning is experienced, small perforation holes can be used to evacuate the trapped air.
- I’VE GOT HOLES (NOT ON SEALS)
Round holes are burn Holes, Burn holes are when to much heat is applied to the shrink film being used. If using a shrink tunnel, speed up conveyor or decrease heat. If using a Chamber machine reduce the temperature and turn down the shrink fan timer.
Rugby ball shaped holes are shrink Film Tears- Three different reasons for this, sharp corners of the product catching the film as its going in to the film, a damaged reel of film or they are often caused from the type of shrink film being used or the thickness of film being used. If experiencing tears, a thicker film should be considered or a different kind of film should be used. If using PVC switch to a polyolefin or a polyethylene.
- SAVING THE PLANET
The miles of plastic used to shrink wrap perishable products such as meat, fruit and vegatables might seem unnecessary, and have been the subject of well-meaning anti-packaging campaigns prior to the advent of recyclable films
But research shows that a wrapped perishables lasts more than three times as long as an unwrapped one. It will also lose just 1.5 per cent of its weight through evaporation after 14 days, compared with 3.5 per cent in just three days for an exposed item.
A longer shelf life, means less frequent deliveries, with all their consequent energy costs, and, crucially, less waste. Globally, we throw out as much as 50 per cent of food, often when it perishes. It typically goes to landfill and gives off methane, a greenhouse gas.