The enhancement is achieved through a specially designed additive package on the films’ reverse side but the processing properties remain the same, providing a stable hot slip over an extended temperature range.
Detlef Huett, engineer, Innovation, Treofan in Neunkirchen, told FoodProductionDaily what makes this film type so special is the combination of low seal ignition temperature and good hot slip properties; and the latter being almost constant over the whole temperature range between 20°C and 60°C.
“There are films on the market that can be sealed at low temperature, and there are others that have constant hot slip properties. Yet the combination of the two, to our knowledge, is an industry first,” said Huett.
“The focus to-date, has been mainly on improving the sealing properties – on lowering the so-called seal ignition temperature for the sealing process to enable higher speed of the packaging line.
“However, to really benefit from higher speed, the film’s hot slip versus the metal parts of the packaging machine must improve, too. That’s exactly what our formulation delivers.
“A temperature of 60°C is a theoretical limit that must never be reached, be it only for reasons of labor safety. We at Treofan have nevertheless set this value as a target, to always be on the safe side under real conditions.
“Take for example the packaging of biscuits where 40°C are commonplace, on a hot summer day maybe even up to 50°C, as this type of product is usually packaged directly after baking, without any intermediate cooling.”
Huett said the main application of transparent heat sealable films like its HNA, HND and HLD is packaging of biscuits where the challenges with respect to heat are particularly high.
The films can also be used for other products – for any type of food that is processed on a horizontal packaging line, as all three films have been developed specifically for HFFS (Horizontal Form Fill and Seal) assets.
“The HNA film in its new, improved version has been produced since about half a year,” he added.
“Based on the positive results, the respective changes were applied to the HND and HLD films as well. Since the beginning of November, all three films have consistently been delivered in the new formulation.”
Huett said the project is an excellent example of Treofan’s innovation strategy based on customer understanding, meaning it must first identify a concrete business need or challenge that one or more customers have, and then go about developing a holistic technology.
“In this specific case, the process included internal laboratory testing, first trials with cooperating partners, and small-scale commercial production for selected customers,” he added.