Extensive research into blown film extrusion in recent years has lead to the development of an innovative solution for blown film extrusion.
UK-based VarDAR Systems worked closely alongside blown film producers in developing its tower mounted system, which was initially designed three years ago in collaboration with British firm Echo Packaging. The team at Echo Packaging were said to be becoming increasingly frustrated that their output was being restricted by the limited roof height available in the factory.
The tower mounted system is designed specifically to boost output, particularly when the height of the blown film line is limited. In addition to installations at UK factories, the company has exported the technology to customers in France, Germany, Austria, Italy and the USA, in a success story for British engineering.
It is provided as a retrofit to existing lines and is also exclusively available from Hosokawa Alpine as an additional system order on new installations. A demonstration system can be seen in action at the Hosokawa Alpine Technical centre in Augsburg, Germany.
Reducing ‘blocking’ and tackiness in blown film
VarDAR’s tower mounted system is a variable diameter air ring (hence, VarDAR) designed to increase productivity of the blown film process by adding additional cooling above the frost line. This reduces such effects as ‘blocking’ (when the inside surface of the bubble sticks to itself at the nip during collapsing, making it nearly impossible to open). It also provides reduced tackiness of the bubble’s outer surface when still hot.
Film blown using the system is easier to handle downstream, says VarDAR Systems. Blocking during production which can make the film harder to separate. Splitting the web is another frustration for machine operators and the easier it is to separate the film, the higher the output of the production line.
Factories using VarDAR’s tower mounted system are seeing improved speeds and output on their production lines, providing a quantifiable return on investment, states VarDAR Systems. Customers have reportedly seen: significant increases in productivity; quicker set up times and easier line monitoring; reductions in blocking and scrap levels (via better separation of film and efficient slitting), and a reduction in need for expensive additives, (as a lower percentage of expensive masterbatches is needed to produce quality film). Aesthetic benefits are said to include better finished reel geometry, and improved overall appearance of the film as a result of less stretching and creasing.
The tower mounted systems are available in a range of sizes which cover most applications from small tube lines for shipping sacks, to large machines with web widths of up to three metres. As it cools the film above the frost line, there is no interference with any of the existing systems that control the line, air ring, internal bubble cooling and or the profile control.
In additional to tube products such as sacks, VarDAR’s tower mounted system is equally effective in the production of single wound sheet, according to its manufacturer.
VarDAR Systems Limited is the sole UK representative for Hosokawa Alpine’s Blown film technology. Its tower mounted systems are manufactured and shipped from its factory in Cheltenham, England.
With K 2022 just around the corner, Andrew Parker, Director at VarDAR Systems, said he is “very much looking forward to the event” where he and his team will be available at the Hosokawa Alpine stand at the show.