" Preblow" - a new development reduces costs
(Naefels, 07. Juni 2012) Netstal has further developed the proven PET-LINE Calitec© System. This innovative cooling system supports preform cooling through internal pressure in the preform. The PET performs are therefore intensively post-cooled without interruption after demolding. Preblow extends this cooling phase with a blow-out process in the base area. The advantages of Calitec are therefore increased still further: Shorter cycle times and continuously improved molding quality.
Innovation
The innovative Preblow process, which is the subject of a patent application, opens up new and even more efficient opportunities for our customers. Its special aspect: During this process, the preform is blown out in the base area directly after the injection molding process. This means that both the base contour and, thus, the surface area can be changed for the first time. By increasing the size of the base contour through the blowing process, we also obtain a thinner wall in the critical base area. During the subsequent blowing process, this effect can be used to heat the base area more specifically and more efficiently. With a larger surface area, the UV lamps in the blowing machine have to heat a thinner wall. The result: LightBase.
There is a clear advantage compared with the "EcoBase" and "Cappello Design" solutions now available on the market since complete consistency is guaranteed throughout the entire process. In addition to the change in the contour, the Netstal experts exerted more influence on the much more important parameters "“ wall thickness and material build-up "“ and improved them significantly. Finally, the wall thickness in an optimum injection molding process is almost invariable.
During an initial test with 1-liter juice bottles, a weight reduction of more than 1 g was attained. The wall thickness was also increased substantially. At the Chinaplas exhibition in April 2012, Netstal presented a system which produced a preform weighing 15.8 g for non-carbonated water. Although the bottle quality remained identical, material consumption was reduced by at least 0.5 g material. Calculated over the year, this corresponds to a saving of around 255 tonnes. The preforms were produced with 128 cavities at a cycle time of around 7.2 seconds. All 128 preforms were then reliably blown out identically. The high reproducibility and the much simpler blowing process compared with EcoBase and Cappello spoke a clear language and impressed the visitors.
"Through the development of the Preblow process, Netstal has managed to achieve a first-rate innovative technology. The larger process window in the blowing process and the additionally reduced cycle time due to lower material build-up on the base represent considerable advances in the production of PET bottles", said Thomas Anderegg, Vice President Sales at Netstal.
Picture explanation:
PET-Preform_comparison_2012_A_sx and B_sx : Weight saving Influence of the different perform tips on the bottle bases.
Preblow process: Innovation Description of the Preblow process
» Download: Foto: PET-Preform_comparison_2012_A_sx
» Download: Foto: PET-Preform_comparison_2012_B_sx
» Download: Foto: Preblow process
» Download: PM_Preblow_en