New production process for oval plastic containers

The ProShape is a module for selective preform tempering and is integrated into the Contiform PET blow molding machine between the heating oven and the blowing wheel.

The German company said the ProShape process is very precise, drawing on an individual temperature profiles, with defined contours and different temperature zones on the perform.

"The preforms readily accept unusual shapes after their treatment. This gives you the opportunity to explore new paths when design­ing PET containers,” ​said the company.

Individual temperature profile​

During the production process, the preform is first heated evenly in the oven and then a transfer starwheel transports it to the ProShape module.

At the ProShape module, water-cooled aluminium plates reduce the preform’s temperature on precisely defined areas during the production process.

Krones said that the technology can obtain an individual temperature profile which is tailored exactly to the blowing process and the final bottle shape.

The company claims that this process allows for “sharply defined temperature boundaries to be achieved, permitting stable thick-walled areas to be provided directly adjacent to thin-walled segments”.​

Krones said that as a positive secondary effect, lightweighting will also be possible. The system can also be switched off when round bottles are to be produced.

According to Krones, another function of the ProShape is that it can orientate preforms very precisely to fit the exact requirement of the bottle cap.

This is acheived by utilising an optical camera system, which takes an image of each in­dividual preform while the preform is still in the transfer starwheel. A software then recognises the position of the orientation mark and calculates in which position the preform must first be transferred to the ProShape module and then to the mould.