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04/12/2016

Improving oval PET bottles: higher quality with preferential heating from KHS

Special bottle shapes make high demands of many stretch blow molders during production. The preferential heating system (PH) developed by the KHS Group now enables bottlers to achieve perfect bottle quality even with extremely oval bottles in an energy-saving, safe and reliable process.

• High-quality appearance and optimized material distribution for oval shapes
• KHS system for new machines and retrofits
• Fast changeovers between round and oval bottles possible

Dortmund, April 12, 2016 – Special bottle shapes make high demands of many stretch blow molders during production. The preferential heating system (PH) developed by the KHS Group now enables bottlers to achieve perfect bottle quality even with extremely oval bottles in an energy-saving, safe and reliable process. The systems provider now also offers this option for its successful InnoPET Blomax Series IV. Regarding the energy-efficient manufacture of PET bottles the InnoPET Blomax Series IV stretch blow molder is one of the most powerful on the market. With preferential heating fillers of oval bottles benefit from a manufacturing process which KHS has been successfully applying in older series of stretch blow molders since the 1990s. Homecare and personal care products in focus In transferring the technology to the latest series of KHS stretch blow molders all the benefits over previous machines are retained. These include the much lower use of energy and the simpler design. Especially when processing items such as cleaning agents, laundry detergents or personal care products, which are very often filled into oval PET bottles, this process has many advantages. "Without preferential heating the preform is heated evenly in the stretch blow molder," explains Marco Böhnke, product manager at KHS Corpoplast. "This means that the areas of the bottle which come into contact with the blow mold first cool down before the others." As a result, the PVC hardens at these points so that the material is distributed unevenly in the ensuing bottle. The walls are also thicker in these places. It is no longer possible to obtain as even a distribution of materials as possible and thus optimum stability and bottle quality in the ongoing stretch blow molding process. If, as is the case with preferential heating, a preform is heated selectively according to its later bottle shape, this undesired effect is compensated for. Special heater segment for a selective heating profile Preferential heating is made possible by a special heater section at the end of the heating segment. Here, the system first rotates the PET preforms through the heater to obtain a basic heating profile. In the downstream PH section rotation is stopped, giving the preform its selective heating profile. The new heater box specially developed for this application plays a big role here, transferring the required heating energy to the preform through two opposite heater levels. "We're generally improving quality, especially the material distribution and stability of the bottle," says Böhnke. Another effect of preferential heating is that "Thanks to this intelligent technology we can realize material savings of up to several grams per bottle." This means that bottlers no longer have to use heavy preforms in order to achieve the same stability with an uneven distribution of materials without the PH process and can thus save on resources. The machine permits very fast changeovers to round bottles, too, which gives converters in particular great flexibility. Preferential heating can not only be used in every new InnoPET Blomax Series IV as an option; it can also be retrofitted into existing systems. About the KHS Group The KHS Group is one of the leading manufacturers of filling and packaging systems for the beverage, food and non-food industries. The KHS Group includes the following companies, among others: KHS GmbH, KHS Corpoplast GmbH, KHS Plasmax GmbH and NMP Systems GmbH. KHS GmbH manufactures modern filling and packaging systems at its headquarters in Dortmund, Germany, and in Kleve, Bad Kreuznach and Worms. The KHS Group's PET expertise is pooled at KHS Corpoplast and KHS Plasmax in Hamburg, Germany, where light PET packaging and innovative coating systems are developed and produced. NMP Systems GmbH, a wholly-owned subsidiary of KHS GmbH based in Düsseldorf in Germany, designs and markets new, resource-saving packaging systems for PET bottles. The group has an international production and service network with over 4,600 employees. In 2015 KHS was awarded the Top 100 seal of approval for exceptional innovative power and outstanding innovative success among German SMEs. In 2014 the group achieved a turnover of €1.08 billion, The companies in the KHS Group are 100% subsidiaries of the MDAX-listed Salzgitter AG corporation.