PETpla.net Insider 08 / 2017

TRADE SHOW PREVIEW PET planet Insider Vol. 18 No. 08/17 www.petpla.net 59 Perfect PET milk bottles by Michael Birchler At this year’s Drinktec, Swiss injection moulding machine manufacturer Netstal will be producing double-layer preforms for milk bottles on its booth. With Prelactia, extremely long-lasting milk products and drinks can be safely, cost-effectively and attractively packaged. The secondary injection unit, with which the grey interior wall is injected, is positioned in an L position toward the main injection unit. (Photos: Netstal) The pure PET Prelactia preform is the product of the combined exper- tise of the Spanish mould manufac- turer Molmasa and Swiss machine manufacturer Netstal. The basis for this is a preform with a double layer that reflects the primary functions: an attractive white outer skin to attract the customer’s eye, and the grey, inte- rior wall that is impervious to light and protects the tasty content. A Prelac- tia bottle blocks virtually 100% of the visible light, and is therefore ideal for extremely long-lasting milk products. In addition to UHT milk, these include trendy milkshakes, yogurt drinks and soy-based vegan milk drinks. Flexible production system for single and double-layer preforms On its stand at Drinktec, Netstal will use a PET-Line 2400-4000/1000 to produce 17g Prelactia preforms for 0.5l bottles. The additional 1000- series injection unit used for the grey interior wall is positioned in a so-called L position toward the main injection unit. In order to flexibly bal- ance capacity fluctuations during the manufacturing operation, the machine can also easily be used for standard preforms (water, CSD etc.). For this purpose, the secondary injection unit software is deactivated. The double- layer Prelactia preforms are produced through overmoulding: in the first step, the dark component is injected into the 32+32 cavity mould in order to form the 1mm-thick grey layer. The blanks are then covered in the 1.4mm-thick white outer skin in sepa- rate cavities. Reduced use of expensive additives Both of these precisely defined layer thicknesses provide an eco- nomic advantage when compared to other processes. In order to increase the barrier effect of PET against damaging UV light, the white pigment titanium dioxide has to be applied to the polymer for the preform produc- tion. The additive also provides the pure white colour of the milk bottles. For single-layer preforms, the propor- tion must be 15% of a preform’s entire weight. With Prelactia, only the outer layer assumes this function, which is why the proportion of the additive can be reduced to 5%. In the context of a yearly quantity of 105 million preforms at 17g each, the use of the high-grade titanium dioxide is reduced to around 180t. The milk bottle as a three- dimensional trademark In addition to featuring numerous technical functions and improving the bottom line, modern-day packaging should also be used as advertising media and a purchasing incentive. Within the soft drink industry, the leading companies have spent many years striving to attract customers by manufacturing their own increasingly sophisticated PET bottle shapes. This has been less prominent within the milk industry, mainly due to the limited options offered by the established HDPE or cardboard milk packag- ing. With PET Prelactia preforms, the manufacturers of milk-based lifestyle, convenience and health products are presented with brand new possibilities and bottle designs that ensure they stand out from the competition. www.netstal.com The milk bottle consists of two PET layers: the attrac- tive white outer skin, and a grey interior wall that is impervious to light to protect the milk. Hall A4 - Booth 321