However, key elements like power: generating the heat required by moulding is determined by local utilities providers. Transport for bringing preforms into the plant and delivering containers is in the hands of the petroleum corporations and material prices are determined on the global commodities exchange. Rarely, does the converter have direct control over these external costs.

Cost cutting

Solutions to the ever present cost-cutting imperative may come from an unfamiliar source, the machine supplier.
“At the core of Aoki’s strategy is customer profit generation through innovation” says Eiji Nishizawa, Section Manager, Sales Planning Group at Aoki Technical Laboratory Inc “What that practically translates to, is using technology to reduce production costs, while giving the flexibility to introduce new shapes, forms and concepts to offer brand owners.”
He is referring mainly to Aoki’s Direct Heatcon system which eliminates off line preform moulding and re-heating, to reduce cycle time, transport and power costs.
About a two hour journey by Shinkansen bullet train North East of Tokyo, in the small town of Ueda, Nagano prefecture, Aoki Technical Laboratory Inc, is the only machine manufacturer in the world with a revolving three-station single stage technology.
With sales offices around the world, Aoki claims an 80 % share of the Australian market.

Aoki claims an 80 % share of the Australian market.

Since it is also possible to blow into the neck area container, even greater lightweighting can see reductions of up to three grams while three to five seconds is saved in the cycle time.

Stage Two: blow moulding

The preforms are then rotated 120o to Station Two: the Stretch-blow moulding station.
By actually using the latent heat from the newly moulded preform, the container is blown, because the preform is still hot, re-heating of the preform is abolished, saving both a time and energy. In addition, with other techniques, according to Aoki, heaters are used to heat condition the preform and there is always a layer of air between the heater unit and preform. This tends too cause temperatures to equalise making heat differentials difficult particularly when blowing non standard shapes.

Stage three: ejection

By eliminating the need for off-line preforming, Aoki’s Eiji Nishizawa points out that the system has several advantages which aren’t immediately obvious; “We basically eliminate transport costs. Many container manufacturers have off-site preform production or buy-in from subcontractors. But by bringing raw feedstock into the plant instead of preforms an 83 % saving in transport costs can be made, assuming packing of around 9,280 preforms per 1m2 box.” For the bottler, subcontracting and buying in finished blown containers the savings escalate, only 1,024 500ml bottles fit into the same 1m2 box, the raw feedstock in the same box would be enough to make 56,421 bottles, a 98.2 % saving in transport costs.
It is not just PET containers which can be blown using Direct Heatcon, but PC for dishwasher-capable containers, PEN high heat resistant with good barrier used in pharma and cosmetic containers, PES mainly used in baby bottles in Japan, PP moisture resistant wide-mouth containers for pharmaceutical tablets etc, PA (or Nylon) a PC replacement for baby bottles and HIPS, high impact polystyrene used in Japan for yogurts and lactic acid beverages.

Sellable shapes

True to its tradition, Aoki Technical Laboratory, prides itself in the ‘lab’ aspect.
“Most components of our machines are constructed by subcontractors though assembled and tested in out Ueda plant” says Nishizawa San, a common manufacturing process in Japan where most of the auto industry buys-in components for assembly “This means that we don’t tie up capital in the manufacturing process, liberating it for R&D”.
With the process, Aoki offers a mould design option to customers, though not a requirement, Aoki labs constantly work on customer inspired shapes and designs – combining technology and creativity – frequent colour changes are simple since the container is moulded from the raw material not a pre-coloured preform.
Off-centre containers, in which the neck of the final container is not centred but offset to allow more efficient pouring by the consumer: trigger sprays, car wax, motor oil and juices are where we would see these.
Achieving uniform thickness was a problem using conventional processes, however with Aoki’s system lightweighting and material cost reductions are possible in addition to stability of output.
Oval containers, most commonly found in shampoo, mayonnaise and detergent applications have the advantage of presenting a wider label surface than the conventional container. Easy to hold they optimise space in the carton when packed, meaning less air-space is shipped per volume.

Ovalizing technology allows more heat to be retained in the areas of the preform which will be stretched, speeding up wall thickness adjustment.
Wide-mouth containers; everything from peanut butter to dried fruit needs wide mouth access to the contents.
In production wide-mouth containers need higher mould-clamping forces during moulding – an Aoki open cylinder system allows greater forces to be applied.
In wide-mouth containers, panels ribs are rarely used, though increased wall thicknesses prevents vacuum deformation, the increased weight tends to result in higher material use/cost.
However, it is possible, in the Direct Heatcon process to localise a thicker
wall at the centre of the container body while reducing wall gauges at the neck or base, counteracting the deformation and reducing weight.

Post Consumer cost savings

In Japan ‘PC’ is the Politically Correct term for Post Consumer, or recycled PET.

With the price of virgin PET spiralling on an ever upward trend, the base cost of materials is beyond the converter’s control.
“But with Japan’s recycling legislation, more than 60 % of PET is being recovered Post Consumer-PET flake prices can deliver a 25 % saving on material costs” says Nishizawa San.

“But with Japan’s recycling legislation, more than 60 % of PET is being recovered Post Consumer-PET flake prices can deliver a 25 % saving on material costs” says Nishizawa San.