Amcor commercialises compression blow forming

Amcor Rigid Plastics is producing pharmaceutical packaging using compression blow forming technology, making it the first company to use a CBF machine on a commercial scale, the company announced at Interphex 2012.

Amcor is manufacturing high density polyethylene bottles using a CBF machine developed by Sacmi Imola.

CBF machines combine elements of compression moulding and blow moulding in a continuous rotary process. According to Amcor, the machines are a “game changer” – they offer a higher output and produce higher quality bottles than traditional injection blow moulding machines.

“The whole technology kind of combines to give a superior and better quality product,” said Bob Israni, manager of pharmaceutical project management.

CBF uses an integrated in-line sequence that does not require station-to-station transfer. Material is extruded, cut and transferred into a compression cavity. A preform is produced, and bottles are then pre-blown before the blow mould cavity closes over the preform. Then, the mould cavity closes and the bottle is blown.

The machine does not use a manifold for melt distribution. Instead an extruded shot of resin is transferred directly into the compression mould, giving producers more control over the quality of the container. The process is “kind of beautiful”, Israni said.

Eliminating a manifold also eliminates differences in temperature, so there’s less chance of particulate contamination, resin burning, and other defects, like the black specks seen with injection blow moulding, he said.

The machine also offers more uniform weight distribution, because the weight of each resin shot is controlled with a servo-controlled melt pump.

The pre-blow process also allows a more consistent and uniform wall thickness by making it easier to separate plastic from the compression core. The blow process begins immediately after compressing the preform, so there’s less chance of material sticking to the metal core rod.

The machine also saves energy compared to other processes, largely thanks to lower process temperatures. The machine's conveyor also features an air conditioner and dehumidifier, so bottles can be taken out hotter. This reduces cycle time, Israni added.

A more uniform weight distribution also offers the potential for lightweighting, without eliminating some of the key qualities required in pharmaceutical packaging, Israni said.

Machines are also equipped with a fully-integrated inline inspection system. The system offers leak detection immediately after the bottle is blown and uses infrared cameras to detect surface and internal contamination, like finish variations or metal particulates.

It also features a plasma surface treatment system as an alternative to flaming. Plasma treatments offer the same benefits of flaming, but cuts down on environmental, health and safety risks, Israni said.

“We strive for zero accidents in our facilities, and this allows us to take a risk factor out,” added Laurel Spencer, vice-president of marketing.

The integrated control system also gives operators more control. Rather than just detecting problems, it shows operators where the error is and why it’s occurred, said Luca Nannetti, sales and marketing manager for Sacmi’s containers division.

If there’s a problem with a mould, operators can decide to stop the machine and replace the mould, a process that takes about 30 minutes. Or, they can decide to just eliminate that specific station and allow the machine to keep producing, he said.

“It gives you the freedom to decide what to do,” Nannetti said.

Sacmi and Amcor collaborated on a 14 month project to bring CBF technology to commercial scale in pharmaceutical packaging.

Amcor’s current CBF machine is a 12-cavity unit that can create monolayer HDPE bottles 24-33mm in size. That machine is at Amcor’s Youngsville, plant.

A 20-cavity unit is in production and should be available for commercial use by the end of the year, Israni said. Amcor said it will have a total of four CPF machines in production by the end of the year.

The 20-cavity machine will also have the ability to run HDPE, polystyrene, polyethylene, and PET. This would make it the only technology on the market that can use the four main resins used in packaging, Nanetti said.

“I’d rather have more time for development than pushing and not having a perfectly-tuned thing,” he added. “But if we can make it, we’ll have one [piece of] equipment for all the resins available on the market, with minor changes.”

The machine is currently running full-scale, making packaging for prescription and over the counter pharmaceutical bottles for an undisclosed customer, Spencer said.

Amcor also is developing stock bottles, 150mm and 300mm in size, for use as single-serve dairy product packaging.

The company would not discuss cost, but Spencer said customers should focus on the value and benefits of the machine.

“At this point, we’re in the beginning stage of the technology and just in the process of really ramping up, we don’t have a good comparison of costs, at least one we’d like to share, Spencer said.

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