The Big Picture

In the world of packaging, the latest trends continue to involve packing products in plastic. Metal is giving way to PET, boxes and cans are being replaced by stand-up pouches, and everything from potato chips to coffee is now being sold in blow-molded containers.

Walk into your local Canadian Tire and you can even buy Dutch Boy interior latex paint in a plastic blow molded container. The four-part construction involves a 3.78-litre HDPE jar with an integrated handle, a one-piece molded handle that fits around the container’s neck, an injection-molded insert in the neck that functions as a spout and a large screw-on lid. Folgers, meanwhile, is packaging ground coffee in its AromaSeal canister — a multi-layer blow-molded canister made of HDPE with moisture and oxygen barriers, incorporating a snap-on lid, foil seal and molded handle. The coffee itself is packed warm from the roaster.

“We’ve seen a few different industries heading to blow-molded PVC containers that were using other methods like glass or cans,” adds Marcus Mielke, Krones Machinery’s vice-president and director of sales for Canada.

Milk, once doled out exclusively in gable-topped fibreboard cartons, is now being distributed in aseptically filled plastic containers with full-body sleeves. Even premium soups that had moved from cans to Tetra-Paks are now being sold in aseptically filled plastic containers, he says. “The consumer can see the product through the container.”

“When these companies are going to aseptic filling processes, it’s actually simplifying the plastic,” Mielke adds, noting how the products once limited to heat-set PET containers can now be bottled in standard PET materials.

“A heat-set PET container is traditionally not cost-competitive because of the extra process it went through. Now by modifying their process to aseptic, cold-filled processes, we can use standard PET containers.”

Tetra-Pak, meanwhile, is in the midst of launching a “pouch-like system” as its latest offering.

But the growth recently experienced in some markets specific to stand-up pouches may be starting to level off, admits Jeff Keller, vice-president of strategic business development and marketing for Tetra-Pak USA. “I think we’ve moved into the mature stage. The excitement from both a manufacturer and consumer standpoint that was created four, five years ago has kind of come down to earth in terms of practicability and cost.

“Between food and beverage, it’s found its limits in a variety of categories.”

Part of the issue seems related to the challenge retailers face managing stand-ups on store shelves — the containers simply don’t stack as easily as cans.

The growth opportunities that remain will involve pouches that add value, such as re-sealable designs, he says. “In the end, if you don’t add something different like that, they really are the same.”

HUGE DEMAND FOR MOLDABLE FOAM

But the advancements haven’t been limited to the outside of the packages either. NOVA chemicals, for example, plans to expand the capacity of its Arcel moldable foam resin plant to 100 million lb/year by 2006.

“Our growth has been 100% per year for the past four years. It’s explosive growth, unlike what we’ve seen in any other product,” says Dan Nelson, vice-president of the company’s global Arcel business. “Our expectation is that our fill rate on that 100 million lb will be very fast. We’re already working on further expansion plans.”

Before now, the product had traditionally been limited to dunnage. But when Hewlett-Packard Co. presented the challenge of people returning products simply because EPS packaging materials had flaked inside the box, a revised form of Arcel was called into service.

Its traditional density of 3 lb/ft3 now matches the 1.2 lb/ft3 levels typical with EPS. To develop the new packaging-grade of Arcel, NOVA worked closely with suppliers of expansion equipment and molding presses such as HIRSCH USA, Kurtz North America, Erlenbach USA and Promass EPS Machines. Any molder with EPS tooling can be up and running with the new product with a mere $10,000 investment. In contrast, it can take $1 million investment to begin processing polyolefin foams, Nelson says.

“Our product is sold as a small bead that’s impregnated with pentane, like EPS,” he explains. “But where steam is added to EPS through a double-pass expansion process, a new double-pass auger system runs the resin through its second pass in a much shorter period of time.”

While more expensive than its counterpart, products packed with Arcel boast a cube savings of 25 to 30%. IBM, for example, was able to pack 24 PCs on a pallet instead of 16.

The added protection associated with the new product is also becoming more important for any goods sent through uncontrolled parcel shippers. “They’re constantly increasing the overpass distance between one and the other, increasing the drop height,” Nelson says. “You used to test from 12 to 24 inches. Today you’re dropping from 42 inches.”

THE GREEN EDGE

Meanwhile, the corn-based plastic called PLA is being trumpeted as an environmentally-friendly packaging alternative to PET. BIOTA Brands of America is using the resin to bottle premium Colorado spring water in a container made from PLA resin supplied by NatureWorks LLC. The company partnered with Husky Injection Molding Systems and SIG Coroplast to develop the bottle. Husky supplied BIOTA with a 24-cavity HyPET 120 system to produce performs for 12 oz., 0.5L and 1L water bottles. SIG Coroplast supplied the company with a BLOMAX-10, 10-cavity stretch blowmolding system.

“There were several differences between PLA and PET in temperature, injection rates, pressures, etc., but we worked through that learning curve and our customer is now making excellent performs,” says Mike Urquhart, vice-president, PET systems at Husky. “The project broke down into several milestones, including preform design, preform prototyping, additive testing, large-volume sampling/testing and tooling optimization. Overall, the project took about seven months from concept to completion. On the equipment side, the capital costs are very close to the same for a PLA system or a PET system.”

“The way [the cost of] crude has been going it certainly makes a good sales pitch: Go with corn,” adds Larry Koester, vice-president of communication with the environmental division of the Society of Plastics Engineers.

Yet, ironically, the material presents challenges to the waste stream, he says. “It’s a killer for the recycling of PET because it looks like PET and acts like PET. The bottle stream will be contaminated. Sure, it will still have a ‘7’ printed on the bottom, but try to spot that in the bales of bottles in a facility that processes at a rate of 50,000 bottles per hour.”

While developed with an eye to composting, those efforts will probably be limited to industrial composing facilities, he adds.

There are other limits as well. “I don’t think it will work for carbonated beverages. It’s too amorphous,” Koester says. “It has good clarity and optics, but it [also] doesn’t have the hinge properties that PET has.”

While sheet can be produced out of PET regrind, there are also questions about how to deal with this product because it isn’t thermally stable, he adds. In fact, if left in a stuffy warehouse where temperatures reach 110 Fahrenheit for 24 hours, the packages will also begin to stick together.

“I [also] put one of them in the dishwasher and it went flat as a pancake.”

Perhaps the biggest challenge is PLA’s present cost of around US$2/lb, he says. “If you have a 300-million-pound-a-year [facility] and you run at 30 million lb your cost could be five bucks a pound.”

Like any of the packaging alternatives, it will be a matter of balancing cost and value.

CLARIFIED PP NOW BEING USED IN HOT-FILL APPLICATIONS

For many years companies have dreamed of using clarified polypropylene in place of PET for the injection mol
ding of bottle pre-forms to be used for a wider range of applications than just bottled water. According to Milliken Chemical, recent technical developments in resin formulation and the design of pre-forms, as well as state-of-the-art, injection-stretch blow molding equipment, is bringing the dream closer to reality.

The perception that clarified PP cannot achieve the same performance capabilities as PET was recently disproved recently after several successful tests using Sidel (series 2+SBO) equipment. The tests have already yielded results in Brazil. As the result of a partnership between Braskem, a PP supplier, Milliken, and Sidel, the packaging manufacturer, Packpet has succeeded in the development of a clarified PP bottle for hot-fill packaging. The new bottle has excellent mechanical resistance and transparency, as well as a competitive cost, thus meeting the target requested by the end user, Marbo, holder of the Tampico brand.

This bottle represents an important alternative for beverage producers, who can now reduce the use of preservatives in their formulas due to the hot-fill packaging of their products and meet the market demand for healthier beverages.