Operations: Cutting costs and materials
September 15, 2008
The U.S. demand for plastic containers will grow 5.4 percent annually through 2012 to nearly $32 billion, creating demand for 15.7 billion pounds of resin, reports Freedonia Group Inc., Cleveland, in its Plastic Containers study.
The research firm says plastic’s gains will be bolstered by the material’s benefits, such as its light weight, shatter resistance, design flexibility, clarity, strength and effective barrier properties. And even though most plastic containers are light by nature, growth in resin volume will be restrained by additional lightweighting and down-gauging efforts aimed at reducing resin consumption, Freedonia says.
The company found that unit expansion will outpace volume increases as a result of consumer preferences for smaller, single-serving containers, especially for beverages and foods. Plastic bottles and jars for all industries accounted for 78 percent of plastic container poundage in 2007, and will remain the leading container type through 2012, Freedonia says. Unit demand will increase 4.8 percent per year through 2012 to 168 billion units, supported by the popularity of smaller-sized beverage bottles and continued expansion of the bottled water market, the largest single market for plastic bottles, it says. In addition, the research firm expects the use of plastic to grow in the beverage and food industries as the improved barrier properties of PET will expand the use of plastic bottles and jars in hot-fill applications.
For total resin sales, the American Chemistry Council, Arlington, Va., is reporting a less optimistic outcome. U.S. production of major plastic resins equaled 6.8 billion pounds during May 2008, which marks a decrease of 6.3 percent compared to the same month in 2007, it says. Year-to-date production was 33.2 billion pounds, a 4.4 percent decrease compared to the same period in 2007.
It’s not news to resin and preform suppliers that demand is soft compared to past summers, says Speed Stodghill, director of sales for Veriplas Containers Inc., Little Rock, Ark. What is continuing to grow are beverage-makers demands for custom bottles.
“They don’t want the generic water bottle, and they want to differentiate themselves, so they will do a custom mold that will be their own special bottle,” Stodghill says.
Another area where Veriplas is preparing for growth is recycled PET (rPET). This fall, the company will introduce containers made with rPET materials.
“We supply over 60 independent water bottlers in the United States with PET containers, and we have already received strong indications of interest in rPET from many of them,” says Breck Speed, chief executive officer at Veriplas’ parent company Mountain Valley Spring Water Co., Hot Springs, Ark. “At the end of the day, it really is a fairly common sense thing to do. PET resin is useful stuff and it is kinda dumb to throw it away.”
Mountain Valley announced in July that it began using FDA-approved rPET resin in its water bottles. The company worked with New Horizons Plastics Recycling, Greenville, S.C., to source the recycled content, which primarily includes post-consumer plastic. Veriplas then worked with New Horizons to combine recycled content with virgin material.
“The missing link in bottled water container recycling in the United States is someone who is willing to buy and reuse the recycled material,” Speed says. “We plan to help kick start and improve PET recycling efforts by creating economic demand for recycled content.”
To meet the changing needs of plastic bottle manufacturing, including faster speeds and increasing changeovers for different bottle shapes and sizes, blowmolding equipment suppliers have stepped up the technology.
One technology that widely is being adopted is the merger of the blowmolder and the filler. Sidel Inc., Norcross, Ga., offers Combi, an integrated blowing, filling and capping solution for PET bottles up to 3 liters. No air conveying is needed between the blowmolder and the filler.
“It’s all positively transferred by the neck from the preform all the way to the filled sealed package,” says Gina Haines, Sidel Inc.’s vice president of marketing and communications. “We’re seeing that the earliest adopters for this have really been in the water segment. We’re also seeing it in CSD. Why it’s so popular is because it allows for maximum lightweighting.”
Sidel has launched its newest lightweighting technologies in the FlexLine, which combines the flexibility of plastic with shape memory. The line, with the help of Sidel’s Combi, is able to blowmold, fill, cap, label, pack and palletize a 500-ml. water bottle weighing less than 10 grams at a rate of 43,200 bottles per hour. By using Combi technology, less energy is used, and 40 percent of the air can be reused due to an air recycling system. Preforms containing rPET also can be used on the FlexLine.
Additional opportunities for lightweighting are substantial.
“The bottle is being handled directly from the blower to the filler and doesn’t get crushed up in the air conveyors, so therefore you can do a more light-weight bottle without risk of damaging,” says Bill Farrant, president of KHS Corpoplast North America Inc., Hillsborough, N.J. “The bottle is strengthened, if you like, once it’s filled with the product, which would bring the extra rigidity to the bottle that it would need to go down the rest of the filling line.”
Lightweighting also places additional demands on the blowmolders. “The handling of the bottle and the preform through the machine has to be more centered because they are gentler, especially once the bottle is blown,” Farrant explains.
For accommodating the lighter bottles, the equipment must be more precisely controlled because less material is available to adjust to any variation that the machine may introduce to the process. “The machine itself needs good heating control and good process control, so you get that stability from one bottle to the next and consistently,” Farrant says.
Additional advantages of coupling the blowmolder and filler and dismissing the need for an air conveyor are the savings of space and expenses, Farrant says. “In terms of a machinery supplier, it’s the drive to get lower cost production by either reducing energy or by reducing the material in the bottle,” he says.
In addition to having an efficient heater control system, two ways to lower energy costs are to reduce the amount of air in the machine by eliminating dead air and to work toward using lower blowing pressures, Farrant says. KHS Corpoplast’s Blomax Series III stretch blowmolding machine has eliminated the need for a low-pressure air system.
“Fifteen years ago, everybody was using something between 35 and 40 bar for blowing pressure, and now we’re seeing blowing pressures around 25 bar,” he says. “Every time you reduce the pressure, you reduce the kilowatts you have to consume at the compressor to generate that compressed air. Compressed air costs are probably the biggest part of production costs.”
In addition, KHS Corpoplast is developing air recovery systems so that after the machine has blown the bottle, the air that is exhausted out of the machine to relieve the pressure will be salvaged and reused in the machine, such as in the compressor, or used in the factory.
Sidel’s Predis technology, available in the Combi, also provides an environmentally friendly approach. Predis, a method of dry decontamination of the internal walls of preforms, can be combined with aseptic Combi equipment for aseptic packaged beverages sold at ambient temperature or ultra-clean Combi equipment for beverages sold in the cold chain.
“It allows high-acid products to be filled in either a warm-fill or an ambient-fill without having to go to hot-fill,” Haines says. “So once again, you have the ability to maximize the lightweighting of the package.”
Predis provides for aseptic-like performance without a conventional aseptic process, which requires several chemicals and generates more waste water, Haines says. The dry preform decontamination system eliminates water, and cleanses by using hydrogen peroxide. BI