What a difference three years make. There was not a single commercial electric machine at Plast 2000, but judging from the exhibition in May, blowmolding machine manufacturers have quickly moved to develop electric servomotor driven machines. Some say processor pressure—not the same as processor demand—is helping the transition.
The market for electric blowmolding machines is not yet as established as that for electric injection molding machines, agree officials at all of the firms cited, but manufacturers without an electric machine in their stable might be accused of falling behind in R&D, explains Giovanna Della Bianca, technical manager at Plastimac (Milan, Italy). "You have to have one these days," she explains. Plastimac and many other manufacturers of extrusion blowmolding machines—Italy is home to more than any other country—used Plast to publicize their hydraulics-free developments. There also were electric injection blow and stretch blow machines, including one of the latter from a new player in the blowmolding industry.
Generally, blowmolding machines with electric servomotor drives cost about 10 to 20 percent more than equivalent-sized hydraulic machines, but offer benefits, including reduced energy consumption and noise levels and quicker set-up for processing. Improved precision and shorter cycle times are also touted as advantages. Though most exhibitors said they had yet to sell an electric machine, for some the market has developed well beyond a niche. Sales of electric machines now comprise about 97 percent of extrusion blowmolding machine demand at Magic (Lonza, Italy) according to Mario Rossi, sales manager. After less than three years of commercial sales, the firm has more than 30 in operation at facilities in Europe, Africa, the U.S., Asia, and Canada. At K 2001, Magic displayed a prototype EP-L3/D dual shuttle for containers to 330 ml, but now the manufacturer makes electric machines for packaging volume up to 8 liters. Rossi says development of larger machines for 10 liters and larger is in advanced stages.
Rossi says demand is increasing as the firm receives, and then passes to potential customers, feedback from some of its first electric machine customers. He says this feedback has proved the machine’s durability in 24/7 operations. Reports show that energy savings of 30 to 50 percent are possible compared to similarly sized hydraulic machines. One prominent customer, Filipe De Botton, president of Portuguese bottle blowmolder Logoplaste, bought eight electric machines from Magic at Plast and told Rossi his firm saves 30 percent or more on energy costs with the machines.
Blow Molding Srl and Plastimac, newcomers to electric blowmolding machinery, both exhibited dual shuttle machines processing HDPE handleware. Plastimac’s machine is so new that technical data sheets are not yet available. Blow Molding, based in Calderara di Reno, claims its electric machines of comparable output save 35 percent compared to the firm’s hydraulic model BM2000D, 48 percent compared to the BM5000D, and 53 percent compared to the BM10,000D. The el.blow bm 5000D running at Plast has 10.5 tonnes clamp force for processing containers with volumes up to 6 liters.
Energy savings continue to be the most common reason cited by manufacturers for processors interest in the electric models, but Marco Russo, sales manager at stretch blowmolding (SBM) machine maker Siapi (San Vendemiano), says speed is also bettered when compared to hydraulic machines. "Electrics allows us to speed the movements of the press, so it’s very useful for small bottles," he says. For large bottles, advantages are not as great, he says, since the clamp stays shut longer. Others, such as Magic’s Rossi, tout that as an advantage since no power is required by the clamp when it’s not moving. Siapi’s Russo predicts that the firm will soon be making these machines for larger bottles, and expects in the next year or two the firm will make units with higher cavitation and output. The firm has also developed a single-cavity SBM machine for processing .5- or 1-liter clarified PP bottles, which he says are seeing solid demand growth in hot-fill applications. Russo says the company also recently shipped its first machines to the U.S. market—two linear SBMs for a New York-based processor of 2-liter edible oil bottles.
Aimed at niche applications such as pharmaceutical containers is the Jet 60 electric three-station injection blow machine, made by Meccanoplastica (Campi Bisenzio). "It’s new for us and new for the market," says Alfredo Santini, commercial director. Clamp force goes up to 50 tonnes on the injection side and up to 10 tonnes on the blow clamp. Total installed power is 50 kW with average consumption of 12 kW. Santini says the first unit has been sold to Italian firm Barnicolo Rocco & Figli.
The pace of machine developments contrasts sharply with the rate of machine sales, now at their lowest point in four years. No demand increase is in near-term sight, according to Bill Petrino, president of Jomar, with manufacturing in Pleasantville, NJ and Minerbio, Italy. The manufacturers are paying for their success, he explains. "Sales between 1997 and 2000 were too good—processors even bought spare machines," he recalls. But with much of the equipment bought in those years underused and still being paid for, processors have little reason to invest in new machines, he says. "It [blowmolding machine demand] will come back globally at about the same time," he predicts, though this may be a year or more away. At Plast, Jomar displayed its 6-liter, double-sided, long-stroke machine, first introduced at K 2001. It differs from most competing models in that, rather than a nodding head, the entire extruder and head lifts parallel to the ground between parisons. Gianluca Maini, GM at Jomar Italia, says nodding heads can create a radius that causes parison movement, resulting in unevenly sized parisons. Plus, he claims, lifting the entire extrusion unit makes for easier head changes.
Crowded field adds a player
New to blowmolding machine manufacturing is Gefit (Fubine), an established manufacturer of injection molds for preforms and closures. Mauro Martinegro, sales engineer, says the firm wants to extend its customer base with its Gefblow 4002 electric linear stretch blowmolding machine. Currently only one model is available, a four-cavity machine for bottles from .33 to 2 liters. It requires only 30 to 32 bar pressure, compared to about 40 bar on standard machines of this size, he says, so processors can save on air compressor costs. Output ranges between 5200 and 6000 bottles/hr. Only one mechanical adjustment is required when changing tooling; all other adjustments, such as lamp settings, stretch dimensions, and blow time can be set at the control panel.
Not at the exhibition was a hybrid hydraulic/electric extrusion shuttle blowmolding machine running dry cycles at Uniloy Milacron’s plant in Magenta. Luca Bertolotti, technical manager, says the machine is equipped with a hydraulic clamp and an electric injection system made in conjunction with Milacron sister firm Ferromatik Milacron (Malterdingen, Germany).
The last six months have been very good for accumulator head machine sales at Uniloy, according to Bertolotti. "We’ve an excellent backlog, about eight machines through the end of July," he said at Plast. Typically these machines, with accumulator heads sized from 1 to 80 liters, are bought by processors of industrial containers. Giovanni Mora, sales manager at Meico (Monza), says the firm will soon introduce an accumulator head machine for blowmolding complex automotive parts, such as polyamide fuel lines.