Single-station Output Up

With more than 2000 bottles and containers on its stand, Aoki made it difficult not to look around. At NPE, however, the container display was background for a brand-new generation of single-stage injection stretch blowmolding machines, represented by the SBIII-250LL-50S. When it was turned on, the machine made 125-ml yogurt drink PET bottles in an eight-cavity mold. It didn’t run for long, though—not at 5000 bottles/hr. The productivity gain in this new machine is noteworthy; the previous generation could produce only 1500 bottles/hr.

The rotating mold table in the machine has three stations: preform molding, stretch blowing, and ejection. Aoki continues to use its patented Direct Heatcon technology in this model, thereby eliminating the need for reheating the preform. Heat conditioning takes place in the preform mold. Transfer and stretch blowmolding are done in a time window designed to have the preform at optimal temperature for bottle formation. Aoki says the lack of separate reheating saves energy costs, besides providing a very stable parison in the blowing station. This stability allows the machine to make both wide and narrow mouth varieties of containers.

Besides PET, this system handles PP, PC, PEN, SAN, PE, PES, PA, and even recycled PET flakes. It also supports off-center and highly ovalized product shapes. Other benefits include a small footprint, simple operation, low maintenance, and a low reject rate. Aoki says that with an FOB price of $370,000, high output rate, and the ability to handle small, variable production lot sizes, this machine has an excellent ROI profile.

Electric Machines Upsizing

The EP-L3/D all-electric extrusion blowmolding machine, new to the U.S. this year, extends Magic North America’s range in electric systems up to 3-liter containers. As with injection molding machines, the first thing you hear about electric blowmolding is the energy savings vs. hydraulic systems. Magic says the energy savings for its electrics is in the range of 50 percent, but the company is emphatic that this is but one of the advantages. Cooling capacity can be reduced by 30 percent. The precision of the electric drives improves both yield and product quality, and Magic emphasizes that the precision remains high over a long life cycle. Clamp force can be adjusted to the exact level needed by a particular container.

The machine is much quieter than a comparable hydraulic system. The lack of hydraulic fluids means the machine is clean, and Magic is actively promoting it for medical and other cleanroom applications. Maintenance, Magic says, costs 75 percent less in time and expense than a hydraulic system.

Magic is no newcomer to electric blowmolding machines, having launched the first one in 1997 to make small pharmaceutical and cosmetic containers. The new EP-L3/D is optional with single-, dual-, triple-, and quadruple-head configurations. The footprint remains compact and the controls are user friendly. An undisclosed number of these machines have been running for some time in full production conditions.

The Industrial Side

Davis-Standard showed a 30-lb Sterling accumulator head with features designed to help open new large applications on the industrial side of the blowmolding sector. Its spiral diverter technology uses overlapping double-helix geometry to minimize temperature and flow variations in the melt for optimum parison wall distribution. The design eliminates knitlines in the finished product. The streamlined flow channels and the elimination of stagnation points allow faster purging during color changes and reduced material consumption during product changes. The technology is now standard on all Sterling accumulator heads and can be retrofitted on various existing units.

Taking on new applications in larger products such as outdoor furniture requires larger parison layflats to deal with the material’s memory effect. An obvious solution would be to increase the head size, but the cost would be high. Using a more economical response to this challenge, Davis-Standard accommodates tooling to 559 mm (22 inches, up from the normal 18 inches), which allows blowmolders to produce larger layflats with reportedly excellent parison control. The new head design also features a solid bronze push-out plunger designed to eliminate material degradation and carbon contamination in the parison by minimizing resin bleedoff.

High-output Rotary Design

NPE 2003 marked the American debut of Sipa’s SFR 16/32 high-output, two-stage rotary stretch blowmolding machine. Using two sets of 16 cavities, the system can produce up to 40,000 bottles/hr and can make containers up to 1-liter capacity. Reduced pitch between molds means a smaller wheel diameter, which minimizes floor space requirements. The system offers quality monitoring of the preforms through shape detection at two locations by optical and mechanical means. The optical control is a sensitive video camera placed just before the ovens, while the mechanical control consists of a pyrometer that measures preform temperature and ejects any preforms outside the thermal window of tolerance. It is possible to regulate final stabilization with variable inversion time. SFR machines handle round, square, and even custom-shaped PET bottles as well as multilayer bottles, PET pasteurizable bottles, and PEN bottles. The machine’s design facilitates quick mold change.

Large, Medium, and Small

Bekum America introduced new models in both its single-station and dual-station blowmolding machine lines. The single-cavity BA-25, which is capable of molding containers up to 30 liters (8 gal), includes completely integrated automation, a hydraulic trimming station, and upright container discharge. With a 200-kN (22-ton) platen suitable for large molds, the BA-25 is aimed at 5-gal water containers in PC/PP, 20-liter automotive lubricant PE containers, or 20 to 30 stackable HMWPE canisters. The machine’s footprint occupies about 11 sq m, which Bekum says is small for a 30-liter-capable system. Optional accessories include view stripe, parison stretching, needle blow, and moving mold section control.

The high-output, double-station Bekum BM-406D is ideal for smaller bottles, but also makes containers up to 12 liters. Clamp dimensions and closing force have been increased to allow for larger cavity centerlines and production of technical parts as well as containers. All linear mold-carriage movements in Bekum “06” machines are made on precise guide rails; this allows more speed, shorter travel distances, low energy usage, and longevity of the guidance system. The modular design concept of the automation cells allows functions such as post cooling, trimming, leak testing, and all the rest to be integrated into the main machine base as needed, and adapted to other products.

More Output

High productivity was the thread connecting the stretch, extrusion, and industrial blowmolding systems in the SIG Group exhibit. SIG Corpoplast has already raised the output levels of its still-recent Blomax Series III line. During NPE, SIG demonstrated the SBM BloMax 20 Series III system making half-liter water bottles. Guaranteed output for this machine is 1500 bottles/hr/cavity. Depending on preform and bottle design, this system can produce up to 30,000 bottles/hr. The Series III machines employ SIG HR technology for hot fill, which includes advanced temperature profile and overall process control, a special hot-fill mold design, reduced cycle times, and modular ovens to match the pitch and form of the bottles.

The double-station SIG Blowtec BlowPac 4/6-100D system featured at NPE included the new Windows NT-based BlowCommand 004 controls. The software now offers remote direct access to the machine controls and direct interface with the control panel. The BlowPac 4 Series can handle cavitation from 2x4 to 2x12 on 100-mm centers using its 180- to 400-kN clamp range. The SIG Kautex SB-8 suction blowmolding machine at NPE is part of a line designed for large technical parts like auto fuel tanks and other containers up to 5000-liter (1321-gal) volume; it molded dual-durometer automotive components.

Sidel said it would hit a record production rate for PET bottles live at NPE. The goal was 3000 bottles/hr/mold in a 20-mold (dual-cavity) Sidel SBO 20 DC system, or 60,000 bottles/hr. When it was turned on, we saw the counter go over 60,000—and that was not the only goal achieved. Sidel has reduced the blowing costs per bottle by 15 percent since the SBO Series was introduced in 2000. Among the contributing improvements: a new 18 percent lighter mold support unit, a U-shaped oven using 40-mm pitch to reduce footprint, and blowing air recovery that reduces the size and cost of the compressors. Optionally, a single-cavity configuration can produce containers up to 3 liters and a 50-mm-pitch oven is available to heat preforms like a 43-mm wide-mouth VHS. An available HR kit supports making packages for hot-fill or pasteurized beverages. Sidel says the previous record holder was one of its clients in England producing 53,000 bottles/hr on a complete bottling line. Sidel began making dual-cavity machines 10 years ago for soft drink makers and there are now 43 of the machines operating around the world.

Advancing on All Fronts

Graham Machinery Group (GMG) displayed machines from its entire range of blowmolding technology, including some brand-new ones. The newest addition to GMG’s water bottle production line is the C30, a reciprocating screw system developed from the Improved line acquired by GMG a few years ago. At NPE, it was running 5-gal PC water bottles. The flow-through die head and the 24:1 L/D reciprocating screw permit high clarity in the finished bottles. The head design prevents material degradation while eliminating the need for frequent disassembly and cleaning. Clamp speed is faster and mold change time has been cut in this design. The in-system trimming/deflashing unit can be retracted from the machine base for easy access to the head, mold, and deflashing unit itself. Depending on bottle weight and design, the C30 can make 120 to 150 5-gal PC water bottles/hr.

GMG’s new GEC4/600 is the next generation of the company’s high-volume rotary shuttle systems, combining wheel technology with the calibrated necks associated with shuttle machines. This four-station indexer, which uses Muller extrusion heads for the calibrated necks, can have up to eight parisons and 32 cavities. The platens on each of the 15-ton clamps are rail-guided for uniformity of force application and parallelism during mold close. As with the C30 system, control is handled by GMG’s XBM Navigator PC controller. The simplified MMI offers 100-point parison programming and data storage that allows much improved monitoring and tracking of production trends. The XBM Navigator is available now across the full GMG line and can be retrofitted to many existing systems in the field.