Blow molding.

Blow molding news at K'95 was most highly concentrated in the field of oriented bottles. One new supplier - Pioneer of Japan - made its debut with a line of reheat stretch-blow machines (see PT, Nov. '95, p. 12). Other suppliers brought out several new stretch-blow machines with higher outputs and greater efficiency and flexibility. PEN was hot, too: Five machine builders gave PEN molding demonstrations, while two others displayed finished PEN bottles.

In extrusion blow molding, foam-core coextrusions attracted particular attention.

PET BOTTLE OUTPUTS CLIMB

A new world's output record is claimed for Sidel's new SBO 48/38 reheat stretch-blow machine. Up to 50,000 PET bottles/hr in 0.2-0.6 liter sizes are molded with 24 two-cavity molds and 38 oven banks. Each mold has two cavities spaced 80 mm apart, which enables two identical preforms to be blown simultaneously.

Sidel also introduced the SBO 1, which is now the smallest in its line. It produces up to 1200 bottles/hr, making it the world's fastest single-cavity PET machine, Sidel claims.

In addition, Sidel demonstrated a brand-new quick-change system that is claimed to save at least 75% of downtime for tool changes. A combination of magnetic clamping and mechanical quick-fastening systems is used to change molds, stretch rods, feeding and guiding components, transfer arms, and water lines. The quick-change system will gradually be phased into the SBO line, and the possibility of retrofits is being researched.

Nissei ASB Co. has supplemented its well-known ASB injection stretch-blow machines with a new PF series designed to provide higher productivity, greater compactness, and lower tooling cost. Two sets of injection cores operate alternately with one set of injection cavities, which allows the next injection cycle to begin while the first preforms are still cooling on their cores. Nissei says the result is up to 25% shorter preform molding times.

A new preform handling system allows the blow mold to cycle three or four times faster than the injection station, reducing the number of blow cavities and, therefore, tool costs. Also, the hot runner is designed as part of the PF machine, eliminating the need to purchase a hot runner for each mold. The new machines reportedly take up about half the floor space of older models and provide 30% greater output per dollar of investment. What's more, tool-change times are cut to two hours.

Nissei ASB offers this system both in one-stage (all-in-one) and two-stage (separate preform injection and reheat-blow) versions. Two-stage models include a preform machine and a reheat-blow machine. The PM-45 preform machine uses a combination of electric drives and variable-volume pumps to reduce energy consumption by up to half and is designed for outputs of approximately 1800 preforms/hr from eight cavities. The new NB-20 PET reheat stretch-blow machine can produce up to 2000 1.5-liter PET bottles/hr from two cavities. The HS-45 hot-fill reheat machine reportedly makes bottles that withstand 185 F at rates up to 1200/hr.

Three new models of high-output ECS machines for integrated injection stretch-blow molding were introduced by SIPA S.p.A. of Italy, which has a new U.S. office. The ECS line utilizes continuous extrusion and alternating injection into four preform mold sets, two on each side of the machine. This system is said to provide increased outputs and flexibility to produce containers of different shapes and weights on the two sides of the machine. The new ECS models 64, 80, and 96 (signifying the numbers of cavities) can mold bottles from 0.25 to 2.5 liters. Max. outputs for l-liter bottles range from 16,450/hr on the ECS 64 to 26,600/hr for the ECS 96. For 0.25 liters, outputs are from 18,000 to 27,000/hr, respectively. The new models reportedly feature 20% lower energy consumption than previous ECS machines, quick changeovers, and heat-setting capability without any modifications.

As reported previously (PT, Sept. '95, p. 63), Krupp Kautex commercialized the first in a line of integrated injection stretch-blow machines for PET and PP. The KBS 5-1500 has one extruder that runs continuously, feeding accumulators at two injection stations. The twin 66-ton clamping units are mounted perpendicularly to each other and the pair rotates 90 [degrees] between injection and transfer positions. Preforms are passed to a four-station rotary system for conditioning, preblowing (for PP), blowing, and ejection. The first model can make from 720 3-liter bottles/hr in two cavities to 3600 0.25-liter bottles/hr in eight cavities. Quick-change couplings are provided on the hot runner, molds, and conditioning units.

MORE ALL-ELECTRICS

The trend toward clean, quiet, energy-efficient all-electric operation is less developed in blow molding than in injection but is still progressing.

The new SSB-25 all-electric reheat stretch-blow machine from Mag-Plastic has a two-cavity blowing unit to produce PET containers at up to 2500/hr. The servo-driven clamp consumes half the energy of a hydraulic clamp, according to general manager Jean Gallay.

A new 7-ton all-electric extrusion blow machine from Tahara of Japan will be marketed here in about six months by Battenfeld (now exclusive marketer for Tahara in Europe and the Americas). The all-electric machine reportedly consumes 30% less energy, is more precise in its motions, and requires less maintenance.

FOAM COEXTRUSION ARRIVES

Along with Borealis of Norway, Krupp Kautex developed a foam blow molding technique for making pallets, collapsible boxes, auto parts, and panels (PT, July '95, p. 14). The technology has been used commercially for about six months to make three-layer solid/foam/solid HDPE parts on a KB 250 continuous-extrusion machine using two extruders. One has a special screw for mixing in the foam masterbatch.