Blow molding.

Most of what follows are additional details on new machines reported in our May show preview. These include machines for bottles, large industrial parts, and stretch-blown PET. But at NPE there were also new developments not previously announced in continuous-extrusion and reciprocating-screw machines, as well as multi-cavity in-mold labeling, multiparison coextrusion, preform testers, bottle leak testers, controls, and downstream automation.

LARGE-PART MACHINES

Cincinnati Milacron's U.S. Plastics Machinery Div., Batavia, Ohio, showed its new Eclipse T line of large industrial blow molders (see PT, Nov. '93, p. 15). Some of the unusual features on these machines include two diagonal tiebars on the clamp, which are said to facilitate mold changes and robotic part removal. Platens are designed for high rigidity (max. deflection of 3 mils/ft) and have extra-wide support bearings riding on the frame. In addition, Milacron has borrowed some hydraulic features from its injection presses: Four rapid-traverse cylinders for opening and closing are supplemented by two high-pressure rams for clamping. Once tonnage is built up, the clamp prefill cylinders close, locking in the tonnage and allowing the machine's variable-volume pump to drop down to an energy-saving low-volume mode.

Milacron added several features to facilitate mold and head changes without resorting to roll-out clamps, which require extra floor space. Instead, the extruder can travel 39 in. laterally to pull the head back from the mold area, and a motor with chain drive on each end of the machine can raise by 24 in. the entire extruder platform. In addition, the head has its own separate provision for up to 8 in. vertical and 20 in. horizontal alignment with the mold.

DESIGNED FOR SIMPLICITY

A new continuous-extrusion machine from a new domestic source is designed for versatility, easy maintenance, and quick job changeovers in short-run molding. The VersaMatic Model 2165 is the first machine from Jackson Machinery, Port Washington, Wis. (sister company of injection-machine builder Rochester Plastic Machinery Inc. at the same location). This machine has a 60-mm, 140-lb/hr vertical extruder mounted on a post for easy height adjustment. The single 10-ton clamp has single-point die-height adjustment so that it can accommodate tooling with backing plates from other makes of machines. It comes with up to three heads for making parts up to 2 gal. Dry-cycle time is 1.9 sec.

Features include easily accessible water valves, indicator lights on proximity switches, plug-in heater-band and thermocouple wiring, drawer-mounted pump (fastened with five bolts), quick-change molds (four bolts), and an easily removable servovalve. Price is about $150,000 for a three-head model.

IN-MOLD FILM LABELING

In-mold labeling, said to be a relatively new capability for multicavity shuttle machines, was demonstrated on a double-sided H-155 machine by Bekum America Corp., Williamston, Mich. The machine molded 18-oz oval HDPE bottles in four cavities per mold with in-mold labels at speeds of 2400 bottles/hr. Film labels of a PE/PP blend (designed to simplify recycling) were supplied by Avery Dennison's Decorating Technologies Div., Framingham, Mass. Avery Dennison also provided the robot label inserter. This system is being used in round-the-clock production on 10 twin-station H-series machines, and five more are on order.

NEW SHUTTLE MACHINES

Bekum also showed one model in its newly redesigned BM shuttle series. Replacing the BM-02 and BM-03 lines, the BM-04 models have been modified for greater flexibility, full automation, and higher productivity. They have larger platens for higher cavitation, increased centerline distances, greater clamping forces, and streamlined overall construction. The latter includes integrating the control cabinet into the machine frame to save floor space and mounting the operator control panel on a swing arm. Besides the traditional three-stage take-out system, BM-04 machines can use a new, simple "handover" system. This version reportedly provides controlled take-out with minimal dedicated tooling, facilitating frequent, fast changeovers. Quick-change features are also provided for molds, trim tooling, and blow pins.

The first model introduced is the U.S.-built BM-304D (also available single-sided) for containers of up to 5 liters (single cavity). Bekum also plans to build here the BM-504D (up to 12 liters) and BM-704D (to 15 liters).

Heins PCM Machinery Ltd. of Brampton, Ont., has come out with three new continuous-extrusion models, including larger sizes than it previously offered. The largest is the CM8000D double-station model for parts up to 8 liters. A "T" version has oriented bottle take-out. Next largest is a new double-station CM5000D for parts up to 5 liters. Also new is the CM3000D(T) with four or six parisons for parts up to 0.5 liter.

The new Plastiblow PB 2000/D continuous-extrusion machine from Plastimac of Italy (represented here by American Jet Stream Inc., East Brunswick, N.J.) has an extruder and head that rock up and down on each cycle, while the dual molds travel horizontally. (This configuration is said to be superior to the diagonal shuttle movement on earlier models.) Position of each blow pin (up to three) is adjusted from outside the machine.

The new unit comes with MACO 6500 control, which is custom programmed with several new features. For example, a "double blow" cycle blows the bottle first at lower pressure, then flushes the bottle with a second puff of fresh air at higher pressure. This second puff is said to speed cooling.

Also, a "pre-lift-up" cycle counters the tendency of small PP bottles to shrink and stick to the blow pins. After blowing, before the bottles have fully cooled, the blow pins retract and are re-inserted only a few millimeters into the bottle neck.

For large containers, Plastimac's "parison vacuum delay" cycle is designed to prevent surface defects caused by the hot parison touching the cold mold in one spot before it is fully blown. The approach is to partially preblow the parison, then suck back some of the air before the mold closes, and then fully blow the container.

ENLARGED RECIPRO-SCREW

Hycon, Inc., Manchester, N.H., recently expanded the clamp on its MHC 20-3.5 reciprocating-screw extrusion blow molder (3.5-lb shot capacity). The 20-ton machine can now handle molds up to 28.5 in. wide and 36 in. long.

NEW COEX CAPABILITY

Meredith-Springfield Associates Inc., Springfield, Mass., reports that three-layer continuous-extrusion coex heads from W. Muller KG of Germany now can run up to 10 parisons. A relatively new application of such a head is putting a half-mil layer of nylon on the outside of HDPE perfume bottles for glossy appearance and aroma barrier. The third layer is an adhesive resin.

FOR ORIENTED BOTTLES

Sidel Inc., Atlanta, revealed more about the nature of its new "preferential heating system" for PET bottles. This temperature-zone profiling system was demonstrated in molding a flat 16-oz salad-dressing bottle. Because the flat-bottle preform must stretch much more in one direction than the other, the preform is conditioned with the aid of a vertical heat shield that rotates along with the preform and "shades" two sides of the preform that will become the short sides of the bottle. This system requires that the preforms be positioned properly in the blow mold so that the cooler side becomes the short side of the bottle.

Krupp Corpoplast, Edison, N.J., reports that its B 66 machine, originally introduced at K'92 with a capacity of 6600 PET bottles/hr, has now been upgraded to 7800/hr. Corpoplast also has designed a new and bigger model, the B 177, with 16 molds and output of 17,600 bottles/hr.

The ASB-70 DPH injection-stretch-blow machine was introduced to the U.S., along with a "T" version for multilayer bottles, by Nissei ASB Co., Atlanta. Touted for its wide- and narrow-neck molding versatility in up to 12 cavities, this 70-ton machine has output capacity between those of Nissei's ASB-250 and 650. A new feature (to be adopted on the ASB-250) is electric turret rotation, which is said to be faster and cleaner than hydraulic. Also, melt drool is prevented by maintaining contact between the injection nozzle and hot-runner manifold. And a new optional Siemens flat-panel display on a swing arm features attractive 3-D graphics.

Aoki Technical Laboratory Inc. of Japan (represented here by Formex Inc., Dayton, Ohio) has learned how to balance its hot-runner system to permit molding odd-numbered cavity configurations. Aoki demonstrated molding of 1-liter PET mineral-water bottles in five cavities.

Magic North America Inc., Markham, Ont., reports that its BMA injection-stretch-blow machine has been modified to accept Nissei ASB tooling.

Bekum reports that it has developed a reheat process for making oriented PP bottles on its RBU stretch-blow machines. Two models produce 1800 and 3600 bottles/hr.

PREFORM TESTERS

Three firms showed new systems for q-c testing of PET preforms. TopWave USA, Inc., South Plainfield, N.J., introduced a Preform Quality Tester (PQT) based on technology licensed from Eastman Chemical Co., Kingsport, Tenn. As an alternative to expensive and time-consuming testing of I.V., Eastman found that a much simpler method of measuring "natural stretch ratio" (NSR) correlates well with I.V. and accurately reflects the effect of I.V. on blowability. (NSR represents the optimum blow-up ratio for a given preform to achieve maximum orientation.)

The NSR method involves reheating the preforms in a temperature-controlled water bath and blowing them without a mold so that they are free to expand without restriction. The volume of the blown preform is measured, giving an NSR value that corresponds to I.V.

A number of preforms can be loaded into the PQT for automatic testing. Test conditions for up to 20 different preforms can be stored in memory. Results can be output to a PC for SPC analysis.

A different sort of automated preform inspection system was introduced by Optical Gaging Products Inc. (OGP), Rochester, N.Y. The Q-See 400 video measuring system uses a motorized, multi-station rotary fixture and video camera to measure preform neck, body, and tip dimensions in several positions. The system provides real-time SPC output, including on-line CRT display of control charts as samples are measured.

BOTTLE LEAK DETECTOR

New leak detectors for blown containers include the RS-4 from Wilco of Switzerland, sold here by PTI, Tuckahoe, N.Y. It can test bottles from 1 oz to 1 gal on-line at rates of 50-120/min. Fast and easy changeover for different containers requires only one part change.

CONTROLS TWO PARISONS

A new feature of the TMC (Total Machine Control) system from Moog Inc.'s Electronics & Systems Div., East Aurora, N.Y., is that it can now control parison programming on two machines independently. Each machine can have up to four heads and the cycles of the two machines do not have to be in synch.

DOWNSTREAM AUTOMATION

MTM Systems Inc., Beaverton, Ore., has added a demoiler to its 2001LCT-7 takeaway system. The servo-driven system is readily adjustable to different bottle sizes and is designed to work primarily with Bekum and Battenfeld machines.