Auxiliary equipment 2000.

Everyday workhorses are about to learn some high-tech tricks. Wireless communications and novel energy sources are coming soon to materials-handling, size-reduction, and mold-cooling auxiliaries.

Ready or not, the next millennium is a mere five years off. It's not too soon to ask what sorts of new developments processors can expect to see in auxiliary equipment. Will the next century bring major technological changes or just incremental improvements?

PLASTICS TECHNOLOGY found several equipment suppliers quite ready and willing to give some concrete answers to those questions. They extrapolated on current trends, shared clues about leading-edge R&D, and hinted at specific changes that will surface in the next five years or so in pneumatic conveying, blending, drying, granulating, and chilling. Microwaves, ultrasonics, fiber optics and infrared lasers will give a new look to otherwise familiar hardware.

STRIDES IN COMMUNICATIONS

Some of the most dramatic changes in the next few years will involve communications both inside and outside the plant. Rick Gilmore, systems sales manager of Novatec, Inc. in Baltimore, says his company is very close to introducing controls that will be "media-independent." For example, the customer will have the option of utilizing low-voltage (12-v) plant wiring as the means of communication between components of a pneumatic materials-conveying system. "The whole concept is designed to cut costs to the customer," he explains. "Controls at each vacuum receiver will be wired back to a central communication panel by way of a common low-voltage cable, making it more economical than current wiring systems, which involve use of a lot of conduit and high installation costs." The technology could later be used to tie in other auxiliary equipment, he adds.

Novatec is not alone in perceiving the advantage of such a system. Universal Dynamics, Inc., Woodbridge, Va. introduced at NPE '94 an "Echo" distributed-control system for materials handling that communicates and supplies system power over low-voltage lines (see PT, May '94, p. 127).

A next step, suppliers say, will be remote dial-up access to auxiliary equipment and molding machines from a host computer for diagnosis and service support. (Such a service is available today for molding presses.) Future conveying systems will communicate materials-usage information to a central plant computer, updating inventory data and allowing the plant's purchasing department to electronically dispatch or adjust orders for just-in-time delivery. Even if the plant does not operate on a JIT basis, such information could keep processors from running out of material or, conversely, over-ordering material they don't need.

RESIN ORDERS VIA SATELLITE

Michael Peyser, manager of marketing services at AEC, Inc., Wood Dale, Ill., expands this concept by noting two methods of computer-aided resin reordering, one that would be driven by the processor and the other by the resin supplier. The first entails the use of EDI (electronic data interchange), whereby the processor's host computer would receive sensor data from a silo or conveying system that indicates a low material inventory. Then the computer would transmit a preformatted order to the supplier. This technology is commonly used

today by the food, apparel, and automotive industries.

The second method would entail the resin supplier monitoring the customer's resin inventory directly via satellite or high-speed modem connection. Through automatic dial-up, the resin supplier could access the processor's silo information system to obtain quick inventory data. Resin reordering would be accomplished by comparing that information to the inventory level the customer typically requires.

Wireless communications within the plant are also being looked at by some suppliers. A host computer would send a message via a radio transmitter located in the production manager's office to each equipment controller, which will have its own code or "address," explains Novatec's Gilmore. This could save on wiring costs, but Gilmore notes that radio transmitters are currently much more expensive than "hard wiring" and are subject to disturbance from external noise.

Meanwhile, AEC's Peyser envisions that microwave or radio-frequency (RF) wireless communication could enable supervisory personnel to monitor machine operating conditions at all times, from any location. For example, the plant manager might carry a "personal digital assistant"--a combination beeper and hand-held PC with a small display--from which he can receive updates or alarms from the plant's auxiliary or primary equipment controllers.

LOADING VIA LASER

Another equipment supplier hinted that infrared laser beams--similar to those used on a tv remote control--might present another means of wireless communication. Hopper loaders, for example, might call for more material by signaling an infrared receptor on a control box mounted on the ceiling. However, this approach could be limited by its reliance on line-of-sight communication between i-r emitter and receptor. Any object blocking that path would disrupt communications.

Peyser thinks in-plant wireless communications will be applicable primarily to mobile auxiliary equipment that is shared among several machines. He sees a more widespread trend toward reduction in electrical wiring. One alternative is fiber-optic cables, which are immune to electromagnetic noise and can carry more signal traffic than a comparably sized metal conductor. Fiber optics, which are now used in some primary process equipment, may be used to connect auxiliary and primary machinery control systems.

EVOLUTION VS. REVOLUTION

Some changes in auxiliary equipment by 2000 will merely reflect continuing refinement of existing technologies. "Advancements will not be revolutionary as much as evolutionary," says John McLeod, v.p. of Thoreson-McCosh Inc., Troy, Mich.

The most notable evolution in auxiliary equipment will come in the area of computer controls. Una-Dyn's Cosner foresees a fusion of today's discrete controls for each item of auxiliary equipment into a unified overall system control. "Fully integrated, closed-loop, real-time system controls will most likely begin to appear at about the turn of the century. They will be integrated in the sense that the primary processing-machine control will also monitor and automatically adjust the operations of auxiliary equipment to optimize overall processing performance and energy efficiency."

Controls of the future will likely be based on PC or PLC platforms using standardized off-the-shelf interface hardware and software. Suppliers expect increased use of user-friendly operating systems such as Windows, along with controls that are more modular and distributed, replacing today's centralized architectures. Distributed controls using serial bus technology will be easier to reconfigure for new applications and changing user needs, says Ken Bullivant, chief technical officer of K-Tron International Corp., Pitman, N.J.

Increased modularity of equipment designs for inexpensive customization, standardization of controls for worldwide use, and miniaturization of components for space savings are among significant changes predicted by Jack Downie, president of Conair Franklin in Franklin, Pa. "Expect to see all of the world's voltages and electrical codes integrated and standardized, as will be specs related to survivability of equipment in harsh environments--i.e., heat, cold, and dust." He adds that future controls will "speak" multiple languages (English, Spanish, German, etc.).

AEC's Peyser says controls on materials-handling equipment of the future will be more sophisticated at performing material analysis at the press. "We're finding that people want to know the exact conditions of the material when it is entering the mold." This could involve using a variety of sensors in drying and conveying devices to provide data on parameters such as temperature and moisture content.

QUICKER CHANGEOVERS

Other incremental improvements will produce equipment that better lends itself to quick material changes. "People increasingly want to run more and smaller batches, requiring equipment that can be easily 'broken down' for ease of cleanability," says K-Tron's Bullivant. Improvements in energy efficiency, safety, and noise levels will also emerge. Says Bullivant, "Manufacturers here [in North America] will look to conform to European Union requirements for safety and perhaps noise, which are more stringent than ours. This will be driven by product-liability issues."

More prevalent use of post-consumer recycled plastics will also affect the design of future auxiliary equipment, according to some suppliers. David Cosner, director of marketing and sales at Una-Dyn, says you can expect to see modifications in granulators, pneumatic conveyors, hoppers, and bins designed specifically for post-consumer regrind. "PCR doesn't convey easily or flow properly through [today's] equipment, which increases the cost of handling."

AEC's Peyser adds that blenders, feeders, dryers, and granulators will be designed to handle a higher percentage of recycled material. "This equipment will be designed to more carefully preserve the integrity of the molecular structure and properties important for the end product."

THE OUTLOOK FOR DRYING

Current resin drying technology is fairly mature, says Pete Stoughton, product sales manager for Conair Franklin. Significant improvements in the future will require a change in direction.

Commercially practical microwave or radio-frequency (RF) drying is expected by some to emerge at the turn of the century. Considering the need for reduced dryer residence times, AEC's Peyser says, "We are all working toward technologies such as microwave or RF that can offer a continuous stream of dried material." There has been limited commercial experience with these technologies in Japan, but research sponsored here by AEC and Conair has produced little tangible result (see PT, Oct. '93, p. 66). Prohibitive cost, cumbersome physical size, lack of adequate process control, and considerable differences between various resins' behavior are hurdles that have yet to be overcome.

John McLeod of Thoreson-McCosh doubts that microwave or RF drying will be important in the short run. But Conair's Downie says RF drying technology can be expected from his company within a few years. Adds Novatec's Gilmore, "While microwave and RF still have drawbacks, you can dry material in less than 20 minutes, whereas it takes a minimum of 4 hr with conventional drying."

Less radical changes in drying technology will also make an impact by the next decade. Una-Dyn's Cosner says a major R&D emphasis will be on providing truly real-time automatic control of several drying parameters simultaneously--such as air flow, temperature, and dewpoint. "Dryers of the future will be capable of sensing moisture content in both the air stream and material and will optimize dryer operating conditions for both maximum performance and energy efficiency."

Cosner notes that greater energy efficiency will be promoted by development of lower-cost natural-gas burners for dryers as small as 100 lb/hr. Currently, gas burners are economical only for dryers used for processing at least 500-750 lb/hr.

FEEDERS & BLENDERS

Gravimetric feeding and blending systems are expected to predominate over volumetric types. Self-calibration has been one key advantage of gravimetrics--doing away with the manual calibration required with volumetric blenders. K-Tron's Bullivant says gravimetrics will also proliferate because of their superior accuracy and the increasing demand for process record-keeping, including records associated with meeting ISO 9000 quality standards. Higher cost has been the main disadvantage of gravimetrics, but suppliers say prices are already dropping.

Both Cosner of Una-Dyn and Rob Northrup, marketing director of Process Control Corp., Atlanta, say gravimetric blending will find use in a wider range of processes. "Historically, it has been used more in extrusion applications, but recent technology improvements have made it economically feasible to apply gravimetric blenders to low-volume injection molding applications."

"Expect to see advanced and more powerful microprocessor controls," says Pat Smith, business unit manager for blenders at Conair Franklin. "This could include increasing the accuracy of gravimetric equipment, such as conditioning the signal of load cells so it is electronically pure to get a very precise reading."

Smith also hints that his company is looking at new ways of metering. "It may be a hybrid of gravimetric and some other technology, but it will not resemble current gravimetric or volumetric feeding and blending systems. It could involve use of optical sensors and definitely more powerful microprocessors." He adds that Conair is aiming to deliver a system that will provide at least comparable accuracy but at dramatically lower cost.

New mixing methods to replace currently used mechanical mixing paddles are also being examined by Conair Franklin, according to Smith. "We are exploring technologies such as acoustics, which is already used in other industrial applications. For example, sound waves are used in dust-collection applications--each particle size will react differently depending on the sound frequency. We think this technology can also be used in mixing."

PNEUMATIC CONVEYING

Trends in pneumatic materials-conveying systems will include more sophisticated controls, brushless motors for longer service life, and increased use of central vacuum systems, dry-air conveying, and regenerative blowers for reducing noise.

Controls of the future are likely to monitor and adjust such conditions as vacuum and air volume to optimize a system's performance, says Cosner. "For example, conveying velocities will be varied according to a resin's propensity for degradation. Future controls will be sufficiently advanced to more readily adjust actual load times and signal when a particular hopper is being filled. Existing technology depends on pressure-sensing devices but is too expensive," he says.

Expect to see flexible conveying systems with a central source of vacuum or air pressure replacing independent hopper loaders, says AEC's Peyser. In such systems, a central conveying control monitors a group of hoppers and reads in-hopper sensors as it scans through the system to determine when material is low or high. "This technology is already taking over in big operations, but in the future it will become more economically viable for smaller plants," says Peyser. He agrees with Cosner that new systems will allow for finer control of material velocity to protect against degradation.

Taking a contrary view, Northrup from Process Control expects a trend toward use of more dedicated pumps for separate applications. "This way, you can keep sizes of your lines down, have less wear, and are not totally dependent on one system." He also suggests that future conveying systems will be regulated by the blending system's controller.

Increased use of dry-air conveying (see PT, Oct. '93, p. 59) is predicted by some suppliers. The disadvantages have been higher cost and complexity, according to Northrup. Still, he and Novatec's Gilmore say dry-air conveying will be driven by the trend toward JIT and the consequent need for short runs and quick material changeovers. Gilmore ventures that dry-air conveying, currently used by about 10% of processors, will approach 30-35% by the year 2000. "People will not spend the money if they don't see payback," he adds. "With this technology you don't see payback until you go to JIT."

Brushless motors will replace current brush-type motors, predicts K-Tron's Bullivant. "Brush-type motors have a very short service life--500-1000 hr. Our data show that brushless motors can go 10-15 times longer with effectively maintenance-free life." While brushless motors are about five times more expensive, they are also much more energy efficient--typically using about one-third less power than their brush-type counterparts. Energy cost savings could result in payback within two years, Bullivant estimates. "Brushless motors are only part of the equation," says Conair Franklin product marketing manager Amy Reissener. Concerning vacuum receivers, she notes, "We expect to see such items as noninvasive, foolproof discharge valves." She also foresees the advent of noncorrosive, noncontaminating, and perhaps even nonmetallic substitutes for carbon steel in loaders.

McLeod of Thoreson-McCosh and Gilmore of Novatec expect continuing development effort to make vacuum pumps quieter through use of regenerative air blowers in place of noisy positive-displacement types. With current technology, use of regenerative blowers is limited to smaller conveying lines. Explains Gilmore, "Positive air displacement is still better for conveying lines over 60 ft long, because regenerative pumps do not pull as a strong a vacuum."

QUIETER SIZE REDUCTION

While granulation technology is pretty mature, several incremental improvements will surface in new equipment. One major focus of R&D is noise control, which may benefit from application of leading-edge technology, according to product sales manager Bob Harrison and systems application engineer Brian Babineau of Conair Martin/Wortex, Agawam, Mass. This company has been examining use of active noise-cancellation control. It involves a microphone to sample the machine noise, a microprocessor to analyze it, and a loudspeaker to generate a sound wave that's 180 [degrees] out of phase. Broadcasting this "anti-noise" cancels out the other noise, explains Babineau.

Anti-noise technology is used in headsets for airplane pilots and vibratory-feeder bowls on assembly equipment (PT, Sept. '94, p. 69). Silencing granulators presents more of a challenge, Harrison cautions, because the noise is randomly variable rather than consistent. He's hopeful that use of advanced digital microprocessors will solve that problem.

Greater use of variable-speed drive controls to obtain energy savings is also projected by suppliers. Although these drives are not new, they are expensive, says Conair's Harrison, and they involve a tradeoff of energy savings for horsepower. "We are now looking at special variable-speed controls that utilize variable-pitch drive shieves, which will increase or decrease rotor speed without affecting horsepower."

Suppliers are also looking for new knife technology and rotor design to minimize fines and maximize wear resistance. Rapid Granulator, Inc. in Rockford, Ill., is evaluating new alloys for knives and cutting chambers because of the increased use of highly glass- and mineral-filled engineering resins. Kirk Winstead, v.p. of sales and marketing, says Rapid is looking at replacing traditional D2 tool steel with the likes of tungsten carbide or CPM 10V (a product of Crucible Specialty Metals, Syracuse, N.Y.). Winstead also hints that his company is evaluating a new hard-coating process that allows use of a less costly metal substrate underneath.

Conair Martin/Wortex is also looking for better wear-resistant metal coatings via new application processes, such as the "Super D Gun" from Praxair, Inc., Danbury, Conn.

David Hahn, v.p. of marketing for Cumberland Engineering Dip. of John Brown Inc., South Attleboro, Mass., sees a need for granulator suppliers to be able to customize each machine for each customer, while maintaining short lead times. Such "agile manufacturing" could utilize interactive on-line communication services between processors and equipment vendors. In this scenario, a processor would use on-line access to input his material application, cutting chamber, throat size, knife type, screen size, materials-handling, throughput, and delivery requirements. The supplier's computer will put all this information together to create specs for a complete machine and expedite those specs to the firm's engineering or manufacturing department.

CHILLERS AWAIT NEW REFRIGERANTS 

Some suppliers do not foresee major efforts to redesign chillers until about 10 years into the new century. Use of the remaining ozone-depleting refrigerants is due to be phased out by 2015. Future substitute refrigerants will likely prompt extensive redesign of chillers--starting with condensers, explains Harry Short, v.p. of Advantage Engineering, Greenwood, Ind. Chiller suppliers have already had to substitute HCFC-22 for banned CFCs (PT, Dec. '93, p. 70). Says Al Fosco, v.p. of sales for Conair Tempro in Elgin, Ill., "We are all waiting for changes from the refrigerant and compressor manufacturers before we expend any major R&D dollars."

Peyser of AEC ventures that between 2000 and 2010, new equipment designs will utilize an "ozone-safe" HFC or some other new type of refrigerant in place of HCFC-22. "Currently, there is no desirable substitute for R-22. HFC 134a is an improvement but requires significantly more horsepower per ton of chilling capacity. It makes sense to use it in some small chillers but not in large ones."

Tom Benson, v.p. of sales and marketing for Thermal Care, Niles, Ill., says one trend that will continue in both central and portable chillers is the use of plate-seal evaporators and condensers in place of traditional shell-and-tube designs. Plate types reportedly permit higher fluid velocities for better heat transfer between the refrigerant and water, and they require much less physical space. Yet another benefit is that they are more "forgiving" in the event of freeze-up, says Benson. "This is currently an expensive problem with shell-and-tube evaporators because a freeze-up usually damages both the evaporator and the compressor."

In central chilling systems, Benson expects to see greater use of variable-frequency drives to improve energy efficiency and extend life of circulating pumps. He also expects to see much higher usage of PLCs because they simplify process control.

Mold-temperature controls are not expected to change dramatically, as suppliers say there have been significant advancements in the last several years. Nearly all manufacturers have gone to all-cast construction to eliminate leak-prone fittings, higher-efficiency pumps to get more flow through the mold, and microprocessor controls. Says Conair's Fosco, "We are already there in terms of accuracy and speed."

Peyser of AEC suggests that mold-temperature control for more sophisticated injection molding equipment could become an integral part of the mold design--perhaps through integration of temperature sensors within the mold instead of measuring and controlling just the oil or water temperature.