Optimization the name of the game

Controls are essential to optimizing processing across all plastics segments, and process control makers—and even some systems integrators—continue tweaking their products and services to maximize efficiency and productivity, and minimize waste. Keying in and controlling variables such as mold temperature, melt temperature, flow rates, and some specific variables such as sheet sag and zone heating (in thermoforming), or consistency of wall thickness in sheet and tube/pipe extrusion, has always been the aim of process controllers.At FACTS Inc. (Cuyahoga Falls, OH), which designs and supplies closed-loop processing control systems, Tim Fisher, a company principal, says the company’s “interest is in the larger systems where we are integrating the whole process, such as inline thermoforming where we can tie the entire line together from resin feed system to finished product.”He says integrated processing control systems are increasingly important as the cost of materials, along with the cost of energy to run the machinery, goes up. “Keeping the power going to a large extruder is pretty expensive,” he notes. “Our approach is to integrate the entire process from material handling through finished product. Retrofits are big business for us right now because upgrading is done more often than purchasing new machinery. We offer solid paths around obsolescence.”FACTS’ systems include data capture and analysis of process variables and events, for workflow optimization, analysis, and record keeping. “You select the recipe and that sets up the whole machine, including which silos are being selected for material delivery, temperatures, speeds, wall thickness for pipe, sheet, or film profiles. We can provide new measurement systems with fewer opportunities for error, faster start-ups, and all operational conditions that will historically give you the right product consistently run after run,” says Fisher.The benefits to an integrated system are that an operator spends less time checking the feed systems, process parameters, and such, explains Fisher. “We want to facilitate the operator’s job and let him or her do what they do best and eliminate the isolated islands of operation,” says Fisher. “To have separate pieces controlling each parameter, each with its own interface, and each requiring an operator to enter information, doesn’t make sense. We provide a complete integrated solution all on one screen that alerts the operator when something needs attention.”FACTS uses a combination of instrumentation and software from a variety of suppliers. “We’ve been investigating and coming up with our own, or, more frequently, other measurement systems, that we can incorporate into our overall systems approach to address processing parameters that may have been overlooked previously,” says Fisher. “For example, we can measure individual layers in film processing, or where there are coatings involved, and control them, where before these were invisible issues. We use an optical device to measure this.”Fisher says that it’s not so much the brand of various process controllers being used, whether it’s for temperature, flow, or other process parameters, but how an entire system can be integrated to facilitate and optimize processing. “We’re selling a total solution that incorporates all that,” he says. “Temperature control is temperature control. What matters is how you tie all that together and make it work as an overall system for the entire process so that individual parameters are no longer a major focus of what the operator is doing.”At competitor Athena Controls Inc. (Plymouth Meeting, PA), new is its Series RMT microprocessor-based dual-zone temperature controller for runnerless molding applications. Specifically designed to provide two zones of control per slot, the controller accepts Type J thermocouples and effectively doubles the zone count per module without doubling the price or expanding the footprint. Doug Krowell, marketing and sales manager for Athena in the U.S., explains, “Before, if you had 12 zones you had to have 12 controllers. Now, you need just six controllers, which saves space and provides a smaller footprint.”Krowell says Athena first designed the RMT controllers for processors in Hong Kong, where manufacturing plants tend to be located in tall buildings and space is at a premium, but that they are ideal for anyone with limited space. Key features include two operator keypads, four LED displays, and discrete indicators for heat output, alarm, degree of F/C indication, manual-, and closed-loop mode.CoolPoint vortex shedding flowmeters from Universal Flow Monitors Inc. (Hazel Park, MI) are non-mechanical meters that can measure and monitor recycled water containing particles. Unlike mechanical switches, the meters have no moving parts to stick or coat, eliminating potential for clogging by these particles. The flowmeters are offered in pipe sizes ranging from 0.25-4 inches, providing 4-20 mA transmitter flow rates ranging from 1.5L per minute (0.4 gal/min) up to 2271 LPM (600 GPM)The CoolPoint meters’ accuracy and repeatability are said to provide the flow consistency needed for consistent cooling, production control, and quality continuity. CoolPoint models are available in 0.5- inch through 2-inch pipe sizes with +/-1% full-scale accuracy; +/-2% FS accuracy is standard on all models. Flow repeatability of +/-0.25% of actual flow is standard on all models. Flow totalizing capability is available to increase the CoolPoint flowmeters’ ability to measure, monitor and control the total amount of cooling water used in a process.West Instruments (Gurnee, IL) is offering a retrofit upgrade for extruder and other temperature-control systems. The modular KS Vario control system can handle up to 30 temperature-control zones in widely varying setups. Without any additional hardware, users get a multi-loop control system with a complete range of functions at a very attractive price, says the company. The BT Vario comes with an HMI industrial color touchscreen, connecting cable, and integrated multiloop controller. Standard features include high and low set-point alarms and ammeters for each heat zone, 110-recipe storage, grouping of zones, Ethernet port, self-tuning, and password protection. Software is preloaded and all screens are standard.Athena Controls | www.athenacontrols.comFacts Inc. | www.facts-inc.comUniversal Flow Monitors Inc. | www.flowmeters.com West Instruments | www.westinstruments.com