Better Blending

Plastics processors know that the heart of a successful blending system is the controller. And with the rising costs of resins, additives and colourants, more than ever today’s controllers are expected to perform a greater variety of functions than just dispensing material.

“The [modern] controller must be able to accurately report material usages, alarm functions, set and control recipes, provide security to limit access to recipes and blender operation, and have the ability to receive downloads of updates and upgrades via a USB port,” Tony Crook, blender products sales manager at Baltimore, Md.-based Novatec, Inc., said.

This is a long list of demands to satisfy, but the good news is that blender controller manufacturers are answering the challenge, delivering touchscreen controllers with new developments to satisfy all of these requirements.

GRAPHIC ILLUSTRATIONS

Perhaps the most basic demand — brought about largely because of the growing complexity of the blender control itself — is for easier communication between controller and operator. “Communications is far and away the most important capability that blender controllers have to have,” B. Patrick Smith, vice president of marketing and sales at Aston, Pa.-based Maguire Products Inc., said. “There are so many options that have to be addressed in the blending process that flexibility in communications is absolutely critical.”

Recent developments in touchscreen controls have made user interface easier than ever before. For example, the new BD series blender controller from auxiliary equipment manufacturer AEC Inc., based in Wood Dale, Ill., has an Allen-Bradley controller interface that provides 3D graphics and bright colours to allow control options and information to stand out on a busy factory floor. “By utilizing graphics instead of words… the operator is now able to visualize the settings for the blender, reducing the possibility of operator error,” the company said.

THE LANGUAGE OF EFFICIENCY

The use of graphics in modern touchscreen controllers also facilitates more efficient operation in processing plants where different languages are spoken, as do developments in language technology that allow non-English speakers to understand written information when necessary.

Novatec’s new blender lines, for example, have microprocessor controllers manufactured by Maguire that have 40 character VFD (vacuum fluorescent) displays in seven languages: English, Czech, Dutch, French, German, Italian and Spanish. The company plans to add five more languages, including Chinese.

MACHINE TO MACHINE

In addition to allowing easier communication between man and machine, many of today’s controllers also allow more effective communication between one machine and another. The touchscreen controllers in Maguire’s new gravimetric blenders, for example, have a USB port to provide wireless connectivity and allow for communication both internally with other blender controllers, and with outside systems, at speeds of up to 100 megabits per second, the company said.

It’s also becoming easier for blender controllers to communicate with systems that would formerly have been incompatible. “Some of the new controllers have ‘fieldbus’ protocols that essentially provide a handshake between incompatible devices,” Maguire’s Smith explained. “It allows a control system to go into an incompatible blender and capture data and then manipulate that data however it wants to.”

In addition to taking information out, varieties of data can also be transmitted into many of the new blender controllers far more easily than ever before.

“Many blender manufacturers now offer a USB port on their controls not only for saving the set-ups between material changeovers, but also to transfer data from one blender to another,” Robert Hodge, technical sales at Nucon Wittmann in Markham, Ont., said.

Maguire, for example, offers blender controllers with a USB port that allows internet connectivity. “Because of the USB port, our customers can download software upgrades, updates or special applications that we send them into their equipment via email,” Maguire’s Smith said.

MANAGING INFORMATION

New techniques for tracking, storing and retrieving data, in fact, top the list of developments that blender manufacturers are offering both their injection molding and their extrusion customers.

For example, with Toronto-based controller manufacturer Mould-tek Industries’ Excel series XLCP-220.6B controller for multiple blenders, loaders and pumps, all data revision, new data entries or browsing can be performed while the blenders are in full operation, allowing multiple materials handling equipment to run uninterrupted at up to 150 kg/hr., on a single controller.

And the company’s Excel series XLCP-220.10 touchscreen controller for mono layer and co-extrusion comes with a built-in data historian that can generate reports per roll, order or shift, the company said.

And the Controlnet touchscreen controller from Motan Inc., based in Plainwell, Mich., has Ethernet interface that allows the user to link into Windows-based reporting and monitoring systems and other functions in various company departments, enabling blending data to be processed in common databases and spreadsheets such as Microsoft Excel.

PASSWORDS TO PROFIT

A key aspect to making blender controllers easier for processors to use is, ironically, to make some information inaccessible to various members of a production team. Unauthorized or accidental changes to colour or mechanical product ratios have been the bane of the blending process for years, but developments in password protection may mean that this longstanding problem is about to become a thing of the past.

Pittsburgh, Pa.-based auxiliary manufacturer Conair’s new TrueBlend controller, for example, has three levels of password access that essentially supply information to operators on a ‘need-to-know’ basis, according to Gary Hovis, Conair commercial manager, blenders. “The lowest level would be the operator; and then the second level is the supervisor, who has more sensitive access levels; and the third level is for management or service,” he explained. “The third level can change passwords to all three, but the bottom two can’t see or change what the other passwords are,” he said.

Faced with a demand for greater blending efficiency, today’s blender control manufacturers are doing their best to help plastics processors achieve the right mix for success.