Vision Suppliers Improve Single Point, End-to-end Solutions for Packaging
| By: Winn Hardin, Contributing Editor
As manufacturers adapt to ‘‘just in time’‘ inventories, flexibility becomes a competitive advantage. Just in time inventories translate to shorter production runs and a broader variety of products. Unfortunately, simply adding new manufacturing lines to accommodate the increased product can quickly bankrupt a company. Flexible manufacturing processes provide the same high-product mix, while reducing costs associated with tool changes, turn around times and changeover delays. Adaptive manufacturing technologies such as robots and machine vision give manufacturers the flexibility to quickly shift production to new products, and this includes the packaging of product, whether it be directly printed on each individual product, or placing primary packages in secondary containers, such as cartons and pallets.
Suppliers of flexible manufacturing solutions, such as machine vision and robots, are responding to the unique needs of packaging suppliers, offering a range of tracking and inspection systems that can adapt to an ever-changing production environment. Whether it's simple presence/absence, track & trace, smart printing, or automated secondary packaging, machine vision is providing powerful automation solutions that seamlessly connect the various parts of an enterprise supply chain system and bridge the final gap between quality control and liability protection.
Simple vision for simple tasks
Much of the growth in machine vision has come from automating complicated production tasks – robot guidance, 3D gauging, colorimetry, etc. – but growth doesn't always come from tackling the complex.
The success of Cognex Corp.'s (Natick, Massachusetts) presence sensor, Checker, proves the point that vision can compete against single-point sensor solutions in cost while providing more functionality. ‘‘We're seeing Checker go into two main areas driven by ease-of-use and cost. Checker allows simple checks to be done, like the presence of date lot codes, that weren't always verified before shipping. Because it can detect patterns, which photoelectric sensors cannot do, Checker can provide very precise timing on when a part passes by to downstream secondary packaging machinery, like shrink wrap machines,’‘ explains John Keating, Product Manager for Checker.
According to Keating, the cost of an optical inspection kept many manufacturers from checking date lot codes on food and beverage and other low-cost commodity items. Ink jets, which typically apply these codes, can run out of ink or stop operating for a variety of reasons and without an inspection step, manufacturers never knew exactly when the date lot code printer stopped, or how many products were not labeled. ‘‘Photoeyes just can't do that, and for Checker's $1500 price tag, that’s a great value to the manufacturer,’‘ Keating says. ‘‘Another application is checking that there are 24 products in a case, for example. That would take 24 photoeyes, one for each product in the case, and positioning has to be very precise if it's to work. We're finding that if an application requires at least 3 photoeyes, then the cost of design, integration and ownership becomes equivalent to one Checker system.’‘
Checker uses an extremely fast pattern finding sensor, allowing the system to detect and inspect at 500 fps. Because Checker sees each part many times, Checker can provide very precise output timing based on when the part crossed in front of Checker. Simple USB connectivity and a simple 4 step setup process makes setting up Checker extremely quick and easy and two optically isolated output allow Checker to easily tie into nearby PLCs, or reject mechanisms.
Small lot packaging
Some industries do not have the luxury of ‘‘choosing’‘ product traceability. Highly regulated industries such as pharmaceuticals require 100% inspection and tracking down to individual products. SYSTECH International (Cranbury, New Jersey) assists pharmaceutical and health care companies with these automation needs, and is focusing on expanding its solutions to integrate with enterprise software, such as ERP systems.
‘‘These companies need vision for many applications: lot codes, component identification, cap verification and similar packaging inspections; making sure the right label is on the bottle, the right bottle is in the right carton, etc., up through the rest of the packaging train to the pallet,’‘ explains SYSTECH's David DeJean, Director of Sales for North America. ‘‘There's also strong demand for blister pack technology. Are the right tablets in the right blister? Companies are also moving to 100% inline printing on the backing material, and as they do that, they have to move to 100% printing inspection. So we've added a lot of standard inspection techniques for blister stock, printing, lot date codes and more, including the recent emergence of RSS [reduced space symbology] barcodes required for Hospital Unit Dose (HUD) products. The industry's been going crazy because of the need to do 100% inline printing, especially for small lot production for clinical trials, for example.’‘
Packaging inspection in pharmaceuticals is more than just reading text with OCR and a variety of barcodes. For instance, the exact colors used can have a functional as well as aesthetic purpose, e.g., color can indicate what type of medication is in the package. The complexity of the pharmaceutical operation and government regulations means that these manufacturers are depending on multiple technologies to track, verify and inspect product, including machine vision, barcode scanners and even radio frequency identification (RFID) technology.
‘‘There are a lot of people looking into the RFID initiative, but RFID doesn’t meet the technical needs of a high speed inspection line,’‘ explains Stephen Lisa, Senior Product Manager at SYSTECH. ‘‘People need to know what, when, where, but only machine vision and barcode technologies can provide that data fast enough for pharmaceutical production.’‘
So while RFID may not track individual products, it is finding uses at the carton and pallet level. Vision companies that want to participate in the pharmaceutical industry have to understand that machine vision data must be able to interface with other data types from other systems. ‘‘The biggest trend in [pharmaceutical] packaging is track and trace, and sending that information up to the ERP systems so that the customer can look at it from a global perspective,’‘ Lisa says. ‘‘We work closely with developers of mySAP, Oracle and other enterprise systems.
‘‘Most of the time it's a customer specific deployment. Everyone's SAP installation is a little different,’‘ notes Joe Costa, Director of Marketing at SYSTECH.
‘‘Emerging standards such as OPC, OMAC and S95 will lower the barriers between supply systems and make the machine vision supplier's job of end-to-end integration easier,’‘ Costa adds. ‘‘It's really about empowerment, where a customer can take raw data and turn it into valuable business information,’‘ Costa concludes.
Printing industry converts to vision
‘‘After several years of proven benefits and market education, machine vision based automatic inspection solutions become almost a standard for high quality packaging and label printers’‘, explains Gal Shamri, Vice President of Marketing at Advanced Vision Technology Ltd. (Hod Hasharon, Israel). ‘‘Installed on printing machines as well as on finishing equipment, vision based systems detect defects such as color variation, register, character misprints, spots and splashes at the earliest stage, eliminating printing waste and reducing the cost of quality,’‘ adds Shamri. ‘‘The next steps for machine vision solutions are complete press control, In-line color measurement and end-to-end quality control solutions,’‘ notes Mr. Shamri.
AVT's Prestige Press Control Package, includes both automatic registration control during press set up and run time, and pressure control for the various ink-spreading rollers, reducing setup time and material enable printers to have shorter turn over and become profitable when producing short runs, Shamri adds.
‘‘AVT IÄEal module enables printers to accurately measure ÄE & ÄL*a*b* color values in line and when SpectralLink is used, the software program can tie into standalone spectrophotometers to guarantee color consistency among different product lines, or even different factories,’‘ Shamri said.
‘‘End-to-end quality data management is also a growing need within the global printing industry. Packaging companies want further reduction of operational costs,’‘ explains Shamri. ‘‘Material prices have gone up dramatically, especially for plastic. The margins are very tough, but you can get better margins if you control operational loss, or get more high quality jobs. To do this, customers aren't looking just for systems on the printing stage, but before, during and after the printing stage. People want the whole process better controlled, more automated and they're willing to spend money on this because it helps increase quality and get higher margin jobs by insuring better quality.’‘
AVT's PrintFlow Master software stores both sample quality inspection results, and 100% inspection results in a SQL database, while the latest software program, WorkFlow link, takes that information and controls the final rewinder, stopping the final roll when a defect was detected and allowing the operator to cut away defective product before shipping. The end result is end-to-end data transparency, and full control over production quality.
Packaging the packages
After the product is packaged, it typically goes into a secondary package, such as cartons or shipping containers that carry the product to its final destination. Machine vision is helping provide flexibility through automation in this area through vision-guided pick-and-place applications. ‘‘When we talk about packaging, it's really about placing material such as food, consumer products, medical devices, electronics, etc., into the primary packaging and in many instances handling product already in a primary package,’‘ explains Tim DeRosett, Manager of Six Axis Business Development at Adept Technology Inc. (Livermore, California), maker of both vision systems and robots.
Adept's ‘‘sweet spot’‘ starts when the product weighs at least 1 to 2 lbs. While there are specialized solutions capable of moving smaller products faster, as the product increases in size and variety, robot handling is the clear choice. When the product is light-weight and fragile, such as electronics, robots beat hard-tool fixtures because of their programmability and greater control of pressure, as well as acceleration rates.
‘‘We can achieve upwards of 120 picks per minute from a moving conveyor belt with our robot control system and integrated vision system. Basically, what makes everything work is the seamless integration of the vision system with the robot controller,’‘ DeRosett says. ‘‘In the past, integration has meant 'everything in the same box or back plane', but what is critically important is powerful object locator tools combined with bullet-proof calibration routines to translate vision results to robot coordinates. Without these two elements high-speed packaging is out of the question. You must also understand and control latencies between the sub-systems to make sure data arrives at a specific time. This means you need a real-time operating system [not consumer based operating systems] and unique processing architectures. We're using distributed processing systems with digital signal processors, so you can off load the demanding servo processing while the robot controller runs high-level planning for the robot. By doing that, we free up a lot of processing capacity for the vision system.’‘
DeRosett continues: ‘‘What we're seeing drive the packaging industry is the need for companies to maintain low inventory levels combined with high product mix. In the past, companies built dedicated lines that did one or two products, and then changed product runs weekly or monthly. Now it's not uncommon for companies to switch product several times a day, and that's near impossible to do with hard automation. Vision certainly comes into place to provide the flexibility these companies need and robots allow you to accommodate rapid product change-over. This is giving domestic manufacturers the ability to compete with off-shore manufacturing in today's global marketplace.’‘