To meet the demands of customers wanting smaller, more efficient machines that also meet exacting design requirements, Triangle Package Machinery Company incorporated IO-Link controls architecture and sensors from Balluff. This allowed Triangle to significantly reduce the footprint, reduce cabling, reduce panel size, improve sanitary features, and enable ease of maintenance in its latest modular machine design.
In the packaging industry, floor space costs money; the wider the machine, the fewer lines you can operate. Triangle, a Chicago-based manufacturer of vertical form fill seal machines primarily for the food packaging industry, was presented a unique challenge by its salad industry customers. Triangle’s research with clients revealed they needed a high production rate on each line, but a lower machine speed to allow leafy greens to fall nicely in the bag. To answer that need, Triangle’s research & development team designed its new Compact Sanitary Bagger (CSB), which is narrow enough to install two machines per line in a twin configuration.
Triangle knows the demands of the food packaging industry very well. A sanitary design is a necessity, so the Triangle team knew they’d build a solid stainless steel frame, fully welded, with round bars so there would be no place where product could accumulate. The control box on Triangle’s existing vertical form fill seal (VFFS) bagging machines sits on one side of the frame. This configuration was useful for cleaning and performing maintenance, but it made the machine about 1.5m wide. Designing a narrower machine would require a different approach.
Three companies were identified for a competitive bidding process with the technology and support to help Triangle realise a new design. The company chose Balluff. Balluff has a large and growing library of IO-Link sensors, and the reputation of its support made this a confident choice. However, the clincher was Balluff’s IP69K stainless steel IO-Link master device block. With an I/O block that met regulatory requirements, some components could be moved out of the control box and onto the machine.
“Usually control boxes are bigger than they need to be,” says Michael Wolf, Research & Development Manager at Triangle. “The control box we typically use, it’s not fully packed if you buy a regular machine. But then if you buy a zipper applicator or other features, you add three or four servos into it, and then that control box is full.”
That accounts for the full-size pivoting control box that’s a standard feature on Triangle’s full-size VFFS bagging machines.
“We operate now with the understanding that pretty much every control box is designed uniquely for the customer who purchased that machine,” adds Wolf. “So, if you can imagine the need to have new electrical drawings, new bills of materials every time you have a new configuration, you can get a sense of the complexity of the design and assembly of these machines.”
Moreover there are a lot of configurations available: standard options include cooling, deflators, deflectors, stagers, and interfaces to labellers or daters; plus special options like ultrasonic sealing, three types of sealing jaws, three types of motors, registration, web edge detection, and stack lights. The number of variations can grow into the tens of thousands.
These options require wiring, including cables that used to penetrate the control box. Using Balluff’s stainless steel master block and hub, Triangle reduced the number of cables penetrating the control box from 40-50, to about 25. This allowed them to reduce the control box size by 50% and mount it into the inside of the machine. IO-Link’s expandability means they can add optional features without running additional cabling to the control box, either during initial assembly or as a retrofit. Triangle now has a standard control box, which can be produced in quantity and stored in inventory, there by reducing assembly time.
With a minimised control box, they were able to build the CSB at only 91cm wide and still produce a 33cm-wide bag. The CSB is about 60% the width of the existing XM model and makes a bag 90% as big. The design also has improved the CSB’s ergonomics. The default discharge height was increased so the CSB could integrate with sanitary conveyors, which must be higher off the floor.
The CSB is designed to have two machines installed side-by-side. This twin configuration makes the most efficient use of available floor space. It also allows salad industry customers to place a single scale over two machines, permitting them to run each machine at 60-70 bags per minute for a total of up to 140 bags per minute.
Using IO-Link enabled Triangle to design a machine with these features and dimensions but choosing IO-Link wasn’t a foregone conclusion. IO-Link is an open standard, so IO-Link products are developed by many different companies. In that way, it is like USB, but many other open standards have not been fully embraced by the marketplace and lost support. The Triangle team decided that IO-Link was a mature enough standard and that the IO-Link market was mature enough to be their choice. And the breadth of Balluff’s IO-Link portfolio helped them draw that conclusion.
Another attractive element of IO-Link is that it allows analogue signals to be added without adding significant cost. Cabling connects to a hub instead of being run to the control box. This allows for added options and future enhancements to the controls without having to redesign the control box. In addition, the digitised data sent through IO-Link opens new problem-solving possibilities.
An example of IO-Link’s ability to turn configurations into recipes is the dancer arm, which maintains the correct tension on the bagging film as it comes off the roll. Triangle’s previous method involved using an analogue sensor, which required configuration by the service technian during initial installation. The technician had to change the physical position of the sensor to calibrate the home location. Now with a Balluff IO-Link sensor on the air cylinder, a technician assembling the machine pulls the dancer to one position and clicks “Teach”, and set-up is complete. Having an IO-Link sensor measuring the full stroke of the cylinder allows them to skip the manual set-up of the sensor.
IO-Link enables diagnostics at the device level – letting users know if a photo sensor is getting dirty, for example. Triangle is additionally using IO-Link data to gather diagnostic data on the machine as a whole. A position sensor was added on the CSB’s back-seal cylinder, which would have been cost-prohibitive in the past. By using a cylinder with a position sensor, Triangle was able to redesign the back-seal assembly and simplify the set-up when a bag size is being changed and the forming tube is swapped out. In addition, this lets them monitor the speed at which it operates and the consistency of the seal time better than they could previously.
“If we start getting a leaky cylinder, we’ll be able to detect that using the sensors and notify a customer to replace a cylinder,” said Wolf.
The position where the cylinder is supposed to stop is different for different-sized air cylinders. Triangle added a continuous sensor so customers can monitor the sealing time, which is a critical parameter, over the whole range without needing to change the hardware configuration when the forming tube is changed.
“The programmer is actually monitoring the amount of time that the sealer is in contact with the film, which is the most critical parameter. Without the sensor, you have to trust that the valve moves. But here we have it verified,” Wolf said. “Without the sensor to get this information, they’d need a servo motor.”
As the machine’s PLC program is enhanced, more predictive maintenance features will become available. That means that if a customer needs help from Triangle, Triangle support staff can connect remotely and see the machine’s status without having to be physically on-site. That can lead to troubleshooting within 30 minutes instead of waiting for someone to fly out or drive to the customer.
To Wolf, calling the CSB a smart machine sounds like marketing lingo, and Triangle hasn’t yet realised all the benefits of IO-Link. Customers, too, aren’t all equally ready to take advantage of the industrial internet of things. There’s sometimes a perception that more technology will make the machine harder to operate or require more training.
Triangle’s new “Smart Machine Ready” design is already an improvement for Triangle’s team. And when end users are ready to take advantage of all its features, the company will be prepared to help them operate faster and more efficiently, using Balluff’s IO-Link solutions.