Tire Industry Automation: When a Photo-Eye Is Failing, Try an Ultrasonic Sensor

Should you use a photo-eye or an ultrasonic sensor for your automation application? This is a great question for tire industry manufacturing.

I was recently at a tire manufacturing plant when a maintenance technician asked me to suggest a photoelectric sensor for a large upgrade project he had coming up. I asked him about the application, project, and what other sensors he was considering.

His reply was a little startling. He said he had always used photo-eyes, but he couldn’t find a dependable one, so he would continually try different brands. My experience in this industry, along with good sensor training and advice from my colleague Jack Moermond, Balluff Sensor Products Manager, immediately made me think that photo-eye sensors were not the right choice for this application.

As I asked more questions, the problem became clear. The tire material the technician was detecting was black and dull. This type of material absorbs light and does not reflect it reliably back to the sensor. Also, environmental factors, such as dust and residue, can diminish a photo-eye’s signal quality.

Ultrasonic sensors for non-reflective materials and harsh environments

The technician didn’t have much experience with ultrasonic sensors, so I went on to explain why these may be a better solution for his application.

While photoelectric sensors send light beams to detect the presence of or measure the distance to an object, ultrasonics bounce sound waves off a target. This means that ultrasonics can be used in applications where an object’s reflectivity isn’t predictable, like with liquids, clear glass or plastic, or other materials. Dust build up on the face of an ultrasonic sensor does not give a false output. Ultrasonic sensors actually have a dead zone a few millimeters from the face where they won’t detect an object until the wave clears the dead zone, so take this into consideration when planning where to install an ultrasonic sensor.

Tire detection for process reliability with BUS ultrasonic sensors

Tire industry applications

The following are some popular tire industry applications where it might be better to choose an ultrasonic sensor over a photo-eye sensor.

    • The tire building process requires a lot of winding and unwinding of material to build the different layers of a tire. As this material is fed through the machines it starts to sag and loop. An ultrasonic sensor in this location will monitor how much sag and loop is in the process.
    • When tires are being loaded into curing presses, the press needs to confirm that the correct size tire is in place. An ultrasonic sensor can measure the height or width of the tire from the sides or top for confirmation.
    • Ultrasonic sensors are great at detecting if a tire or material is in place before a process starts.
    • Hydraulic systems are common in tire manufacturing. Ultrasonic sensors are good for hydraulic fluid level monitoring. Tying them to a SmartLight offers a visual reference and alarm output if needed.
    • Everyone knows the term “wig-wag” in tire mixing and extrusion. The sheets of wig-wag require monitoring as they are fed through the process. When this material gets close to being used up, a new wig-wag must be used.
Wig-wag stacks

So, when there is an application for a photo-eye, especially in a tire manufacturing plant, keep in mind that, rather than a photoelectric sensor, an ultrasonic may be a better option.

The maintenance technician I spoke with is now looking at different options of ultrasonics to use. He said I gave him something new to think about for his machines and opened the door for adding this technology to his plant.

Happy hunting!

Automation is “Rolling Out” in the Tire Industry

Automation is everywhere in a tire plant – from the old manual plants and mid-hybrid automated plants to the newest plants with the latest automation technology all over the world.

Industry challenges

Some tire industry automation challenges are opportunities for automation suppliers and machine builders. These can vary from retrofitting old machines and designing new machines to including smarter components to bring their production into the IIoT.

Plants want to save CapX dollars on new machines, so they are looking to upgrade old ones. Tire plants are learning from the past. They are limited by their older technology, but it has been hard to upgrade and integrate new technology, so there are long-term needs for adding flexible automation on machines. This requires new processes and recommissioning machines quickly. A good example of this is the addition of a vision system to improve quality inspections.

More automation is also needed due to a lack of skilled labor in the industry combined with the desire for higher throughout. The addition of robots on the line can aid with this. Plants can also simplify their wiring by migrating away from control panel i/o/analog to an IP67 network and IO-Link master and hubs.

The use of IO-Link also allows for more continuous condition monitoring. There is an increased need for quality inspections and process improvements. Plants are collecting more data and learning how to use it and analytics (Industry 4.0, IIoT) to achieve operational excellence. Plants need more technology that supports preventive and predictive failure solutions.

Additionally, there are automation needs on new machinery as tire designs are in an evolutional growth/change period – in the electric vehicle (EV) market, for example, where rapid change is happening across all vehicle manufacturing. Smart tires are being designed using RFID and sensors embedded in the tire ply.

Successfully matching up automation products to meet plant needs first requires understanding the plant’s main processes, each with millions of dollars of automation needs.

How tires are made

    1. Raw materials logistics – raw materials are transported to the mixing and extrusion areas for processing.
    2. Mixing and extrusions – up to 30 ingredients are mixed together for a rubber blend tire.
    3. Tire components – extruded rubber ply is measured and cut to size to meet the needs of the specific tire and then loaded onto reels feeding the tire building machines.
    4. Tire build machines – tires are built in stages from the inside out. They are crated without tread and transferred to the curing press machines.
    5. Tire curing press machines – here, the “green” tires are vulcanized, a chemical process that makes the tire more durable. Tire parts are then compressed together into the final shape and tread pattern.
    6. Inspection and test machines – tires are quality tested and undergo visual, balance, force, and X-ray inspections.
    7. Logistics material handling, conveyor, ASRS, AGV – finished tires are taken to the warehouse for sorting and shipping.

In the past, not many people outside the tire industry understood the complexity and automation needs of these high volume, high quality, highly technical plants. Tires are so valuable to the safety of people using them that manufacturers must be held to the highest standards of quality. Automation and data collection help ensure this.

In the meantime, check out these futuristic tires and imagine all the automation to manufacture them.

RFID Gaining Traction in Tire Manufacturing

RFID is one of the hottest trending technologies in the tire industry. It has the potential to increase efficiency in tire production and logistics processes and gather large amounts of data for IIoT.

This technology will:

  • Reveal transparency deep in the processes
  • Minimize the number of rejected tires
  • Improve production processes for fewer failures
  • Increase control of materials
  • Improve the overall quality of individual tires

The challenge of using RFID in the tire industry is dealing with the harsh environments of some of the production areas in automotive plants. But the benefits of RFID to the tire industry are becoming more and more a reality. Suppliers of RFID are talking to tire manufacturing engineers, automation teams, material handling teams and R&D development engineers to develop better tools. For now, here are some examples of where RFID can be implemented in the tire creation process to improve efficiency, quality and cost.

In the mixing process, RFID “labels” are applied to all the chemicals and rubber compounds to assure the mixing of the right recipe of materials. RFID readers can be mounted on TBMs (Tire Build Machines), which are located before the curing press process, to assure the right material reels, parts and tools are in place before the expensive tire build process occurs.

There is also a growing need for RFID in the curing and mold processes. It important to manage the molds and the parts of the mold, like the bead rings, mold containers and mold segments. These are very expensive and there are hundreds in the average plant. Tags need to be able to sustain temperatures above 300 °F continuously for 8 hour shifts with little to no cooling down time.

RFID is an excellent tool to monitor material flow throughout the whole manufacturing process. RFID can be added to a trolly, AGV, conveyors and hook-chain conveyors.

While RFID is already being implemented by some tire manufacturers, there is much room for much growth in this conservative industry. As more manufacturers lean into IIoT and the need for data, RFID will surely be used more and more often.

The tire industry is excited to roll in RFID technology and pumped up to implement it where it makes the most sense and ROI dollars.

For more information about the tire industry, visit https://www.balluff.com/local/us/industries-and-solutions/industry/mobility/tire-industry/