How RFID Can Error-Proof Appliance Assembly

Today, appliance manufactures are using RFID more frequently for error proofing applications and quality control processes.

Whether the appliance assembly process is automatic or semiautomatic, error-proofing processes using RFID are as important as the overall assembly processes. Now, RFID systems can be used to tell a PLC how well things are moving, and if the products and parts are within spec. This information is provided as an integral part of each step in the manufacturing process.

RFID systems installed throughout the manufacturing process provide a way of tracking not only what has happened, but what has gone right. RFID records where something has gone wrong, and what needs to be done to correct the problem.

Appliance manufacturers often need to assemble different product versions on the same production line. The important features of each part must be identified, tracked and communicated to the control system. This is most effectively done with an RFID system that stores build data on a small RFID tag attached to a build pallet. Before assembly begins, the RFID tag is loaded with the information that will instruct all downstream processes the correct parts that need to be installed.

Each part that goes into the appliance also has a RFID tag attached to it. As the build pallet moves down the assembly conveyor to each station, the tag on the build pallet is read to determine what assembly and error proofing steps are required. Often, this is displayed on an HMI for the operator. If the assembly requires testing, the results of those tests can be loaded into the data carrier for subsequent archiving. The operator scans the tag on each part as it is being installed. That data is then written to the tag on the build pallet. For example, in the washing machine assembly process, the washing machine body sits on the build pallet, and as it moves from station to station, the operators install different components like electronic boards, wiring harnesses, and motors. As each one of these components is installed, its RFID tag is scanned to make sure it is the correct part. If they install the wrong part, the HMI will signal the error.

RFID technology can also be used to reduce errors in the rework process. RFID tags, located on either on the assembly or the pallet, store information on what has been done to the appliance and what needs to be done. When an unacceptable subassembly reaches the rework area, the RFID tag provides details for the operator on what needs to be corrected. At the same time, the tag can signal a controller to configure sensors and tools, such as torque wrenches, to perform the corrective operations.

These are just a few examples of how appliance manufactures are using RFID for error proofing.

For more information, visit https://www.balluff.com/local/us/products/product-overview/rfid/.

Injection Molding: Ignore the Mold, Pay the Price

Are you using a contract molding company to make your parts? Or are you doing it in house, but with little true oversight and management reporting on your molds? As a manufacturer, you can spend as much on a mold as you might for an economy, luxury or even a high-performance car. The disappointing difference is that YOU get to drive the car, while your molder or mold shop gets to drive your mold. How do you know if your mold is being taken care of as a true tooling investment and not being used as though it were disposable, or like the car analogy, like the Dukes of Hazzard used the General Lee?

What steps can you take in regard to using and maintaining a mold in production that can help guarantee your company’s ROI? How can you ensure your mold is going to produce the needed parts and provide or exceed the longevity required?

It is important for any manufacturer to understand the need for the cleaning and repair required for proper tool maintenance. The condition of your injection mold affects the quality of the plastic components produced. To keep a mold in the best working order, maintenance is critical not only when issues arise, but also routinely over time.

In the case of injection molds specifically, there are certain checks and procedures that should be performed regularly. An example being that mold cavities and gating should be routinely inspected for wear or damage. This is as important as keeping the injection system inspected and lubricated, and ensuring all surfaces are cleaned and sprayed with a rust preventative.

Figure 1 An example of the mold usage process.

The unfortunate reality is that some molders wait until part quality problems arise or the tool becomes damaged to do maintenance. One of the biggest challenges with injection molders is being certain that your molds are being run according to the maintenance requirements. Running a mold too long and waiting until problems arise to perform routine maintenance or refurbish a mold can result in added expense, supply/stock issues, longer time to market and even loss of the mold. However, when molders have a clear indication of maintenance and production timing, and follow the maintenance procedures in place, production times and overall costs can decrease.

Figure 2 Balluff add-on Mold ID monitoring and traceability system.

Creating visibility and accuracy into this maintenance timing is something today’s automation technology can now address. With todays modern, industrial automation technology, visibility and traceability can be added to any mold machine, regardless of machine age, manufacturer and manufacturing environment.

With the modern networked IIoT (industrial internet of things)-based monitoring and traceability system solutions available today, the mold can be monitored on the machine in real-time and every shot is recorded and kept on the mold itself using, for example, an assortment of industrial RFID tag options mounted directly on the mold. Mold shot count information can be tracked and kept on the mold and can be reported to operations or management using IIoT-based software running at the molder or even remotely using the internet at your own facility, giving complete visibility and insight into the mold’s status.

Figure 3 Balluff IIoT-based Connected Mold ID reporting and monitoring software screens.

Traceability systems record not only the shot count but can provide warning and alarm shot count statuses locally using visual indicators, such as a stack light, as the mold nears its maintenance time. Even the mold’s identification information and dynamic maintenance date (adjusted continuously based on current shot count) are recorded on the RFID tag for absolute tracability and can be reported in near real-time to the IIoT-based software package.

Advanced automation technology can bring new and needed insights into your mold shop or your molder’s treatment of your molds. It adds a whole new level of reliability and visibility into the molding process. And you can use this technology to improve production up-time and maximize your mold investments.

For more information, visit https://www.balluff.com/en/de/industries-and-solutions/solutions-and-technologies/mold-id/connected-mold-id/

Custom Sensors: Let Your Specs Drive the Design

Customized sensors, embedded vision and RFID systems are often requirements for Life Science devices to meet the needs for special detection functions, size constraints and environmental conditions. Customization can dramatically raise costs and you don’t want to pay for stock features, such as an external housings and universal outputs, that are simply not needed. So, it comes down to your specification driving the design. A qualified sensor supplier can create custom orders, allowing your specifications to drive the design, building just what you need and nothing you don’t.

It’s as easy as putting a model together.

The process is fairly straight forward. After reviewing your specifications, the sensor supplier develops a plan to supply a functional prototype for your testing phase. Qualified sensing companies can quickly build prototypes either by starting with a standard product or using standard modules. Both methods have advantages.

Standard Product approach: This is the fastest method to get a prototype up and running. Here, the focus is on providing a solution for the basic sensing/detection application. Once testing confirms the functionally, a custom project is started. The custom project ensures seamless integration into your device. Also, cost control measures can be addressed.

Standard Module approach: This will handle the most demanding applications. When a standard product is not able to meet the basic required functionally, we turn to the base component modules. An ever-growing field of applications are solved by combining options from the hundreds of available modules. While this takes more time, the sensing company can deliver a near final prototype in much less time than if they were creating an internal development.

Qualified sensor companies can easily handle the production side as well. With significant investments in specialized automated manufacturing equipment, production can be scaled to meet varying demands. And as components go obsolete, sustaining engineering projects are routinely handled to maintain availability. This can be disruptive for internal production or contract manufacturers. Sensor companies will take on the responsibility of life-cycle management for years to come. It’s part of their business model.

So, make sure your sensor, embedded vision or RFID supplier has a large model kit to pull from. Your projects will exceed your specification and be completed on time without long-term life-cycle issues.

For more information , visit https://www.balluff.com/en/de/service/services/productbased-service/.

 

Using Long-Range RFID for Metal Stamping Die Identification

Using incorrect dies for metal stamping operations can result in lost time and production as well as severe damage to the presses and a risk to human lives.

In recent years, there was a case where the use of the incorrect die caused catastrophic press damage resulting in significant downtime and, because the press was so large, it had to be cut up before it could be removed and replaced. These types of occurrences can prove disastrous to the survival of a company.

When not in use, dies are generally stored in specified storage areas. Often, the die is in the wrong place, and the crane operator needs to know what he/she is retrieving for the next process in the correct die.

To help ensure that these types of errors do not occur, some manufacturers use long-range UHF RFID technology. This can ensure that the correct dies are chosen when they are staged outside of a press. And with handheld devices, it can help the operator find the correct die in storage if it has been misplaced.

Since long-range UHF RFID technology allows the verification of the correct dies from as little as one foot away to as far as several meters, it can be used in both large and small stamping presses. The long-range allows the reader antennas to be placed in strategic locations where the correct readings will be possible but in positions where they will not be damaged by the operation of the press and dies.

I recently assisted with a metal stamping operation that first brought this idea to my attention. This manufacturer was having the problem of the wrong dies being staged for installation into the press. So far, none of the dies had made it past the staging area and into the press. Still, the possibility of that happening was clearly present, and they were experiencing lost production due to having to remove the incorrect die and find the correct one.

The manufacturer wanted to interlock the press so that if the incorrect dies were not in place, the machine would not be able to run. He also wanted to know ahead of time of a wrong die so that it could be replaced promptly to not impact production.

The solution we developed was to place multiple reader antennas at multiple staging locations at the press and interlock the RFID reads with the PLC that controlled the press.

Additionally, he incorporated handheld readers to help find misplaced dies in the storage area.

This solution required testing and tuning of the UHF RFID system to ensure that all die RFID tags were being read when the dies were staged. But once this was completed, it proved to work effectively and reduce the errors and downtime.

It should be noted that due to the physics of UHF RFID technology versus other types of RFID technology, implementing long-range UHF RFID systems in any application should be preceded by a feasibility study that tests the system in the real world environment of the plant.

Be Driven by Data and Decrease Downtime

Being “driven by data” is simply the act of making decisions based on real data instead of guessing or basing them on theoretical outcomes. Why one should do that, especially in manufacturing operations, is obvious. How it is done is not always so clear.

Here is how you can use a sensor, indicator light, and RFID to provide feedback that drives overall quality and efficiency.

 

Machine Condition Monitoring

You’ve heard the saying, “if it ain’t broke, don’t fix it.” However, broken machines cause downtime. What if there was a way to know when a machine is getting ready to fail, and you could fix it before it caused downtime? You can do that now!

The two main types of data measured in manufacturing applications are temperature and vibration. A sudden or gradual increase in either of these is typically an indicator that something is going wrong. Just having access to that data won’t stop the machine from failing, though. Combined with an indicator light and RFID, the sensor can provide real-time feedback to the operator, and the event can be documented on the RFID tag. The machine can then be adjusted or repaired during a planned maintenance period.

Managing Quality – A machine on its way to failure can produce parts that don’t meet quality standards. Fixing the problem before it affects production prevents scrap and rework and ensures the customer is getting a product with the quality they expect.

Managing Efficiency– Unplanned downtime costs thousands of dollars per minute in some industries. The time and resources required to deal with a failed machine far exceed the cost of the entire system designed to produce an early warning, provide indication, and document the event.

Quality and efficiency are the difference makers in manufacturing. That is, whoever makes the highest quality products most efficiently usually has the most profitable and sustainable business. Again, why is obvious, but how is the challenge. Hopefully, you can use the above data to make higher quality products more efficiently.

 

More to come! Here are the data-driven topics I will cover in my next blogs:

  • Part inspection and data collection for work in process
  • Using data to manage molds, dies, and machine tools

Tag, You’re It: Choosing the Right Type of Tags for Your RFID System

Many companies have already discovered the benefits of implementing RFID into their systems. Traceability within the manufacturing process provides a competitive advantage of both efficiency and profitability. RFID tags are a major component of this technology. But it’s important to select the correct type for your specific application. These tags are classified into categories based on how they obtain power and how they use that power. The three categories are as follows:

  • Passive tags
  • Semi-passive tags
  • Active tags

Understanding the difference between these can help narrow down your decision when looking into implementing RFID systems to your process.

Passive tags do not have their own power source. The tag receives power only when the RFID reader is in range. These tags are limited since the power supplied is minimal. The biggest advantages of passive tags are that they are small and inexpensive. They can be useful in specific applications where space is limited. Also, if the environment in which the tag is being placed is harsh, the passive tag may be a good option because it can be cheaply replaced if damaged. Since these tags do not generate power, their read distance of just a few inches to about two feet is much shorter than others. Passive tags are also limited to the amount of data storage they possess. Depending on the application this can be an advantage or disadvantage.

Semi-Passive tags, as the name implies, are similar to passive tags in that they do not have an active transmitter. They still require an RFID interrogator to be in range for the device to work, although the semi-passive tags have their own battery to power the IC. If you are looking for longer read ranges than the passive tag, this could be an option. Since the read range of the passive sensor is solely based on how far away the interrogator can power the device and not the signals coming in, adding a battery unit to the semi-passive tags increases this distance. These distances can range up to 100 feet. Another advantage is the amount of data they can store. These added features do come with added costs. The onboard power supply also makes these tags larger and heavier. The electronics inside the tag are susceptible to harsh environments like high or low temperatures, resulting in shorter lifespans.

Active tags have both a battery and transmitter built within their housings. The typical read range is again increased to around 300 to 750 feet depending on the battery power and the antenna. This allows the tags to store more data with their increased memory capacity. Active tags display the most configurability in comparison to passive and semi-passive tags. They can be set up to conserve battery power when the interrogator is out of range and respond only when the reader is within range. They can also be set up as a beacon, which is when the tag does not wait until it receives a signal from the interrogator. Instead, the active tag can be configured to send the information in set time intervals. Since active tags contain an active transmitter, they can contribute to radio noise. They are also more expensive and usually larger in size and weight due to the increased electronics within its housing.

It’s important when selecting a tag for your RFID system to consider the application needs and the advantages and disadvantages of these different options.

Add Transparency and Traceability with RFID

How can traceability and easy data collection help make the assembly line more transparent and efficient? I’m sure if you ask any manufacturing engineer if being able to track vendor and lot information is going to benefit them in some way, they are going to say yes! All companies have some type of ERP system set up to track parts coming in and products going out, but what goes on between those lines? If a customer reports a missing or faulty component how do you easily know where it came from?  How do you know when the product was made or who made it?

This is where RFID comes in. RFID read/write heads and data collectors can help you track and control production on the assembly. These data collectors or “tags” come in various shapes and sizes. They can be small chips attached to the workpiece carrier or they can even come as a bolt that you screw right into your part. Read/write heads also come in different sizes and have variable read/write distances or frequencies (i.e. low frequency, high frequency, and ultra-high frequency). The read/write heads connect to a processor unit that ties directly back to the PLC. Once the PLC receives this information, it can provide it to the ERP system. This takes all the information on the floor level and makes it available to the management system.

For example, say you have an unexperienced line worker on your assembly line. You are producing large diesel engines and he has the job to put together the pistons at the front of the line. Many times, he snaps the O-rings putting them on. Other times, the rings aren’t put completely in place, but he still sends the engine to the next station. When customers start calling faulty O-rings, you need an easy way to locate the source of the problem.

If you have 10 different lines changing out various engines every day, it could be difficult to narrow down the source of the problem. But if you have RFID read/write heads at each station on the line and a tag on each engine, you can look into your ERP system and track down on which line the engines in question were assembled and who was responsible for putting together the pistons.

You can then determine if the problem was human error or if the cause was due to poor quality parts, and take steps to rectify the situation. If it is determined that the rings are poor quality, you can easily determine every engine that these rings have been used on and recall only those engines. This is just a small example of how RFID can help with transparency on the assembly line. If you are looking for better ways to track inventory, vendors, or just make data more accessible to you and your company, then RFID is your answer!

RFID Minimizes Errors, Downtime During Format Change

Today’s consumer packaged goods (CPG) market is driving the need for greater agility and flexibility in packaging machinery. Shorter, more customized runs create more frequent machine changeover. Consequently, reducing planned and unplanned downtime at changeover is one of the key challenges CPG companies are working to improve.

In an earlier post, I discussed operator guided changeover for reducing time and errors associated with parts that must be repositioned during format change.

In this post, I will discuss how machine builders and end users are realizing the benefits of automated identification and validation of mechanical change parts.

In certain machines, there are parts that must be changed as part of a format change procedure. For example, cartoning machines could have 20-30 change parts that must be removed and replaced during this procedure.

This can be a time consuming and error-prone process. Operators can forget to change a part or install the wrong part, which causes downtime during the startup process while the error is located and corrected. In the worst scenarios, machines can crash if incorrect parts are left in the machine causing machine damage and significant additional downtime.

To prevent these mistakes, CPG companies have embraced RFID as a way to identify change parts and validate that the correct parts have been installed in the machine prior to startup. By doing so, these companies have reduced downtime that can be caused by mistakes. It has also helped them train new operators on changeover procedures as the risk of making a mistake is significantly reduced.

Selecting the correct system

When looking to add RFID for change part validation, the number of change parts that need to be identified and validated is a key consideration. RFID operating on the 13.56 MHz (HF) frequency has proven to be very reliable in these applications. The read range between a read head and tag is virtually guaranteed in a proper installation. However, a read head can read only a single tag, so an installation could need a high number of read heads on a machine with a lot of change parts.

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It is also possible to use the 900 MHz (UHF) frequency for change part ID. This allows a single head to read multiple tags at once. This can be more challenging to implement, as UHF is more susceptible to environmental factors when determining read range and guaranteeing consistent readability. With testing and planning, UHF has been successfully and reliably implemented on packaging machines.

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Available mounting space and environmental conditions should also be taken into consideration when selecting the correct devices. RFID readers and tags with enhanced IP ratings are available for washdown harsh environmental conditions. Additionally, there are a wide range of RFID read head and tag form factors and sizes to accommodate different sized machines and change parts.

 

 

Manufacturers Track Goods, Reduce Errors, Decrease Workload with RFID

More and more, retailer sellers are starting to require that manufacturers place RFID tags on their products before they leave the production facility and are shipped to those retail locations. From high-end electronics all the way down to socks and underwear are being tagged.

These tags are normally supplied by the retailer or through a contracted third party. Typically disposable UHF paper tags, they are only printed with a TID number and a unique EPC that may or may not correspond to the UPC and barcode that was used in the past. Most cases I have seen require that the UPC and a barcode be printed on these RFID tags so there is information available to the human eye and a barcode scanner when used.

While this is being asked for by the retailers, manufacturers can use these tags to their own advantage to track what products are going out to their shipping departments and in what quantities. This eliminates human error in the tracking process, something that has been a problem in the past, while also reducing workload as boxes of finished goods no longer must be opened, counted and inspected for accuracy.

A well-designed RFID portal for these items to pass through can scan for quantities and variances in types of items in boxes as they pass through the portal. Boxes that do not pass the scan criteria are then directed off to another area for rework and reevaluation. Using human inspection for just the boxes that do not pass the RFID scan greatly reduces the labor effort and expedites the shipping process.

I recently assisted with a manufacturer in the garment industry who was having to tag his garments for a major retailer with RFID tags that had the UPC and a barcode printed on them. The tags were supplied through the retailer and the EPCs on the tags were quite different then the UPC numbers printed on them.

The manufacturer wanted to know how many garments of each type were in each box. Testing showed that this could be done by creating a check point on his conveyor system and placing UHF RFID antennas in appropriate locations to ensure that all the garments in the box were detected and identified.

In this case, the manufacturer wanted was a simple stand-alone system that would display a count of different types of garments. An operator reviewed the results on a display and decided based on the results whether to accept the box and let the conveyor forward it to shipping or reject it and divert it to another conveyor line for inspection and adjustment.

While this system proved to be relatively simple and inexpensive, it satisfied the desires of the manufacturer. It is, however, possible to connect an RFID inspection station to a manufacturing information system that would know what to expect in each box and could automatically accept or reject boxes based on the results of the scans without human intervention and/or human error.

Palletized Automation with Inductive Coupling

RFID is an excellent way to track material on a pallet through a warehouse. A data tag is placed on the pallet and is read by a read/write head when it comes in range. Commonly used to identify when the pallet goes through the different stages of its scheduled process, RFID provides an easy way to know where material is throughout a process and learn how long it takes for product to go through each stage. But what if you need I/O on the pallet itself or an interchangeable end-of-arm tool?

Inductive Coupling

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Inductive coupling delivers reliable transmission of data without contact. It is the same technology used to charge a cell phone wirelessly. There is a base and a remote, and when they are aligned within a certain distance, power and signal can be transferred between them as if it was a standard wire connection.

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When a robot is changing end-of-arm tooling, inductive couplers can be used to power the end of arm tool without the worry of the maintenance that comes with a physical connection wearing out over time.

For another example of how inductive couplers can be used in a process like this, let’s say your process requires a robot to place parts on a metal product and weld them together. You want I/O on the pallet to tell the robot that the parts are in the right place before it welds them to the product. This requires the sensors to be powered on the pallet while also communicating back to the robot. Inductive couplers are a great solution because by communicating over an air gap, they do not need to be connected and disconnected when the pallet arrives or leaves the station. When the pallet comes into the station, the base and remote align, and all the I/O on the pallet is powered and can communicate to the robot so it can perform the task.

Additionally, Inductive couplers can act as a unique identifier, much like an RFID system. For example,  when a pallet filled with product A comes within range of the robot, the base and remote align telling the robot to perform action A. Conversely, when a pallet loaded with product B comes into range, the robot communicates with the pallet and knows to perform a different task. This allows multiple products to go down the same line without as much changeover, thereby reducing errors and downtime.