Weld Immune vs. Weld Field Immune: What’s the difference? 

In today’s automotive plants and their tier suppliers, the weld cell is known to be one of the most hostile environments for sensors. Weld slag accumulation, elevated ambient temperatures, impacts by moving parts, and strong electromagnetic fields can all degrade sensor performance and cause false triggering. It is widely accepted that sensors will have a limited life span in most plants.

Poor sensor selection does mean higher failure rates which cause welders in all industries increased downtime, unnecessary maintenance, lost profits, and delayed delivery. There are many sensor features designed specifically to withstand these harsh welding environments and the problems that come along with them to combat this.

In the search for a suitable sensor for your welding application, you are sure to come across the terms weld immune and weld field immune. What do these words mean? Are they the same thing? And will they last in my weld cell?

Weld Immune ≠ Weld Field Immune

At first glance, it is easy to understand why someone may confuse these two terms or assume they are one and the same.

Weld field immune is a specific term referring to sensors designed to withstand strong electromagnetic fields. In some welding areas, especially very close to the weld gun, welders can generate strong magnetic fields. When this magnetic field is present, it can cause a standard sensor to perform intermittently, like flickering and false outputs.

Weld field immune sensors have special filtering and robust circuitry that withstand the influence of strong magnetic fields and avoid false triggers. This is also called magnetic field immune since they also perform well in any area with high magnetic noise.

On the other hand, weld immune is a broad term used to describe a sensor designed with any features that increase its performance in a welding application. It could refer to one or multiple sensor features, including:

    • Weld spatter resistant coatings
    • High-temperature resistance
    • Different housing or sensor face materials
    • Magnetic field immunity

A weld field immune sensor might be listed with the numerous weld immune sensors with special coatings and features, but that does not necessarily mean any of those other sensors are immune to weld fields. This is why it is always important to check the individual sensor specifications to ensure it is suitable for your application.

In an application where a sensor is failing due to impact damage or weld slag spatter, a steel face sensor with a weld resistant coating could be a great solution. If this sensor isn’t close to the weld gun and isn’t exposed to any strong magnetic fields, there is really no need for it to be weld field immune. The important features are the steel face and coating that can protect it against impact and weld slag sticking to it. This sensor would be classified as weld immune.

In another application where a sensor near the weld gun side of the welding procedure where MIG welding is performed, this location is subject to arc blow that can create a strong magnetic field at the weld wire tip location. In this situation, having a weld field immune sensor would be important to avoid false triggers that the magnetic field may cause. Additionally, being close to a MIG weld gun, it would also be wise to consider a sensor with other weld immune properties, like a weld slag resistant coating and a thermal barrier, to protect against high heat and weld slag.

Weld field immunity is just one of many features you can select when picking the best sensor for your application. Whether the issue is weld slag accumulation, elevated ambient temperatures, part impact, or strong electromagnetic fields, there are many weld immune solutions to consider. Check the placement and conditions of the sensors you’re using to decide which weld-immune features are needed for each sensor.

Click here for more on choosing the right sensor for your welding application.

 

Lithium Ion Battery Manufacturing – RFID is on a Roll

With more and more consumers setting their sights on ‘Drive Electric,’ manufacturers must prepare themselves for alternative solutions to combustion engines. This change will no doubt require an alternative automation strategy for our electric futures.

The battery

The driving force behind these new electric vehicles is, of course, the battery. With this new wave of electric vehicles, the lithium ion battery manufacturing sector is growing exponentially, creating a significant need for traceability and tracking throughout the manufacturing processes.

Battery manufacturing is classified into three major production areas:

    1. Electrode manufacturing
    2. Cell assembly
    3. Finishing formation, aging and testing

These processes require flexible and efficient automation solutions to produce high quality batteries effectively. As such, there are numerous areas that can benefit from RFID and/or code reading solutions. One of the biggest of these is the electrode manufacturing process, specifically on the individual mother and daughter electrode rolls. This is a great application for UHF (Ultra-High Frequency) RFID.

The Need for RFID

The electrode formation process involves numerous production steps, including mixing, coating, calendaring, drying, slitting and vacuum drying. Each machine process generally begins with unwinding turrets and ends with winding ones. A roll-to-roll process.

Two of the three primary components of the lithium ion battery, both the anode and cathode electrode, are produced on rolls and require identification, process step validation and full traceability all the way through the plant.

During the slitting process both larger mother rolls are unwound and sliced into multiple, smaller daughter rolls. These mother and daughter rolls must also be tracked and traced through the remaining processes, into storage and ultimately, into a battery cell.

Solution

Working with our battery customers and understanding their process needs, a UHF RFID tag was developed specifically to withstand the electrode production environment. Having a tag that can withstand a high temperature range is crucial, particularly in the vacuum drying lines. This tag is capable of surviving cycling applications with temperatures up to 235 °C. Its small form factor is ideal for recess mounting in the anode and cathode roll cores with an operating range reaching 4 meters.

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The tag embedded in the roll core paired with an RFID processor and UHF antenna provides all the necessary hardware in supporting battery plants to achieve their desired objective of tracking all production steps. Customers not only have the option of obtaining read/writes, via fixed antennas at the turrets, but also handheld ones for all storage locations — from goods receiving to daughter coil storage racks within a plant.

This UHF RFID system allows for tracking from the initial electrode coils from goods received in the warehouse, through the multiple machines in the electrode manufacturing process, into the storage areas, and to the battery cell assembly going in the electric vehicle — ultimately linking all battery cells back to a particular daughter roll, and back to its initial mother roll. RFID is on a Roll!