The business case for upgrading from metal detector to x-ray inspection

upgrading from metal detector to x-ray inspection

Is it time to be upgrading from metal detector to X-ray inspection?

Over recent years, Australia’s major supermarkets – Coles, Woolworths and Aldi – have been pushing suppliers to implement metal detection systems. The strawberry needle crisis of 2018 forced the hand of many fresh produce suppliers, especially. 

There were some interesting lessons for Australian food processors in the strawberry crisis. And if you deal in fresh produce, you may find this round up of pros and cons for metal detectors in fresh produce inspection informative. 

But there comes a point when metal detection is not enough. 

Granted, it’s a great starting point for inspection, but it comes with a few major drawbacks and limitations that could be holding back your business and putting your product quality at risk. 

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If that’s the case, it could be time to be upgrading from metal detector to X-ray inspection. 

X-ray inspection equipment can identify foreign contaminants by evaluating the density through the product and packaging, even through thick foil pouches and cans. 

Today’s advanced X-ray systems can inspect virtually any packaged productto find contaminants embedded right inside the product. 

But upgradingfrom metal detector to X-ray inspection is not a cut-and-dry decision. X-ray systems tend to be more expensive up-front than metal detection systems. Plus, metal detectors last up to five times longer.

So, you need to weigh up the advantages of an X-ray inspection system before upgrading to see whether it will pay for itself in the long term. 

Start by looking at the benefits of X-ray inspection over metal detectors.

X-Ray Inspection vs Metal Detectors

X-ray inspection systems offer more capabilities than metal detectors

Metal detectors can detect metals, but if you want to detect glass, stone or bone in your products, X-rays have greater capabilities.

X-rays can also do other things beyond inspecting for foreign materials, including checking the shape and size of items, and counting the number of items present. This is particularly important for products such ready-made meals where it’s important that a set number of items are present. (Check out the rise of ready meals – “TV dinners” step aside!)

X-ray equipment is less sensitive to environmental factors

One of the biggest drawbacks of metal detectors is their sensitivity to a number of environmental factors, including temperature changes, vibrations along the line, and air-borne electrical interference. 

These factors can significantly impact the inspection system’s performance. Let’s say your line is a freezing tunnel or hot water wash-down: this can result in false reject signals for products, which is costly in the long term. 

While there are ways to manage this sensitivity, you may reach a stage where X-ray inspection becomes a more viable option – especially if you extend your product line to include a wet area or temperature variations. 

Another drawback for metal detectors – but not X-ray inspection – is the “orientation effect”. This means that metal detectors are more sensitive to some metals when they are facing a certain way, and vice versa. The strawberry needle crisis is a good example – metal detection can detect a pin in strawberries so long as the pin is facing “the right way”. 

This is not an issue for X-ray inspection equipment, meaning your products are at less risk. 

X-ray is less sensitive to the “product effect”

When we talk about the “product effect”, we’re referring to how certain product characteristics can disrupt the voltage balance between the receiver coils in a metal detector. This causes the metal detector to react as though there is a metal contaminant present. 

The result? 

False rejections. 

Some characteristics that cause the “product effect” include:

  • high salt 
  • high moisture content
  • high iron content
  • variations in the product’s temperature, e.g.frozen products thaw along the line

So, if you extend your product range to include items with a high salt or iron content, for example, it might be worth upgrading to an X-ray inspection system. 

When to upgrade to X-Ray inspection

With the factors outlined above, you need to work out whether the risks and costs involved in using metal detection are more than if you upgraded to an X-ray inspection system. 

Here are some scenarios where it will be worthwhile upgrading:

1. You plan to extend or change your product range 

If you are introducing new products to your range, it could be worth investing in an inspection solution with fewer limitations and sensitivities. X-ray offers more reliable results as it is not susceptible to the “product effect”, “orientation effect” or a multitude of environmental factors. 

X-ray machines can inspect almost any type of products, including packed goods, loose free-flowing goods, pumped products (such as meat, cheese, dough), liquids and more. 

2. You need to meet increasingly stringent QA standards

While X-ray inspection is not mandatory, retailers are tightening the rules for product quality control. It’s surely only a matter of time before X-ray is added to the list. After all, X-ray inspection can detect glass, stone and bone. It can also detect the shape and size of products, voids (missing items), and can inspect packaging for things such as open flaps on a box, items present, gross weight and more.

This helps you demonstrate to your customers that the most reliable QA processes are in place and reduce the likelihood of a recall or withdrawal. 

3. You need to show an audit trail

Both a metal detector and X-ray system will tell you how many products have been checked, the number of rejects, and so on. However, an X-ray system goes a step further by recording an image of every product checked. 

This is a huge selling point for suppliers who are dealing with major retailers, because if there’s a complaint, you can check every image from that day and prove what the product looked like when it left your premises. 

4. You want your inspection system to ‘do more’

Don’t upgrade for the sake of upgrading. Consider how you can get the most value for your business. X-ray inspection is the most complete inspection system available for Australian manufacturers. They can perform many checks in addition to detecting for contaminants, which can add significant value to your processes and your brand reputation. 

For example, X-ray systems can see inside a container to identify if items are missing from a pack — something a metal detector cannot do. They can also measure the shape of a product, count items or use density to estimate the weight of a product. All of these added capabilities improve your QA processes and ensure you ae getting the maximum value from your technology investment. 

The bottom line

If you only need to inspect small, dry products, upgrading to an X-ray system is an expense you probably cannot justify. However, if you need to go beyond the basics now, or plan to grow your business, the business case for upgrading is strong. 

If you’re considering upgrading your system from metal detector to X-ray inspection, or are investing in your first inspection system, Matthews can help. Talk to our experts about the right inspection system for your unique business needs. 

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Image credit: iStock/ tang90246 (main)

Matt Nichol
Matt is a laser marking expert and has in-depth knowledge of product ID technologies. He is a regular at international trade shows like Pack Expo and is constantly looking at emerging trends and technologies.
Matt Nichol

by Matt Nichol

Matt is a laser marking expert and has in-depth knowledge of product ID technologies. He is a regular at international trade shows like Pack Expo and is constantly looking at emerging trends and technologies.

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