Inspection technology overview: what they do, how they can help you

Posted by AFN Staff Writers on 7th March 2016

Quality and compliance are everything in manufacturing, but more complex processes and faster production lines mean humans just cannot inspect for packaging errors, contamination and quality standards without impacting severely efficiency.

Purely relying on human inspection means problems may only be found well after they first appear, and countless contaminated products could have been produced in the meantime.

However, automation drives quality improvement through repeatable and reliable inspection, with automatic data capture to measure reject rates and alarm operators. So what do you need? Here’s my guide to the inspection systems every manufacturer should know…

Young woman inspecting an aluminum can through her glasses

Without automated inspection, brands run the risk of recalls, a damaged reputation and high costs. if you think recalls aren’t too much to worry about, check out how costly they really are, and again here.

For many businesses, automating inspection is the best solution. Inspection systems not only have a far higher detection rate than humans, but they are also able to streamline and improve your line’s efficiency.

However, not all inspection technologies are made equal. So, the first step is to understand which inspection machinery will drive quality and process improvement while delivering the best return on investment (ROI). That’s even more important in light of the growing capability of techniques and equipment available.

So here’s what I think you — and every manufacturer — should know:


What does it inspect?

Vision inspection is mostly used to inspect packaging integrity and product conformance, including:

  • Inspecting presence, position and formation of a code (date code, barcode,)
  • Validating label presence and position
  • Checking closures of tamper seals, correct caps by colour
  • Detecting packaging content and fill levels in bottles or jars
  • Sorting food and beverage products based on marking
  • Counting products

Why invest?

All-in-one vision systems are instrumental in identifying a wide range of quality issues — things that humans are unable to do reliably and consistently.

Certainly, vision systems have been around a while, but technology improvements mean they are faster, more robust and can handle a greater range of inspection tasks per camera. Today’s cameras are also taking better and clearer images, which are necessary to identify defects. The better the image and software configuration, the less likely the vision system is to reject something falsely.

Another benefit is that manufacturers can tie a vision inspection system into automated processes to reduce production-line errors that could ruin an entire batch of goods. That alone could deliver the return on investment you’re looking for. (You may find this article on 3 essential inspection technologies for FMCG interesting, and find out more about vision inspection.)


What does it inspect?

Checkweigh systems are used to reduce waste and overfill. Checkweigh systems can support weight compliance for two standards: AQS and non-AQS (UTML). Leading retailers have their own compliance requirements — such as the Woolworths WQA, where checkweighing is essential for Home Brand products, and highly recommended for all products. These typically sit at the end of the line, where they can precision weigh at required line speeds. If a product is overweight or underweight, the checkweigher will instantly reject the product by removing it from the line, and alert you to the issue immediately, so you can address it before producing thousands of out-of-spec products.

Why invest?

Checkweighers are best associated with compliance to regulations, but they can also boost your bottom line by reducing waste, tightening tolerances and ensuring more consistent products. By improving weighing precision, checkweighers are proven to provide an immediate contribution to productivity and profits. The more accurate your checkweigher, the more money you can save. So even with a packet of nuts, saving the tiniest amount of overfill could add up to massive savings over time.

Because checkweigh technology can help manufacturers detect issues with product overfill (or under-fill), you are able to correct the problem fast and save costs.


What does it inspect?

Metal detection systems only inspect products for metal. They are ideal for inspecting dry products (think flour, salt, sugar) and frozen products, plus also give very good results on a wide range of other products. Metal detection systems sit towards the end of the line in most cases and check the “final product”.

Why invest?

One of the biggest culprits for food contamination today is metal and non-magnetic stainless steel. This is where metal detection technology is extremely effective. Unlike their predecessors, the advanced metal detection systems today can be configured to detect contaminants even within high moisture content. 

However, metal detection systems come with a few issues. They can be affected by electrical interference and cannot handle aluminium packaging. Also, traditional metal detectors cannot inspect goods in tin cans or foil pouches or metalised film – an increasingly common packaging type in the food industry., so don’t waste money on buying a metal detector that the supplier tells you will work for products in foil film. The development of X-ray metal detection technologies provides a solution. (Find out more about metal detection.) 


What does it inspect?

Metal isn’t the only culprit of food recalls. Glass, stone, rubber and other contaminants can make their way into the product. By evaluating density through the product and packaging, X-ray inspection equipment can identify these foreign bodies. Advanced X-ray inspection systems can perform in-line quality checks to:

  • Detect physical defects
  • Measure product mass
  • Identify missing or broken products
  • Inspect packaging seal integrity

Why invest?

Unlike metal detection, X-ray inspection is ideal for a wide range of packaging, especially in bottles, cans, jars, pouches and foils. Better yet, it can detect contaminants embedded right in the product and tell the operator where in the product the contaminant sits.

Over recent years, X-ray equipment has become a lot faster, making it ideal for high-speed production lines. This makes it a worthy investment for those processors who want to reduce contamination and protect against recalls.

However, these extra capabilities come at a cost – X-ray equipment is more expensive than metal detection. (You may find it interesting to compare metal detection with X-ray inspection.)


What does it inspect?

Barcode scanners ensure barcodes are present and correct for use through the supply chain and with point-of-sale. They can inspect barcodes on cartons, pallets and individual items. Barcode scanners can be linked to databases using software to even check if the right barcode is on the right product.

Why invest?

By scanning a barcode on the line, barcode scanners help manufacturers drive greater profitability and productivity. Doing this on line, rather than at the end of the batch or shift, identifies errors in packaging or labelling immediately. The same system can be linked to a stock control system to increment products counts as the products are being made, so warehouse tallies are always up to date.

So that’s my basic rundown on five different types of inspection equipment. To find out what the best inspection technology is for your production line, speak to our experts.

You may also find it interesting to read our free white papers on objective QA, automating your way to lean manufacturing, avoiding recalls and the benefits of integrating identification with inspection. Click on the link below to access our free whitepaper on lean manufacturing.

* Andrew Key is Matthews Australasia’s Product Manager for Inspection Technologies, with more than 25 years’ experience with packaging machinery, inspection technologies and ID technologies. Andrew’s career spans across organisations such as Alfa Laval and TNA, among others, helping manufacturers to effect process improvement using the latest technology from around the globe. In his current role, Andrew is constantly looking at cutting-edge technologies for Matthews’ customers to improve quality control.