Remakes cost glass processors and IGU manufactures with hundreds of thousands each year. So just imagine how much extra profit you could make if they didn’t. We report.
The stakes are high. Margin in IGU manufacture is on a knife-edge and not much better in processing, yet the glass industry writes off hundreds of thousands each year in failed units or remakes, which are picked up (if you’re lucky) at quality control and dispatch or at point of installation.
“Everyone is scrapping it out for more business”, says Promac Group’s Mike Whitlam. “It is tough but there are a lot of people who aren’t making the most of their existing business because of what they’re losing to remakes.
“It’s very difficult to pick up failures early in the production cycle when the cost of correcting them are by definition less, than the end of the manufacturing process.
“You simply don’t see a defect in edge quality until toughening or dimensional or surface defects or anisotropy, until when unit has been made up.
“At this point you have a lot of additional cost to account for in process and labour. Intercept that failure earlier and you save thousands and thousands in remakes.”
And he’s speaking from experience. Mike joined Promac Group as its new specialist in glass sales from Pioneer Trading Company earlier this year, where he was Group Operations Director. This encompassed a post as Group Operations Director at Tudor Glass in Chelmsford.
“I’ve lived it”, he continues. “There’s that moment of dread when the phone rings and you’ve got a customer on the line who is having to go back out to the end customer because the washer hasn’t quite picked up everything or there’s a little bit of sealant inside the unit.
“Individually, they’re small things. People are always going to miss those little imperfections but the homeowner doesn’t, by which time, it’s too late. It’s not only the cost of replacing the unit or the glass but the relationship with the customer.
“Most IGU manufacturers will absorb the cost of replacement units but the installer still has to pick up the cost of replacement. It doesn’t make for a great relationship.
“Pick up those imperfections, and earlier in the manufacturing cycle, and you reduce costs associated with your own process – labour and materials but more importantly, you deliver a better service to your customer. That’s going to help you retain and win business.”

Glass defects are notoriously difficult to spot, easily slipping through the production process and quality control unchecked. “If you’re dealing with something like anisotropy, you can only see it in certain light frequencies”, continues Mike.
“We simply can’t spot it, however much care and attention we apply throughout the production cycle. It needs to be an automated process.”

An end to remakes?

This has driven SoftSolution’s development of its linescanner technology. The automatic glass defect systems leader has developed a new all-in-one system, which is designed to pick-up all quality issues which have the potential to impact on glass, and particularly IGU supply earlier in the manufacturing cycle.
“It’s a revolutionary piece of kit”, continues Mike. “If you can catch a defect in edge quality before it goes into the toughening plant or any other form of edge stress you cut out production cost further down the line.
“That’s labour, materials, processing costs but perhaps most importantly – reputation. This isn’t just about cutting the cost of remakes. It’s about retaining the business you have, developing a reputation for quality winning new business on the back of it.”
And the list of potential problems that the SoftSolution All-in-One Linescanner can pick up is a comprehensive one.
At the start of the manufacturing process, this includes glass thickness and coating composition. It also provides checks for edge and surface quality, picking up a range of defects from inclusions, scratches, finger prints, coating defects and dirt.
It also introduces new dimensional checks on cut and processed glass – critically, doing so, without impacting on cycle time. Achieved using telecentric imaging technologies, this includes external contours, inner contours and edge cut-outs. The SoftSolution LineScanner will also inspect drill hole location and diameter.
“The SoftSolution LineScanner is a very low-cost investment, when you consider the improved product quality and potential savings it delivers. For me it’s a genuine no-brainer”, Mike adds.

Real-time checks on tempering quality, isotropy and edge stress

One of the key features highlighted by Mike as delivering significant advantages to IGU manufacturers is the SoftSolution LineScanner’s ability to pick up to monitor and check tempering quality, isotropy and edge stress in real-time.
“It delivers a real shift paradigm. You’re not simply picking up a fault but you have the ability to adapt production to minimise the impact of something like edge stress before it becomes a problem impacting on quality”, he says.
Checks on tempering quality include not only edge stress and anisotropy but the anisotropy pattern, and overall bending. This includes calculating the light delay for each individual pixel (0.015mm²) of a glass sheet, then calculating the stress direction per pixel and corresponding light delay to map the anisotropy pattern.
This data allows glass processors to minimize anisotropy by optimizing the initial quenching and oscillation speed but also to understand its impact, what percentage of the glass is effected and if it’s going to be likely to be a problem in position and when exposed to polarized light.
“The value of this kind of insight is massive”, says Mike. “You can adjust your production run to minimize the impact of anisotropy – but it also allows you to make a critical call. ‘Do I go on? Is the end quality of the product going to be good enough? Or, do I cut my losses?’.
“Either way you get that insight and save costs down the line. This is particularly high value as the industry moves to production of ever larger IGUs, the costs of getting it wrong, multiplying with scale.”

Final QC checks, including cavities and butyl defects

“It’s so annoying. The unit’s been supplied and fitted and then someone spots butyl inside the IGU or a finger print or something. Over the years I’ve seen just about everything that you could imagine seeing, inside the cavity of an IGU!”, continues Mike.
“Final QC checks are critical.The SoftSolution LineScanner can check for the composition and build of the IGU, including particles in the cavity and butyl defects, in addition to further checks for edge defects, scratches and contaminates.
“You aren’t going to send anything out with something in it that you don’t know about”, he adds.
The SoftSolution LineScanner will also pick-up on-screen printing errors and errors on logos, including position and rotation, even down to ink thickness.
“With a background in production, the value-add that this technology delivers is enormous. If you’re in it to make margin, it’s an absolutely critical bit of kit from the very start to the end of the IGU manufacturing process”, Mike concludes.