How Glass Inspection Technology Improves Fabrication and Glass Quality

By Jordan Scott

Inspection technology is transforming the landscape of glass manufacturing.
And, as fabricators gain further control over the quality of their products, architects increasingly include more stringent demands in their project specifications. Inspection equipment makes the fabrication process easier and raises the bar industry-wide.

Inspection Interface

Automation has been a major buzzword in the glass industry for years due to its ability to increase efficiencies and safety. The key to increasing the functionality of automated machinery and equipment is software.

FeneTech’s FeneVision ERP connects the entire production process from ordering to fabrication and shipping. It can also interface with inspection equipment such as Softsolution North America’s LineScanner. AJ Piscitelli, who is in charge of business development for FENml at FeneTech of Aurora, Ohio, says that instead of accessing the information at the LineScanner, the user can access it in their FeneVision Business Intelligence (BI) app.

Using the FeneVision program, a company can input the specifications required and the scanner can detect whether or not the glass is “in or out of spec.” If it is out of spec, it will alert the operator who can then make the determination about whether to approve the glass.

“What’s somewhat new is taking that rejection data and getting it into the ERP side. Companies are able to pull up the information about a unit scanned if the customer calls with a quality issue. The company can pull up the scan sheet to see if there was an issue or if the defect happened after the glass left the factory,” says Piscitelli.

Another way software is improving the production process is by storing data about glass rejected on the production floor. When that glass type is being processed again, the software will send the rejected glass back to the cutting table.

“We’re looking at ways to facilitate making the process easier. I see a lot more quality and rejecting enhancements coming into the software over the next year or two,” says Piscitelli.

He emphasizes that software plays a key role in being able to create actionable information from the data collected during the fabrication process.

“We have to have software to understand where the defects are coming from. There could be a common factor such as the conveyor line, a defect in certain glass types from the manufacturing, down to a customer ordering glass that can’t be produced due to physical limitations,” he says. “The software gives companies the power to make that determination; before they had to do that by gut feeling.”

Having this technology allows fabricators to produce better products overall, according to Piscitelli, and thus increases customer satisfaction.

“If a customer gets a bad product there could be a waste of time and resources on the company’s part due to potential financial penalties or logistics costs. Really, it’s in the manufacturer’s best interest to consistently send out perfect product as often as possible.”

Assessing Cullet

Softsolution’s LineScanner isn’t the only inspection equipment the Glenview, Ill.- based company offers. Its CulletScanner uses the same hardware as the LineScanner but is implemented differently at the end of a company’s tempering furnace. The technology allows the user to break a lite of tempered glass and then scan and record a high-resolution image of the fragmentation pattern that is then stored digitally. If a company needs to meet ANSI Z97.1 for example, the scanner will highlight the ten heaviest fragments and notify the operator of the estimated weight. If the weight exceeds the value set by the standard, the lite fails. All companies are required to perform this test at the start of a production run, when a recipe is changed and at least every hour while that recipe is being run.

Despite the availability of this technology, there are still many companies counting cullet manually. Nate Huffman, president of Softsolution North America, says people who are unaware that the technology exists have impeded widespread adoption. However, that’s not the only reason. “We first started selling this in 2008 or 2009 and everyone would ask if it was certified by the Safety Glazing Certification Council (SGCC). I talked with John Kent with the SGCC and he said they don’t certify any machine. Once I found that out, it’s helped a lot and people don’t ask as much,” he explains.

Huffman also points out that it’s been easier to introduce the technology to the European market where the test size is more uniform than in the U.S. where the test size should, ideally, be as close to the production size as possible. The company has had to create a larger scanner for the
U.S. market.

Huffman believes demand for the CulletScanner ultimately will continue to grow due to the equipment’s benefits. The system allows the company to store a digital record with a more exact estimate than if the ten cullets were chosen manually. Huffman says this saves paper, cost and space compared to storing rolled up pieces of paper with cullet outlines.

Glaston Corp., based in Tampere, Finland, offers the Glaston Siru mobile application, which can be used by anyone for free once downloaded. The app supports both the ANSI and European (EN) standards. It uses an operator’s mobile phone camera to take a picture of a glass fragmentation pattern in a 5- by 5-cm area on the glass and, after its analysis is complete, the app lets the operator know if the glass passes. Users can save the photo and analysis in the app’s history with data about the glass thickness or order number for tracking purposes.

Kimmo Kuusela, sales director for Glaston in North America, says that one benefit of the app compared to a stationary cullet scanner is that it can be used on any glass size. Another is that it can be used anywhere that a phone can be used, such as on the jobsite.

“It doesn’t have to be used by a glass specialist,” he adds. “Anybody could use it. The app checks the glass automatically. You don’t have to know anything about the test itself. You just have to break the glass and take a picture.”

Low-E Detection

Coating detectors are another type of inspection equipment that can make the glass fabrication and installation process more efficient and consistent. EDTM, based in Toledo, Ohio, offers a variety of portable, handheld coating detectors.

Mark Imbrock, co-owner and vice president, says the detectors include one for edge deletion, another that can check one side of a single lite to determine if it has a coating, one that can check if the coating is on the top or bottom side of a glass lite, and its most advanced version, which can detect the surface of an insulating glass unit that is coated.

This technology allows operators to know if glass needs to be flipped during production and allows installers to ensure they are orienting the glass correctly.

“You never want the coating to touch the rollers. Having a detector that can check both sides halves the time it takes to test,” says Imbrock. “Some companies check every lite and some check each pallet. If the low-E side is up on one lite it should be for all … If you mix in human interaction and the lites aren’t all stacked by machine, then in those cases it’s better to check. Every time humans are involved there’s a chance of error.”

In the past, prior to the invention of low-E detectors, the only option available to glass and glazing professionals was an ohmmeter, which could tell if a material was conductive by reading the ohms on the glass.

“Those aren’t rugged, durable things but they were the only thing that really existed previously,” explains Imbrock.

In recent years, the company has introduced a low-E card which includes the same technology in a credit card-sized format. Imbrock says these are more often used in the field and handed out as marketing tools, though many use them in factories as well. Going forward, the company plans to create more interfaces with the detectors to expand the ways they communicate.

Inspection equipment plays an important part in the quality control process for many companies and as the technology becomes more advanced and cost-effective, its adoption will likely increase.

What’s New With Anisotropy?

If polarized light hits a glass façade with high levels of anisotropy, it could appear distorted to the eyes of those looking upon it—including the architect. Advances in equipment that can detect the presence of anisotropy have given fabricators the tools they need to make changes to their tempering furnaces that will prevent the equipment from producing glass with high levels of anisotropy.

There are several anisotropy scanners on the market, and the industry is working to standardize the way this equipment measures anisotropy. Louis Moreau, head of technology and innovation at AGNORA in Collingwood, Ontario, is the chair of the ASTM task group working on this standard, currently titled, Standard Test Method for Measuring Optical Anisotropies in Flat Architectural Glass.

A task group in the flat glass architectural committee was created in June 2018. First balloting was completed in fall 2019 and the second level in spring 2020.

“Each time there’s a negative comment we have to address it and make it work. We’re hoping to final ballot in a couple of months,” says Moreau, who expects it will be re-balloted in September or October.

He explains that this test method doesn’t try to set limits.

“My goal was to get all of the manufacturers together to come up with a common unit of measure so people aren’t talking about elephants and zebras. They’ll all have the same measurements,” says Moreau, who adds that if a glass lite is measured on three different machines that should all give roughly the same measurement.

He says that the industry accepted anisotropy as something inherent to the glass fabricating process that couldn’t be fixed in the past. Now, thanks to new scanning technology, the problem can be mitigated. Moreau’s company recently purchased a scanner and has used its data to tweak its tempering process to create even higher quality glass. He says that, if a company masters anisotropy, it will master several other things, such as roller wave distortion, in the process.

“The same glass can show different results depending on where it is. It takes two to tango. You have to have anisotropy built into the glass and a polarized light environment to notice it,” he says, explaining why anisotropy often goes unnoticed.

After this standard is published, Moreau says the next step would be to come up with a second standard that would refer to the first and propose a standard way to evaluate the data companies get from the machine.

“I don’t envision at the moment that it will go further than that,” he says. “This will take a lot of research. It’s all fairly new … We’re at the beginning of an era.”

For more information about anisotropy, see the article, “Mitigating the Menace,” in the August 2019 issue of USGlass magazine.

Jordan Scott is an assistant editor for USGlass magazine. She can be reached at jscott@glass.com.

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