Guardian Protective Devices Relies on SST Checkweigher from Mettler-Toledo Hi-Speed

Guardian Protective Devices is a leading manufacturer of pepper sprays for law enforcement, military agencies, security personnel and civilians. They also offer specialized contract packaging of mission-critical aerosol cans to private label customers. To protect the quality of their products, they installed an SST checkweigher from Mettler-Toledo Hi-Speed. Unlike traditional checkweighers, the SST fits over an existing conveyor because its unique design lifts the package off the production line to detect under- and overfilled cans. Despite their space limitations, Guardian was able to add checkweighing to maximize final product quality and improve yields.

“The SST is the only suspended scale checkweigher on the market, to my knowledge. We added it right over our line with no major changes so installation was a breeze,” said Herb Schreidber, CEO of Guardian Protective Devices. “It’s a small machine doing a big job. We made the right choice – it’s a good fit for us.”

With little room to spare, finding a checkweigher was a challenge for Guardian. It wasn’t an option to break the existing line and add several more feet of conveyor, which other checkweighers require. The SST is unique because it is cantilevered over a conveyor, eliminating the need for time-consuming, expensive and sometimes impossible line modifications.

The cantilevered design is possible thanks to the SST’s patented side-grip weigh conveyor, which weighs the can by slightly raising it off the production line and gently returning it while maintaining proper line spacing. A reject device downstream automatically removes under- and over-weight packages. Guardian also collects data from the checkweigher to adjust the filler, improve overall equipment effectiveness and provide reports to customers.

With an accuracy of +/- 0.5 to 2 g, the SST is able to weigh up to 350 cans per minute. “Our throughput is easy for this checkweigher. It’s not even breaking a sweat,” noted Schreiber. “We like that it has the capability to grow with us as our production increases.”

“The primary reason we installed this checkweigher was to eliminate off-weight cans and to document fill weights for our filling records. This is for quality control and to generate our COC (Certificate of Conformance) that we give to our customers” said Schreiber. “As a manufacturer of precision products that people rely on for their personal protection, it’s important that we provide the highest quality possible. We’ve outperformed the 800-pound gorillas out there and have the credentials to prove it.”

“This checkweigher also improves our yields. If we’re running 550 g cans and putting in a little extra every time, that cuts into our profit margin,” explained Schreiber. “On top of that, every can that gets rejected is lost product, and that costs money. Our checkweigher helps us ensure that the filler is within specs, reducing rejects and product giveaways.”

At Guardian, the SST is installed on a line that currently produces 85 unique SKUs. These round aerosol cans range in size from 38mm by 85mm to 65mm to 260mm and weigh 45 to 550 g. New product co-development is part of Guardian’s contract packaging services, which specialize in mission-critical aerosol cans, like mini fire extinguishers. “We recently assisted a company in developing a proprietary foaming gun oil – the only one on the market,” said Schreiber. “It’s all about helping our customers create high-quality products that increase their sales.”

“We handle a wide variety of products on the SST, so fast and accurate product changeovers are essential. The fill weight is changed on the control panel,” noted Schreiber. “Changes to the height and diameter of the can require mechanical adjustments. That takes about ten minutes on this checkweigher, with no change parts or tools needed.”

Guardian’s SST utilizes Hi-Speed’s XE controller, including a 7-inch color touch screen, 100-product memory and a ‘dashboard’ user interface design for ‘at a glance’ monitoring of the production process. “This equipment is intuitive. It’s easy to train our people to use and our operators are very satisfied with it,” said Schreiber. “During production, the graphical display alerts us to issues on the line, allowing us to take corrective action quickly. Our checkweigher has had no downtime and is very reliable.”

“Mettler Toledo’s customer service has also been excellent, and we’ve enjoyed doing business with them,” said Schreiber. “Our sales rep, Joe Young from Reliant Packaging Systems, was extremely helpful in getting us the right solution for our operation.”

“We make serious equipment for professionals, and civilians receive the same high standards. Our products have to do what we say they’re going to do,” concluded Schreiber. “We’re very happy with our choice of the SST checkweigher. It helps us make a consistent quality product and fulfill our quality commitment to our customers.”

About Mettler-Toledo Hi-Speed

Mettler-Toledo Hi-Speed is a wholly owned subsidiary of Mettler-Toledo Inc., a global supplier of precision instruments with sales and service locations in 37 countries. The Mettler-Toledo Product Inspection Division, which includes the companies CI-Vision, Hi-Speed, PCE and Safeline, is an industry leader and innovator in the field of automated product inspection solutions with vision inspection, checkweighers, track-and-trace systems, metal detectors and x-ray inspection systems. Industries including food, pharmaceutical, nutraceutical, chemical and personal care use our solutions to continuously improve the quality of their products and improve the efficiency of their manufacturing and packaging processes.

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