Eriez Targets Pharmaceuticals With Metal Detection
Published: May 9th, 2012
Eriez (www.eriez.com) supplies its metal detectors for integration on existing conveyor lines or incorporated with conveyor systems designed and built by Eriez. A space-saving solution for pharmaceutical inspection, the E-Z Tec DSP (digital signal processing) Pharmaceutical Metal Detector is mounted on a portable vertical stand for use on tablet press machines.
The system includes an E-Z Tec DSP Metal Detector, an easy-to-clean product chute, and high-speed reject value.
“Customers typically put the unit at the discharge end of their tablet press machines for metal inspection before packaging,” says Jeff Kaveney, manager of product marketing and administration.
“Pharmaceutical customers with some metal detection experience and knowledge of proper conveyor design and construction suited for a metal detector can purchase just the metal detector head,” Kaveney adds.
The metal detector is capable of detecting all types of metal, but to varying degrees. So it is essential that customers specify sensitivity requirements. Carbon (mild) steel is the easiest to detect of all metal types. Non-ferrous contaminants such as aluminum, copper, and brass are more difficult to detect, while 300-series stainless steel is the most difficult to defect, Kaveney explains.
“If a metal detector is rated for detecting a 1-mm carbon steel sphere and the product is dry and non-conductive, the minimum size of non-ferrous metal you can expect to detect is equal to 1.2 x the rated sphere for carbon steel. The multiplier for 300-series stainless steel is 1.5. Customers have to specify the type of stainless steel as 400-series stainless steel is magnetic and easily detected,” Kaveney says.
Eriez quotes sensitivities based on metal spheres being located in the center of the aperature or metal detector opening, as this is the least sensitive area. “If it is detected in the center, there will be no problem seeing it elsewhere.”
If ferrous “fines” or micro-sized contaminants exist in a customer’s product, Eriez recommends using an Xtreme Rare Earth Magnetic Separator to remove them as no metal detector can detect these minute particles.
“With the Xtreme Rare Earth Magnets, we offer the industry’s most powerful magnetic circuits. If a customer is looking to install a metal detector and has a high percentage of ferrous contamination, we will always recommend putting a magnet ahead of the detector to remove as much of the ferrous content as possible,” Kaveney says.
Metal detection is not an option for post-packaging inspection if the packaging includes foil as the foil will yield a large signal that must be phased out. After phasing out the signal, ferrous metals are typically the only metal that can be detected.
X-ray inspection systems can be used to detect many foreign objects other than metal, as well as inspect for missing pills and seal integrity.
“More companies are looking at X-ray equipment to help them solve their metal contamination issues. The biggest issues pharmaceutical companies have had with implementing X-ray technology is two fold: First, it is cost-prohibitive to place it on all packaging lines, and second, it would be very costly and time consuming to validate as new technology into their processes,” Kaveney says.