However, the 54 year-old family-owned company could not just insert any type of metal detector. "Due to spacing in the plant, we required a very small metal-free zone of only two inches on either side of the aperture," says Jim Spangler, engineering manager. "We needed to position the digital signal metal detector at the most terminal point in the process to assure customer confidence as well as satisfy government and independent audits."
Crest produces stabilizers for sour creams, yogurts, buttermilk and cottage cheese dressings. After blending various ingredients, the free-flowing finished product discharges into an auger that feeds product through the four-in. diameter, tube-style metal detector. Product volume ranges up to 150 lbs. a minute. Reject procedures on the digitally controlled system consists of a butterfly valve located three inches past the end of the detector's aperture. If contamination is detected, the butterfly valve automatically closes, an alarm sounds and the feeding system shuts down. Operators know to remove the bag that was in the filler for inspection.
"We looked at several vendors and decided on Fortress for several reasons," notes Spangler. "They were the only company who could readily accommodate our metal-free zone requirements, their price was very competitive, and the system itself has proven to be especially simple to operate."
While metal or any other contamination was never a problem for Crest, having the Phantom detector in place adds another measure of safety for the company. "It is considered as one of the critical control points in our HACCP plan," adds Spangler. "We regularly test the machine with a two millimeter sphere of 300-series stainless steel as part of our quality control procedures." While those were the specifications set by Crest, Fortress boosts even greater detection capabilities down to 0.8-mm ferrous and non-ferrous metal and 1.2 mm stainless steel.