Jun 05, 2026
Pharmaceutical Metal Detector Guide: How Tablets and Capsules Are Checked Before Packaging
Metal fragments in tablets and capsules can come from worn punches and dies, sieves, screws, transfer parts, capsule filling stations, dedusters, or other product-contact components. A pharmaceutical metal detector checks products before they enter bottles, blister packs, cartons, or other final packs, then rejects units that may contain ferrous metal, non-ferrous metal, or stainless steel particles. In solid dosage production, metal detection works best when the machine is placed where tablets or capsules are still loose, controlled, and easy to reject. Product size, line speed, aperture size, dust level, vibration, static electricity, and reject timing all affect the result. A detector after tablet compression may need a different chute and reject method from one installed before a counting line or blister packaging machine. For solid dosage lines, the key points are detector position, product flow, sensitivity by metal type, and reliable rejection before final packaging. What Is a Pharmaceutical Metal Detector? A pharmaceutical metal detector is an inline inspection machine used to find metal contaminants in pharmaceutical and nutraceutical products. In solid dosage production, it is commonly used for tablets, capsules, pills, softgels, granules, and similar small products. Most systems create an electromagnetic field inside a detection aperture. As products pass through, the detector monitors signal changes. If a metal particle changes the signal beyond the accepted limit, the machine sends a reject command. The reject system may use a flap, chute, air jet, or diverter for loose tablets and capsules. Larger bottles or cartons may need a conveyor reject device. The machine does not check label text, barcode readability, tablet color, capsule fill weight, carton completeness, or cap tightness. Those checks belong to other inspection systems. Metal detection has a narrower job: find metal contamination and keep suspect products out of the accepted product flow. How Does a Pharmaceutical Metal Detector Work? The detector reads changes caused by metal passing through the inspection field. Ferrous metal usually gives a strong response. Non-ferrous metals such as aluminum, copper, and brass behave differently. Stainless steel can be harder to detect, especially some non-magnetic grades. Real performance depends on more than the detector head. Product size, aperture size, speed, vibration, static electricity, dust, and the position of the metal particle all affect detection. A narrow product path usually supports better sensitivity because tablets or capsules pass closer to the detection field. Sample testing is important. Round tablets, oblong tablets, coated tablets, hard capsules, softgels, dusty products, and mineral-containing formulas may not behave the same way. Testing with real products helps confirm sensitivity, product flow, false reject behavior, and reject accuracy before full production. ...
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