{"id":495,"date":"2026-06-17T03:00:44","date_gmt":"2026-06-17T03:00:44","guid":{"rendered":"https:\/\/seiwag-us.com\/blog\/?p=495"},"modified":"2026-06-17T04:23:35","modified_gmt":"2026-06-17T04:23:35","slug":"motor","status":"publish","type":"post","link":"https:\/\/seiwag-us.com\/blog\/motor\/","title":{"rendered":"Why Does a Powder Feeder Stop Feeding Even When the Motor Is Running?"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Introduction<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A common complaint in powder handling systems is:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>&#8220;The motor is running, but the powder is not feeding.&#8221;<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When this happens, many operators initially suspect the feeder itself.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, the feeder is not always the source of the problem.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In many cases, the issue originates from the powder behavior inside the hopper.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding these powder-related issues can help improve feeding stability and reduce unexpected production interruptions.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Cause 1: Bridging<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">One of the most common reasons for feeding failure is bridging.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bridging occurs when powder particles form a stable arch above the screw inlet, preventing material from flowing downward.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The screw continues rotating, but little or no powder reaches it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bridging is more likely to occur when handling:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Fine powders<\/li>\n\n\n\n<li>Cohesive materials<\/li>\n\n\n\n<li>Moisture-sensitive powders<\/li>\n\n\n\n<li>Powders with poor flowability<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The problem may appear intermittently, making it difficult to identify.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Cause 2: Ratholing<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Another common problem is ratholing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In this case, powder flows only through a narrow channel above the screw while material near the hopper walls remains stationary.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As the rathole develops, the amount of powder reaching the screw becomes inconsistent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Typical symptoms include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Fluctuating feed rates<\/li>\n\n\n\n<li>Gradually decreasing output<\/li>\n\n\n\n<li>Sudden interruptions in feeding<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Ratholing is often observed in cohesive powders or materials that have been compacted during storage.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Cause 3: Agglomerates and Lumps<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Sometimes the powder itself contains agglomerates or lumps.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These may be caused by:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Moisture absorption<\/li>\n\n\n\n<li>Long-term storage<\/li>\n\n\n\n<li>Transportation compaction<\/li>\n\n\n\n<li>Natural powder cohesion<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Large agglomerates can affect how powder enters the screw and may temporarily block narrow passages.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In some cases, operators notice that feeding accuracy changes significantly even though the feeder is mechanically operating normally.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Cause 4: Powder Properties Change Over Time<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Powder characteristics are not always constant.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Factors such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Bulk density<\/li>\n\n\n\n<li>Moisture content<\/li>\n\n\n\n<li>Particle shape<\/li>\n\n\n\n<li>Storage conditions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">may change over time.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As a result, the amount of powder entering the screw can vary even when operating conditions remain the same.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This effect becomes more noticeable in low feed rate applications where small variations have a greater impact on feeding accuracy.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Possible Solutions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The best solution depends on the powder characteristics and process requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Several approaches are commonly used:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vibrators<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Vibrators apply external vibration to the hopper.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They are often selected when contamination concerns are important because there are no moving parts inside the product area.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, vibrators may not be effective for all powders.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Agitators<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Agitators directly move the powder inside the hopper.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They can help maintain powder flow and reduce the risk of bridging or ratholing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Agitators are often used for cohesive powders or materials with poor flowability.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Hopper and Feeder Modifications<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In some applications, small modifications can significantly improve feeding stability.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Examples include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Air or nitrogen purging<\/li>\n\n\n\n<li>Hopper geometry changes<\/li>\n\n\n\n<li>Discharge mesh screens<\/li>\n\n\n\n<li>Pressure-resistant construction<\/li>\n\n\n\n<li>Intermittent feeding operation<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The most effective solution depends on the specific application and powder properties.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">The Feeder Itself May Not Be the Problem<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When powder feeding stops unexpectedly, replacing the feeder is not always the answer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Many feeding problems originate from:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Powder flowability<\/li>\n\n\n\n<li>Material storage conditions<\/li>\n\n\n\n<li>Hopper design<\/li>\n\n\n\n<li>Environmental conditions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding how the powder behaves inside the hopper is often the first step toward finding a practical solution.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If the motor is running but powder is not feeding, the feeder itself may not be malfunctioning.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bridging, ratholing, agglomerates, and changes in powder properties can all affect feeding performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because powder behavior varies from material to material, there is rarely a universal solution.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Evaluating the powder characteristics and process requirements can help identify the most appropriate approach and improve feeding reliability.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Related articles<br><a href=\"https:\/\/seiwag-us.com\/blog\/effective-bridging-prevention\/\">https:\/\/seiwag-us.com\/blog\/effective-bridging-prevention\/<\/a><br><a href=\"https:\/\/seiwag-us.com\/blog\/powder-bridging-2\/\">https:\/\/seiwag-us.com\/blog\/powder-bridging-2\/<\/a><br><a href=\"https:\/\/seiwag-us.com\/blog\/cohesive\/\">https:\/\/seiwag-us.com\/blog\/cohesive\/<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><br><\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/seiwag-us.com\/\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"330\" src=\"https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2-1024x330.png\" alt=\"Screw feeder\" class=\"wp-image-28\" srcset=\"https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2-1024x330.png 1024w, https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2-300x97.png 300w, https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2-768x247.png 768w, https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2-1536x494.png 1536w, https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2.png 1600w, https:\/\/seiwag-us.com\/blog\/wp-content\/uploads\/2024\/09\/Powder-and-liquid-equipments-8000-\u00d7-1600-px\u306e\u30b3\u30d4\u30fc-2-1024x330.png 856w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Introduction A common complaint in powder handling systems is: #8220;The motor is running, but the powder is 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