INPAK SYSTEMS offers a wide variety of scales that weigh and fill paper or plastic open mouth bags, boxes, drums and totes. Open mouth bagging machines can handle 5-120 lbs. bags at speeds up to 14 bags/minute.
Gross Weigh vs. Net Weigh
Open Mouth Baggers can be divided into two types: gross weigh baggers and net weigh baggers. Gross weigh scales weigh the material in the bag as it is being filled. Net weigh scales pre-weigh the material in a hopper and then dump it into a bag. Typically, a net weigh scale is about 2x faster as a comparable gross weigh scale because, as the hopper of a net weigh scale is being filled, the bag can be positioned.
Mechanical vs. Electrical Scale
Open Mouth Baggers have either a mechanical or electronic scale. Mechanical scales, sometimes called beam scales, have weights that are added &/or moved to set the desired weight. Mechanical scales are less expensive and some do not require electricity or compressed air. Electronic scales have one or more load cells that measure the weight and are more accurate. Some electrical sales can output their measurements to a printer or computer.
Open mouth baggers are designed with different feeders: gravity, auger, belt and vibratory. The characteristics of the material (particle size, fragility, dryness, free-flowing, stickiness, floodable, etc.) determine the best type of feeder. For a list of material characteristics click here.
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Open Mouth Auger Baggers Auger baggers are designed to fill 20-110 lbs. open mouth bags, pails, boxes and containers with dry, free-flowing materials like: flour, cake mix, chemical powders, starches, cement grouts, livestock supplements and similar materials. Product flows by gravity from a fill hopper into a single or dual auger feeder where it is delivered to a gross weigh or net weigh scale. With a dual auger system, dual augers deliver most of the material and then a single, sometimes smaller, auger will “dribble” in the balance of the material. When the desired weight is achieved the augers stop and a cutoff gate closes. Auger baggers can fill 1-10 bags/minute with an accuracy of +/-0.25%.
Open Mouth Belt Baggers A belt bagger is designed to fill 20-110 lb. open mouth bags, pails, boxes & containers with non-free products such as: vegetables, cake mix, mulch, wood chips, molasses based animal feeds, soils, damp sand & gravel and similar materials that do not gravity feed well. Gross weigh & net weigh open mouth belt baggers are available with either a mechanical or electronic scale. From a fill hopper, material is deposited on a belt where it is dumped directly in to a bag (gross weigh) or a weigh hopper (net weigh). When the target weight is reached the belt stops. More accurate weighments can be accomplished with a bulk-dribble two speed feed belt. Belt baggers can fill 1-9 bags/minute with an accuracy of +/-0.25%.
Open Mouth Gross Weigh Gravity Baggers Gross weigh gravity baggers are designed to fill 20-110 lbs. open mouth bags with free-flowing, granular materials and pellets like seeds, grains, sand, rock salt, plastic pellets fertilizer, corn, soybeans, salt, sugar, sand, limestone, refractory materials and plastic pellets. Gross weigh gravity baggers are available with a mechanical or electronic scale. Material flows by gravity from the fill hopper through a gate and into a funnel spout, filling the bag. The gate opening is adjusted to determine the flow rate. When the desired weight is obtained, the gate closes. Gross weigh gravity baggers can fill 1-14 bags/minute with accuracy up to +/- 2 oz.
Open Mouth Net Weigh Gravity Baggers Net weigh gravity baggers are designed to fill 20-110 lbs. open mouth bags with free-flowing, granular and pelleted materials such as seed, grain, fertilizer, minerals, crystalline materials, fertilizer, corn, soybeans, salt, sugar, sand, limestone, refractory materials and plastic pellets. Net weigh gravity baggers are available with an electronic scale. The material is loaded into a fill hopper. A flow gate is adjusted to determine the flow rate into the weigh hopper. When the desired weight is obtained, the fill gate closes. Then a 2nd gate at the bottom of the weigh hopper opens and the material drops through a funnel spout into a bag. Net weigh gravity baggers can fill 1-15 bags/minute with accuracy up to +/- 2 oz.
Open Mouth Vibratory Baggers Vibratory baggers are designed to fill 5-110 lb. open mouth bags, pails, boxes, and containers with wet or dry powdered, pelleted, granular or odd shaped materials of varying densities such as rice, nuts, candies, plastic pieces, dry foods, seeds, feed pellets, gravels, and similar materials. Gross weigh and net weigh open mouth vibratory baggers are available with a single speed vibratory pan (usually with a mechanical scale) or a more accurate, two speed vibratory pan (usually with an electronic scale). With the two speed vibrator, 95% of the material is added at a high rate (bulk fill) and then the balance is added at a slow rate (dribble fill). Vibratory baggers can fill 1-6 bags/minute with accuracy up to +/- 0.25%.