| Free-flowing granules | Examples: rice, plastic pellets, and some fertilizers. The material generally flows readily through a hopper. | Open-mouth woven or paper bags; valve bags may suit compatible products and filling systems. | Gravity or controlled-feed filling with a weighing system; select the feeder and scale for the product’s flow behavior. | Check particle size, bulk density, flow consistency, target weight, and whether the bag must be sewn, sealed, or otherwise closed. |
| Powders and dusty materials | Examples: flour, mineral powders, and powdered chemicals. Fine particles can become airborne during filling. | Valve bags or open-mouth bags with a suitable liner or dust-control arrangement. | Auger or other controlled-feed filling; consider an enclosed filling head and dust extraction where appropriate. | Assess dustiness, aeration, product flow, containment needs, cleanability, and any applicable workplace or product-safety requirements. |
| Irregular or fragile solids | Examples: seeds, flakes, pellets with a tendency to break, or other non-uniform solids. | Open-mouth paper, woven, or plastic bags, chosen for product protection and handling conditions. | A controlled gravity or belt-feed system may help limit impact; final selection depends on product flow and fragility. | Test for bridging, segregation, breakage, and consistent discharge. Confirm bag strength and the required closure method. |
| Bag format and closure | Determine whether bags are supplied individually, on a roll, or in a form that requires forming and filling. | Pre-made open-mouth bags, valve bags, or roll-stock bags formed into bags during the process. | Choose equipment designed for the selected bag presentation; closure may involve sewing, heat sealing, or a compatible valve-bag process. | Verify bag dimensions, material, liner, opening style, closure requirements, and compatibility with downstream handling. |
| Weight and filling accuracy | Define the target net weight and the allowable variation for each bag. | Any compatible format, provided the bag can be held and filled consistently. | Use a weighing and feed-control arrangement suited to the required accuracy and product behavior. | Ask for test results using the actual product and bag. Confirm calibration, check-weighing needs, and applicable legal metrology rules. |
| Production and integration | Establish the required bags per hour, operating schedule, changeover frequency, and staffing plan. | Bag choice should support the desired handling, storage, and transport process. | Compare manual, semi-automatic, and automatic configurations; include conveying, bag closing, and palletizing if needed. | Base capacity estimates on the complete line and actual product trials. Check utilities, floor space, access, maintenance, and changeover time. |
| Product and operator safety | Consider combustible dust, corrosive or hazardous materials, food-contact needs, and operator exposure where relevant. | Select bag materials and liners that are compatible with the product and intended storage conditions. | Specify suitable guarding, dust control, material-contact construction, and protective measures based on a site-specific risk assessment. | Confirm applicable local regulations and product standards. Review cleaning procedures, electrical requirements, and safe access for maintenance. |