Powder Packing Machine —Auger, Impeller & Net Weight

Net Weight / Gravimetric

The most-asked-about machine in our range, and for good reason — it is the only system that handles bulk density variation without operator intervention. Every bag is weighed individually: the fill starts fast (coarse flow), slows to a trickle when approaching the set-point (fine flow), and cuts off when the load cell reads the exact target weight. Tare correction for bag weight variation is automatic.

At 25 kg bags with a 500 g/L bulk density product, we see ±0.3–0.5% accuracy in sustained production. That translates to less than 75 g per bag, well inside most regulatory tolerances. For products with ±10% batch-to-batch bulk density variation — which is common in agricultural powders and recycled materials — this is the only fill system that delivers consistent weight without constant recalibration.

• Bag weight range:1 kg – 50 kg
• Speed:4–14 bags/min (product-dependent)
• Accuracy:±0.3–0.8% at production scale
• Fill principle:Dual-speed: coarse + fine flow
• Bag types:Open-mouth PP, PE, paper, FFS

Auger Filler

Rotating screw metering for free-flowing and moderately cohesive powders. Reliable and cost-effective for products with consistent bulk density: spices, flour, dried milk, fine chemicals, cement (dry blends). Accuracy is typically ±0.5–1.5% for small fills (100 g – 1 kg) and ±1–2% for larger weights where screw variation accumulates.

• Fill range:50 g – 5 kg per cycle
• Speed:Up to 60 fills/min (small containers)
• Accuracy:±0.5–1.5%
• Best for:Free-flowing powders, consistent bulk density

Impeller / Rotary Valve

For cohesive and poorly-flowing powders (talc, carbon black, titanium dioxide, fumed silica) that bridge in an auger, the impeller filler uses a spinning rotor to force product into the bag against the pack pressure. Consistent fill weight depends on constant head pressure above the impeller — hopper level management is critical for this type.

• Fill range:5 kg – 50 kg
• Speed:3–8 bags/min
• Accuracy:±1–2%
• Best for:Cohesive and aerated powders

Open-Mouth Bag Filler

Dedicated system for PP woven, multi-wall paper, and PE open-mouth sacks from 5 to 50 kg. Bag is presented open on a fill spout, fills under gravity or net weight, then passes to a sealer. Integrated bag clamp and de-aeration spear improve fill density. Most 25 kg industrial product bags in chemical, mineral, and agricultural markets use this format.

• Bag weight:5 kg – 50 kg
• Speed:Up to 600 bags/hr
• Sealing:Stitching or heat seal integration
• Bag types:PP woven, paper, PE, laminated

Valve Bag Filler

For cement, lime, gypsum, and other fine mineral powders packed into valve bags where the fill spout inserts into a sleeve valve that closes under bag pressure. Impeller-type rotary packers achieve 600–800 bags/hr. Dust containment at the spout is essential — improperly sealed valve bags are the primary dust source in cement packing operations.

• Bag weight:20 kg – 50 kg
• Speed:Up to 800 bags/hr (6-spout)
• Accuracy:±1–1.5%
• Best for:Cement, lime, dry mortar, mineral powders

FFS / Form-Fill-Seal

Vertical FFS machines form bags from roll stock film and fill in-line — suited for small retail packs (100 g to 5 kg) where bag cost and fill rate both matter. Auger metering for free-flowing powders; vibratory metering for granules. Output can reach 80–120 bags/min for small pack sizes, but FFS machines require more maintenance than open-mouth fillers.

• Pack weight:50 g – 5 kg
• Speed:20–120 bags/min
• Film:PE, laminate, kraft-PE
• Best for:Retail packs, food powders, chemicals

The empty bag is presented on the fill spout (automatic or manual). The load cell under the bag reads the empty bag weight, sets the tare, and calculates the target gross weight. Bag weight variation of ±10 g is handled automatically — the fill target adjusts per bag, not per shift.

Product flows at full rate until approximately 80–90% of target weight is reached. Fill rate at this stage is optimised for speed — the bottleneck on most powder lines is not the fill speed itself, but the time to transition from coarse to fine flow without overshoot.

At 90% of target, flow rate drops to 10–20% of coarse speed. The load cell monitors weight continuously and triggers the cut-off valve when the net weight target is reached. PLC correction factors account for product in flight between cut-off and final weight reading.

The filled bag is released from the spout onto a discharge conveyor and passes through a bag flattener (de-aeration) before sealing. A checkweigher downstream confirms net weight before sealing — out-of-tolerance bags are diverted to rework, not sealed and shipped.

Pigments, detergent powders, zeolite, silica, sodium carbonate, and technical minerals. Dust containment specification varies widely by OEL classification — some products require simple extraction hoods; others need full contained filling with local exhaust ventilation. We ask for the product SDS (safety data sheet) before specifying a containment level.

Flour, sugar, salt, dried milk, protein powder, spices, and seasonings. Food-grade contact materials (304 SS, food-safe plastics) and CIP-compatible product paths. For sticky or hygroscopic products, temperature-controlled fill environments and nitrogen purge options are available to prevent bridging and caking during filling.

Cement, gypsum, dry mix mortar, tile adhesive, and lime. Valve bag packing is standard for cement and gypsum — impeller rotary packers at 600–800 bags/hr. Wear-resistant contact parts (manganese steel, hardened liners) are specified as standard for abrasive mineral products with Mohs hardness above 4.

GMP-compliant powder filling for API intermediates, excipients, and finished pharmaceutical products. High-containment filling (OEL below 10 µg/m³) requires isolator or glove-box configuration. 316L stainless, Ra ≤0.8 µm surface finish, full audit documentation. ATEX classification for solvent-associated powders.

Granular and powdered fertilizers, pesticide WP (wettable powder) formulations, seed treatments, and soil amendments. Fill weight accuracy matters at scale — a 1% overfill on a $0.80/kg fertilizer product costs $800 per 100,000 bags. Corrosion-resistant contact materials for ammonium nitrate and acidic formulations.

Powdered milk replacers, vitamin premixes, protein supplements, and medicated feed powders. FDA/EU-compliant materials and cleanability are the key specifications. Products that contain fats or oils have specific temperature sensitivity requirements during filling — fat-coated powders cake above 28–30°C ambient.

We ask for your product’s Carr Index or angle of repose before specifying a fill system — not because it is on a checklist, but because we have seen buyers receive auger fillers for titanium dioxide (which air-entrains and bridges in an auger) and spend months trying to make it work. Fill principle selection takes 10 minutes if the right information is provided upfront. It takes 6 months and significant cost if it is discovered after delivery.

Every net weight system ships with a 30-bag accuracy test report, signed by our QC team. The report includes mean fill weight, standard deviation, min/max, and the fill principle settings used. This is the baseline you use to confirm the machine is performing correctly on installation. If your line shows worse accuracy than the report, the problem is in commissioning, not the machine — and we will help you find it remotely.

We do not default everyone to the same extraction hood spec. Before we design the containment system, we review your product SDS, the OEL or WEL for the active ingredient, and your local regulatory requirements. The difference between a standard extraction hood and a full contained fill station is $15,000–$40,000. Getting the specification right means not under-spending on a hazardous product or over-spending on benign mineral powder.

We are the manufacturer. No distributor is adding 20–35% to the price between our factory and your purchasing department. The technical file, CE Declaration of Conformity, and risk assessment that come with every machine are our documents — not a third party’s paperwork that arrived with the machine and nobody at the distributor can interpret. Buyers who have had CE issues at customs or with their health-and-safety auditors understand why this matters.

High-speed bagging for free-flowing powders, granules, and pellets. Net weight systems with integrated bag handling.

Standalone gravimetric packing scales for industrial powders and bulk materials. Same net weight principle in a standalone format.

Specialised valve bag packers for cement, gypsum, and fine mineral powders. Impeller type for high-speed abrasive product filling.

Complete powder packing lines integrating filling, sealing, checkweighing, and palletising into a single turnkey system.