Most check weighing happens on individual retail packs. But many customer complaints start one step later: a shipper carton with 23 packs instead of 24, a case missing its leaflet bundle, or a sack filled light. A heavy duty check weigher at case level catches these before the pallet is wrapped. This guide covers why case weighing matters, how TCT's two heavy models differ, and how to design rejects, integration, data and guarding around loads of up to 25 kg.
Why weigh at case level
Missing units. Case packers occasionally drop or miss a pack, especially during start-up, jams and changeovers. One missing 500 g pack in a 12 kg case is a 4% shortfall, easily visible to a properly specified case check weigher.
Short shipments and customer claims. Distributors and modern-trade retailers increasingly weigh inbound cases. A short case leads to a debit note, a chargeback or a full-load rejection. Weighing every case gives you evidence that what left your dock was complete.
Mixed or wrong product. If two SKUs share a case size but differ in weight, a weight check can flag a case packed with the wrong product.
Bag and sack fill control. For sacks of sugar, flour, chemicals or feed, the check weigher verifies the bagging scale and tracks drift.
Regulatory context. In India, the Legal Metrology (Packaged Commodities) Rules, 2011 apply to retail packages. Packages above 25 kg and those sold to industrial or institutional consumers are excluded from several of its provisions, but the retail packs inside your shipper are still covered. A missing retail unit is therefore a commercial and a compliance problem.
Heavy-duty vs large-package models
TCT offers two models for end-of-line loads. Both are listed as TCW-450 and TCW-600 variants; the table shows the TCW-450 figures published on the product pages.
In simple terms, choose by footprint first, capacity second. If your case is wider or longer than a standard belt allows, the large-package model's wider platform is the deciding factor. If your loads are compact but heavy, such as drums or dense sacks, the heavy-duty frame is the natural fit. Confirm both capacity and footprint against the current spec sheet for your variant.
Conveyor and reject design for heavy loads
Moving a 20 kg case off a line is a different engineering problem from blowing a 50 g sachet off a belt.
Conveyor type. Belt conveyors give the most stable weighing. Roller conveyors suit very heavy or rigid loads upstream and downstream but are rarely used on the weigh section itself.
Reject devices. The common options are:
Why weigh at case level
Missing units. Case packers occasionally drop or miss a pack, especially during start-up, jams and changeovers. One missing 500 g pack in a 12 kg case is a 4% shortfall, easily visible to a properly specified case check weigher.
Short shipments and customer claims. Distributors and modern-trade retailers increasingly weigh inbound cases. A short case leads to a debit note, a chargeback or a full-load rejection. Weighing every case gives you evidence that what left your dock was complete.
Mixed or wrong product. If two SKUs share a case size but differ in weight, a weight check can flag a case packed with the wrong product.
Bag and sack fill control. For sacks of sugar, flour, chemicals or feed, the check weigher verifies the bagging scale and tracks drift.
Regulatory context. In India, the Legal Metrology (Packaged Commodities) Rules, 2011 apply to retail packages. Packages above 25 kg and those sold to industrial or institutional consumers are excluded from several of its provisions, but the retail packs inside your shipper are still covered. A missing retail unit is therefore a commercial and a compliance problem.
Heavy-duty vs large-package models
TCT offers two models for end-of-line loads. Both are listed as TCW-450 and TCW-600 variants; the table shows the TCW-450 figures published on the product pages.
In simple terms, choose by footprint first, capacity second. If your case is wider or longer than a standard belt allows, the large-package model's wider platform is the deciding factor. If your loads are compact but heavy, such as drums or dense sacks, the heavy-duty frame is the natural fit. Confirm both capacity and footprint against the current spec sheet for your variant.
Conveyor and reject design for heavy loads
Moving a 20 kg case off a line is a different engineering problem from blowing a 50 g sachet off a belt.
Conveyor type. Belt conveyors give the most stable weighing. Roller conveyors suit very heavy or rigid loads upstream and downstream but are rarely used on the weigh section itself.
Reject devices. The common options are:
- Pusher arms: a pneumatic or electric arm pushes the case sideways onto a reject table. Simple and robust for rigid cartons. TCT's heavy models use push rejection as standard.
- Diverter arms or swing gates: guide the case onto a reject lane without impact. Better for soft sacks and tall cases that might topple.
- Pop-up roller or belt transfers: lift and transfer the case at 90 degrees. Gentle on heavy loads but more complex.
Reject table capacity. Size the reject area for the number of cases you might reject before an operator responds, for example during a case-packer fault. A full reject table should stop the line.
Air supply. Pneumatic rejecters need a clean, stable supply; TCT specifies 0.2–0.6 MPa for these models.
Integrating with case packers and palletisers
A case check weigher sits between two automated machines, so the line-control signals matter as much as the weighing.
Air supply. Pneumatic rejecters need a clean, stable supply; TCT specifies 0.2–0.6 MPa for these models.
Integrating with case packers and palletisers
A case check weigher sits between two automated machines, so the line-control signals matter as much as the weighing.
- Upstream stop. If the reject area is full or the weigher faults, it must stop the case packer, or divert cases to an accumulation lane.
- Downstream ready. The weigher should hold cases if the palletiser or robot is not ready.
- Consecutive reject alarm. Several rejects in a row usually point to an upstream fault, such as a jammed pack feed. Use it to stop the case packer and call a technician.
- Code or label checks. Many lines combine case weighing with a label or barcode check. Plan the order of stations so a rejected case never reaches the palletiser.
- Signal types. Agree on digital I/O or fieldbus/Ethernet signals with your line integrator at the design stage.
Data for dispatch and traceability
Case weights are valuable dispatch evidence. At minimum, record for each batch or shift: total cases, accepted, rejected, mean weight and standard deviation. TCT's heavy models store 100 product recipes and show these statistics on the touch screen.
For stronger traceability, link each case weight to its case label or SSCC barcode. Then, if a customer claims a short case, you can look up the weight recorded at your dock. Ask how data is exported (USB, network) and how long it is retained. For pharma shipper cases, align data handling with your revised Schedule M data-integrity procedures.
Safety and guarding
Heavy loads moving at up to 60 m/min, plus pneumatic pushers, create crush, impact and entanglement hazards.
- Guard the reject zone. Fixed or interlocked guards should prevent hands reaching the pusher's path. Opening a guard door should stop the pusher and isolate air.
- Emergency stops. Within reach at the infeed, the reject table and the outfeed.
- Nip points. Check belt ends and transfer points for gaps that can trap fingers.
- Lifting. Operators clearing rejected 20–25 kg cases need a reject table at working height, or a roller table that brings cases to them.
- Risk assessment. Carry out and document a machinery risk assessment at installation; internationally, ISO 12100 is the usual reference method.
- Status lights and alarms. Make faults visible from a distance on a busy dispatch floor.
Request a free line assessment or product trial.
Frequently asked questions
What is the heaviest case TCT's check weighers can handle? Both heavy models are published for loads of 0.05–25 kg.
Can a case check weigher detect one missing pack? Usually yes, if the pack weight is clearly larger than the weigher's accuracy plus the normal variation in case weight. Test with a deliberately short case.
Pusher or diverter for sacks? Diverters are gentler on soft sacks; pushers suit rigid cartons.