QINFENG Custom FIBC manufacturer since 2001
Food & Ingredients Application brief
Bulk bags for flour, starch and sugar: hygiene-led construction, complete discharge, and a liner that protects the product rather than the bag.
Mills, ingredient blenders, sugar refiners and food packers, plus the distributors that supply bakeries and food processors. Buyers are usually quality or packaging managers working to their own supplier-approval process and their own hygiene standard.
Flour, Starch, Sugar and other dry bulk solids, typically 0.8–1.6 t/m³.
Handling chain
Filling is often through a spout into a lined bag, sometimes in a controlled area where the bag itself is inspected before use. Lifting is by forklift on four corner loops. Storage is indoors on pallets, and the bag is opened at the food plant and emptied into a hopper or mixer.
Filled on automated spouts or semi-manual toll lines. High-speed de-aeration shapes the square footprint before the bag leaves the fill station.
Stacked two to three tiers high in transit warehouses. A baffle construction that does not bulge keeps the stack square instead of leaning into the aisle.
Lifted three to five separate times by port stevedores. Reinforced loop anchoring and cross-corner loops resist fork abrasion and tine punctures.
Has to fit inside the container wall, at roughly 2,350 mm internal width. A square footprint uses the cube without the bag dragging on the wall.
What fails in this chain
Contamination is the dominant risk and it is mostly about construction discipline: a liner that stays in place during filling, a spout that does not shed fibre into the product, clean handling between the sewing floor and the pallet, and a bag that can be inspected before it enters a food area. Moisture pickup shows up as caking in flour and starch and as lumps in sugar. Leakage of fine flour at the seam is both a loss and a housekeeping problem. Puncture risk comes from pallet nails and forklift tines more often than from the product.
Hazard: A standard tubular bag rounds out as it fills, wasting container volume and leaning in a warehouse stack.
QINFENG defense: Internal perforated ultrasonic baffles hold a square profile after fill, which is what makes three-high stacking in a shed predictable.
Hazard: Repeated lifting by rough tines tears side seams or frays loop attachment bases at transhipment hubs.
QINFENG defense: Heavier coated fabric with reinforced corner perimeter wraps and extra loop reinforcement backing, specified from the number of relifts.
Hazard: Faded printing or a torn document pouch causes customs delays and rejected cargo at the destination port.
QINFENG defense: Flexographic printing with UV-cured inks and a reinforced document pocket sewn onto the body seam, agreed before production.
Hazard: Unsheltered storage while awaiting vessel arrival degrades untreated polypropylene yarn within weeks.
QINFENG defense: UV-stabilised masterbatch in the tape, selected for how long the consignment actually waits on the quay rather than for the total storage period.
What we would quote
A loose or glued-in PE liner is normal for flour and starch; sugar is usually bagged with a liner as well. Where the plant empties bags in a controlled area, a construction that discharges cleanly and can be opened without cutting into the product is worth more than a heavier fabric. Hygiene requirements, the applicable standard and the evidence we can supply are confirmed per project and per destination market - we do not claim a certification on this page.
Before we can quote
Bag dimensions, baffle spacing and the safety margin all follow from these. Answer the ones you can and leave the rest; the missing details can be settled with our engineers.
Flour, starch, sugar or a blend, and whether it cakes or picks up moisture readily.
Your own supplier standard or the scheme you are audited to, so we can confirm what we can evidence.
Loose, glued-in or form-fit liner, and the gauge if you already specify one.
Actual fill weight, and the SWL to be marked.
Hopper, mixer or manual tipping, and whether the bag is emptied in a controlled area.
Any specific controls your audit requires on the bag itself, such as a documented inspection step.
This page describes construction options for dry food ingredients. It does not certify a bag for any food-safety scheme, and it does not replace the customer's own supplier approval, auditing or incoming inspection. Specific market requirements are confirmed per project.
Talk to the applications team
We will come back with the construction we would build, the safety factor it carries and the dimensions that fit your loading plan — with drawings and a prototype before any bulk run.