QINFENG Custom FIBC manufacturer since 2001
Construction & Building Materials Application brief
Concrete washout and slurry intercepted where wagons, pumps and rigs are washed out: the bag holds the solids while they settle and set, and drains the water, which stays alkaline and stays the site's responsibility.
Ready-mix plants, concrete frame and groundworks contractors, pump-hire firms, precast yards and piling contractors. The buyer is usually a site or plant manager who needs the wash point to move with the work and cannot build a fixed washout pit.
Waste Materials and other dry bulk solids, typically 0.8–1.6 t/m³.
Handling chain
The bag sits at the wash point, on the ground or in a support frame, and washout is discharged into it from a chute, a hose or a pump line. Solids settle and set inside the bag while water drains through the base and side panels. Once the contents have set, the bag is lifted away whole and a spare bag takes its place, so the wash point keeps working. At a piling rig, a pump cleanout point or a precast yard the wash point moves with the work and the bags move with it.
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
Where the water goes is the controlling risk: washout water is alkaline and carries fines, so a bag that overflows, splits or is set where the base cannot drain puts that water into drains or ground. The set material is heavier than the wet volume suggests, so loops and any frame are sized on the set load rather than the pour. Chutes and pump lines discharge at whatever rate the wash produces, so the top of the bag has to take impact and splash. Bags that stand outside for weeks need UV-stabilised fabric, and a bag that is reused at several wash points is handled far more often than one that stays in place.
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
Size the bag from the volume one wash produces and how often it is emptied, not from a stock list. Where the wash point moves with the work, several smaller bags are easier to swap than one large one. If the site's permit requires a lined or bunded washout facility, the bag sits inside that arrangement rather than replacing it. Tell us how the drained water is collected, because that decides whether the base needs a collection tray or liner under it. Where a support frame is used, send its dimensions so the bag is made to sit in it.
Bag families we would send for this application
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.
How much water and solids one washout produces, and how often the bag is filled.
Chute, hose or pump line, the height it falls from, and whether it is a single wash or a running cleanout.
Where the water goes after it leaves the bag, whether a tank, bund or an authorised discharge point, which stays with your site.
Ready-mix wagon wash, pump-line cleanout, precast yard or piling rig, and whether it stays in one place.
Crane, forklift or jib, so the loops and the bag can be sized on the set load.
If the bag sits in a frame or between support sides, send the dimensions.
This page covers fabric bags for concrete washout, pump-line cleanout water and similar slurry at wash points on ready-mix, precast, piling and general building sites. It is not a treatment or neutralisation system: the water that drains from the bag is still alkaline washout water, and its capture, storage and discharge stay with the site under its own permit. Hazardous and contaminated waste is not covered. Size and drainage behaviour are confirmed per project against the customer's own washout.
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.