- Angle of repose
- The steepest slope a poured pile of granular material will hold. Above about 45° the material is cohesive and will bridge in square corners.
- Backhaul
- Loading a trailer for its return leg instead of running it empty. Often a lower-cost way to move recovered packaging.
- Bale
- Recovered fiber compressed and tied for transport. Baling makes corrugated far easier to move than loose boxes.
- Basis weight
- The mass of paper per unit area, quoted in pounds per thousand square feet in North America. Higher basis weight liner means a stronger, heavier and more expensive board.
- Bliss box
- A box built from two end panels and a wrap, with fewer joints than a slotted container. Stronger per pound of board, but it needs its own tooling.
- Box Maker's Certificatealso: BMC, joint stamp
- The round stamp on a bottom flap giving board construction, burst or edge crush rating, size limit and gross weight limit. The single most useful document in packaging.
- Bridging
- Free-flowing material arching across a container's corners instead of discharging. The reason octabins exist.
- Bulk bin
- Agricultural term for a pallet-footprint corrugated container, usually wider and shorter than an industrial gaylord.
- Bulk density
- Weight per unit of fill volume, in lb per cubic foot. Denser material generally needs more walls.
- Caliper
- Board thickness. Thicker board generally means more walls and more strength.
- Capalso: Telescoping lid
- A separate lid that slides over the body of a bulk box. Restores closure and most rim stacking strength, and is what makes a cut-top box economic.
- Creep
- Gradual deformation of board under sustained load. Time-dependent and accelerated by humidity, which is why storage duration belongs in a packaging specification.
- Cube out
- A trailer that fills by volume before it reaches its weight limit. The normal case for corrugated, and the reason flat-packing matters so much.
- Cut top
- A box whose top flaps have been removed, usually to speed filling or emptying. Loses closure and most top-edge stacking strength; pairs well with a telescoping cap.
- Delamination
- Separation of a liner from the fluted medium. A structural failure, not cosmetic damage.
- Derate
- Reducing a box's assumed load rating to account for use, age or humidity. Used stock should be treated as weaker than its original rating.
- Detention
- A charge for holding a driver beyond the free window at a dock, after a free window. Usually a scheduling issue.
- Die-cut
- A blank cut to a custom shape with a tool rather than slotted on standard equipment. Higher tooling cost, and the only way to get non-standard geometry.
- Double-sorted OCC (#12)
- A cleaner recovered-corrugated grade than #11, with tighter limits on prohibitives and outthrows. Commands a premium.
- Drop trailer
- A trailer left at a site to be loaded or unloaded on the site's own schedule and collected later. Converts an unpredictable detention risk into a fixed pool cost.
- Dunnage
- Anything placed inside packaging to restrain or protect the contents: pads, corner board, honeycomb blocks, moulded pulp, void fill.
- Eco-modulation
- Varying extended producer responsibility fees by how recyclable a packaging format is. Plain corrugated sits at the favourable end; composites and coated board do not.
- ECT
- Edge Crush Test. Compression resistance measured on edge in pounds per inch of width. Predicts stacking performance — the right specification for bulk boxes.
- EPR
- Extended producer responsibility — schemes that make whoever places packaging on the market pay for its end-of-life management, assessed per tonne by material category.
- FIBCalso: Bulk bag, super sack
- Flexible Intermediate Bulk Container — a woven polypropylene bulk bag. 5:1 safety factor bags are single-trip; only 6:1 bags may be reconditioned for multi-trip service.
- FIBC Type A–D
- Electrostatic classification of bulk bags. Type A has no static protection; Type B resists propagating brush discharge; Type C is conductive and must be grounded; Type D is static-dissipative and does not require grounding.
- Fines
- Very short fibre fragments generated by repeated pulping. They drain poorly and contribute little strength, which is what eventually limits how many times fibre can be recycled.
- Flute
- The wavy medium between liners. Profiles run A (thickest) through E (finest); bulk boxes use combined A/C profiles across multiple walls.
- FOL
- Full Overlap Slotted Container. Top and bottom flaps overlap fully — the strongest common bulk box style and the one to specify for stacking.
- Fourdrinier
- The moving wire mesh on which a paper web is formed from slurry. The first stage of turning recovered fibre back into board.
- Gaylord boxalso: Bulk box, pallet box, skid box, tote box
- A pallet-footprint corrugated bulk container, typically 48 × 40 inches and 24 to 60 inches tall. Named after the Gaylord Container Company.
- Glue lap
- The narrow flap where a box blank is joined into a tube. Also called the manufacturer's joint; the Box Maker's Certificate usually sits near it.
- GMA pallet
- The 48 × 40 inch stringer pallet standardised by the Grocery Manufacturers Association. The reason 48 × 40 is the default box footprint in North America.
- Grade (box)
- A condition classification for used containers, conventionally A through F. There is no certifying body, so ask what each supplier's grades mean physically.
- Gross weight limit
- Maximum combined weight of a box and its contents, stated on the Box Maker's Certificate. Exceed it and the certification lapses.
- Honeycomb
- Kraft paper formed into a hexagonal cell structure. Exceptional compression strength per pound; used for pallet decking and edge protection.
- HSC
- Half Slotted Container. A box with no top flaps, designed to pair with a separate telescoping lid. Faster to fill from above.
- Hydrapulper
- The large agitated vessel where bales are broken down into fibre slurry with water. The first step inside a paper mill.
- ISPM-15
- The international standard requiring wood packaging in export to be heat treated or fumigated and stamped. Plastic pallets sidestep it entirely.
- Knocked down (KD)
- Shipped flat rather than erected. A set-up bulk box is mostly air; flat-packing multiplies what fits on a trailer.
- Kraft
- Paper made by the sulphate pulping process, and by extension the unbleached brown colour associated with it. Strong, cheap and the default for corrugated.
- Landed price
- The delivered cost at your dock, including freight. On used packaging it is the fairest price to compare, because freight is often a large part of the cost.
- Liner (board)
- The flat facing sheets of corrugated board, bonded to either side of the fluted medium.
- Liner (poly)
- A plastic bag fitted inside a bulk box. In food applications the liner — never the box — is the food-contact surface.
- LTL
- Less-than-truckload freight, where a shipment shares a trailer with others. Larger shipments are often cheaper per unit by truckload.
- Medium
- The fluted inner layer of corrugated board, between the liners. Usually made from recycled fiber.
- Mill-direct
- Selling recovered fibre straight to a paper mill rather than through intermediaries. Fewer intermediaries between the source and the mill.
- Moulded pulp
- Packaging formed from recovered fibre slurry in a mould. Used in place of expanded polystyrene for trays and corner blocks; accepted for recycling in many programs.
- Mullen test
- Bursting strength — resistance to a force pushed through the board face. Predicts puncture tolerance; not convertible to ECT.
- Nested
- Items stacked so that each sits inside the one below, saving volume. Common for stampings and trays; increases the risk of surface marring without interleaving.
- OCC
- Old Corrugated Containers. The recovered-paper grade for used corrugated, traded by the short ton.
- Octabin
- An eight-sided bulk container. The 135-degree interior corners stop free-flowing material bridging, which square boxes cannot avoid.
- Outthrows
- Recovered paper that is not the specified grade but is still usable. Tolerated in small percentages; prohibitives are not.
- Pinwheel
- Alternating pallet orientation to fit 26 positions of 48 × 40 across a 53-foot trailer floor.
- Point loading
- Concentrating a load onto a small contact area rather than spreading it. The most common cause of a bulk box failing far below its rating, and it is fixed with a deck rather than with more board.
- PP
- Polypropylene. The polymer used for woven bulk bags and for most strapping. Single-polymer construction makes FIBC fabric unusually recyclable.
- Prohibitive
- A material that renders a recovered-paper bale unusable or damages mill equipment: wax coating, plastic film, food residue, metal, textiles.
- Prohibitives
- Materials that render a recovered-paper bale unusable or damage mill equipment: wax coating, plastic film, food residue, metal.
- Pulper
- The vessel where bales are agitated with water into fiber slurry. The first step in turning old board into new board.
- Pulper reject
- Material screened out during pulping — bale wire, plastic, staples, textiles. Disposed of or burnt for energy depending on the region.
- Rathole
- Material discharging only through a narrow central channel while the rest stays stuck to the walls. A flow failure distinct from bridging and usually caused by wall friction.
- Reconditioning
- Restoring handling life to a used container by patching, score re-forming, liner replacement or cap pairing. It restores service life, never certification.
- Reuse ratio
- The share of recovered material that leaves as a product in its existing form rather than as a commodity for reprocessing. A more meaningful measure than a diversion rate alone.
- RSC
- Regular Slotted Container. The standard shipping carton, where all flaps are the same length and the outer pair meet at the centre.
- Safety factor
- For an FIBC, the ratio of tested failure load to safe working load. 5:1 is certified for a single trip; only 6:1 and above may be reconditioned for multi-trip service.
- Score
- A crease line that allows board to fold. Blown scores — crushed or split — are a common reason a box drops a grade.
- Scuffing
- Surface abrasion on a panel. Almost always cosmetic — panels are not the part carrying the stack load.
- Short ton
- 2,000 lb. The unit recovered fiber is traded in throughout North America. Not to be confused with the metric tonne.
- Single-face
- One liner bonded to one fluted medium, with no second liner. Used as patch stock and as wrapping material rather than as box board.
- Slip sheet
- A thin sheet of board or plastic used in place of a pallet, or between courses of a stacked load to spread compression.
- Stickies
- Pressure-sensitive adhesive residue surviving the pulping process. A paper mill's most persistent contaminant problem.
- SWL
- Safe working load — the maximum fill weight marked on an FIBC. Never exceeded regardless of the bag's apparent condition.
- Tare
- The weight of the empty container. Subtracted from gross weight to give the net weight of contents, and needed for packaging tonnage in EPR reporting.
- Telescoping lidalso: Cap
- A separate cap that slides over the body of a box. Makes fill height adjustable and restores closure to a cut-top box.
- Tipping fee
- What a landfill or transfer station charges per ton to accept waste. One of the costs that recycling and reuse can reduce.
- Trip
- One loaded journey of a reusable container. Counting trips rather than units is the basis of both reuse economics and most EPR reporting.
- Triple wallalso: 3-wall
- Three fluted layers between four liners. The most common bulk box construction, used for general-purpose bulk boxes.
- VCI
- Volatile Corrosion Inhibitor. Treated liners and papers that protect machined metal surfaces during storage and transit.
- Void fill
- Loose material filling empty space inside packaging. Recovered kraft paper is the recyclable alternative to air pillows and loose fill.
- Weigh out
- A trailer that reaches its weight limit before it fills by volume. The normal case for baled fibre and dense bulk material.
- Wet strength
- Board treated with resin so it retains strength when damp. Essential for produce in coolers; complicates recycling if the treatment is heavy.
- Wicking
- Board drawing moisture upward from a damp floor or pallet. Weakens the bottom of the box first, which is the part carrying the compression load.
Where these terms show up
Most of them appear on a quote or a spec sheet. The size guide explains the sizing ones in depth, and the FAQ covers the questions they usually prompt.
Frequently asked questions
What does ECT mean on a corrugated box?
ECT stands for Edge Crush Test, a measure of how much force the board can take on its edge before crushing. It is the main predictor of a box's stacking strength.
What is OCC in cardboard recycling?
OCC means old corrugated containers, the recycling grade for used cardboard boxes. Mills buy baled OCC to pulp into new linerboard and medium.
What is the difference between ECT and Mullen burst test?
ECT measures stacking strength, while the Mullen burst test measures resistance to puncture and rupture. Modern boxes are usually rated by ECT; older specs often use Mullen.
What is an FIBC?
An FIBC is a flexible intermediate bulk container, commonly called a bulk bag. Its safety factor, such as 5:1 single-trip or 6:1 multi-trip, sets whether it can be reused.
What does bridging mean in bulk packaging?
Bridging is when free-flowing material arches across a container corner and stops discharging. Octabins reduce it because their 135-degree corners are harder to arch across.