OCC 11 vs DS OCC 12 vs DLK: Grade Comparison

OCC 11 vs DS OCC 12 vs DLK: The Official Difference

The current ReMA/ISRI online specifications directory still lists item codes 11, 12 and 13 as Old Corrugated Containers, Double-Sorted Old Corrugated and New Double-Lined Kraft Corrugated Cuttings. The detailed grade pages use the definitions and tolerance limits effective July 14, 2022.^[1][2][3]

OCC 11: The Standard Used-Corrugated Grade

Grade 11 OCC is the broadest of the three. Its official definition is concise: corrugated containers with either test-liner or kraft liners. The 1% prohibitive limit and 5% combined outthrow-plus-prohibitive limit leave room for normal imperfection, but not for uncontrolled mixed waste.^[1]

In practice, this grade can arrive from distribution centers, retail stores, warehouses, municipal collection or industrial generators. Those sources do not create the same bale. A warehouse that flattens shipping cases indoors may produce dry, consistent material. A mixed-recycling facility may produce bales with more labels, boxboard, film and hidden non-paper items. Both may be sold as OCC 11, yet the front-end inspection burden is very different.

What processors should expect

• More variation in bale density, sheet size and folding pattern.
• Plastic stretch wrap, strapping, labels, tape and boxboard may appear.
• Moisture can vary between the bale surface and core.
• Staples, nails, wire fragments and hard objects require a defined removal route.
• Food-soiled, waxed, wet-strength or heavily treated board can create rejection risk.

That does not make OCC 11 a poor grade. It means the purchasing price, sorting cost, yield and reject burden must be evaluated together. A low-cost bale that needs extensive manual removal and produces a high reject fraction may be more expensive per accepted ton than a cleaner load.

DS OCC 12: Cleaner Because the Source and Sorting Are Controlled

DS OCC is not defined only by a lower contamination number. ReMA/ISRI describes it as double-sorted corrugated containers generated from supermarkets and/or industrial or commercial facilities. The material is specially sorted to be free of boxboard, off-shore corrugated, plastic and wax. Prohibitives are limited to 0.5%, while the combined limit is 2%.^[2]

The phrase double-sorted should influence the entire operating plan. It implies a deliberate second quality-control step, not a cleaner-looking OCC bale selected from the yard. The exact arrangement can vary—source separation, floor sorting, conveyor sorting, bale opening and inspection, or a combination—but the finished pack must support the agreed grade.

Where DS OCC projects often fail

One common mistake is to mix several supplier streams and assume that a final magnet or air separator will restore Grade 12 quality. Ferrous removal can capture exposed steel. Air separation can remove selected light fractions. Neither machine can reliably identify every piece of boxboard, waxed corrugated, treated board or wrong fiber once the load has been aggressively shredded.

Another mistake is losing traceability after sorting. Clean bales can be stored beside standard OCC, loaded with shared equipment, or contaminated by a wet floor. The process needs controls after the sorter as well as before it.

DLK Grade 13: New Corrugated Cuttings, Not “Premium OCC”

DLK is frequently described in commercial conversation as a high-quality brown grade. That shorthand is useful only when the origin remains clear. Grade 13 consists of new corrugated cuttings with test-liner or kraft liners. It excludes treated medium or liners, insoluble adhesives, butt rolls, slabbed medium and hogged medium. Prohibitive materials are not permitted, and the combined outthrow-plus-prohibitive limit is 2%.^[3]

The new-cutting requirement separates DLK from both OCC grades. It is normally generated by box plants and corrugated converting operations before the packaging enters use. Depending on the buyer’s specification, qualifying material may include clean trim, die-cut offcuts and other new production cuttings. The source and excluded materials still need to be verified.

Why DLK can need less sorting but more discipline

A stable converter can generate a predictable stream with little post-consumer contamination. That can reduce the need for heavy front-end sorting. However, the line must prevent contamination from entering a clean stream. Mixed production waste, treated board, hot-melt adhesive, floor sweepings, wood, plastic cores or maintenance debris can quickly damage a DLK pack.

DLK also should not be over-processed without a reason. Clean cuttings may feed directly to baling, conveying or controlled size reduction. Aggressive shredding can create more fines, increase dust load and make later visual inspection harder. The equipment route should start from the buyer’s required form, not from an assumption that every fiber stream needs a shredder.

Outthrows, Prohibitives and Zero-Tolerance Material

The terms are easy to repeat and easy to misunderstand. ReMA/ISRI defines outthrows as papers that make the pack undesirable and unsuitable for consumption as the specified grade. Prohibitive materials include materials that make the pack unacceptable when they exceed the allowed amount, as well as materials that may damage equipment. The paper-stock terms also define zero-tolerance material to include medical, organic, food, hazardous, poisonous, radioactive or toxic waste and other harmful substances or liquids.^[3]

AF&PA’s recyclability guidance explains that recovered paper is sorted before baling and that mill pulping and contaminant-removal stages separate items such as staples, plastic liners, coatings, tape and adhesives.^[4] That downstream capability should not be used as an excuse for poor upstream control. Every unwanted kilogram adds handling, disposal, wear or process instability somewhere in the system.

Can OCC 11 Be Upgraded to DS OCC 12—or to DLK?

OCC 11 may sometimes be sorted into a pack that meets a buyer’s DS OCC requirement. Whether it qualifies depends on the actual composition after sorting, the excluded materials, the contamination percentages and the governing purchase agreement. The label cannot be changed merely because the material passed through a shredder, magnet or second conveyor.

Used OCC cannot be converted into DLK. DLK is defined by its origin as new corrugated cuttings. Cleaning a used box does not make it pre-consumer converting scrap. This distinction is important when a quotation promises to “produce DLK” from mixed OCC. The line may produce a cleaner corrugated fraction, but the material origin remains unchanged.

What equipment can legitimately change

• Open dense bales so hidden material becomes visible.
• Meter bulky sheets into a stable inspection or processing stream.
• Remove exposed ferrous contamination.
• Separate selected light fractions or size classes when the feed supports it.
• Reduce oversized cartons or cuttings for downstream conveying.
• Mechanically open fiber-rich material when the required output is a dry prepared fraction.

What equipment cannot prove by itself

• The original source of the material.
• Compliance with a grade across an entire truckload.
• Absence of wax, wet-strength treatment or insoluble adhesive in every piece.
• The mill yield, strength or furnish behavior without agreed testing.
• A trade-grade upgrade based only on particle size.

Processing Requirements Change With the Grade

A useful processing plan should preserve the value already present in the feed while removing the risks the buyer will not accept. That leads to different priorities for the three grades.

OCC 11 processing priorities

Start with receiving inspection, safe bale-wire handling and representative opening of variable loads. Remove obvious film, wood, metal and unacceptable board before aggressive size reduction. Where a dry preparation line is required, controlled feeding and buffering matter because loose cardboard has low bulk density and can surge or bridge. The guide to choosing an industrial cardboard recycling machine explains why a baler, a shredder and a complete line solve different process boundaries.

DS OCC processing priorities

Protect the double-sorted status. Supplier qualification and source segregation are often more valuable than another downstream machine. If bales are opened, the inspection method should be designed to identify boxboard, plastic, wax and nonconforming corrugated without fragmenting them too early. Sorted material should move through dedicated or cleaned conveyors and storage zones to avoid remixing.

DLK processing priorities

Keep converter scrap separate at the source. Identify treated grades and insoluble adhesive before they reach the clean cuttings stream. Clean trim may only need metering and baling. Shredding is justified when the cuttings bridge, are too large for the next conveyor, or must be mechanically opened for a defined downstream product. It is not automatically a quality upgrade.

How to Inspect and Sample OCC Bales

The outer layer of a bale is not a reliable sample. A bale that looks uniformly brown from the trailer door may still contain film, boxboard or wet material in the center. A receiving plan should define which bales are selected, how they are opened, how sample fractions are separated and which weight forms the denominator.

At receiving

• Confirm grade, seller, load number, bale count, gross and tare documentation.
• Check trailer cleanliness, odor, broken bales and obvious water exposure.
• Identify mixed-grade loads and keep each grade physically separated.
• Record bale condition before unloading changes it.

During bale opening

• Use a safe, documented method for wire or strap removal.
• Expose the bale core rather than sampling only loose surface sheets.
• Separate specified corrugated, other paper, plastic, metal, treated board and other rejects.
• Use agreed moisture locations and test procedures.

In the purchase agreement

The ReMA/ISRI terms state that paper should be packed dry and identify 12% as the maximum dry limit, while requiring buyer and seller to agree on the moisture percentage and test method. The same terms emphasize that the purchase or sales agreement is the governing document and should specify quality, quantity, packing unit and shipping terms.^[3]

EPA’s paper-grade guidance makes the same practical point from the mill side: mills buy recovered paper according to recipes and specifications, while the grade inside a bale reflects the collection and processing used to recover it.^[5]

What the Grade Means for Equipment Selection

The grade name should appear in the equipment RFQ, but it is not enough. Two OCC 11 projects can need different systems because one receives loose warehouse cartons and the other receives dense bales from variable suppliers. Equipment should be selected from the feed form, contamination, required output and acceptance test.

For projects that continue beyond baling, it is also important to define the handoff between dry preparation and paper-mill stock preparation. The comparison of dry OCC fiber recovery and wet stock preparation explains why loose or baled dry fiber-rich material is not the same accepted product as pumpable, screened paper stock.

Safety and dust are part of the line

Paper handling is not a low-risk activity simply because the material is lightweight. OSHA identifies moving machinery, unexpected startup, crushing hazards, bale handling and combustible dust among the hazards in paper recycling.^[6] OSHA also lists paper and pulp among materials that can be explosible in dust form.^[7] Bale opening, jam clearing, shredder access, dust collection and maintenance therefore need site-specific guarding, lockout and dust-hazard controls.

Where the YUXI OCC Dry Pulping Line Fits

The topic-appropriate pillar for this article is the YUXI OCC paper dry pulping and cardboard recycling line. Its published process combines controlled feeding, primary shredding, ferrous-metal removal, buffer and metering, mechanical dry fiber opening, dust management, collection and optional baling.

That line can support projects where corrugated boxes, kraft offcuts or selected paperboard waste must be opened, protected from metal, mechanically prepared and collected as a dry fiber-rich product. It does not turn a wrong feed into a compliant grade by itself. For OCC 11, DS OCC or DLK, the quotation still needs representative samples, bale details, moisture, excluded materials and the downstream buyer’s acceptance criteria.

RFQ and Purchase Agreement Checklist

The strongest RFQ describes a measurable material transformation. It does not ask a supplier to guarantee “Grade 12 output” from an unknown mix. It defines the feed, the process boundary and the method used to decide whether the outgoing pack meets the buyer’s contract.

FAQ