Bulletin 014 · regrind

PP regrind from rackable and rigid plastic pallets

Last reviewed Nov 12, 20267 stages

The short answer

PP regrind from plastic pallets comes from stiff, rack-ready designs. Polypropylene is more rigid than HDPE, and it is kept in its own pile through sorting and grinding.

Rehrig Pacific’s 40 x 48 rackable pallet is high-pressure injection moulded co-polymer polypropylene, so PP often means a rackable.

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A mesh screen sets the flake size. What passes goes on; the oversize goes back to the grinder.

Why PP turns up in rackables

Nelson notes that PP is more rigid than HDPE and recommends it for unsupported racking. A rackable pallet carries an edge-rack rating of 2,000 lb on one Rehrig model, with a static rating of 10,000 lb. Stiffness is the point.

How to tell PP from HDPE

The moulded code is usually 5 on PP and 2 on HDPE. Many pallets carry no code. A stiffer feel, a lighter weight and a rackable shape point to PP. When unsure, we read the part.

Keep it apart

PP in an HDPE pile spoils the regrind. The two have different melt behaviour, so mixed flake makes a poor moulding. Sorting PP out is the whole job.

Where PP regrind goes

Moulders of stiff parts use it. Recycled-content rackables are one use. Rehrig offers a rackable with options for up to 15 percent black recycled content, so the loop exists even at modest percentages.

Why PP shows up in a pile

Rackable and heavy-duty pallets are often PP because it is stiffer. If you see a pallet that feels rigid and snaps cleanly, it may be PP. A moulded triangle with a 5 settles it.

Keeping PP clean of HDPE

The two resins melt at different temperatures and do not blend well. A small share of HDPE in PP, or the reverse, lowers the grade. That is why the sort comes first.

Buying PP regrind

State the colour, the allowed contamination and whether a blend is acceptable. If you need an exact melt flow, say so; we do not state one for pallet scrap.

Two rackables, side by side

Example models from each maker.
Spec	Rehrig 40 x 48 rackable	Nelson nestable, stackable, rackable
Weight	44.2 lb	18.0 lb
Static	10,000 lb	10,500 lb
Dynamic	4,000 lb	3,100 lb
Racking	2,000 lb edge rack	2,700 lb
Resin	Co-polymer polypropylene	High-density polypropylene

What the sources say

rehrigpacific.comRehrig Pacific's 40 x 48 rackable pallet is high-pressure injection molded co-polymer polypropylene, with 540 per 53 ft trailer.
nelsoncompany.comNelson Company defines dynamic capacity as the load a pallet carries in motion, always below static; static as the load at rest and the bottom pallet's limit in a stack; racking as the load across an open rack span, often the lowest and given only for pallets designed for it.
rehrigpacific.comRehrig Pacific offers the standard-duty nestable with recycled content of up to 90 percent in black, and describes it as 100 percent recyclable.
nelsoncompany.comHDPE is the most common resin in plastic pallets; PP is more rigid and the page recommends it for unsupported racking.
rehrigpacific.comRehrig Pacific's rackable pallet has a two-piece snap-lock design for quick repair and options for FDA-approved colours, RFID and up to 15 percent black recycled content.
rehrigpacific.comRehrig Pacific's 40 x 48 rackable pallet weighs 44.2 lb with a dynamic rating of 4,000 lb, static 10,000 lb and edge rack 2,000 lb.
nelsoncompany.comFor products touching the pallet directly, stricter federal requirements may call for non-blended virgin HDPE; recycled pallets often meet general FDA needs.
nelsoncompany.comAdvanced composite material pallets are 100 percent recycled polyolefins, cheaper with a shorter life, and suit export where the pallet is not returned.
rehrigpacific.comRehrig Pacific says its reusable products are designed to be recyclable at end of life and run a buyback program.
nelsoncompany.comA Nelson 48 x 40 x 4.8 in nestable, stackable, rackable polypropylene pallet weighs 18.0 lb with ratings of 10,500 lb static, 3,100 lb dynamic and 2,700 lb racking, and is listed as ISPM 15 exempt.
resource-recycling.comIn April 2017, HDPE HMW regrind from drums and IBCs was 24 to 27 cents per pound picked up in the US South (historical, not current).
en.wikipedia.orgPlastic pallets are often described as lasting 100 trips or more, and can cost roughly 10 times as much as hardwood pallets.
rehrigpacific.comRehrig Pacific's heavy-duty nestable can be made with post-consumer or post-industrial recycled material, up to 30 percent in black and up to 10 percent in colour, and is RFID compatible.
rehrigpacific.comRehrig Pacific's 40 x 48 standard-duty nestable pallet weighs 26.5 lb with a static rating of 10,000 lb and dynamic 3,000 lb.

Terms on this page

PP: Polypropylene. More rigid than HDPE and better with heat and harsh chemicals; used where rack stiffness matters.
Regrind: Plastic ground from used or scrap parts into flakes for moulding again.
HDPE: High-density polyethylene, resin code 2. The most common resin in plastic pallets; tough and moisture resistant.
Granulator: A machine with rotating knives that cuts plastic down to a set size, then pushes it through a screen.
Rackable: Rated to sit on rack beams, with a stated racking load.
Injection moulding: Pallet made by forcing molten resin into a mould at high pressure.
Racking load: Weight a pallet carries bridging an open span in unsupported racking. Often the lowest rating.
Static load: Weight a pallet carries at rest, or the bottom pallet carries when stacked. The highest of the three ratings.
Flake: The small, irregular pieces a granulator makes. Flake is regrind before it is sold or melted.
Moulder: A manufacturer that melts regrind or pellets and forms them into parts, such as pallets.
Recycled-content pallet: A pallet moulded partly or wholly from post-industrial or post-consumer resin.
Resin identification code: Number on a plastic part for the resin, which does not itself say whether it is recyclable.
Contamination: Anything in a load that is not the target resin: labels, metal, dirt, wood, food residue or another plastic.
Dynamic load: Weight a pallet carries while moving on a forklift, pallet jack or conveyor.

Questions people ask

Is PP recyclable?

Yes. PP pallets are ground and moulded like HDPE ones, in their own stream.

Why is PP rarer than HDPE?

HDPE is the most common pallet resin. PP is chosen where stiffness matters.

Can I mix PP in an HDPE load?

You can send it. Say so, and it is sorted out.

Does PP crack more easily than HDPE?

PP is stiffer and can be less tough in cold conditions. A pallet that cracks cleanly is often PP.

Is PP recycled less often than HDPE?

We state no figures. Pallet PP is accepted by processors who sort for it.

Sources, reviewed Nov 12, 2026: Rehrig Pacific, 40 x 48 rackable pallet; Nelson Company, what material is used for plastic pallets.