When customers put items in a recycling bin, the materials go to a Material Recovery Facility (MRF) — the industrial facility that actually sorts mixed recyclables into separated material streams for downstream processing. MRFs are the operational backbone of the US recycling system. Understanding how they work — what they can sort, what they can’t, where contamination causes problems, and how compostable packaging interacts with MRF operations — provides essential context for B2B foodservice operators making packaging decisions.
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This guide is the foundational reference on MRFs from a B2B foodservice perspective.
What an MRF Actually Does
A Material Recovery Facility receives mixed recyclables from collection trucks, sorts the mixed materials into specific commodity streams (PET plastic, HDPE plastic, aluminum, glass, paper, cardboard), and bales the sorted materials for shipment to downstream processors who turn them into recycled product.
The facility footprint typically includes:
– Receiving area where collection trucks dump loads
– Initial inspection and large-item removal
– Conveyor systems carrying material through sorting equipment
– Sorting equipment (manual sorters, optical sorters, magnetic separators, density separators, screens)
– Baling equipment that compresses sorted material into shipping bales
– Storage area for baled material awaiting shipment
– Quality control and contamination handling
Modern MRFs process tens of thousands of tons of mixed recyclables annually. Larger facilities may process over 100,000 tons.
The Standard MRF Sorting Sequence
Mixed recyclables move through MRFs in a typical sequence:
Stage 1: Initial Receiving and Pre-Sort
Collection trucks dump loads onto receiving floor. Workers remove obvious contamination — large items that don’t belong (electronics, hazardous materials), film plastic that wraps and jams equipment, oversized items.
Stage 2: Bag Breakers and Initial Conveying
Mechanical bag breakers open plastic bags that customers put recyclables in. Materials transfer to conveyor belts that carry them through downstream sorting.
Stage 3: OCC (Old Corrugated Cardboard) Separation
Disc screens or star screens (rotating discs that allow smaller items to fall through but transport larger flat items forward) separate cardboard from other materials. OCC is one of the highest-value recovered materials for MRFs.
Stage 4: Paper Separation
Additional screens separate paper from container materials. Paper bales are valuable but require clean separation from contamination.
Stage 5: Magnetic Separation for Steel
Powerful magnets pull steel cans (tin cans, aerosol cans) out of the material flow. Steel is among the cleanest recoverable materials.
Stage 6: Eddy Current Separation for Aluminum
Eddy currents (alternating magnetic fields) repel aluminum, separating aluminum cans from other materials. Aluminum is high-value recovered material.
Stage 7: Optical Sorting for Plastics
Optical sorters use cameras and infrared spectroscopy to identify specific plastic types. Air jets blow identified plastics into sorted streams (PET into one stream, HDPE into another).
Stage 8: Manual Sort Quality Control
Workers visually inspect sorted streams and remove residual contamination or misclassified items. Manual sort is the final quality check.
Stage 9: Glass Separation (Where Applicable)
Some MRFs include glass separation; others ship mixed glass to specialized glass processors. Glass tends to break during MRF processing, creating both safety and quality issues.
Stage 10: Baling
Sorted material streams are compressed into bales for shipping. Bales are the standard commodity unit for downstream sale.
Stage 11: Residual Disposal
Material that can’t be sorted (heavily contaminated, wrong material types, broken/unrecognized items) becomes residual — sent to landfill or sometimes incineration.
What MRFs Can and Cannot Sort
MRF capabilities are real but bounded:
MRFs can sort cleanly:
– PET (#1) plastic bottles — optical sorting works well
– HDPE (#2) plastic bottles — optical sorting works well
– Aluminum cans — eddy current separation
– Steel cans — magnetic separation
– Cardboard — screen separation
– Paper — screen separation
MRFs struggle to sort:
– Plastic film (wraps around equipment, causing problems)
– Multi-material composite items (laminated structures that confuse optical sorters)
– Black plastic (optical sorters can’t read black against background)
– Small items that fall through screens
– Contaminated items (food residue, mixed materials)
– Items smaller than ~3 inches in any dimension
MRFs cannot sort effectively:
– Most #3-7 plastics other than HDPE — limited end markets, limited optical sorting capability
– Electronics
– Hazardous materials
– Compostable packaging (different stream entirely)
How Compostable Packaging Interacts With MRFs
For B2B foodservice operators, the MRF interaction matters:
Compostable packaging shouldn’t go to MRFs. Compostable items aren’t designed for recycling streams. They go to commercial composting facilities, which have completely different processing infrastructure.
Compostable items in MRFs cause contamination problems. Clear PLA cups visually similar to PET get sorted into PET streams, then contaminate the PET bale. Some PLA can hydrolyze in PET recycling processes, ruining the recycled output.
This creates customer education challenge. Customers who don’t know the difference put compostable items in recycling bins. The sustainability programs at foodservice operations need to communicate clearly about disposal pathway.
Bin labeling matters operationally. Operations with on-site customer-facing bins need clear signage distinguishing trash, recycling, and compost streams.
The full compostable food containers, compostable bowls, compostable cups and straws, and compostable bags ranges all require commercial composting infrastructure for proper end-of-life — not MRF recycling streams.
What This Means for B2B Procurement Decisions
The MRF context shapes packaging procurement and customer communication:
Don’t claim compostable packaging is recyclable. The two systems are different; conflating them creates customer confusion and operational problems.
Communicate disposal pathway clearly. Customers should know to put compostable packaging in compost bins (where available) — not recycling bins.
Match disposal options to customer markets. Operations in markets with curbside compost have honest “compostable, dispose in compost bin” claims. Operations without local composting have honest “compostable materials, currently no local composting infrastructure” framing.
Consider operational signage. On-site customer-facing bin signage distinguishing trash, recycling, and compost streams supports correct customer disposal.
The supply chain across compostable foodware categories provides items designed for the composting pathway specifically — not for the MRF recycling stream that handles conventional plastics, aluminum, paper, and cardboard.
What “Done” Looks Like for MRF-Aware Procurement
A B2B operator with MRF-aware sustainability communication:
- Compostable items procured through suppliers with appropriate certification
- Customer-facing communication clearly distinguishes compostable disposal from recycling disposal
- Bin signage supports correct customer sorting
- Awareness of why compostable items shouldn’t enter MRF recycling streams
- Local composting infrastructure access mapped per market
The MRF system is real industrial infrastructure but bounded in capability. Compostable packaging operates through different infrastructure (commercial composting facilities) entirely. Operations that understand the distinction make better procurement decisions and provide clearer customer communication. Operations that conflate the systems create customer confusion that undermines the broader sustainability program.
Apply the framework above through procurement and customer communication, and the compostable packaging program operates within the appropriate end-of-life infrastructure rather than creating contamination issues for the recycling stream.
Background on the underlying standards: ASTM D6400 defines the U.S. industrial-compost performance bar, EN 13432 harmonises the EU equivalent, and the FTC Green Guides govern how “compostable” can be marketed on packaging in the United States.