Glossary

Sorting glossary: optical, color, NIR and material sorting terms

Plain-language definitions for the terms buyers meet when choosing optical sorters, NIR material sorters, plastic recycling sorters, glass sorters and food sorting machines. Each term says where it applies, what it is not, and which platform it belongs to.

Quick decision path

If you do not know where to start, work these five in order — material form decides the platform before the sorting criterion does.

Is the material still in whole-bottle form?Start with whole-bottle sorting: MAS-B, or MAS-B Pro when material identity is needed.
Is it already prepared as rigid flakes?Decide whether the problem is color, material, or both.
Is the accepted product PET?PET flake purification: MAS-P, or MAS-PC when color also matters.
Is the task PP vs PE, ABS vs PS or another difficult split?Hard polymer separation: MAS-P Pro, or MAS-PC Pro when color also matters.
Is the feed pellets or soft film?These are boundary terms, not applications of the current MAS plastic platforms.

The four comparisons buyers ask for

Each row restates a distinction the definitions below make in prose.

Color sorting or material sorting?

The distinction the whole product line turns on: is your quality defined by what a piece looks like, or by what it is made of?

Aspect	Color sorting	Material sorting
Defines quality by	What the piece looks like	What the piece is made of
Main technology	Visible-light inspection	NIR / spectral recognition
Typical example	Remove green flakes from clear PET	Remove clear PVC from clear PET
Cannot catch	A color-correct piece of the wrong polymer	Black and carbon-black pieces

MAS-P or MAS-P Pro?

Both are material sorters for prepared flakes, and they are asked different questions. MAS-P Pro is listed on this site as the MAS 3D Polymer Sorter.

Platform	The decision it makes	Use it when
MAS-P	PET vs confirmed non-PET rejects	The accepted product is PET and everything else is reject
MAS-P Pro	One polymer against another	PP vs PE, ABS vs PS, PC vs PMMA and other difficult rigid polymers

MAS-PC or MAS-PC Pro?

The combined configurations, when one pass has to make both a material and a color decision.

Platform	Combines	Use it when
MAS-PC	MAS-P purification + MAS-C color sorting	PET flakes need non-PET removal and a color cleanup
MAS-PC Pro	MAS-P Pro separation + MAS-C color sorting	Harder polymer streams also need off-color rejection

Whole bottles or prepared flakes?

Material form decides the platform before the sorting criterion is discussed — and shredding is irreversible.

Material form	Direction	Note
Whole bottles, before shredding	MAS-B / MAS-B Pro	Standard sorts color and appearance; Pro adds material recognition
Prepared rigid flakes	MAS-C / MAS-P / MAS-P Pro / MAS-PC / MAS-PC Pro	Color and material handled as staged decisions
Pellets or soft film	Not these platforms	Trajectory cannot be reliably controlled by air ejection

Core concepts

The distinctions that decide which machine you actually need.

Optical sorting

Also optical sorter · automatic sorting machine

Automated separation of a material stream by inspecting every particle in flow and ejecting the pieces that do not belong. A repeatable result depends on the whole chain — feeding, presentation, lighting, capture, recognition and ejector timing — not on recognition alone.

Where it applies: Any stream that can be fed evenly and presented consistently: rigid plastic flakes, whole bottles, glass cullet, coarse metal scrap, grains, seeds and nuts.
What it is not: Not image recognition on its own. A piece can be detected correctly and still end up in the wrong stream if the material does not travel predictably — which is why pellets and soft film fail even though a camera can see them perfectly well.
Mayson platform: Every MAS platform is an optical or NIR sorter in this sense. FR-XRT sits beside them rather than inside this definition: it reads internal X-ray attenuation rather than visible appearance.

Color sorting

Also colour sorting · color sorter · colour sorter · plastic color sorter

Sorting that classifies color, transparency, shape and visible defects using visible-light inspection. A plastic color sorter keeps the target color fraction and ejects off-color, opaque or black pieces.

Where it applies: Prepared rigid flakes and fragments where the quality boundary is visible: off-color pieces, black fragments, and foreign objects such as wood, metal, stone, rubber and paper.
What it is not: It does not identify polymer type. PET and PVC can look identical, so a color sorter cannot catch clear PVC in clear PET no matter how it is tuned — that is not a tuning question.
Mayson platform: MAS-C on flakes; MAS-B on whole bottles; the color half of MAS-PC and MAS-PC Pro.

Material sorting

Also material separation · polymer sorting

Sorting that separates by what a piece is made of rather than what it looks like, using NIR or spectral response. It catches the case color sorting cannot: a color-correct piece that is still the wrong material, such as PVC hiding in clear PET.

Where it applies: Prepared flakes where the accepted product is defined by polymer, and whole-bottle streams in Pro configurations.
What it is not: It does not always mean every polymer is split into its own product stream. MAS-P is PET-focused — it removes confirmed non-PET rejects from PET flakes, and is not intended to sort that reject fraction into PP, PE, PS and PMMA. Polymer-against-polymer separation is a different machine.
Mayson platform: MAS-P for PET vs non-PET; MAS-P Pro for polymer-against-polymer.

Material and color sorting

Also combined material and color sorting · polymer and color sorting · MAS-PC

A configuration that makes a polymer decision and a visible-color decision on the same stream, rather than choosing between them.

Where it applies: PET flakes that need non-PET removal and a color cleanup, or harder polymer streams that need PP/PE/ABS separation plus off-color rejection.
What it is not: Not the same as color sorting with a better camera, and not the same as MAS-P Pro on its own — MAS-P Pro is primarily a material sorter. Whether one combined machine or two staged machines is right depends on the project.
Mayson platform: MAS-PC combines MAS-P PET purification with MAS-C color sorting; MAS-PC Pro combines MAS-P Pro polymer separation with MAS-C color sorting. MAS-P plus MAS-C staged in a line is the alternative.

PET flake purification

Also PET purification · non-PET removal

Removing non-PET pieces — PVC, PE, PP, PS, PMMA, PC and similar — from a washed PET flake stream using NIR material recognition. PVC is the priority target because it looks almost identical to PET but ruins PET recyclate even in tiny amounts.

Where it applies: Washed, size-reduced PET flake streams where the accepted product is PET.
What it is not: Not a color cleanup. The decision it makes is PET vs non-PET, so an off-color but genuine PET flake is an accepted piece unless a color stage is added.
Mayson platform: MAS-P; MAS-PC when a color decision is needed on the same stream.

Whole-bottle sorting

Also bottle sorting · pre-shredding sorting

Sorting that happens before shredding, while bottle color, shape, label condition, brand appearance and deformation are still readable on the intact bottle. It sets up the flake stages that follow rather than replacing them.

Where it applies: Mixed post-consumer bottle streams of roughly 0.5–2 L, before size reduction.
What it is not: The standard configuration is not a material sorter. MAS-B sorts by color and AI-recognized appearance; separating PET from PP, HDPE and PVC bottles by material needs MAS-B Pro, which adds NIR polymer identification.
Mayson platform: MAS-B for color and appearance; MAS-B Pro when material identity is required.

Flake sorting

Also post-shredding sorting · rigid flake sorting

Sorting that happens after crushing and washing, for higher-purity flake purification. Color and material identity are handled as distinct, staged decisions rather than one blurred step.

Where it applies: Rigid flakes, sheets and fragments that can be presented consistently in a chute.
What it is not: Once material is shredded, the whole-bottle route is no longer available. Anything that had to be decided at bottle level — label condition, bottle class, deformation — cannot be recovered later.
Mayson platform: MAS-C, MAS-P, MAS-P Pro, MAS-PC and MAS-PC Pro all operate at this stage.

Sorting technologies

How a sorter sees the material — each one reads a different property, and each one is blind to something.

Visible-light inspection

Also visible light sorting · RGB inspection

Camera, lighting and recognition logic working together to separate material by visible color, shape and surface differences. It reads what a piece looks like, not what it is made of.

Where it applies: Any stream whose quality boundary is visible to a camera under controlled lighting.
What it is not: Not a polymer identification method, and not lighting-independent — a reflective or dusty surface changes what the camera reads, which is why illumination is tuned on the real material.
Mayson platform: MAS-C, MAS-B, the color half of MAS-PC and MAS-PC Pro, and the food and glass series.

Visible-light inspection

NIR inspection

Also near-infrared sorting · NIR sorting · NIR sorter · near infrared inspection

Near-infrared analysis reads material response across multiple wavelengths to support polymer separation. Each polymer returns a distinct spectral fingerprint, so pieces that look identical to a camera can still be separated by what they are made of.

Where it applies: Light-colored and translucent plastics with clean, dry surfaces, presented in a stable flow. Accuracy depends on validated spectral libraries and periodic calibration.
What it is not: Not a universal polymer identifier. NIR cannot reliably identify black or carbon-black plastics, because black material absorbs the signal. It is also not the route to removing wood, metal, stone or other non-plastic foreign objects — that is color sorting.
Mayson platform: Basic NIR recognition in MAS-P and MAS-PC for PET-focused purification; multi-spectral recognition in MAS-P Pro and MAS-PC Pro for harder polymer separation; MAS-B Pro for whole bottles.

Basic NIR recognition

Also single-decision NIR · PET-focused NIR

The NIR configuration used when the decision is one accepted polymer against everything else — typically PET against confirmed non-PET rejects.

Where it applies: PET flake purification, where the accepted product is PET and the rest is reject.
What it is not: Not intended to sort the rejected non-PET fraction into individual polymer categories such as PP vs PE or PS vs PMMA. That is a harder question and a different configuration.
Mayson platform: MAS-P; the material half of MAS-PC.

MAS-P PET material sorter

Multi-spectral recognition

Also advanced polymer recognition · multi-spectral NIR · MAS 3D · MAS 3D polymer sorter

Broader spectral analysis used when polymers have to be separated from each other rather than from a single accepted class — PP against PE, ABS against PS, PC against PMMA.

Where it applies: Prepared mixed-polymer flakes and rigid fragments where one-dimensional sorting is not enough.
What it is not: Still blind to black and carbon-black material, and still not a substitute for a color decision. When a line needs both, MAS-P Pro pairs with MAS-C or combines as MAS-PC Pro.
Mayson platform: MAS-P Pro, listed on this site as the MAS 3D Polymer Sorter; the material half of MAS-PC Pro.

MAS-P Pro polymer sorter

AI-assisted recognition

Also AI sorting · machine-learning recognition

Recipe-linked models working alongside conventional sorting rules to recognise subtle, variable or hard-to-parameterise defect classes.

Where it applies: Defect classes that resist fixed parameters — variable appearance, mixed causes, or classes that shift between batches.
What it is not: Not a replacement for human judgement, and not self-validating. The model assists the operator, and accuracy is confirmed on representative samples before it drives production decisions.
Mayson platform: Available across the MAS platforms as a recognition layer, configured per recipe.

AI-assisted recognition

Multi-view inspection

Also multi-camera inspection · dual-view sorting

Multiple synchronised viewpoints revealing surfaces, edges and orientation-dependent defects that a single camera angle can miss.

Where it applies: Products whose defects hide on one face — nuts, beans and seeds, and other streams where orientation decides visibility.
What it is not: A configuration pattern, not a universal claim for every product family. It depends on stable flow and consistent particle spacing and rotation, both of which are tested.
Mayson platform: MAS N nuts, MAS AS beans and seeds, and other food configurations.

Multi-view inspection

Lighting and ejector control

Also ejector control · ejector timing · air ejection · compressed-air ejection

The control layer that synchronises inspection visibility, decision timing and reject actuation to the millisecond, so the right air pulse meets the right particle.

Where it applies: Every optical sorting platform; the recipe is documented per material test.
What it is not: Not a detail that can be tuned after the fact from a data sheet. A correct decision still produces a wrong cut if it fires at the wrong moment, and compressed air, product speed and material spread all move that moment.
Mayson platform: Common to all MAS and FR platforms.

Lighting and ejector control

Chute-fed sorting

Also chute sorter · chute configuration

A machine layout in which material slides down a chute in free fall past the inspection point, and is ejected in flight by compressed air. Machine capacity is scaled by the number of chutes.

Where it applies: Rigid flakes, sheets, fragments, grains, seeds, nuts and cullet.
What it is not: Not suitable for every plastic. Film, bags, soft films and very light flexible plastics cannot be sorted this way because air-jet ejection cannot reliably control their trajectory, and Mayson's plastic flake sorting machines are not designed for pellets.
Mayson platform: MAS-C, MAS-P, MAS-P Pro, MAS-PC and MAS-PC Pro, sized C5–C12 and P3–P8 by chute count.

Plastics recycling

Dual-energy XRT

Also X-ray transmission sorting · XRT sorting · dual energy X-ray

Dual-energy X-ray transmission reads internal attenuation to identify density and effective atomic-number differences in coarse recycled metal streams.

Where it applies: Coarse aluminium-rich scrap, Zorba upgrading, heavy metal removal and remelter feed cleaning. FR-XRT Pro adds RGB imaging when appearance must be reviewed alongside density.
What it is not: Not a surface method — oxidized, dusty or coated pieces are not judged only by visible appearance. It also cannot promise fixed purity, universal separation or guaranteed alloy separation without sample testing; cast versus wrought aluminium in particular should not be promised universally.
Mayson platform: FR-XRT; FR-XRT Pro for complex mixed streams.

Common sorting decisions

The separations buyers ask for by name, and what each one actually requires.

PET vs non-PET sorting

Also PET purification decision · non-PET rejection

The decision where PET is the accepted product and everything else — PVC, PE, PP, PS, PMMA, PC and other non-PET materials — is reject, made by NIR material recognition.

Where it applies: Washed PET flake streams carrying mixed non-PET contamination.
What it is not: Not polymer-by-polymer separation. The reject stream leaves as one mixed non-PET fraction; splitting it further is a separate job.
Mayson platform: MAS-P; MAS-PC when color also matters.

MAS-P PET material sorter

PVC removal from PET flakes

Also PET PVC separation · removing PVC from PET

The priority target within PET purification. Clear PVC can look almost identical to PET and pass color sorting, so NIR material response is used to separate accepted PET from PVC-rich reject classes.

Where it applies: PET flakes; on whole bottles the same separation happens before shredding.
What it is not: Not achievable by color sorting at any setting, and not made food-grade by removal alone — food-grade compliance depends on the complete washing, decontamination, extrusion, testing and certification process.
Mayson platform: MAS-P on flakes; MAS-B Pro on whole bottles; MAS-PC when color also matters.

PP vs PE separation

Also separating PP from PE · PP purification · PE purification

Separating two polymers that share color, transparency and shape, so the difference is not visible at all. It requires material recognition rather than a better camera.

Where it applies: Mixed rigid PP/PE flake streams. On whole bottles the same separation is done before shredding with NIR whole-bottle material recognition.
What it is not: Not the same job as removing PP and PE from PET. When the accepted product is PET, the decision is PET vs non-PET and MAS-P is the direction — that machine is not being asked to tell PP from PE.
Mayson platform: MAS-P Pro or MAS-PC Pro on flakes; MAS-B / MAS-B Pro on whole bottles.

Hard polymer separation

Also ABS vs PS separation · PC vs PMMA separation · difficult polymer sorting

Separating engineering and rigid polymers from each other — PP, PE, ABS, PC, PMMA and PS — where several classes must be told apart in the same pass.

Where it applies: Prepared mixed-polymer flakes and rigid fragments, after any black fraction is removed.
What it is not: Not a promise that every mixed stream can be fully resolved. Which classes can be separated, and how cleanly, is confirmed on representative samples of the real feed.
Mayson platform: MAS-P Pro; MAS-PC Pro when color also matters.

MAS-P Pro polymer sorter

Black plastic sorting

Also carbon-black plastic · sorting black material

Black and carbon-black plastics absorb near-infrared light, so NIR cannot identify their polymer type. They are removed instead as visible color rejects, before the material separation runs on what remains.

Where it applies: Any flake or bottle stream carrying a meaningful black fraction ahead of a polymer decision.
What it is not: Removing black material by color does not identify what polymer it was. And black is not simply 'not an interference' — it is an interference for NIR material identification, and a routine reject for color sorting. Both halves of that sentence matter.
Mayson platform: MAS-C, MAS-B, MAS-PC and MAS-PC Pro remove black items as color rejects.

Foreign material removal

Also wood metal stone removal · non-plastic contaminants · foreign object rejection

Wood, metal, stone, rubber, paper and similar objects look clearly different from the surrounding plastic in color, brightness and surface appearance, and that visible difference is what color sorting detects.

Where it applies: Plastic recycling streams, glass cullet, and grain, seed and nut streams. The result does not depend on polymer type — a wood chip leaves an HDPE stream the same way an off-color flake does.
What it is not: Usually not an NIR-first job. Wood, paper, rubber, stone and other visible foreign objects are normally removed by color sorting, and a large ferrous fraction is often handled upstream by a magnetic separator so the sorter can concentrate on the fine separation. NIR is for polymer decisions, so presenting it as the way to find wood, metal or stone is wrong.
Mayson platform: MAS-C, MAS-PC, MAS-PC Pro on flakes; MAS-B on whole bottles; the food and glass series.

MAS-C plastic color sorter

CSP removal

Also ceramics stones porcelain · CSP contamination · cullet contaminant removal

Removing ceramics, stones and porcelain from glass cullet. CSP looks similar to glass but degrades the recovered product, which makes it a priority removal rather than one contaminant among several.

Where it applies: Recycled glass cullet, alongside metals, off-color glass, heat-resistant and leaded glass, organics and labels.
What it is not: Not a setting that transfers between plants. Glass is reflective and mixed by particle size, so illumination and the reject classes are tuned on the real input; detailed performance claims need verified equipment and sample conditions.
Mayson platform: Glass recycling sorter.

Glass recycling sorter

Off-color and opaque rejection

Also off-color flakes · opaque flakes · yellowed flakes

Removing pieces that sit outside the accepted color window — off-color, opaque, yellowed or otherwise off-class — so a clear, white or single-color fraction can be recovered.

Where it applies: PET and rigid flake streams recovered as a clear or single-color product, and whole-bottle streams separated by bottle color.
What it is not: Not a judgement about polymer. A yellowed or opaque flake can be perfectly good PET; it is rejected because it fails the color target, not because it is the wrong material.
Mayson platform: MAS-C on flakes; the color half of MAS-PC and MAS-PC Pro; MAS-B on whole bottles.

MAS-C plastic color sorter

Pre-sorting and magnetic separation

Also pre-sorting · magnetic separator · upstream removal

Line steps ahead of the optical sorter — manual checks, screening, magnets — that remove large or unsuitable objects before fine separation begins.

Where it applies: Feed carrying oversized objects or a significant ferrous fraction.
What it is not: Not a limitation of the sorter, and not a step Mayson supplies. Where the feed carries a large amount of ferrous metal, a magnetic separator ahead of the sorter is standard line practice, because it lets the sorter concentrate on the fine separation.
Mayson platform: Customer or third-party equipment. The MAS platforms sit downstream of it.

Plastics recycling

What you sort on

The property that separates an accepted piece from a rejected one.

Sorting by color and appearance

Also colour and appearance

Separating by visible color, transparency, surface staining or discoloration — keeping the clean fraction and rejecting off-color or off-class pieces.

Where it applies: Streams whose quality target is defined by how a piece looks.
What it is not: Silent about what the piece is made of.

Buyer's guide

Sorting by material type

Removing non-target material that a visible check cannot catch. A color-correct piece can still be the wrong material — PVC hiding in clear PET, or ceramic in glass.

Where it applies: Streams whose quality target is defined by what a piece is made of.
What it is not: Silent about how a piece looks, so off-color accepted material stays accepted.

Buyer's guide

Sorting by shape, size and foreign material

Removing broken, deformed or undersized pieces plus stones, husk, shell, metal and other non-target objects that have to leave the stream.

Where it applies: Grain, seed and nut streams especially, and any feed carrying foreign objects.
What it is not: Not a polymer or density decision — it reads geometry and visible difference.

Sorting by material density (XRT)

Also density sorting · effective atomic number

For metal, color is not enough. Dual-energy X-ray transmission reads density and effective atomic number to split aluminium from dense heavy metals; FR-XRT Pro adds RGB for complex streams.

Where it applies: Coarse metal scrap: Zorba upgrading, remelter feed cleaning, ASR, IBA and e-waste.
What it is not: Not applicable to fine particles — FR-XRT is a coarse scrap sorter, not a fine-particle color sorter, and the recommended size range comes from the technical data rather than from a rule of thumb.

Material forms

How the material arrives at the sorter, which decides the platform before anything else — including the forms these platforms do not handle.

Whole bottles

Also intact bottles · pre-shred bottles

Post-consumer bottles before shredding — roughly 0.5–2 L — with caps, labels, color and deformation still in the stream.

Where it applies: Mixed bottle streams: PET, HDPE, PP, PE, PVC, PS and other complete plastic bottles.
What it is not: Not a flake stream, and not interchangeable with one. The platform is decided by this before the sorting criterion is even discussed.
Mayson platform: MAS-B; MAS-B Pro when material identity is required.

MAS-B bottle sorter

Prepared flakes and rigid fragments

Also plastic flakes · rigid flakes · rigid fragments · sheet fragments

Washed or unwashed plastic flakes, sheets and rigid pieces that have already been size-reduced and can be presented consistently.

Where it applies: PET flakes, mixed rigid polymer flakes, and off-color flake streams.
What it is not: Not pellets and not film. Both travel unpredictably in a chute, so neither is a fit for the plastic flake platforms.
Mayson platform: MAS-C, MAS-P, MAS-P Pro, MAS-PC and MAS-PC Pro.

Plastic pellets

Also granules · regrind pellets

Extruded or re-granulated plastic in pellet form, downstream of flake preparation.

Where it applies: Recyclate after pelletizing, as a stream that some plants want checked.
What it is not: Not a fit for Mayson's plastic flake sorting machines, which are not designed for pellet sorting. Listing it here is a boundary, not an application.
Mayson platform: None of the current plastic flake platforms.

Plastics recycling

Soft plastic film

Also plastic bags · flexible film · soft plastics

Film, bags, soft films and very light flexible plastics.

Where it applies: Film recycling streams, which are a different sorting problem entirely.
What it is not: Not suitable for these platforms, because air-jet ejection cannot reliably control the trajectory of a light flexible piece. The limit is mechanical, not a recognition limit — the camera can see film perfectly well.
Mayson platform: None of the current plastic platforms.

Plastics recycling

Crushed glass cullet

Also cullet · recycled glass · flint glass · amber glass · green glass

Recycled glass cullet recovered by color — flint (clear), amber, green and blue or other tinted side fractions — with ceramics, stone, porcelain and metal removed.

Where it applies: Mixed-color incoming cullet, where single-color output is worth more than mixed.
What it is not: Not a stable feed. Reflection, particle size and dust load change what the camera reads, so lighting and the accepted color window are set on the real cullet rather than carried over.
Mayson platform: Glass recycling sorter.

Glass recycling sorter

Coarse metal scrap

Also Zorba · ASR · IBA · remelter feed · aluminium scrap

Aluminium scrap, Zorba-type streams and complex metal residues (ASR, IBA, e-waste) sorted by material density with XRT.

Where it applies: Medium-to-large belt-fed metal pieces where density and effective atomic-number response define material quality.
What it is not: Not fine particles, and not a stream where surface color decides quality — oxidation, dust and coatings make appearance unreliable here.
Mayson platform: FR-XRT; FR-XRT Pro for complex mixed streams.

Grains, seeds and nuts

Also rice · paddy · beans · kernels

Rice, beans, seeds and nuts sorted by visible color, shape, size and foreign material — colour defects, chalky grains, broken kernels, stones and husk fragments.

Where it applies: Dry, free-flowing food streams that can be presented as a consistent single layer.
What it is not: Not a stream where one recipe covers every origin. What counts as accepted product and what counts as reject is defined per variety, origin and market grade during testing.
Mayson platform: MAS RG for rice and paddy, MAS AS for beans and seeds, MAS N for nuts.

Testing and results

The vocabulary of a material test, where every configuration is actually settled.

Representative sample

Also material sample · test sample

A sample that reflects the real production stream — its composition, size distribution, color spread, moisture and contaminant load — rather than a clean selection of it.

Where it applies: Every machine selection and every configuration decision.
What it is not: Not a formality. Particle size, thickness, presentation and contaminant rate all move the decision boundary, so a sample that is cleaner than production produces a configuration that does not survive it.

Request a material test

Accepted product

Also accept stream · product stream

The output the sorter is set up to keep, defined explicitly before a recipe is built — for example clean single-color cullet, PET flakes with confirmed non-PET removed, or rice matching a defined grade target.

Where it applies: Every recipe, in every material family.
What it is not: Not a fixed standard that transfers between plants. It is defined per stream and per market grade during testing.

Request a material test

Reject class

Also reject stream · reject category

A named category of material the sorter is configured to eject — for example PVC-rich non-PET, off-color flakes, black fragments, ceramics and stones, or discolored and broken grains.

Where it applies: Recipe setup and reject review after a test.
What it is not: Not assumed from a material list. Reject classes are mapped from examples that actually appear in the customer's stream, and the reject outlet is audited against them.

Request a material test

Borderline sample

Also boundary class · borderline piece

A piece that sits at the edge between accepted and reject. Borderline material is collected deliberately, because it is where a recipe is actually decided.

Where it applies: Sample preparation, alongside clear accept and clear reject examples.
What it is not: Not an edge case to be discarded. A configuration built only from obvious accepts and obvious rejects has no defined behaviour for the pieces that matter most.

Request a material test

Material recipe

Also sorting recipe · recipe

The documented configuration for one material and one quality target: lighting, recognition settings, accepted and reject class definitions, and ejector timing.

Where it applies: Each material, origin and grade the machine runs.
What it is not: Not portable. Recipes are documented per material test and must not be copied across unrelated streams.

Lighting and ejector control

Reject ratio

Also carry-out rate · reject rate

How much material leaves through the reject outlet relative to the feed. It is a configuration outcome, traded against how strictly the accepted class is defined.

Where it applies: Recipe tuning and reject review after a test.
What it is not: Not a number that can be quoted in advance. It moves with raw material composition, contamination level and how tight the quality target is.

Request a material test

Throughput

Also capacity · t/h

How much material a configuration processes per hour. Published capacity ranges are stated per chute configuration on each product page.

Where it applies: Machine sizing, from compact lines to high-throughput plants.
What it is not: Not independent of quality. Published figures may vary with contaminant rate, and pushing throughput changes what the same recipe delivers — which is why final model selection is confirmed on samples.

Product platforms

Purity and recovery

Also product purity · yield · recovery rate

Two different measures of the same pass: how clean the accepted stream is, and how much of the target material ended up in it. Tightening one generally costs the other.

Where it applies: Setting the quality target before a recipe is built.
What it is not: Not something this site publishes as a guaranteed figure. Mayson may describe a reference reject-removal range in early discussion — under suitable material conditions and proper machine setup, at least about 90–98 out of every 100 target reject pieces — but that is a reference range, not a final product purity, and it does not replace sample testing. Exact purity, yield and throughput depend on the material, defect load, target boundary and machine configuration confirmed by testing.

Request a material test

Surface and moisture condition

Also label residue · moisture · cleanliness

How clean, dry and label-free the material arrives. Cleanliness, moisture and label residue affect the practical sorting boundary before any setting does.

Where it applies: Washed flake streams especially, and any feed carrying dust or fines.
What it is not: Not a downstream detail. NIR performs best on clean, dry surfaces, and moisture, ageing or contamination show up as a signal that does not match the reference library cleanly.

NIR inspection

Additives, coatings and fillers

Also fillers · coatings · masterbatch

Substances mixed into or applied onto a polymer that shift its spectral response away from a clean reference.

Where it applies: NIR material decisions on recycled feed, where composition varies between batches.
What it is not: Not invisible to the machine, and not automatically a failure — the shift is itself something NIR reports. It does mean a library validated on clean reference material may not match a heavily filled or coated piece.
Mayson platform: Relevant to every NIR configuration: MAS-P, MAS-PC, MAS-P Pro, MAS-PC Pro and MAS-B Pro.

NIR inspection

Dust and fines

Also fine particles · surface dust

Very fine particles and surface dust in the feed. They reduce visible contrast and can mask color, so particle-size condition is reviewed before a recipe is set.

Where it applies: Glass cullet especially, and any dry stream that has been crushed or handled repeatedly.
What it is not: Not only a housekeeping question. Fines change what the camera reads, so a recipe tuned on clean material behaves differently on a dusty batch.

Glass recycling sorter

Compressed-air demand

Also air consumption · air supply

How much compressed air a configuration needs for ejection, published per chute configuration on each product page in m³/min.

Where it applies: Utility planning alongside installed power and machine footprint.
What it is not: Not a fixed figure independent of how the machine is run. Compressed air, product speed and material spread all affect final rejection behaviour, and a heavier reject load draws more air.

Product platforms

Line integration

Also line planning · feeding and integration

Planning how the sorter joins the rest of the line: feeding, compressed air, reject routing, and the upstream and downstream steps owned by the customer or third parties.

Where it applies: Every installation — optical sorting is one controlled decision layer inside a longer line.
What it is not: Not something settled after purchase. Feeding stability and material presentation decide whether a tested recipe survives production.

Services

Common questions

The same distinctions, phrased the way they are searched.

What is the difference between color sorting and material sorting?

Color sorting classifies what a piece looks like — color, transparency, shape and visible defects — using visible-light inspection. Material sorting identifies what a piece is made of using NIR or spectral response. A color-correct piece can still be the wrong polymer, which is the case color sorting cannot catch.

Can a color sorter identify plastic polymer type?

No. A color sorter separates by color and appearance, and PET and PVC can look identical. Identifying polymer type needs NIR-based material sorting, such as MAS-P for PET purification or MAS-P Pro for harder polymer mixes.

What is PET flake purification?

What is the difference between MAS-P and MAS-P Pro?

MAS-P is PET-focused: it identifies PET and ejects confirmed non-PET rejects, and is not intended to split that reject fraction into individual polymers. MAS-P Pro, also called MAS-P Pro, is the multi-spectral sorter for polymer-against-polymer separation such as PP vs PE or ABS vs PS.

What is material and color sorting?

A configuration that makes a polymer decision and a visible-color decision on the same stream. MAS-PC combines MAS-P purification with MAS-C color sorting; MAS-PC Pro combines MAS-P Pro polymer separation with MAS-C color sorting. Staging MAS-P and MAS-C separately in a line is the alternative.

Can NIR sort black plastic?

No. Black and carbon-black plastics absorb near-infrared light, so NIR cannot identify their polymer type. Black pieces can be removed as visible color rejects by optical sorting first, but removing them by color does not identify which polymer they were.

What is the difference between whole-bottle sorting and flake sorting?

Whole-bottle sorting happens before shredding, while bottle color, shape, label condition and deformation are still readable. Flake sorting happens after crushing and washing, where color and material identity are handled as staged decisions. Once material is shredded the whole-bottle route is no longer available.

Why is a representative sample required before choosing a sorter?

Particle size, thickness, presentation and contaminant rate all move the decision boundary, so accepted and reject classes are built from material that reflects real production. A sample cleaner than the production stream produces a configuration that will not survive it.

Still unsure which one applies to your material?

The sorting route is confirmed on a representative sample, not on a definition. Send your material and we return the separation direction.

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