PET vs HDPE vs PP/PE recycling lines require different equipment because each material behaves differently in sorting, washing, drying, melting, and pelletizing. PET bottles usually need label removal, hot washing, and strict PVC control. HDPE rigid plastics need strong size reduction and sink-float separation, while PP/PE film needs aggressive washing, squeezing, drying, degassing, and stable feeding.
This comparison helps recycling plant buyers choose the right line before ordering machinery. If you want to compare full equipment categories while reading, start with our industrial plastic recycling machines page.
Quick Comparison: PET, HDPE, and PP/PE Lines
PET, HDPE, and PP/PE lines differ most in feed form, contamination control, drying demand, and final product target. A plant can share some equipment concepts, but it should not copy one material line design directly onto another feedstock.
| Material stream | Common input | Main equipment route | Typical output | Critical risk |
|---|---|---|---|---|
| ANIMAL DE COMPAGNIE | Beverage bottles, trays, thermoforms | Debaler, label remover, crusher, cold/hot wash, sink-float, dryer, sorter | Clean PET flakes, sometimes pellets | PVC, labels, glue, moisture, color mix |
| HDPE rigid | Milk jugs, drums, crates, bottles, caps | Shredder or granulator, friction washer, sink-float, dryer, pelletizer if needed | Clean flakes or pellets | PP mix, labels, metal, heavy dirt, melt flow variation |
| PP/PE film | Agricultural film, stretch film, bags, woven sacks | Shredder, friction washer, float tank, squeezer, dryer, cutter-compactor pelletizer | Dry flakes or pellets | Water, sand, ink, low bulk density, unstable feeding |
Why One Recycling Line Cannot Fit Every Plastic
One recycling line cannot fit every plastic because resin density, melt behavior, packaging design, and contamination type change the process. PET sinks in water, while HDPE and PP usually float. Film also carries more water and dirt per kilogram than many rigid plastics because of its large surface area.
According to the U.S. EPA, plastics generation in U.S. municipal solid waste reached 35.7 million tons in 2018, and plastic containers and packaging accounted for more than 14.5 million tons. EPA also reported 2018 recycling rates of 29.1% for PET bottles and jars and 29.3% for natural HDPE bottles. Source: EPA Plastics: Material-Specific Data.
Those numbers show why line design matters. PET bottles, HDPE containers, and PP/PE films may all enter a recycling business, but each stream needs a process that protects yield and output quality.
PET Recycling Line: Equipment and Quality Priorities
A PET recycling line is built to remove labels, caps, PVC, glue, dirt, and moisture from bottle or tray streams. PET flake buyers often care about color, PVC level, label residue, moisture, and fine dust because these factors affect downstream extrusion, fiber, sheet, or bottle-grade applications.
- Front-end sorting: Remove non-PET bottles, metal, glass, stones, and difficult colors before crushing.
- Label removal: Reduce label load before washing so flakes and wash water stay cleaner.
- Réduction de taille : Use a crusher or wet granulator to create consistent PET flakes.
- Cold and hot washing: Remove dirt, sugar, glue, oil, and surface contamination.
- Sink-float separation: Separate floating caps and labels from sinking PET flakes.
- Drying and air classification: Reduce moisture and remove light labels or fines.
The Association of Plastic Recyclers warns that label materials, inks, adhesives, and coverage area can affect PET recycling quality. Non-releasing adhesives and incompatible label materials can travel with flakes and lower output value. Source: APR Design Guide for PET Rigid Packaging.
For PET projects, start with our Chez Rumtoo, nous spécialisons dans la conception et la fabrication de systèmes de recyclage industriels qui permettent aux entreprises de répondre à ces exigences. Ce guide ne s'agit pas seulement du “pourquoi” du recyclage – c'est du “comment”. Nous vous guiderons à travers tout le processus industriel de recyclage des bouteilles en PET, de la transformation des balles brutes à la production de paillettes rPET de grade supérieur, et démontrerons comment un système de recyclage de bouteilles en PET stratégiquement choisi page. If PVC control is your main risk, read our guide on controlling PVC in PET bottle recycling lines.
HDPE Rigid Recycling Line: Equipment and Quality Priorities
An HDPE rigid recycling line is built for bottles, drums, crates, caps, and other thick-wall polyolefin items. The process usually focuses on size reduction, washing, density separation, drying, and optional pelletizing.
- Shredding or granulation: Choose shredding for bulky drums, crates, and large rigid parts; use granulation for bottles and smaller items.
- Friction washing: Remove surface dirt, labels, and organic residue after size reduction.
- Sink-float separation: Keep floating HDPE and PP while removing denser materials where possible.
- Séchage: Use centrifugal and thermal drying based on moisture target and output form.
- Pelletisation : Add extrusion, melt filtration, and pellet cutting when buyers need pellets instead of flakes.
APR lists HDPE density at 0.94-0.97 g/cm3, which means HDPE usually floats in water. APR also notes that PP can contaminate HDPE when mixed in extrusion and may reduce impact properties if the level becomes too high. Source: APR HDPE Rigid Guidance.
For rigid HDPE and PP containers, see our corde à linge en plastique rigide. If you are still choosing between shredding and crushing, compare the equipment on our plastic recycling machine selection guide.
PP/PE Film Recycling Line: Equipment and Quality Priorities
A PP/PE film recycling line is built around low bulk density, high moisture, heavy dirt, and unstable feeding. Film recycling often needs more washing, squeezing, drying, and feeding control than rigid plastic recycling.
- Pre-shredding: Open bulky film bales and reduce wrapping around downstream equipment.
- Friction washing: Remove sand, labels, paper, organics, and surface dirt.
- Float washing: Separate heavy contaminants while keeping polyolefin film afloat.
- Squeezing and drying: Remove water before extrusion, especially for agricultural film and washed bags.
- Cutter-compactor feeding: Densify film before extrusion to prevent unstable intake.
- Degassing and filtration: Control ink, moisture, adhesives, and volatiles during pelletizing.
APR describes PE flexible packaging as bags, pouches, wraps, sachets, liners, and other film formats. It also notes that North American residential post-consumer film is commonly collected at retail locations and may include LDPE, LLDPE, HDPE, and multilayer packages. Source: APR PE Flexible Guidance.
For film projects, start with our PP/PE film recycling line guide. If moisture after washing is your bottleneck, review how a plastic film squeezer reduces moisture.
Equipment Comparison by Process Stage
PET vs HDPE vs PP/PE recycling lines are easiest to compare by process stage. The same stage name can hide very different equipment choices, especially in washing, drying, and pelletizing.
| Process stage | PET line | HDPE rigid line | PP/PE film line |
|---|---|---|---|
| Tri | High priority: remove PVC, color, metals, non-PET | Remove metals, labels, PVC, mixed resin | Remove paper, hard plastics, string, metal, colored film |
| Réduction de taille | Wet crusher or granulator for flakes | Shredder or granulator based on part size | Shredder or wet crusher to open film |
| La lessive | Cold wash, hot wash, rinsing, label control | Friction wash and float separation | Friction wash, float washing, sand removal |
| Séchage | Centrifugal and thermal drying for flake moisture | Centrifugal and thermal drying as needed | Squeezer plus thermal drying for high water load |
| Extrusion | Optional; depends on flake or pellet target | Common when selling pellets | Common for pellet output; needs strong feeding |
| Filtration and venting | Important for pellet-grade PET | Important for labels, fines, and mixed melt | Very important for ink, moisture, and volatiles |
Sorting Differences: PET Needs Purity, Polyolefins Need Separation
PET needs strict removal of PVC and non-PET materials, while HDPE and PP/PE streams need polyolefin separation and color control. Sorting quality affects yield, washing cost, flake value, and pellet stability.
TOMRA states that sensor-based sorting can separate polymers and colors across mixed plastics, PET, polyolefins, PVC, and film. TOMRA also reports that automated sorting can reach over 95% purity in HDPE and PP recovery in suitable applications. Source: TOMRA plastics sorting applications.
Use optical sorting when manual sorting cannot meet your purity target or labor cost becomes too high. Use simpler manual sorting when the input is small, clean, and highly visible, such as one-color post-industrial scrap.
Drying and Moisture: The Hidden Difference
Drying demand changes sharply across PET, HDPE, and PP/PE film. Film usually holds more surface water, while PET flake buyers often set tight moisture limits for downstream processing.
| Matériel | Moisture challenge | Practical drying choice |
|---|---|---|
| Flocons de PET | Moisture affects flake storage and downstream processing | Centrifugal dryer plus hot air or thermal drying |
| HDPE rigid flakes | Water stays in labels, caps, and irregular shapes | Centrifugal dryer; thermal drying if pelletizing or bagging demands it |
| PP/PE film | Film traps water and carries high surface moisture | Squeezer or screw press plus thermal drying before pelletizing |
When testing samples, ask suppliers to measure moisture after drying and then run the material through extrusion if pellets are the target. In our experience, a washing line that looks strong on paper can still fail if the dryer cannot meet the extruder’s feeding and venting needs.
Output Target: Flakes or Pellets?
The right output target decides whether your line ends after washing and drying or continues into extrusion and pelletizing. PET projects often sell clean flakes, while HDPE and PP/PE projects often add pelletizing when buyers need uniform feedstock.
- Choose flakes when buyers can process washed material and accept flake specifications.
- Choose pellets when buyers need easier dosing, stable melt behavior, or direct use in extrusion, injection, or film blowing.
- Choose both if your plant can sell high-grade flakes and pelletize lower-grade or internal streams.
If you need pellets, compare screw design, filter type, degassing, cutter style, cooling, and silo storage. Our les lignes de granulation plastique page explains the main pelletizing equipment options.
Cost and Layout Differences Buyers Should Check
Cost differences come from contamination level, equipment count, throughput, automation, water treatment, drying demand, and pelletizing scope. PET vs HDPE vs PP/PE recycling lines should be priced with the same boundary, or the comparison will mislead your team.
- Define the input: bale, loose bottles, crushed flakes, film rolls, drums, crates, or mixed rigid plastics.
- Define the output: washed flakes, dried flakes, pellets, or both.
- Ask each supplier to include conveyors, platforms, electrical cabinets, water treatment, dryers, filters, spare parts, installation, and training.
- Compare utilities: power, water, compressed air, wastewater, floor space, ceiling height, and maintenance access.
- Run a sample test and record kg/h, moisture, washing result, filter pressure, pellet quality, and downtime.
For budget planning, read our plastic recycling machine cost guide. For floor space and process flow, use our plastic recycling plant layout guide.
Decision Matrix: Which Line Fits Your Feedstock?
This decision matrix helps you choose the right line when you have mixed project options. Use it before asking for a formal quotation.
| Feedstock condition | Recommended line | Reason |
|---|---|---|
| Sorted PET bottle bales with labels and caps | Ligne de lavage de bouteilles PET | PET needs label removal, sink-float, washing, drying, and PVC control |
| HDPE bottles, drums, crates, and PP caps | Rigid plastic washing line | Rigid polyolefins need shredding, friction washing, density separation, and optional pelletizing |
| Agricultural film with sand and moisture | PP/PE film washing and pelletizing line | Film needs strong washing, squeezing, drying, degassing, and filtration |
| Clean factory PP or PE trim | Crusher plus pelletizing line | Clean post-industrial scrap can often skip full washing |
| Mixed PET, HDPE, PP, PE, and PVC | Sorting-first system before material-specific lines | Mixed polymers need separation before washing and extrusion can protect value |
FAQ: PET vs HDPE vs PP/PE Recycling Lines
Peut une ligne de recyclage traiter du PET, de l'HDPE et du PP/PE ?
Une ligne peut partager certains concepts de tri ou de réduction de taille en amont, mais elle ne devrait pas traiter PET, HDPE et PP/PE comme un flux mélangé si l'objectif est d'obtenir un produit de haute valeur. Les matériaux nécessitent des réglages de séparation, de lavage, de séchage et d'extrusion différents.
Quelle ligne nécessite le plus d'équipements de lavage ?
Les lignes de bouteilles en bouteille en PET et en film PE/PP nécessitent souvent le plus grand équipement de lavage, mais pour des raisons différentes. Le PET nécessite un contrôle des étiquettes, de la colle et du PVC ; le film nécessite le contrôle du sable, de l'eau, de l'encre et de la manipulation à faible densité.
Pourquoi le film PP/PE nécessite-t-il généralement un compacteur ?
Le film PP/PE nécessite généralement un compacteur car le film fin contient une forte humidité superficielle après le lavage. Le compactage densifie le film et réduit l'humidité avant le séchage thermique ou l'extrusion.
Est-ce que le HDPE est plus facile à recycler que le PET ?
L'HDPE peut être plus facile lorsque le flux est propre et trié, mais il nécessite toujours un contrôle pour les étiquettes, le mélange PP, la saleté, le métal et le débit de fusion. Le PET peut livrer des paillettes à haute valeur, mais il nécessite un contrôle plus strict du PVC et de l'humidité.
Dois-je vendre des paillettes ou des granulés ?
Vendez des paillettes lorsque les acheteurs peuvent gérer le matériel lavé et que votre ligne peut répondre aux spécifications de paillettes. Choisissez des granulés lorsque les acheteurs ont besoin d'une dose uniforme, d'un comportement de fusion stable et d'une utilisation plus facile dans l'extrusion, l'injection ou le soufflage de film.
Next Step: Match the Line to the Material
PET vs HDPE vs PP/PE recycling lines should be chosen by material behavior, contamination source, output target, and buyer requirements. PET lines protect flake purity. HDPE rigid lines protect yield and polyolefin quality. PP/PE film lines solve moisture, feeding, and degassing problems.
To move from comparison to line design, send Rumtoo your material photos, target kg/h, contamination details, floor plan, and output goal. Our engineers can help you compare a PET bottle line, rigid plastic washing line, PP/PE film line, or complete recycling plant layout.
