{"id":9946,"date":"2025-02-28T07:02:00","date_gmt":"2025-02-28T06:02:00","guid":{"rendered":"https:\/\/www.recyclemachine.net\/?p=9946"},"modified":"2026-11-03T05:51:57","modified_gmt":"2026-11-03T05:51:57","slug":"pvc-dans-le-recyclage-des-bouteilles-en-pet-comprendre-les-defis-et-les-solutions","status":"publish","type":"post","link":"https:\/\/www.energycle.com\/fr\/pvc-dans-le-recyclage-des-bouteilles-en-pet-comprendre-les-defis-et-les-solutions\/","title":{"rendered":"Contamination par le PVC dans le recyclage des bouteilles PET : impact chimique, limites de ppm et technologies de s\u00e9paration"},"content":{"rendered":"<p>Polyvinyl chloride (PVC) is the single most damaging contaminant in polyethylene terephthalate (PET) recycling. Because PVC and PET have almost identical densities (both sink in standard water baths), conventional wash plants cannot separate them by simple buoyancy. During downstream thermal processing at 260\u00b0C to 285\u00b0C, residual PVC rapidly dehydrochlorinates, releasing acidic hydrogen chloride (HCl) gas. Even microscopic trace contamination as low as 50 parts per million (ppm) degrades PET polymer chains, drops intrinsic viscosity (IV), causes irreversible yellow discoloration, and corrodes expensive extruder screws and mold cavities. Achieving high-value recycled flake output requires a defense-in-depth architecture combining upstream optical bottle sorting, aggressive mechanical de-labeling, and post-wash flake-level sensor separation.<\/p>\n<p>For recyclers manufacturing high-grade rPET flakes, controlling PVC contamination determines the commercial boundary between high-margin bottle-to-bottle preforms ($1,100\u2013$1,350 per metric ton) and heavily discounted staple-fiber regrind ($450\u2013$650 per metric ton). This technical guide details the precise chemical degradation mechanics of PVC inside PET melts, establishes allowable ppm thresholds across industrial applications, and compares sensor-based separation technologies across both whole-bottle and flake-sorting process points.<\/p>\n<h2>Why PVC Destroys Recycled PET: The Chemical &#038; Thermal Degradation Mechanism<\/h2>\n<p>The fundamental incompatibility between PET and PVC stems from their widely divergent thermal stability thresholds. Post-consumer PET requires processing temperatures between 260\u00b0C and 285\u00b0C for melt extrusion, pelletizing, and solid-state polycondensation (SSP). In contrast, rigid unplasticized PVC (uPVC) undergoes severe thermal degradation and dehydrochlorination starting between 180\u00b0C and 200\u00b0C, with violent gas liberation peaking above 220\u00b0C.<\/p>\n<p>When even minuscule PVC fragments enter a PET extruder barrel, four catastrophic failure modes occur simultaneously:<\/p>\n<ul>\n<li><strong>Autocatalytic Acid Generation:<\/strong> The thermal decomposition of PVC releases gaseous hydrogen chloride (HCl). Under high melt pressures (120 to 180 bar inside the extruder), HCl acts as a powerful acidic catalyst that violently accelerates the hydrolytic and thermal degradation of neighboring PET ester bonds.<\/li>\n<li><strong>Intrinsic Viscosity (IV) Collapse:<\/strong> As HCl severs the polyester polymer backbone (random chain scission), the molecular weight distribution broadens and intrinsic viscosity plummets from virgin-equivalent levels (0.78\u20130.84 dl\/g) down below 0.65 dl\/g. Flakes with degraded IV fail structural drop tests, crack during preform blow-molding, and cause frequent filament breakage in spinning plants.<\/li>\n<li><strong>Conjugated Polyene Formation &#038; Yellowing:<\/strong> When PVC sheds chlorine atoms, conjugated polyene sequences form along the remaining polymer skeleton. These structures act as intense chromophores, shifting optical absorbance into the visible spectrum and causing pronounced yellowing, gray haze, and dark brown streaking. Flake batches with elevated b* color values are instantly rejected by food-contact packaging buyers.<\/li>\n<li><strong>Carbonized Black Specks &#038; Tooling Pitting:<\/strong> Heavily degraded PVC cross-links into hard, insoluble carbonaceous char. These microscopic black specks plug spinneret screens, cause melt-blown holes in thermoformed sheet, and pit the chrome plating of extruder screws, barrels, and pelletizing die faces through chemical chloride attack.<\/li>\n<\/ul>\n<h2>Where PVC Enters the PET Bottle Stream<\/h2>\n<p>Post-consumer PET bales collected from municipal material recovery facilities (MRFs) and deposit return schemes (DRS) rarely consist of pure polyester. PVC enters the processing line through four primary vectors:<\/p>\n<ul>\n<li><strong>Full-Body Heat Shrink Sleeves:<\/strong> Historically, PVC was the predominant polymer for heat-shrink labels due to its high contraction ratio (up to 60%) at low steam temperatures. Although global packaging guidelines have largely transitioned toward PETG, floatable polyolefins, and cPET, legacy packaging, promotional multi-packs, and imports still carry full-wrap PVC sleeves that tightly adhere through bale opening.<\/li>\n<li><strong>Lookalike Non-PET Containers:<\/strong> In household chemical, personal care, and cooking oil segments, clear blow-molded PVC bottles closely resemble clear PET containers in color, neck geometry, and transparency. Manual sorting operators cannot reliably distinguish clear PVC bottles from clear PET on high-speed conveyors.<\/li>\n<li><strong>Tamper-Evident Seals and Cap Liners:<\/strong> Pharmaceutical bottles, mouthwash containers, and premium beverage bottles frequently utilize PVC shrink bands around neck rings and plastisol cap liners inside aluminum or rigid polypropylene closures.<\/li>\n<li><strong>Secondary Post-Industrial Bales:<\/strong> Mixed plastic bales containing blister packaging, thermoformed clamshells, and construction scrap frequently mix unplasticized PVC film with clear PET rigid packaging.<\/li>\n<\/ul>\n<h2>The Physics Failure: Why Density Sink-Float Tanks Cannot Separate PVC from PET<\/h2>\n<p>A widespread operational mistake among newer recycling plant operators is expecting a standard water-based <a href=\"https:\/\/www.energycle.com\/sink-float-separation-tank\/\">sink-float separation tank for plastic recycling<\/a> to eliminate PVC contamination. Float-sink systems rely on water&#8217;s specific gravity of 1.00 g\/cm\u00b3 to float polyolefin cap materials (polypropylene at 0.90\u20130.92 g\/cm\u00b3 and high-density polyethylene at 0.94\u20130.96 g\/cm\u00b3) while sinking PET.<\/p>\n<p>However, the specific gravity of amorphous and semi-crystalline post-consumer PET ranges from 1.33 to 1.40 g\/cm\u00b3, while rigid unplasticized PVC exhibits a specific gravity between 1.35 and 1.52 g\/cm\u00b3. Because both polymers are denser than water, both settle rapidly to the bottom of the float-sink tank and are discharged together via the heavy-fraction auger. Attempting to modify water density with chemical salt solutions (such as calcium chloride or zinc chloride) to float PET while sinking PVC is commercially unviable: the narrow density overlap (1.35\u20131.40 g\/cm\u00b3) causes substantial cross-contamination, leaves chemical salt deposits on the flakes, and creates severe wastewater treatment compliance penalties.<\/p>\n<h2>Physical &#038; Chemical Comparison: PET vs. PVC in Mechanical Recycling<\/h2>\n<p>The table below summarizes the key material properties, degradation behaviors, and sorting limitations governing mechanical recycling lines.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr>\n<th>Property \/ Parameter<\/th>\n<th>Polyethylene Terephthalate (PET)<\/th>\n<th>Polyvinyl Chloride (Rigid PVC)<\/th>\n<th>Recycling Line Impact &#038; Challenge<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Specific Gravity (Density)<\/strong><\/td>\n<td>1.33 \u2013 1.40 g\/cm\u00b3<\/td>\n<td>1.35 \u2013 1.52 g\/cm\u00b3<\/td>\n<td>Complete density overlap; standard water float-sink tanks cannot separate them.<\/td>\n<\/tr>\n<tr>\n<td><strong>Melting \/ Processing Range<\/strong><\/td>\n<td>250\u00b0C \u2013 285\u00b0C<\/td>\n<td>160\u00b0C \u2013 205\u00b0C (degrades rapidly above 210\u00b0C)<\/td>\n<td>PVC decomposes and scorches into acidic char long before PET reaches full melt flow.<\/td>\n<\/tr>\n<tr>\n<td><strong>Thermal Breakdown Mechanism<\/strong><\/td>\n<td>Thermal ester cleavage, transesterification<\/td>\n<td>Dehydrochlorination (releases HCl acid gas)<\/td>\n<td>HCl gas triggers chain scission, dropping PET IV and pitting steel equipment.<\/td>\n<\/tr>\n<tr>\n<td><strong>Optical Behavior (Cold State)<\/strong><\/td>\n<td>Crystal clear, high gloss<\/td>\n<td>Crystal clear to translucent<\/td>\n<td>Human manual sorters cannot distinguish clear bottles at belt speeds over 0.5 m\/s.<\/td>\n<\/tr>\n<tr>\n<td><strong>Optical Behavior (Heated 200\u00b0C)<\/strong><\/td>\n<td>Remains clear or shows slight haze<\/td>\n<td>Rapidly turns dark yellow, brown, and black<\/td>\n<td>Forms basis for the standard QA laboratory thermal beaker test.<\/td>\n<\/tr>\n<tr>\n<td><strong>NIR Spectral Signature<\/strong><\/td>\n<td>Distinct ester absorption bands (1660, 1950 nm)<\/td>\n<td>Distinct C-Cl overtones and CH bonds (1700\u20131800 nm)<\/td>\n<td>Enables high-precision, sub-millisecond automated optical sorting.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<h2>Multi-Stage Separation Technologies: Whole-Bottle vs. Flake Sorting<\/h2>\n<p>Because no single equipment station achieves 100% sorting efficiency, industrial recycling plants utilize a multi-tier cascade. Removing PVC at the whole-bottle stage is 50 to 100 times more cost-effective than attempting to sort tiny 8 mm to 12 mm flakes after granulation.<\/p>\n<h3>1. Upstream Mechanical De-Labeling (Whole-Bottle Stage)<\/h3>\n<p>Before optical scanning, bales must be broken and fed into an aggressive <a href=\"https:\/\/www.energycle.com\/plastic-bottle-label-removal-machine\/\">plastic bottle label removal machine<\/a>. By shearing full-body shrink sleeves from container shoulders and bodies without puncturing the bottle walls, up to 90% of PVC sleeves are detached and pneumatically discharged via an integrated zigzag air classifier. Exposing the underlying clear PET bottle body is essential for downstream sensor accuracy; bottles with intact PVC wrap will cause optical sensors to misidentify the entire container or fail to read the underlying resin.<\/p>\n<h3>2. Near-Infrared (NIR) &#038; X-Ray Transmission (XRT) Optical Bottle Sorters<\/h3>\n<p>High-speed sensor belts running at 2.5 to 3.0 m\/s transport singulated bottles beneath high-frequency halogen illuminators and hyperspectral cameras. NIR spectroscopy analyzes the diffuse reflection spectrum in the 1,000 to 2,500 nm range. The distinct C-Cl vibration bands of PVC allow the system to trigger targeted high-pressure pneumatic air valves (operating at 6 to 8 bar), ejecting PVC containers and sleeves into a reject chute. For opaque, heavily printed, or black containers where NIR signals are absorbed, X-ray transmission (XRT) detects the elemental presence of heavy chlorine atoms directly, independent of surface color or label graphics.<\/p>\n<h3>3. Caustic Hot Washing &#038; Friction Washing (Flake Stage)<\/h3>\n<p>Granulated flakes enter a hot washing tank charged with 1.0% to 2.0% sodium hydroxide (NaOH) and surfactants heated to 85\u00b0C\u201390\u00b0C. While hot washing does not melt PVC, it saponifies hot-melt adhesives, releases trapped label fragments, and removes surface plasticizers. Transferring the slurry through a <a href=\"https:\/\/www.energycle.com\/friction-washer-guide\/\">high-speed friction washer for PET flakes<\/a> generates intense mechanical shear that strips softened PVC glue and labels prior to post-rinse and mechanical drying.<\/p>\n<h3>4. Flake-Level Optical Sorters (Color + NIR \/ Laser)<\/h3>\n<p>After mechanical drying, clean flakes flow over high-precision vibration feeders in a thin, uniform monolayer falling through optical inspection chutes. Advanced flake sorters utilize dual-sided high-resolution RGB matrix cameras combined with multi-wavelength InGaAs NIR sensors. The optical engine detects discolored yellowish flakes, opaque fragments, and transparent PVC flakes, firing ultra-fast micro-pneumatic valves to reject contaminated particles with minimal loss of good PET material.<\/p>\n<h3>5. Triboelectric Electrostatic Flake Separators<\/h3>\n<p>For operations demanding sub-20 ppm purity without the yield loss associated with air-jet reject systems, triboelectric separation provides a physical dry separation method. Clean, dry flakes (moisture content below 0.1%) are fed into a specialized rotating charging drum. Through intense particle-to-particle and particle-to-wall friction, differences in electron work functions cause PET flakes to accumulate a positive surface charge, while PVC flakes accumulate a strong negative charge. When dropping through a high-voltage electrostatic field (25,000 to 60,000 volts), positively charged PET flakes deflect toward the negative electrode, while negatively charged PVC flakes deflect toward the positive electrode, achieving sharp mechanical separation.<\/p>\n<h2>Allowable PVC Purity Limits Across rPET End-Use Markets<\/h2>\n<p>Recycled PET flake buyers establish strict contract specifications based on their downstream thermal profile and product sensitivity. The table below outlines allowable contamination thresholds, associated operational failures, and required line configurations.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr>\n<th>rPET End-Use Market<\/th>\n<th>Maximum Allowable PVC (ppm)<\/th>\n<th>Operational Failure If Exceeded<\/th>\n<th>Recommended Plant Control Configuration<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Bottle-to-Bottle (Food Grade \/ B2B)<\/strong><\/td>\n<td>&lt; 5 \u2013 10 ppm<\/td>\n<td>Severe preform haze, black specks, mold plating, acetaldehyde spikes, food contact failure.<\/td>\n<td>De-labeler + 2x Whole-Bottle NIR sorters + Hot wash + Flake optical sorter + Dual-channel SSP.<\/td>\n<\/tr>\n<tr>\n<td><strong>Thermoforming Sheet (Clear Clamshells)<\/strong><\/td>\n<td>&lt; 30 \u2013 50 ppm<\/td>\n<td>Gels, optical fish-eyes, cross-direction sheet embrittlement, trim web cracking.<\/td>\n<td>Mechanical de-labeling + Whole-bottle NIR + Hot washing + Post-drying flake optical sorter.<\/td>\n<\/tr>\n<tr>\n<td><strong>High-Tenacity Industrial Filament<\/strong><\/td>\n<td>&lt; 30 \u2013 50 ppm<\/td>\n<td>Spin pack filter screen clogging, filament strand breakage in drawing ovens.<\/td>\n<td>NIR bottle sorting + Intensive friction washing + Flake color &#038; polymer sorting.<\/td>\n<\/tr>\n<tr>\n<td><strong>Polyester Staple Fiber (PSF &#8211; Textile)<\/strong><\/td>\n<td>&lt; 100 \u2013 150 ppm<\/td>\n<td>Dye-uptake unevenness, fiber yellowing, spinneret hole carbonization.<\/td>\n<td>Manual sorting + Standard wash line + Air classification + Downstream melt filtration.<\/td>\n<\/tr>\n<tr>\n<td><strong>Industrial Strapping &#038; Core Layers<\/strong><\/td>\n<td>&lt; 200 \u2013 300 ppm<\/td>\n<td>Tensile shock split under rapid elongation, extruder screw wear over prolonged runs.<\/td>\n<td>Standard wash line with float-sink tank + continuous backflush melt filtration.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<h2>Diagnostic Troubleshooting Matrix: Symptoms, Root Causes &#038; Line Adjustments<\/h2>\n<p>When plant quality control identifies elevated PVC in finished flakes or extrusion lines, engineering teams must isolate the failure point using the countermeasure matrix below.<\/p>\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr>\n<th>Observed Production Defect<\/th>\n<th>Root Cause Mechanism<\/th>\n<th>Diagnostic Verification Method<\/th>\n<th>Immediate Operational Countermeasure<\/th>\n<th>Long-Term Line Upgrade Path<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Extruded pellets exhibit yellowing (b* value &gt; 3.0) and burnt smell.<\/td>\n<td>Thermal breakdown of PVC releasing HCl and creating conjugated polyenes.<\/td>\n<td>Thermal beaker bake test on incoming flake lot (200\u00b0C for 45 min).<\/td>\n<td>Reduce extruder zone 1\u20132 temperatures by 10\u00b0C; increase vacuum degassing rate.<\/td>\n<td>Install flake-level NIR sorter before the extrusion feed silo.<\/td>\n<\/tr>\n<tr>\n<td>Extruder melt pressure spikes rapidly; filter screen packs blind within 2 hours.<\/td>\n<td>Charred, cross-linked PVC residues accumulating on 80\/120 mesh screens.<\/td>\n<td>Inspect spent screen mesh under microscope for black carbonaceous particles.<\/td>\n<td>Switch to coarse secondary filter screen temporarily; sample upstream washer flakes.<\/td>\n<td>Retrofit an automated continuous backflush rotary melt filtration unit.<\/td>\n<\/tr>\n<tr>\n<td>Pitted cavities and corrosion marks on extruder screw flights and die plate.<\/td>\n<td>Prolonged chemical attack from concentrated hydrochloric acid gas.<\/td>\n<td>Measure pH of condensing water vapor around extruder vacuum vents (pH &lt; 4).<\/td>\n<td>Flush barrel with virgin PET purged with acid scavengers; neutralize vent exhaust.<\/td>\n<td>Replace barrel liners with bimetallic nickel-chromium corrosion-resistant alloys.<\/td>\n<\/tr>\n<tr>\n<td>Optical bottle sorter miss rate increases above 5% on incoming PET feed.<\/td>\n<td>High belt loading, bottle overlap, or dusty optical camera protection glass.<\/td>\n<td>Visual inspection of optical sorter calibration dashboard and ejector logs.<\/td>\n<td>Clean camera lenses and LED bars; reduce infeed belt speed to ensure single-layer bottle spread.<\/td>\n<td>Install vibrating bottle spreader table and pre-screening trommel before optical sorter.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<h2>Plant Quality Control: Three Proven PVC Detection Protocols<\/h2>\n<p>To prevent rejected containers and contentious buyer claims, recycling plants must execute standardized quality control tests on every production shift before blending flakes into finished gaylords:<\/p>\n<h3>1. Thermal Beaker Bake Test (Standard Fast Plant QC)<\/h3>\n<p>The thermal bake test is the industry&#8217;s most reliable, cost-effective method for verifying PVC purity in real time:<\/p>\n<ol>\n<li>Weigh a representative 500-gram sample of washed, dried PET flakes using an analytical scale.<\/li>\n<li>Spread the sample evenly onto an aluminum tray or glass Pyrex baking dish in a thin layer.<\/li>\n<li>Place the tray into a preheated laboratory convection oven maintained strictly at 200\u00b0C (\u00b12\u00b0C) for 45 to 60 minutes.<\/li>\n<li>Remove the sample and allow it to cool. Clear PET flakes will remain clear or turn slightly milky white due to crystallization. Any PVC flakes will scorch into dark brown, black, or reddish-brown caramelized particles.<\/li>\n<li>Manually pick out the discolored particles, weigh them on a micro-scale, and calculate ppm concentration: <code>PPM = (Weight of discolored flakes \/ 500 g) \u00d7 1,000,000<\/code>.<\/li>\n<\/ol>\n<h3>2. Caustic Soda Staining Test<\/h3>\n<p>When distinguishing PVC from PET flakes without high-temperature baking, place a 100-gram sample into a boiling 10% sodium hydroxide (NaOH) solution for 15 minutes. Under basic hydrolysis, PET flakes develop a white, frosted surface film, while PVC flakes resist saponification and display a distinctive yellow or pale brown tint.<\/p>\n<h3>3. Benchtop &#038; In-Line XRF Elemental Chlorine Screening<\/h3>\n<p>For high-throughput plants supplying multinational beverage brand preform molders, benchtop X-ray fluorescence (XRF) analyzers measure chlorine (Cl) concentrations down to 1 ppm within 60 seconds, completely independent of flake color, transparency, or surface moisture.<\/p>\n<h2>Frequently Asked Questions<\/h2>\n<h3>Why is PVC such a destructive contaminant in PET bottle recycling?<\/h3>\n<p>Even at trace concentrations below 50 ppm, PVC thermally degrades at PET melt temperatures (260\u00b0C\u2013285\u00b0C) to release corrosive hydrogen chloride (HCl) gas. HCl catalytically severs PET ester bonds, causing a steep drop in intrinsic viscosity (IV), severe yellow discoloration, black specks, and structural embrittlement in downstream preforms and fibers.<\/p>\n<h3>Why can&#8217;t a standard water float-sink tank separate PVC from PET?<\/h3>\n<p>Float-sink tanks rely on water density (1.00 g\/cm\u00b3) to separate light polyolefins (PP caps at ~0.91 g\/cm\u00b3 and HDPE at ~0.95 g\/cm\u00b3) from sinking PET (1.33\u20131.40 g\/cm\u00b3). Because rigid PVC has a specific gravity of 1.35\u20131.52 g\/cm\u00b3, both polymers sink to the tank bottom together, making buoyancy separation completely ineffective.<\/p>\n<h3>What is the maximum allowable PVC limit for food-grade bottle-to-bottle rPET?<\/h3>\n<p>Food-grade bottle-to-bottle preform manufacturers enforce a strict PVC threshold between 5 ppm and 10 ppm (maximum 0.001%). Exceeding this limit triggers optical haze, acetaldehyde spikes, mold plating, and failure of food-contact migration tests.<\/p>\n<h3>How does a recycling plant test for PVC contamination on the production floor?<\/h3>\n<p>Plants primarily rely on the thermal beaker bake test: 500 grams of clean, dry flakes are baked at 200\u00b0C for 45 to 60 minutes in a convection oven. PET remains clear or turns slightly milky, while PVC particles caramelize into dark brown or black specks that can be easily picked, weighed, and converted to parts per million.<\/p>\n<h3>What is the difference between whole-bottle optical sorting and flake-level sorting?<\/h3>\n<p>Whole-bottle NIR\/XRT optical sorters scan full containers at high speeds to eject PVC bottles and shrink sleeves before granulation, preventing massive cross-contamination. Flake-level sorters inspect 8 mm to 12 mm flakes post-wash using high-resolution cameras and narrow-beam sensors to eliminate the microscopic residual PVC that slipped past upstream inspection.<\/p>\n<h2>Engineering a Contamination-Free PET Recycling Facility<\/h2>\n<p>Zero-PVC performance is not achieved by an individual separator operating in isolation; it requires an engineered system matching bale opening, mechanical de-labeling, optical bottle interception, intensive hot washing, and post-drying flake sorting to your regional bale feedstock. Plant operators that invest in robust multi-tier sorting eliminate load rejections, secure long-term purchase agreements with packaging converters, and capture top-tier market pricing.<\/p>\n<p>Explore our complete <a href=\"https:\/\/www.energycle.com\/pet-bottle-recycling-system\/\">PET bottle washing line and recycling system<\/a> engineered with integrated high-efficiency de-labeling and multi-stage washing, or consult our <a href=\"https:\/\/www.energycle.com\/pet-recycling-machines\/\">PET recycling machines buyer&#8217;s guide<\/a> to evaluate system capacities, optical sorting configurations, and operating economics for your plant.<\/p>\n<p><script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why is PVC such a destructive contaminant in PET bottle recycling?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Even at trace concentrations below 50 ppm, PVC thermally degrades at PET melt temperatures (260\u00b0C\u2013285\u00b0C) to release corrosive hydrogen chloride (HCl) gas. 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Flake-level sorters inspect 8 mm to 12 mm flakes post-wash using high-resolution cameras and narrow-beam sensors to eliminate the microscopic residual PVC that slipped past upstream inspection.\"\n      }\n    }\n  ]\n}\n<\/script><\/p>\n","protected":false},"excerpt":{"rendered":"<p>D\u00e9couvrez pourquoi la contamination par le PVC constitue un d\u00e9fi majeur dans le recyclage des bouteilles en PET et comment le tri, la d\u00e9tection, le lavage et le contr\u00f4le des processus permettent de r\u00e9duire ce risque.<\/p>","protected":false},"author":1,"featured_media":12519,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[143],"tags":[],"class_list":["post-9946","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-recycling-news"],"_links":{"self":[{"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/posts\/9946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/comments?post=9946"}],"version-history":[{"count":3,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/posts\/9946\/revisions"}],"predecessor-version":[{"id":20767,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/posts\/9946\/revisions\/20767"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/media\/12519"}],"wp:attachment":[{"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/media?parent=9946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/categories?post=9946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.energycle.com\/fr\/wp-json\/wp\/v2\/tags?post=9946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}