{"id":7622,"date":"2026-10-27T02:37:56","date_gmt":"2026-10-27T02:37:56","guid":{"rendered":"https:\/\/uplastech.com\/pvc-profile-weathering-colour\/"},"modified":"2026-10-27T02:37:56","modified_gmt":"2026-10-27T02:37:56","slug":"pvc-profile-weathering-colour","status":"publish","type":"post","link":"https:\/\/uplastech.com\/fr\/pvc-profile-weathering-colour\/","title":{"rendered":"PVC Profile Weathering: TiO2, Stabilisers and Colour Retention"},"content":{"rendered":"<style>\n.upl-blog{font-size:17px;line-height:1.78;color:#1f2937}\n.upl-blog p{margin:0 0 18px}\n.upl-blog h2{font-size:26px;line-height:1.3;color:#0b2b33;margin:46px 0 14px;font-weight:700;letter-spacing:-.015em}\n.upl-blog h3{font-size:19.5px;color:#0d3b47;margin:28px 0 10px;font-weight:700}\n.upl-blog ul,.upl-blog ol{margin:0 0 20px;padding-left:22px}\n.upl-blog li{margin:0 0 9px}\n.upl-blog figure{margin:0 0 34px}\n.upl-blog figure img{width:100%;height:auto;display:block;border-radius:10px}\n.upl-blog figcaption{font-size:13px;color:#6b7280;margin-top:10px;line-height:1.5}\n.upl-blog .toc{background:none;border:0;border-radius:0;padding:0;margin:0 0 34px}\n.upl-blog .toc .lwptoc{margin:0}\n.upl-blog .toc h4{margin:0 0 10px;font-size:13px;letter-spacing:.1em;text-transform:uppercase;color:#0d5563}\n.upl-blog .toc ol{margin:0;padding-left:18px;font-size:14.5px}\n.upl-blog .toc li{margin-bottom:6px}\n.upl-blog table{width:100%;border-collapse:collapse;font-size:14.5px;margin:0 0 10px}\n.upl-blog th{background:#0d3b47;color:#fff;text-align:left;padding:11px 13px;font-weight:600;font-size:13.5px;border:0}\n.upl-blog td{padding:11px 13px;border:0;border-bottom:1px solid #e8ebed;vertical-align:top}\n.upl-blog tbody tr:nth-child(even){background:#fafbfc}\n.upl-blog .tablecap{font-size:12.5px;color:#6b7280;margin:0 0 30px}\n.upl-blog .myth{background:#fff8ef;border:1px solid #f6ddbd;border-radius:8px;padding:16px 20px;margin:0 0 26px;font-size:15.5px}\n.upl-blog .myth b{color:#a85c10}\n.upl-blog .callout{background:#f2f8f9;border-radius:8px;padding:18px 22px;margin:0 0 26px;font-size:15.5px;border-left:3px solid #14707f}\n.upl-blog .faq h3{border-top:1px solid #eceff1;padding-top:22px;margin-top:0;font-size:18px}\n.upl-blog .faq h3:first-of-type{border-top:0;padding-top:0}\n.upl-blog .cta{background:linear-gradient(135deg,#0b2b33,#0d5563);color:#fff;border-radius:12px;padding:34px;margin:48px 0 30px}\n.upl-blog .cta h2,.upl-blog .cta .cta-h{color:#fff;margin:0 0 10px;font-size:24px;font-weight:700;line-height:1.3}\n.upl-blog .cta p{color:#c9dee3;margin:0 0 20px;font-size:16px}\n.upl-blog .btn{display:inline-block;background:#e07a1f;color:#fff;text-decoration:none;font-weight:700;padding:13px 26px;border-radius:8px;font-size:15.5px}\n.upl-blog .rel{border-top:1px solid #e8ebed;margin-top:40px;padding-top:26px}\n.upl-blog .rel h4{font-size:13px;letter-spacing:.1em;text-transform:uppercase;color:#6b7280;margin:0 0 14px}\n.upl-blog .rel ul{list-style:none;padding:0;margin:0}\n.upl-blog .rel li{padding:11px 0;border-bottom:1px dashed #e8ebed}\n.upl-blog .rel a{text-decoration:none;font-weight:600;font-size:15.5px}\n@media(max-width:640px){.upl-blog h2{font-size:22px}.upl-blog table{font-size:13px}.upl-blog .cta{padding:24px}}\n\/* \u5355\u7bc7\u9875\u9690\u85cf WhatsApp \u81ea\u52a8\u5c55\u5f00\u7684\u95ee\u5019\u5361\uff0c\u53ea\u4fdd\u7559\u5706\u5f62\u6c14\u6ce1\uff0c\u907f\u514d\u906e\u6321\u4fa7\u680f\u8be2\u76d8\u63d0\u4ea4\u6309\u94ae *\/\nbody.single-post .ht_ctc_chat_greetings_box{display:none !important}\n<\/style>\n<div class=\"upl-blog\">\n<figure>\n<img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/uplastech.com\/wp-content\/uploads\/2026\/10\/pvc-weathering.jpg\" alt=\"White and laminated PVC window profile samples on an outdoor weathering rack after several years of exposure\" width=\"1536\" height=\"909\"><figcaption>Profile samples on an outdoor exposure rack. The white sample on the left has been in the sun for years and is still white; the laminated one beside it has started to lift at the edge \u2014 which is the failure mode nobody sees until it is on a building.<\/figcaption><\/figure>\n<div class=\"toc\"><\/div>\n<h2 id=\"problem\">Why white PVC stays white, and why it sometimes does not<\/h2>\n<p>Unplasticised PVC is inherently susceptible to ultraviolet light. The polymer chain contains allylic chloride structures \u2014 defects formed during polymerisation \u2014 and UV energy is enough to break the carbon-chlorine bond, releasing hydrogen chloride. Once that starts, it propagates: the liberated HCl catalyses further dehydrochlorination, and the result is a conjugated polyene sequence that absorbs visible light. That is why degraded PVC turns yellow, then brown, then black.<\/p>\n<p>Two things stop it. The first is <strong>titanium dioxide<\/strong>, which absorbs UV and scatters it before it reaches the polymer. The second is a <strong>stabiliser system<\/strong>, which intercepts the HCl and the radical species. Both have to be present at the right level, and both are the first things a cost-reduced formulation cuts.<\/p>\n<div class=\"callout\">\n<p><strong>The number that governs exterior life:<\/strong> TiO<sub>2<\/sub> at <strong>4 \u2013 6 phr<\/strong> for a white exterior profile. At 3 phr the profile yellows within 3 \u2013 5 years in a sunny climate; at 4 \u2013 6 phr it holds colour for 20 \u2013 25 years. That is 1 \u2013 2 % of the formulation cost deciding two decades of service life.<\/p>\n<\/div>\n<h2 id=\"tio2\">TiO<sub>2<\/sub>: grade matters as much as loading<\/h2>\n<table>\n<thead>\n<tr>\n<th>Propri\u00e9t\u00e9<\/th>\n<th>Rutile, surface treated<\/th>\n<th>Rutile, untreated<\/th>\n<th>Anatase<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>UV screening<\/td>\n<td>Excellent<\/td>\n<td>Bon<\/td>\n<td>Poor for PVC<\/td>\n<\/tr>\n<tr>\n<td>Photocatalytic activity<\/td>\n<td>Low (coated)<\/td>\n<td>High \u2014 degrades PVC<\/td>\n<td>Very high<\/td>\n<\/tr>\n<tr>\n<td>Chalking<\/td>\n<td>Faible<\/td>\n<td>Mod\u00e9r\u00e9<\/td>\n<td>Severe<\/td>\n<\/tr>\n<tr>\n<td>Used in exterior PVC?<\/td>\n<td>Yes \u2014 the only correct choice<\/td>\n<td>Rarely<\/td>\n<td>Non<\/td>\n<\/tr>\n<tr>\n<td>Relative cost<\/td>\n<td>Highest<\/td>\n<td>Moyen<\/td>\n<td>Lowest<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 1 \u2014 TiO<sub>2<\/sub> grades. Anatase is cheaper and is the wrong choice \u2014 it photo-catalyses the PVC it is supposed to protect.<\/p>\n<p>The mechanism matters: untreated TiO<sub>2<\/sub> generates free radicals on its surface when it absorbs UV, and those radicals attack the polymer. A surface coating \u2014 alumina, silica, or a combined treatment \u2014 passivates the particle so it absorbs UV without catalysing degradation. A cheap formulation using untreated or lightly treated TiO<sub>2<\/sub> will chalk badly, and the chalk is not dirt: it is degraded PVC leaving the surface.<\/p>\n<p>Loading interacts with wall thickness. A thin wall (2.5 mm) needs the higher end of the range because there is less material to screen the UV; a thick wall can work at the lower end. This is why two profiles with the same formulation but different wall classes do not weather identically.<\/p>\n<h2 id=\"stabiliser\">Stabilisers: lead, calcium-zinc and tin<\/h2>\n<table>\n<thead>\n<tr>\n<th>System<\/th>\n<th>Status<\/th>\n<th>Weathering<\/th>\n<th>Notes<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Lead (Pb) stabiliser<\/td>\n<td>Phased out in EU, still used in some markets<\/td>\n<td>Very good long-term<\/td>\n<td>Toxic; restricted under REACH; being replaced globally<\/td>\n<\/tr>\n<tr>\n<td>Calcium-zinc (CaZn)<\/td>\n<td>Current standard<\/td>\n<td>Good, with co-stabilisers<\/td>\n<td>Requires a lubricant and co-stabiliser package to match lead<\/td>\n<\/tr>\n<tr>\n<td>Organotin<\/td>\n<td>Used in some rigid applications<\/td>\n<td>Excellent<\/td>\n<td>Higher cost; being displaced by CaZn in windows<\/td>\n<\/tr>\n<tr>\n<td>Barium-zinc<\/td>\n<td>Niche<\/td>\n<td>Bon<\/td>\n<td>Used where CaZn plate-out is a problem<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 2 \u2014 Stabiliser systems. CaZn replaced lead for regulatory reasons, not performance ones.<\/p>\n<p>The shift from lead to calcium-zinc is the biggest formulation change in the PVC window industry in thirty years, and it is not a drop-in substitution. Lead stabilisers are excellent lubricants as well as stabilisers, so removing lead changes the fusion behaviour of the dry blend. A CaZn formulation needs a carefully balanced package of internal lubricant, external lubricant and co-stabiliser to get the same fusion and the same surface. Formulations that simply swapped the stabiliser and adjusted nothing else produced profiles with poor fusion, plate-out and \u2014 in the field \u2014 early yellowing.<\/p>\n<h2 id=\"colour\">Colour options and what each costs you<\/h2>\n<table>\n<thead>\n<tr>\n<th>Option<\/th>\n<th>M\u00e9thode<\/th>\n<th>Weathering<\/th>\n<th>Cost premium<\/th>\n<th>Notes<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>White<\/td>\n<td>TiO<sub>2<\/sub> pigmented<\/td>\n<td>Best<\/td>\n<td>Baseline<\/td>\n<td>The reference against which everything else is measured<\/td>\n<\/tr>\n<tr>\n<td>Through-coloured (grey, beige, black)<\/td>\n<td>Pigment in the compound<\/td>\n<td>Good if stabilised for the colour<\/td>\n<td>+5 \u2013 15 %<\/td>\n<td>Dark colours get much hotter in sun \u2014 up to 70 \u00b0C surface<\/td>\n<\/tr>\n<tr>\n<td>Co-extruded cap<\/td>\n<td>Thin coloured or wood-grain skin<\/td>\n<td>Good \u2014 cap carries the weathering<\/td>\n<td>+20 \u2013 35 %<\/td>\n<td>Core can be a cheaper formulation<\/td>\n<\/tr>\n<tr>\n<td>Laminated film<\/td>\n<td>PVC or PMMA film, adhesive<\/td>\n<td>Fair to good<\/td>\n<td>+15 \u2013 30 %<\/td>\n<td>Edge lift is the failure mode<\/td>\n<\/tr>\n<tr>\n<td>Foil wrapped<\/td>\n<td>PVC\/PET foil, hot melt<\/td>\n<td>Fair outdoors<\/td>\n<td>+20 \u2013 40 %<\/td>\n<td>Best for interior and sheltered exterior<\/td>\n<\/tr>\n<tr>\n<td>Painted \/ coated<\/td>\n<td>Spray or powder<\/td>\n<td>Juste<\/td>\n<td>+10 \u2013 25 %<\/td>\n<td>Requires re-coating; not a 25-year finish<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 3 \u2014 Colour options. The dark-colour note is the one that causes field failures.<\/p>\n<p>Dark colours are the fastest-growing segment and the most demanding. A black or anthracite profile in direct summer sun reaches 65 \u2013 75 \u00b0C surface temperature, against 40 \u2013 45 \u00b0C for white. That is above the heat deflection temperature of standard rigid PVC, so the profile softens, creeps and can bow \u2014 and the differential between the sunlit face and the shaded one produces thermal stress that a white profile never sees.<\/p>\n<p>The industry answer is a cap layer or a laminate over a white or light-grey core. The dark surface gives the appearance; the light core gives the thermal and structural performance. A through-coloured dark profile requires a formulation specifically stabilised for it, and even then it is usually limited to lighter shades.<\/p>\n<h2 id=\"testing\">How weathering is actually tested<\/h2>\n<table>\n<thead>\n<tr>\n<th>Test<\/th>\n<th>Standard<\/th>\n<th>Exposure<\/th>\n<th>Acceptance<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Xenon arc<\/td>\n<td>EN 513<\/td>\n<td>4,000 h<\/td>\n<td>&Delta;E &le; 3, impact retention &ge; 70 %<\/td>\n<\/tr>\n<tr>\n<td>Xenon arc, extended<\/td>\n<td>EN 513<\/td>\n<td>8,000 h<\/td>\n<td>For 25-year claims<\/td>\n<\/tr>\n<tr>\n<td>QUV (UVA-340)<\/td>\n<td>ASTM G154<\/td>\n<td>1,000 \u2013 2,000 h<\/td>\n<td>Screening only, not a substitute<\/td>\n<\/tr>\n<tr>\n<td>Natural exposure, Florida<\/td>\n<td>ASTM G7<\/td>\n<td>12 \u2013 24 months<\/td>\n<td>The reference; slow but real<\/td>\n<\/tr>\n<tr>\n<td>Natural exposure, Arizona<\/td>\n<td>ASTM G7<\/td>\n<td>12 \u2013 24 months<\/td>\n<td>Hotter and drier than Florida<\/td>\n<\/tr>\n<tr>\n<td>Heat reversion<\/td>\n<td>EN 478<\/td>\n<td>30 min at 150 \u00b0C<\/td>\n<td>&le; 2 % \u2014 a stress check, not a weathering one<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 4 \u2014 Weathering tests. 4,000 hours of xenon arc is roughly two years of Florida sun.<\/p>\n<p>The acceleration factor is worth knowing so you can read a test report critically: 4,000 hours of xenon arc approximates 18 \u2013 24 months of Florida exposure, which is a small fraction of a 25-year claim. That is why serious profile systems run extended tests and combine them with natural exposure data. A supplier claiming 25-year colour stability on the basis of 1,000 hours of QUV is extrapolating far beyond what the test supports.<\/p>\n<div class=\"myth\">\n<p><b>Myth: \"it passed 4,000 hours of xenon arc, so it will last 25 years.\"<\/b> 4,000 hours is about two years of real sun. The extrapolation to 25 years relies on a known degradation model and on natural exposure data to calibrate it. Ask for the natural exposure results as well \u2014 a supplier who has them will show them.<\/p>\n<\/div>\n<h2 id=\"failure\">Field failures and what causes them<\/h2>\n<table>\n<thead>\n<tr>\n<th>Failure<\/th>\n<th>Apparence<\/th>\n<th>Cause<\/th>\n<th>Fix<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Yellowing<\/td>\n<td>Gradual shift from white to cream<\/td>\n<td>Insufficient TiO<sub>2<\/sub>, or stabiliser depletion<\/td>\n<td>Reformulate; test to EN 513<\/td>\n<\/tr>\n<tr>\n<td>Chalking<\/td>\n<td>White powder wipes off<\/td>\n<td>Untreated or anatase TiO<sub>2<\/sub>; photocatalytic degradation<\/td>\n<td>Switch to coated rutile<\/td>\n<\/tr>\n<tr>\n<td>Pink \/ brown staining<\/td>\n<td>Patchy discolouration<\/td>\n<td>Lead stabiliser reacting with sulphur in the atmosphere<\/td>\n<td>Move to CaZn<\/td>\n<\/tr>\n<tr>\n<td>Edge lift on laminate<\/td>\n<td>Film peeling from the edge<\/td>\n<td>Adhesive failure at the machined edge; moisture ingress<\/td>\n<td>Seal the edges; use a co-extruded cap instead<\/td>\n<\/tr>\n<tr>\n<td>Surface crazing<\/td>\n<td>Fine cracks in the surface<\/td>\n<td>Stress plus solvent cleaning agents<\/td>\n<td>Reduce residual stress; specify a mild cleaner<\/td>\n<\/tr>\n<tr>\n<td>Colour mismatch between profiles<\/td>\n<td>Adjacent profiles differ<\/td>\n<td>Batch-to-batch pigment variation<\/td>\n<td>&Delta;E &le; 1.0 within a batch, &le; 2.0 between batches<\/td>\n<\/tr>\n<tr>\n<td>Warping in dark colours<\/td>\n<td>Profile bows in summer sun<\/td>\n<td>Surface temperature above HDT<\/td>\n<td>Cap layer over a light core; higher HDT formulation<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 5 \u2014 Field failures. The pink staining is specific to lead stabilisers and is a good diagnostic.<\/p>\n<p>The pink and brown staining deserves a note because it is misdiagnosed constantly. Lead-stabilised PVC reacts with hydrogen sulphide and other sulphur compounds in the atmosphere \u2014 from industrial emissions, from rubber gaskets, even from some sealants \u2014 to form lead sulphide, which is brown-black. Customers report it as \"mould\" or \"dirt\". The cure is not a cleaner; it is a change of stabiliser system.<\/p>\n<h2 id=\"cleaning\">Cleaning and maintenance: what damages a profile<\/h2>\n<table>\n<thead>\n<tr>\n<th>Agent<\/th>\n<th>Effect on PVC<\/th>\n<th>Verdict<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Water with mild detergent<\/td>\n<td>None<\/td>\n<td>Recommended<\/td>\n<\/tr>\n<tr>\n<td>Isopropanol<\/td>\n<td>None at short contact<\/td>\n<td>Acceptable<\/td>\n<\/tr>\n<tr>\n<td>White spirit<\/td>\n<td>Slight swelling on long contact<\/td>\n<td>Use sparingly<\/td>\n<\/tr>\n<tr>\n<td>Acetone<\/td>\n<td>Attacks the surface, causes crazing on stressed parts<\/td>\n<td>Avoid<\/td>\n<\/tr>\n<tr>\n<td>Cellulose thinner<\/td>\n<td>Softens and dissolves PVC<\/td>\n<td>Never<\/td>\n<\/tr>\n<tr>\n<td>Abrasive cleaner \/ scouring pad<\/td>\n<td>Removes the surface skin and the UV protection<\/td>\n<td>Never<\/td>\n<\/tr>\n<tr>\n<td>Chlorine bleach, concentrated<\/td>\n<td>Long-term degradation<\/td>\n<td>Dilute only, rinse well<\/td>\n<\/tr>\n<tr>\n<td>Silicone spray<\/td>\n<td>Cosmetic only; attracts dirt<\/td>\n<td>Not recommended<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 6 \u2014 Cleaning agents. Abrasive cleaning is the most common cause of customer-induced damage.<\/p>\n<p>Abrasive cleaning is worse than it looks. The TiO<sub>2<\/sub> is distributed through the wall, but the surface 0.1 mm carries the highest concentration and the least degraded polymer. Scouring that layer off removes the UV protection and starts a yellowing process that no subsequent cleaning will reverse. Windows that \"went yellow after the builders cleaned them\" were usually scrubbed with an abrasive pad.<\/p>\n<h2 id=\"specify\">What to put in a specification<\/h2>\n<table>\n<thead>\n<tr>\n<th>Item<\/th>\n<th>What to state<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Colour<\/td>\n<td>Reference to a physical master, not just \"white\"<\/td>\n<\/tr>\n<tr>\n<td>Colour tolerance<\/td>\n<td>&Delta;E &le; 1.0 within a batch, &le; 2.0 between batches<\/td>\n<\/tr>\n<tr>\n<td>Weathering<\/td>\n<td>EN 513, 4,000 h (or 8,000 h for a 25-year claim), &Delta;E &le; 3<\/td>\n<\/tr>\n<tr>\n<td>Impact retention<\/td>\n<td>&ge; 70 % after weathering<\/td>\n<\/tr>\n<tr>\n<td>Stabiliser<\/td>\n<td>Calcium-zinc, lead-free, stated in writing<\/td>\n<\/tr>\n<tr>\n<td>TiO<sub>2<\/sub><\/td>\n<td>Rutile, surface coated, loading stated in phr<\/td>\n<\/tr>\n<tr>\n<td>Surface finish<\/td>\n<td>Gloss level, and whether a cap layer is present<\/td>\n<\/tr>\n<tr>\n<td>Cleaning<\/td>\n<td>A written cleaning instruction to pass to the end user<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 7 \u2014 A weathering specification. The cleaning instruction is the cheapest item and the one most often missing.<\/p>\n<p>The cleaning instruction is worth insisting on because most colour complaints are not manufacturing failures. A window that has been scrubbed with an abrasive, or wiped with a solvent, has been damaged by its owner \u2014 and the supplier absorbs the complaint because nobody told the owner what not to use. A one-page instruction in the handover pack prevents it.<\/p>\n<h2 id=\"faq\">Frequently asked questions<\/h2>\n<div class=\"faq\">\n<h3>How long will a white PVC window stay white?<\/h3>\n<p>With 4 \u2013 6 phr of coated rutile TiO<sub>2<\/sub> and a calcium-zinc stabiliser, 20 \u2013 25 years in a temperate climate with normal cleaning. In a hot, high-UV climate expect 12 \u2013 18 years. The first visible change is usually a slight cream shift, not a dramatic yellow.<\/p>\n<h3>Why did my white profile turn pink or brown?<\/h3>\n<p>Lead stabiliser reacting with sulphur compounds in the atmosphere. It is not dirt and it will not clean off. The fix is a calcium-zinc stabiliser system \u2014 which is now standard in Europe and increasingly required elsewhere.<\/p>\n<h3>Can I paint a PVC window?<\/h3>\n<p>Yes, with a paint designed for PVC \u2014 usually a two-part acrylic or a PVC-compatible primer plus topcoat. Standard emulsion will not adhere. Painting is normally done to change colour on an existing installation, and it needs re-coating every 5 \u2013 8 years.<\/p>\n<h3>Is a laminated profile as good as a co-extruded one?<\/h3>\n<p>For interior use, yes. For exterior use, a co-extruded cap is better because the colour is part of the extrusion rather than an adhesive film. Laminates fail at the edges, where moisture gets under the film \u2014 and window profiles have a lot of edges.<\/p>\n<h3>Why do dark colours cost more?<\/h3>\n<p>Three reasons: the pigment itself is more expensive, the formulation needs additional stabilisation to cope with the higher surface temperature, and dark profiles are usually made as a cap over a light core, which needs a co-extrusion die and a second extruder.<\/p>\n<h3>What is the surface temperature of a black profile in summer?<\/h3>\n<p>65 \u2013 75 \u00b0C in direct sun at 30 \u00b0C ambient, against 40 \u2013 45 \u00b0C for white. That is at or above the heat deflection temperature of standard rigid PVC, which is why dark profiles need a higher-HDT formulation or a light core.<\/p>\n<h3>Does cleaning damage the surface?<\/h3>\n<p>Not if it is done with water and mild detergent. Abrasive cleaners and scouring pads remove the surface layer that carries most of the UV protection, and the profile will yellow faster afterwards. Solvent cleaners can cause crazing on stressed areas.<\/p>\n<h3>How do I check a supplier's weathering claim?<\/h3>\n<p>Ask for the EN 513 test report \u2014 4,000 or 8,000 hours \u2014 and for natural exposure data if they have it. Ask what TiO<sub>2<\/sub> grade and loading they use. A supplier who can answer all three has done the work; one who quotes \"25 years\" without a report has not.<\/p>\n<\/div>\n<div class=\"cta\">\n<p class=\"cta-h\">Specifying an exterior PVC profile? Ask what the formulation actually contains<\/p>\n<p>Send the colour, the climate and the service life you need. We will tell you the TiO<sub>2<\/sub> loading, the stabiliser system and whether the colour needs a cap layer.<\/p>\n<p><a class=\"btn\" href=\"https:\/\/uplastech.com\/fr\/profiles-en-pvc\/\">Talk to a PVC formulation engineer<\/a>\n<\/div>\n<div class=\"rel\">\n<h4>Continue reading<\/h4>\n<ul>\n<li><a href=\"https:\/\/uplastech.com\/fr\/pvc-profile-extrusion\/\">PVC Profile Extrusion: Rigid, Flexible and Cellular PVC<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/fr\/pvc-window-profile-design\/\">PVC Window Profile Design: Chambers, Steel and Drainage<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/fr\/pvc-profile-welding-fabrication\/\">PVC Profile Welding and Fabrication: Corner Strength and Parameters<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/fr\/co-extrusion-profiles\/\">Co-Extrusion Profiles: Cap Layers, Bonding and Dies<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/fr\/extrusion-quality-control\/\">Extrusion Quality Control: Inspection, SPC and Acceptance<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Why white PVC turns yellow and what stops it: TiO2 grade and loading, stabiliser systems compared, the cost of colour options, how weathering is tested, and the field failures that trace back to formulation.<\/p>","protected":false},"author":1,"featured_media":7616,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"PVC Profile Weathering: TiO2, Stabilisers & Colour","_seopress_titles_desc":"PVC profile weathering: why white turns yellow, TiO2 grade and loading, stabiliser systems, colour option costs, test methods and field failure causes.","_seopress_robots_index":"1","_seopress_robots_follow":"1","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"36","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"https:\/\/uplastech.com\/pvc-profile-weathering-colour\/","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"pvc profile weathering","footnotes":""},"categories":[17,36],"tags":[],"class_list":["post-7622","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-plastic-extrusion-process","category-profile-extrusion"],"meta_box":{"post-to-quiz_to":[]},"_links":{"self":[{"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/posts\/7622","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/comments?post=7622"}],"version-history":[{"count":0,"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/posts\/7622\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/media\/7616"}],"wp:attachment":[{"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/media?parent=7622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/categories?post=7622"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/uplastech.com\/fr\/wp-json\/wp\/v2\/tags?post=7622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}