{"id":7619,"date":"2026-10-27T02:37:48","date_gmt":"2026-10-27T02:37:48","guid":{"rendered":"https:\/\/uplastech.com\/pvc-window-profile-design\/"},"modified":"2026-10-27T02:37:48","modified_gmt":"2026-10-27T02:37:48","slug":"pvc-window-profile-design","status":"publish","type":"post","link":"https:\/\/uplastech.com\/de\/pvc-window-profile-design\/","title":{"rendered":"PVC Window Profile Design: Chambers, Steel Reinforcement and Drainage"},"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-window-profile.jpg\" alt=\"White PVC window profile cross sections stacked on a workshop bench with a galvanised steel reinforcement insert beside them\" width=\"1536\" height=\"909\"><figcaption>Cut sections of a white PVC window profile, with the galvanised steel reinforcement that goes into the main chamber. The chambers, the steel, the gasket grooves and the drainage slots are all decided before the die is cut \u2014 and none of them are visible once the window is assembled.<\/figcaption><\/figure>\n<div class=\"toc\"><\/div>\n<h2 id=\"what\">What a window profile actually is<\/h2>\n<p>A PVC window profile looks like a simple extruded shape and is in fact one of the most highly engineered profiles made. A single sash profile carries six separate functions at once: structural stiffness, thermal separation, drainage, gasket retention, hardware attachment and a visible surface that must stay white for twenty-five years.<\/p>\n<p>Every one of those functions occupies a chamber, a groove or a wall in the section, and they compete for the same space. That is why window profile design is a discipline of its own rather than a variation on general profile design.<\/p>\n<div class=\"callout\">\n<p><strong>The number that governs everything:<\/strong> wall thickness. EN 12608 defines Class A at 2.8 mm minimum on the visible outer walls and Class B at 2.5 mm. That 0.3 mm is the difference between a profile rated for a 25-year service life and one that is not \u2014 and it is invisible to the customer, which is why it is the first thing a cheap profile reduces.<\/p>\n<\/div>\n<h2 id=\"chambers\">Chambers: the thermal architecture<\/h2>\n<p>The number of chambers is the headline specification of a window profile, and it is quoted in every brochure: three-chamber, five-chamber, six-chamber. What the number actually controls is convection inside the profile.<\/p>\n<table>\n<thead>\n<tr>\n<th>Chamber count<\/th>\n<th>Typical U<sub>f<\/sub> value<\/th>\n<th>Markt<\/th>\n<th>Anmerkungen<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>2 \u2013 3 chamber<\/td>\n<td>1.8 \u2013 2.2 W\/m\u00b2K<\/td>\n<td>Budget, warm climates<\/td>\n<td>Fails modern European U-value requirements<\/td>\n<\/tr>\n<tr>\n<td>4 chamber<\/td>\n<td>1.5 \u2013 1.7 W\/m\u00b2K<\/td>\n<td>Mid-market<\/td>\n<td>Common in Eastern Europe and Asia<\/td>\n<\/tr>\n<tr>\n<td>5 chamber<\/td>\n<td>1.2 \u2013 1.4 W\/m\u00b2K<\/td>\n<td>Standard European<\/td>\n<td>The baseline for EN 14351-1 compliance in many markets<\/td>\n<\/tr>\n<tr>\n<td>6 chamber<\/td>\n<td>1.0 \u2013 1.2 W\/m\u00b2K<\/td>\n<td>Passive-house adjacent<\/td>\n<td>Often with a foam-filled centre chamber<\/td>\n<\/tr>\n<tr>\n<td>7 \u2013 8 chamber<\/td>\n<td>0.9 \u2013 1.1 W\/m\u00b2K<\/td>\n<td>Passive house<\/td>\n<td>Requires foam fill and wide sections<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 1 \u2014 Chamber count versus frame U-value. The gains flatten above six chambers without a foam fill.<\/p>\n<p>The reason more chambers help is that each chamber traps air, and still air is a good insulator \u2014 but only if the chamber is small enough that convection does not start circulating. A chamber wider than about 25 mm develops a convection cell and the insulation value falls. So the design trend is not just \"more chambers\" but \"smaller chambers\", which is why a modern six-chamber profile is not much wider than an old three-chamber one.<\/p>\n<p>Above six chambers the returns diminish, and the next step is filling the largest chamber with foam \u2014 usually polystyrene or polyurethane. A foam-filled chamber takes the frame U-value to 0.9 \u2013 1.1 W\/m\u00b2K, at 15 \u2013 25 % more profile cost and a slower extrusion line because the foam fill is a second process.<\/p>\n<h2 id=\"steel\">Steel reinforcement: when it is needed and how much<\/h2>\n<p>PVC has a modulus of about 2.8 GPa. Aluminium is 70 GPa and steel is 210 GPa. A window is a structural element that must resist wind load and its own weight over a 25-year life, and unreinforced PVC cannot do it above a certain size.<\/p>\n<table>\n<thead>\n<tr>\n<th>Anmeldung<\/th>\n<th>Reinforcement<\/th>\n<th>Typical steel thickness<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Small fixed window, &lt; 0.8 m\u00b2<\/td>\n<td>Often none<\/td>\n<td>\u2014<\/td>\n<\/tr>\n<tr>\n<td>Casement, 0.8 \u2013 1.5 m\u00b2<\/td>\n<td>Required in the sash and frame<\/td>\n<td>1.0 \u2013 1.2 mm<\/td>\n<\/tr>\n<tr>\n<td>Casement, 1.5 \u2013 2.5 m\u00b2<\/td>\n<td>Required, full perimeter<\/td>\n<td>1.2 \u2013 1.5 mm<\/td>\n<\/tr>\n<tr>\n<td>Large fixed or tilt-slide<\/td>\n<td>Required, heavier section<\/td>\n<td>1.5 \u2013 2.0 mm<\/td>\n<\/tr>\n<tr>\n<td>Doors and patio doors<\/td>\n<td>Required, heavy section<\/td>\n<td>1.5 \u2013 2.0 mm<\/td>\n<\/tr>\n<tr>\n<td>High wind load (above 1.5 kPa)<\/td>\n<td>Required, and often a wider steel box<\/td>\n<td>2.0 mm+<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 2 \u2014 Reinforcement guidance. The actual requirement depends on wind load, span and the profile's own section properties.<\/p>\n<p>Three rules that are frequently broken:<\/p>\n<ol>\n<li><strong>The steel must be continuous through the corners.<\/strong> A window with steel in the straight runs but nothing in the corner joint has a hinge at every corner. Corner connectors are screwed into the steel, and the steel must be present where the screw goes.<\/li>\n<li><strong>The steel must fit the chamber.<\/strong> A steel insert 3 mm narrower than the chamber allows the PVC to deflect before the steel takes load, which defeats the purpose. Clearance should be 0.5 \u2013 1.0 mm per side, not 3 mm.<\/li>\n<li><strong>Galvanised, not painted.<\/strong> Condensation forms inside window profiles. Painted steel rusts from a scratch; galvanised steel does not.<\/li>\n<\/ol>\n<div class=\"myth\">\n<p><b>Myth: \"the steel is what makes the window strong.\"<\/b> The steel and the PVC work as a composite. The PVC carries the local loads and protects the steel; the steel carries the global bending. A window with the right steel but a 2.5 mm wall deflects more than one with the right steel and a 2.8 mm wall, because the PVC is what transfers load into the steel through the chamber walls.<\/p>\n<\/div>\n<h2 id=\"drainage\">Drainage and pressure equalisation<\/h2>\n<p>Water gets into every window. The design question is not whether it enters but whether it leaves, and whether it leaves without getting inside the building.<\/p>\n<table>\n<thead>\n<tr>\n<th>Merkmal<\/th>\n<th>Funktion<\/th>\n<th>Typical specification<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Drainage slot<\/td>\n<td>Lets water out of the frame<\/td>\n<td>5 \u00d7 25 mm, or 8 mm round, at the lowest point<\/td>\n<\/tr>\n<tr>\n<td>Pressure equalisation slot<\/td>\n<td>Lets air in so water can flow out<\/td>\n<td>Smaller than the drain, offset vertically<\/td>\n<\/tr>\n<tr>\n<td>Baffle \/ flap<\/td>\n<td>Prevents wind-driven rain entering through the drain<\/td>\n<td>Required in exposed locations<\/td>\n<\/tr>\n<tr>\n<td>Slope to drain<\/td>\n<td>Moves water to the outlet<\/td>\n<td>2 \u2013 3\u00b0 minimum in the bottom chamber<\/td>\n<\/tr>\n<tr>\n<td>Drain cover cap<\/td>\n<td>Keeps insects out, looks finished<\/td>\n<td>Push-fit, colour matched<\/td>\n<\/tr>\n<tr>\n<td>Glazing rebate drain<\/td>\n<td>Lets water out from behind the glass<\/td>\n<td>Aligned with the frame drain<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 3 \u2014 Drainage features. The pressure-equalisation slot is the one most often omitted on cheap windows.<\/p>\n<p>The pressure equalisation slot is what makes the drainage work. Water leaves a chamber because gravity pulls it down and because the air behind it can escape. If the chamber is sealed, the water sits in a trapped pocket and eventually finds its way inward through a joint. A small slot \u2014 3 \u2013 5 mm \u2014 at the top of the same chamber lets air in and the water out.<\/p>\n<p>In exposed locations, wind pressure on the outside can exceed the head of water inside the drain and blow rain back in. That is what baffles and flap valves are for, and it is why a window rated for a sheltered site and one rated for a 20-storey building are not the same product even when the profile is identical.<\/p>\n<h2 id=\"section\">The rest of the section<\/h2>\n<table>\n<thead>\n<tr>\n<th>Merkmal<\/th>\n<th>What it does<\/th>\n<th>Design constraint<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Gasket groove<\/td>\n<td>Retains the EPDM or TPE seal<\/td>\n<td>Groove geometry must match the gasket; a 0.2 mm error causes leaks<\/td>\n<\/tr>\n<tr>\n<td>Glazing rebate<\/td>\n<td>Holds the glass and the setting blocks<\/td>\n<td>Depth determines maximum glass thickness<\/td>\n<\/tr>\n<tr>\n<td>Hardware chamber<\/td>\n<td>Takes the espagnolette and hinges<\/td>\n<td>Must align across sash and frame<\/td>\n<\/tr>\n<tr>\n<td>Screw boss<\/td>\n<td>Anchors hinges and keeps<\/td>\n<td>Needs 2 \u00d7 screw diameter of material<\/td>\n<\/tr>\n<tr>\n<td>Weather bar \/ rebate<\/td>\n<td>Overlap between sash and frame<\/td>\n<td>Sets the water tightness<\/td>\n<\/tr>\n<tr>\n<td>Glazing bead groove<\/td>\n<td>Retains the bead<\/td>\n<td>Must release for re-glazing without damage<\/td>\n<\/tr>\n<tr>\n<td>Thermal break<\/td>\n<td>Separates inner and outer faces<\/td>\n<td>Needs a narrow, deep slot to work<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 4 \u2014 The non-thermal features of a window section. Each one is a separate tooling decision.<\/p>\n<p>The gasket groove deserves a note because it is the most tolerance-sensitive feature in the whole profile. A gasket is a compression seal, and it only seals within a narrow range of compression \u2014 typically 25 \u2013 35 % of its free height. If the groove is 0.3 mm too deep, the gasket is under-compressed and leaks; 0.3 mm too shallow and it is over-compressed, takes a permanent set, and leaks a year later. That is why gasket grooves are usually specified to &plusmn;0.1 mm while the rest of the profile is at &plusmn;0.3 mm.<\/p>\n<h2 id=\"tolerance\">Tolerances and what drives them<\/h2>\n<table>\n<thead>\n<tr>\n<th>Dimension<\/th>\n<th>Typical tolerance<\/th>\n<th>Warum<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Overall width \/ height<\/td>\n<td>&plusmn;0.3 mm<\/td>\n<td>Sets the visible joint lines<\/td>\n<\/tr>\n<tr>\n<td>Wall thickness<\/td>\n<td>&plusmn;0.2 mm<\/td>\n<td>Structural and thermal performance<\/td>\n<\/tr>\n<tr>\n<td>Gasket groove<\/td>\n<td>&plusmn;0.1 mm<\/td>\n<td>Sealing function<\/td>\n<\/tr>\n<tr>\n<td>Hardware chamber position<\/td>\n<td>&plusmn;0.2 mm<\/td>\n<td>Hardware alignment across sash and frame<\/td>\n<\/tr>\n<tr>\n<td>Geradheit<\/td>\n<td>1.5 \u2013 2.5 mm\/m<\/td>\n<td>Assembly and appearance<\/td>\n<\/tr>\n<tr>\n<td>Twist<\/td>\n<td>&lt; 1\u00b0\/m<\/td>\n<td>Corner welding alignment<\/td>\n<\/tr>\n<tr>\n<td>Cut length<\/td>\n<td>&plusmn;0.5 mm<\/td>\n<td>Welding allowance<\/td>\n<\/tr>\n<tr>\n<td>Colour<\/td>\n<td>&Delta;E &le; 1.0 within a batch<\/td>\n<td>Visible on adjacent profiles<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 5 \u2014 Window profile tolerances. The gasket groove is the tightest feature in the section.<\/p>\n<p>Straightness matters more than it does on most profiles because the profile is welded into a frame. A profile with 2 mm\/m of bow produces a frame that is visibly out of square after welding, and the welder cannot correct it. The usual cause is asymmetric cooling in the calibration tank, and the usual fix is balancing the spray rather than changing the die.<\/p>\n<h2 id=\"design\">Design rules<\/h2>\n<ol>\n<li><strong>Minimum 2.8 mm on visible walls<\/strong> for Class A. Do not accept 2.5 mm on an exterior application.<\/li>\n<li><strong>Keep chamber widths under 25 mm<\/strong> to avoid convection cells.<\/li>\n<li><strong>Put the steel in the chamber that carries the bending load<\/strong> \u2014 usually the outer chamber of the sash, not the centre.<\/li>\n<li><strong>Design the drain before the die.<\/strong> A drain that has to be punched afterwards is a hole in a wall that was not designed for it.<\/li>\n<li><strong>Slope every horizontal chamber towards a drain.<\/strong> Water that cannot leave will find a joint.<\/li>\n<li><strong>Radius every internal corner at R1.0 minimum.<\/strong> Sharp corners are where PVC stress-cracks after years of thermal cycling.<\/li>\n<li><strong>Allow for thermal expansion in the frame.<\/strong> A 1.5 m white PVC profile moves 4.5 mm over a 60 K swing; a dark laminated profile moves more.<\/li>\n<li><strong>Match the gasket groove to a real gasket<\/strong>, not to a nominal dimension. Send the gasket drawing to the die maker.<\/li>\n<\/ol>\n<h2 id=\"standards\">The standards that apply<\/h2>\n<table>\n<thead>\n<tr>\n<th>Standard<\/th>\n<th>Covers<\/th>\n<th>What to check<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>EN 12608-1<\/td>\n<td>PVC-U profiles for windows<\/td>\n<td>Class A \/ B wall thickness, heat reversion, impact<\/td>\n<\/tr>\n<tr>\n<td>EN 14351-1<\/td>\n<td>Windows as a product<\/td>\n<td>U-value, watertightness, wind load, acoustic<\/td>\n<\/tr>\n<tr>\n<td>EN 477<\/td>\n<td>Impact resistance of profiles<\/td>\n<td>Falling ball at \u221210 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>EN 478<\/td>\n<td>Heat reversion<\/td>\n<td>Residual stress indicator, &le; 2 % after 30 min at 150 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>EN 513<\/td>\n<td>Weathering<\/td>\n<td>Colour change and impact retention after 4,000 h xenon arc<\/td>\n<\/tr>\n<tr>\n<td>EN ISO 1163<\/td>\n<td>PVC-U material specification<\/td>\n<td>K-value, impurity level<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 6 \u2014 The standards a window profile is actually tested against. Heat reversion is the one that reveals residual stress.<\/p>\n<p>Heat reversion (EN 478) is worth understanding because it is a direct measure of how well the profile was extruded. A 200 mm sample is placed in an oven at 150 \u00b0C for 30 minutes and the length change is measured. Well-extruded profile reverts by under 2 %; poorly cooled profile with high frozen-in stress reverts by 4 \u2013 6 %. The test is cheap, fast and it catches a problem that no dimensional check will find.<\/p>\n<h2 id=\"faq\">Frequently asked questions<\/h2>\n<div class=\"faq\">\n<h3>How many chambers do I actually need?<\/h3>\n<p>It depends on the U-value target, not on the chamber count itself. Five chambers typically reaches 1.2 \u2013 1.4 W\/m\u00b2K, which satisfies most European regulations. Six chambers plus a foam fill reaches 1.0 \u2013 1.1 W\/m\u00b2K for passive-house work. Below five chambers you will struggle to meet modern requirements without a foam fill.<\/p>\n<h3>Is steel reinforcement always required?<\/h3>\n<p>No. Small fixed lights under about 0.8 m\u00b2 often need none. Anything opening, anything above 1.5 m\u00b2, and anything with high wind load needs it. The calculation depends on span, wind pressure and the profile's moment of inertia \u2014 ask for it in writing rather than accepting a rule of thumb.<\/p>\n<h3>Why do my window corners open up after a year?<\/h3>\n<p>Three causes: the corner weld was made at the wrong temperature or pressure; the steel does not run through the corner so the joint carries all the load; or the profile has high residual stress from the extrusion line and the corner has been slowly relaxing. Heat reversion testing on the raw profile will tell you whether it is the third.<\/p>\n<h3>Can PVC windows be recycled?<\/h3>\n<p>Yes, and PVC window profiles are one of the better-established recycling streams in Europe. Post-consumer windows are collected, ground, and the PVC is separated from glass, steel and gaskets, then re-compounded. Recyclate is normally used in the core of a co-extruded profile rather than on the visible surface, because the colour and weathering performance of recyclate is not equivalent to virgin.<\/p>\n<h3>What is the difference between Class A and Class B profiles?<\/h3>\n<p>EN 12608 wall thickness: Class A requires 2.8 mm minimum on the outer walls, Class B 2.5 mm. The difference is 0.3 mm, which is about 11 % of the wall and a significant reduction in stiffness and thermal performance. Class B is legal in some markets and not accepted in others.<\/p>\n<h3>Why does my white profile turn yellow?<\/h3>\n<p>Either insufficient TiO<sub>2<\/sub> (below about 4 phr) letting UV reach the polymer, or a stabiliser system that is degrading. Lead-stabilised profiles yellow differently from calcium-zinc ones. The test is EN 513 xenon arc, and the acceptance criterion is normally &Delta;E &le; 3 after 4,000 hours.<\/p>\n<h3>How much does a window profile die cost?<\/h3>\n<p>A single-cavity PVC window profile die runs \u20ac8,000 \u2013 \u20ac18,000 in China and \u20ac22,000 \u2013 \u20ac45,000 in Europe, plus calibration. A co-extrusion die with a cap layer adds 30 \u2013 60 %. Lead time is 6 \u2013 8 weeks plus trials.<\/p>\n<h3>Can the same profile be used for windows and doors?<\/h3>\n<p>Rarely. Doors carry far higher loads and need a deeper section and heavier steel. Some systems share the frame profile and use a different sash for doors, but a dedicated door profile is normal above a certain size.<\/p>\n<\/div>\n<div class=\"cta\">\n<p class=\"cta-h\">Developing a PVC window profile system?<\/p>\n<p>Send the section drawing, the target U-value and the wind-load class. We will tell you where the chambers need to change, what steel the section needs, and what the die and calibration will cost.<\/p>\n<p><a class=\"btn\" href=\"https:\/\/uplastech.com\/de\/pvc-profile\/\">Talk to a PVC profile engineer<\/a>\n<\/div>\n<div class=\"rel\">\n<h4>Continue reading<\/h4>\n<ul>\n<li><a href=\"https:\/\/uplastech.com\/de\/pvc-profile-extrusion\/\">PVC Profile Extrusion: Rigid, Flexible and Cellular PVC<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/de\/pvc-profile-welding-fabrication\/\">PVC Profile Welding and Fabrication: Corner Strength and Parameters<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/de\/pvc-profile-weathering-colour\/\">PVC Profile Weathering and Colour: TiO2, Stabilisers and Lamination<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/de\/hollow-profile-design\/\">Hollow Profile Design: Stiffness, Weld Lines and Wall Balance<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/de\/profile-calibration-cooling\/\">Vacuum Calibration and Cooling in Profile Extrusion<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>What a PVC window profile has to do at once: chamber layout and U-values, when steel reinforcement is required, drainage and pressure equalisation, and the EN 12608 wall thickness classes that decide whether a section passes.<\/p>","protected":false},"author":1,"featured_media":7613,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"PVC Window Profile Design: Chambers & Steel Reinforcement","_seopress_titles_desc":"PVC window profile design: chamber layout and U-values, steel reinforcement rules, drainage and pressure equalisation, and EN 12608 wall thickness classes.","_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-window-profile-design\/","_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 window profile design","footnotes":""},"categories":[17,36],"tags":[],"class_list":["post-7619","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\/de\/wp-json\/wp\/v2\/posts\/7619","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/comments?post=7619"}],"version-history":[{"count":0,"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/posts\/7619\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/media\/7613"}],"wp:attachment":[{"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/media?parent=7619"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/categories?post=7619"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/uplastech.com\/de\/wp-json\/wp\/v2\/tags?post=7619"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}