{"id":7632,"date":"2026-10-27T06:50:07","date_gmt":"2026-10-27T06:50:07","guid":{"rendered":"https:\/\/uplastech.com\/packaging-tube-tolerances-wall-thickness\/"},"modified":"2026-10-27T06:50:07","modified_gmt":"2026-10-27T06:50:07","slug":"packaging-tube-tolerances-wall-thickness","status":"publish","type":"post","link":"https:\/\/uplastech.com\/tr\/packaging-tube-tolerances-wall-thickness\/","title":{"rendered":"Packaging Tube Tolerances: Diameter, Wall Thickness and Ovality"},"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\/pkg-tube-measure.jpg\" alt=\"Digital caliper measuring the outside diameter of a thin walled plastic packaging tube with cut sections on a clean bench\" width=\"1536\" height=\"909\"><figcaption>Measuring outside diameter with a caliper, and cut sections standing beside it so the wall can be checked. The caliper reading is the easy part. The hard part is knowing which number to write on the drawing, and at what point in the tube's life to measure it.<\/figcaption><\/figure>\n<div class=\"toc\"><\/div>\n<h2 id=\"why\">Tolerances are set by the filling line, not by the drawing<\/h2>\n<p>A tube drawing usually arrives with four dimensions and four tolerances, and the tolerances were copied from a previous supplier's drawing without anyone asking why they are what they are. That is how a project ends up paying for \u00b1 0.10 mm on a diameter that the filling nozzle does not care about, while a length tolerance that the crimping jaws absolutely do care about is left loose.<\/p>\n<p>The right way round is to work backwards from the filling line:<\/p>\n<ul>\n<li>Bu <strong>outside diameter<\/strong> sets the cap fit and the print mandrel fit<\/li>\n<li>Bu <strong>inside diameter<\/strong> sets whether the filling nozzle enters without scoring the wall<\/li>\n<li>Bu <strong>wall<\/strong> sets the squeeze feel and the crimp seal<\/li>\n<li>Bu <strong>length<\/strong> sets whether the tube sits squarely in the tail crimper<\/li>\n<li>Bu <strong>ovality<\/strong> sets whether it prints evenly and caps without cross-threading<\/li>\n<li>Bu <strong>squareness of the cut<\/strong> sets the weld quality at the shoulder<\/li>\n<\/ul>\n<p>Everything else is decoration. Tightening a dimension that does not appear in that list costs money and buys nothing.<\/p>\n<h2 id=\"numbers\">The four dimensions that matter<\/h2>\n<table>\n<thead>\n<tr>\n<th>Dimension<\/th>\n<th>Typical range<\/th>\n<th>Normal tolerance<\/th>\n<th>Tight tolerance<\/th>\n<th>What drives the limit<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Outside diameter<\/td>\n<td>13 \u2013 60 mm<\/td>\n<td>\u00b1 0.15 mm<\/td>\n<td>\u00b1 0.08 mm<\/td>\n<td>Cap fit, print mandrel<\/td>\n<\/tr>\n<tr>\n<td>Wall thickness<\/td>\n<td>0.40 \u2013 0.90 mm<\/td>\n<td>\u00b1 10 %<\/td>\n<td>\u00b1 6 %<\/td>\n<td>Crimp seal, squeeze feel<\/td>\n<\/tr>\n<tr>\n<td>Length<\/td>\n<td>60 \u2013 200 mm<\/td>\n<td>\u00b1 0.8 mm<\/td>\n<td>\u00b1 0.4 mm<\/td>\n<td>Tail crimper, carton fit<\/td>\n<\/tr>\n<tr>\n<td>Ovality<\/td>\n<td>\u2014<\/td>\n<td>\u2264 2 % of D<\/td>\n<td>\u2264 1 % of D<\/td>\n<td>Print registration, capping<\/td>\n<\/tr>\n<tr>\n<td>Concentricity<\/td>\n<td>\u2014<\/td>\n<td>\u2264 10 % of wall<\/td>\n<td>\u2264 6 % of wall<\/td>\n<td>Wall uniformity, crimp strength<\/td>\n<\/tr>\n<tr>\n<td>Cut squareness<\/td>\n<td>\u2014<\/td>\n<td>\u2264 0.5 mm<\/td>\n<td>\u2264 0.25 mm<\/td>\n<td>Shoulder weld integrity<\/td>\n<\/tr>\n<tr>\n<td>Bow (straightness)<\/td>\n<td>\u2014<\/td>\n<td>\u2264 1 mm \/ 100 mm<\/td>\n<td>\u2264 0.5 mm \/ 100 mm<\/td>\n<td>Automatic feeding<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 1 \u2014 Typical tube body tolerances. The \"tight\" column is achievable but roughly doubles the reject rate and needs in-line gauging.<\/p>\n<p>Notice that wall thickness is expressed as a percentage, not an absolute. A \u00b1 0.05 mm tolerance is 10 % on a 0.5 mm wall and only 5.5 % on a 0.9 mm wall \u2014 the same tolerance band means different things on different products, which is why absolute wall tolerances in drawings cause arguments at goods-in inspection.<\/p>\n<h2 id=\"where\">Where each tolerance comes from<\/h2>\n<table>\n<thead>\n<tr>\n<th>Dimension<\/th>\n<th>Primary cause of variation<\/th>\n<th>Secondary<\/th>\n<th>Correctable in-line?<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Outside diameter<\/td>\n<td>Vacuum level, sizing sleeve wear<\/td>\n<td>Melt temperature, haul-off tension<\/td>\n<td>Yes \u2014 vacuum and haul-off trim<\/td>\n<\/tr>\n<tr>\n<td>Wall thickness<\/td>\n<td>Die concentricity, draw-down ratio<\/td>\n<td>Screw output fluctuation<\/td>\n<td>Partly \u2014 die centring screws<\/td>\n<\/tr>\n<tr>\n<td>Concentricity<\/td>\n<td>Mandrel alignment in the crosshead<\/td>\n<td>Thermal drift of the die body<\/td>\n<td>Yes \u2014 centring, then it drifts<\/td>\n<\/tr>\n<tr>\n<td>Length<\/td>\n<td>Cutter timing, haul-off speed drift<\/td>\n<td>Tube stretch after the puller<\/td>\n<td>Yes \u2014 encoder feedback<\/td>\n<\/tr>\n<tr>\n<td>Ovality<\/td>\n<td>Cooling rate, residual stress<\/td>\n<td>Haul-off belt pressure<\/td>\n<td>No \u2014 set by cooling design<\/td>\n<\/tr>\n<tr>\n<td>Bow<\/td>\n<td>Uneven cooling around the circumference<\/td>\n<td>Spool or box packing tension<\/td>\n<td>Partly \u2014 spray ring balance<\/td>\n<\/tr>\n<tr>\n<td>Cut squareness<\/td>\n<td>Blade wear, tube movement at the cutter<\/td>\n<td>Haul-off grip<\/td>\n<td>Yes \u2014 blade change schedule<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 2 \u2014 Root causes. Ovality and bow are the two that cannot be fixed by turning a knob while running.<\/p>\n<p>Concentricity is the one that drifts. A crosshead die is centred with four screws before the run starts, and the mandrel moves as the die body heats and as the melt pressure changes. A die that was centred cold at 0.02 mm can be at 0.08 mm two hours into the run. On a 0.5 mm wall, 0.08 mm of eccentricity means the thin side is 0.42 mm and the thick side is 0.58 mm \u2014 a 32 % variation that fails most specifications while the average wall reads perfectly in the middle of the band.<\/p>\n<div class=\"callout\">\n<p><strong>The measurement that catches it:<\/strong> never check wall thickness at one point. Take four readings at 0\u00b0, 90\u00b0, 180\u00b0 and 270\u00b0 on the same section. The average tells you whether the wall is right; the spread tells you whether the die is centred. A plant that only measures one point will ship eccentric tubes for months without knowing.<\/p>\n<\/div>\n<h2 id=\"ovality\">Ovality is a time-dependent property<\/h2>\n<p>This is the single most misunderstood number in tube extrusion, and it causes more rejected batches than any other dimension.<\/p>\n<p>A tube measured at the end of the line is round, because it is still held by the geometry it was cooled in. Cut it, stack it, leave it overnight, and the residual stress from cooling relaxes. The section creeps into an oval. On a thin-wall PE tube with aggressive cooling, the ovality can grow from 0.1 mm to 0.4 mm in 24 hours.<\/p>\n<table>\n<thead>\n<tr>\n<th>Time after cutting<\/th>\n<th>Measured ovality (35 mm PE, 0.5 mm wall)<\/th>\n<th>Verdict if measured now<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Immediately<\/td>\n<td>0.08 mm<\/td>\n<td>Pass (0.23 %)<\/td>\n<\/tr>\n<tr>\n<td>1 hour<\/td>\n<td>0.19 mm<\/td>\n<td>Pass (0.54 %)<\/td>\n<\/tr>\n<tr>\n<td>4 hours<\/td>\n<td>0.31 mm<\/td>\n<td>Marginal (0.89 %)<\/td>\n<\/tr>\n<tr>\n<td>24 hours<\/td>\n<td>0.41 mm<\/td>\n<td>Fail (1.17 %) if the limit is 1 %<\/td>\n<\/tr>\n<tr>\n<td>72 hours<\/td>\n<td>0.43 mm<\/td>\n<td>Stable<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 3 \u2014 Ovality development after cutting. Most of the growth happens in the first four hours, but it is not finished until the next day.<\/p>\n<p>The cure is in the cooling design, not in the inspection. Slower cooling, warmer water, a longer trough, or a post-cooling tunnel all reduce residual stress. A plant that measures immediately and passes the batch has not solved anything \u2014 it has measured a tube that does not exist yet.<\/p>\n<p>The practical rule: hold the samples for 24 hours before the final ovality check, and do the first-article approval on aged samples. If you need to release product the same day, run the check on a sample from the previous day's production of the same setup.<\/p>\n<h2 id=\"measure\">Measuring, on-line and off-line<\/h2>\n<table>\n<thead>\n<tr>\n<th>Y\u00f6ntem<\/th>\n<th>What it measures<\/th>\n<th>H\u0131z<\/th>\n<th>Best used for<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Laser diameter gauge (2-axis)<\/td>\n<td>OD in two directions, ovality<\/td>\n<td>S\u00fcrekli<\/td>\n<td>In-line control, closed loop to vacuum<\/td>\n<\/tr>\n<tr>\n<td>Laser gauge (4-axis)<\/td>\n<td>OD, ovality, some bow<\/td>\n<td>S\u00fcrekli<\/td>\n<td>Thin wall, tight tolerance<\/td>\n<\/tr>\n<tr>\n<td>Ultrasonic wall gauge<\/td>\n<td>Wall, eccentricity, rotating<\/td>\n<td>S\u00fcrekli<\/td>\n<td>In-line wall control<\/td>\n<\/tr>\n<tr>\n<td>Digital caliper<\/td>\n<td>OD, length<\/td>\n<td>Manual<\/td>\n<td>Spot checks, goods-in<\/td>\n<\/tr>\n<tr>\n<td>Micrometer with ball anvils<\/td>\n<td>Wall on a cut section<\/td>\n<td>Manual<\/td>\n<td>Reference measurement<\/td>\n<\/tr>\n<tr>\n<td>Optical comparator \/ vision<\/td>\n<td>Section geometry, concentricity<\/td>\n<td>Manual<\/td>\n<td>First article, disputes<\/td>\n<\/tr>\n<tr>\n<td>Weighing<\/td>\n<td>Average wall by calculation<\/td>\n<td>Manual<\/td>\n<td>Fast lot check, no section needed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 4 \u2014 Measurement options. The weighing method is underrated: mass per unit length divided by circumference gives the average wall to within a few percent.<\/p>\n<p>Weighing deserves a note because it is the cheapest capable method. Cut a known length, weigh it, divide by the density and by the circumference, and you have the average wall. It will not show eccentricity, but it will show a drift in output or a die gap change immediately, and it takes thirty seconds.<\/p>\n<p>The in-line laser gauge is the right answer for anything under \u00b1 0.12 mm. It closes the loop to the vacuum and haul-off, so the operator is supervising a controller rather than chasing a number. On a manual line, the operator checks every 30 minutes and the process drifts between checks \u2014 which is fine for a \u00b1 0.20 mm tolerance and not fine for \u00b1 0.08 mm.<\/p>\n<h2 id=\"filling\">Matching the tube to the filling line<\/h2>\n<p>The tolerances only matter because of what happens downstream. These are the interfaces where a marginal tube becomes a line stop.<\/p>\n<table>\n<thead>\n<tr>\n<th>Interface<\/th>\n<th>Dimensional requirement<\/th>\n<th>Failure mode if out<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Filling nozzle entry<\/td>\n<td>ID clearance 0.5 \u2013 1.5 mm<\/td>\n<td>Nozzle scores the wall, or misses and spills<\/td>\n<\/tr>\n<tr>\n<td>Cap application<\/td>\n<td>OD \u00b1 0.15 mm, ovality \u2264 2 %<\/td>\n<td>Cross-threading, cap not seating, torque scatter<\/td>\n<\/tr>\n<tr>\n<td>Print mandrel<\/td>\n<td>ID clearance 0.3 \u2013 0.8 mm<\/td>\n<td>Tube will not load, or slips and misregisters<\/td>\n<\/tr>\n<tr>\n<td>Tail crimper<\/td>\n<td>Length \u00b1 0.5 mm, squareness \u2264 0.5 mm<\/td>\n<td>Seal weak on one corner, leaks in transit<\/td>\n<\/tr>\n<tr>\n<td>Shoulder welder<\/td>\n<td>Cut squareness, OD \u00b1 0.10 mm<\/td>\n<td>Incomplete weld, flash, leak at the shoulder<\/td>\n<\/tr>\n<tr>\n<td>Cartoning<\/td>\n<td>Length and bow<\/td>\n<td>Jams in the magazine, bent tubes<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 5 \u2014 Where tube tolerances meet the filling line. The crimper is the most sensitive interface and the least often specified.<\/p>\n<p>The tail crimper is the one people forget. It closes the tail flat and applies heat or ultrasound to weld the two walls together. If the cut is not square, one side of the tail is longer than the other, the jaws grip unevenly, and the seal is thin at one corner. That corner is where the tube bursts when the consumer squeezes hard, and it will be a complaint three months after the batch shipped.<\/p>\n<h2 id=\"loosen\">How to relax tolerances and save money<\/h2>\n<p>Every tightening step costs yield. On a typical line the relationship is roughly:<\/p>\n<table>\n<thead>\n<tr>\n<th>OD tolerance<\/th>\n<th>Approximate yield<\/th>\n<th>Extra cost per 1,000<\/th>\n<th>Needs<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u00b1 0.30 mm<\/td>\n<td>99 %<\/td>\n<td>Baseline<\/td>\n<td>Manual checks<\/td>\n<\/tr>\n<tr>\n<td>\u00b1 0.20 mm<\/td>\n<td>97 %<\/td>\n<td>+3 %<\/td>\n<td>Manual checks, tighter die<\/td>\n<\/tr>\n<tr>\n<td>\u00b1 0.15 mm<\/td>\n<td>94 %<\/td>\n<td>+7 %<\/td>\n<td>Regular checks, stable cooling<\/td>\n<\/tr>\n<tr>\n<td>\u00b1 0.10 mm<\/td>\n<td>88 %<\/td>\n<td>+15 %<\/td>\n<td>In-line laser gauge<\/td>\n<\/tr>\n<tr>\n<td>\u00b1 0.08 mm<\/td>\n<td>80 %<\/td>\n<td>+26 %<\/td>\n<td>In-line gauge plus closed loop<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 6 \u2014 Yield against tolerance, indicative. The curve steepens because the process distribution does not narrow as fast as the tolerance band does.<\/p>\n<p>Three practical ways to avoid paying for precision you do not need:<\/p>\n<ol>\n<li><strong>Specify the diameter that the cap actually sees.<\/strong> The cap contacts the neck of the moulded head, not the tube body. The body OD tolerance only needs to suit the print mandrel, which is usually looser than the cap.<\/li>\n<li><strong>Use a percentage wall tolerance, not an absolute one.<\/strong> It survives a product change without renegotiation and it matches how the process actually behaves.<\/li>\n<li><strong>Put the tight tolerance on the length, not the diameter.<\/strong> Length is controlled by an encoder and a cutter, and \u00b1 0.4 mm is cheap. Diameter is controlled by vacuum, cooling and draw-down, and \u00b1 0.08 mm is expensive.<\/li>\n<\/ol>\n<div class=\"myth\">\n<p><strong>Common assumption:<\/strong> \"the wall thickness tolerance is what makes the tube fail the pressure test.\"<\/p>\n<p>Usually it is the weld, not the wall. A tube with a 10 % thin wall on one side will still hold 1.5 bar; a tube with a 0.2 mm unsquare cut will leak at the shoulder at 0.6 bar. If a batch is failing leak tests, section a few tubes and look at the weld interface before blaming the extruder.<\/p>\n<\/div>\n<h2 id=\"drawing\">What a good tube drawing contains<\/h2>\n<p>A tube drawing that can be quoted without a meeting has these on it:<\/p>\n<ul>\n<li>Nominal OD with tolerance, and whether it is measured over the print or the plain body<\/li>\n<li>Nominal ID, derived from OD and wall \u2014 not specified independently<\/li>\n<li>Wall with a percentage tolerance<\/li>\n<li>Length with tolerance, and the datum (cut face to cut face)<\/li>\n<li>Ovality limit and the ageing period before measurement<\/li>\n<li>Cut squareness<\/li>\n<li>Resin grade or performance requirement, plus colour<\/li>\n<li>Any co-extrusion layer structure with individual layer percentages<\/li>\n<li>Packaging format, because nesting affects ovality in transit<\/li>\n<\/ul>\n<p>The one that is most often missing is the ageing period for the ovality measurement. Without it, the supplier measures at the machine, the customer measures at goods-in a week later, and both are technically correct and completely incompatible.<\/p>\n<div class=\"faq\">\n<h3>What is a normal ovality tolerance for a packaging tube?<\/h3>\n<p>Two percent of the outside diameter is standard, one percent for tight work. On a 35 mm tube that is 0.7 mm and 0.35 mm respectively. It must be measured at least 24 hours after cutting, because ovality develops as residual stress relaxes and can double in the first day.<\/p>\n<h3>Why does my tube measure in tolerance at the machine but fail at goods-in?<\/h3>\n<p>Because you are measuring two different states. At the machine the tube is newly cut and still round; a week later the stress has relaxed and the section has gone oval. The specification needs to state the ageing period, and the supplier needs to hold samples for it.<\/p>\n<h3>How do I check wall thickness without cutting the tube?<\/h3>\n<p>Ultrasonically, with a rotating gauge, or indirectly by weighing a known length. Weighing gives the average wall to a few percent and costs nothing, but it cannot show eccentricity. For eccentricity you need a section or a rotating ultrasonic scan.<\/p>\n<h3>What causes a thick and thin side on the same tube?<\/h3>\n<p>The mandrel is off-centre in the crosshead die. It is set with centring screws before the run and drifts as the die heats. On a 0.5 mm wall, 0.08 mm of eccentricity is a 32 % variation. Re-centre after the die reaches temperature, not before.<\/p>\n<h3>Can I specify the inside diameter instead of the wall?<\/h3>\n<p>Not independently. The extrusion sets the outside diameter and the wall; the inside diameter is what is left. If you specify ID and wall, the OD is determined and you may not get the OD the cap needs. Specify OD and wall, and derive the ID.<\/p>\n<h3>How tight can the length tolerance be?<\/h3>\n<p>\u00b1 0.4 mm is routine on a servo cutter with encoder feedback, and \u00b1 0.2 mm is possible on a well-controlled line. It is the cheapest tight tolerance on the drawing, so put the precision here rather than on the diameter.<\/p>\n<h3>Does wall thickness tolerance affect the crimp seal?<\/h3>\n<p>Yes. The crimper welds wall to wall, so a thin spot on one side means less material to fuse. A 10 % wall tolerance is normally fine; 20 % is not. This is the reason the wall tolerance is often tighter than the OD tolerance on tubes that will be filled and sealed.<\/p>\n<h3>What is cut squareness and why does it matter?<\/h3>\n<p>How perpendicular the cut face is to the tube axis. If it is off, the tube does not sit flat in the shoulder welder or the tail crimper, and the joint is thin on one side. 0.5 mm is the usual limit; 0.25 mm for high-barrier tubes where the weld carries the shelf life.<\/p>\n<\/div>\n<div class=\"cta\">\n<p class=\"cta-h\">Need a tolerance band you can actually hold?<\/p>\n<p>Send the drawing and the filling line constraints. We will tell you which tolerances are free, which cost yield, and what the process can hold on your diameter and wall.<\/p>\n<p><a class=\"btn\" href=\"https:\/\/uplastech.com\/tr\/boru-ve-tup-ekstruzyonlari\/\">Review tube tolerances with an engineer<\/a>\n<\/div>\n<div class=\"rel\">\n<h4>Continue reading<\/h4>\n<ul>\n<li><a href=\"https:\/\/uplastech.com\/tr\/plastic-packaging-tube-extrusion\/\">Plastic Packaging Tube Extrusion: From Die to Finished Tube<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/tr\/packaging-tube-extrusion-defects\/\">Tube Extrusion Defects: Gels, Die Lines and Weld Lines<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/tr\/profile-tolerance-secondary-operations\/\">Profile Tolerances and Secondary Operations<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/tr\/abl-pbl-pe-packaging-tube-materials\/\">ABL, PBL or PE: Choosing the Tube Body Material<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/tr\/extrusion-quality-control\/\">Extrusion Quality Control: Parameters, SPC and Retention<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Which tube dimensions the filling line actually cares about, where each tolerance comes from, why ovality must be measured a day after cutting, and how much yield a tighter tolerance costs.<\/p>","protected":false},"author":1,"featured_media":7627,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"Packaging Tube Tolerances: Diameter, Wall and Ovality","_seopress_titles_desc":"Packaging tube tolerances: OD, wall, length, ovality and concentricity limits, root causes, measurement methods, filling line interfaces and the yield cost of tightening.","_seopress_robots_index":"1","_seopress_robots_follow":"1","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"17","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"https:\/\/uplastech.com\/packaging-tube-tolerances-wall-thickness\/","_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":"packaging tube tolerances","footnotes":""},"categories":[17],"tags":[],"class_list":["post-7632","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-plastic-extrusion-process"],"meta_box":{"post-to-quiz_to":[]},"_links":{"self":[{"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/posts\/7632","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/comments?post=7632"}],"version-history":[{"count":0,"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/posts\/7632\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/media\/7627"}],"wp:attachment":[{"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/media?parent=7632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/categories?post=7632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/uplastech.com\/tr\/wp-json\/wp\/v2\/tags?post=7632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}