{"id":8207,"date":"2026-03-06T09:00:00","date_gmt":"2026-03-06T09:00:00","guid":{"rendered":"https:\/\/uplastech.com\/thermoforming-food-trays\/"},"modified":"2026-03-06T09:00:00","modified_gmt":"2026-03-06T09:00:00","slug":"thermoforming-food-trays","status":"publish","type":"post","link":"https:\/\/uplastech.com\/nl\/thermoforming-food-trays\/","title":{"rendered":"Thermoformed Food Trays: Material, Barrier and the Filling Line"},"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 \u95ee\u5019\u5361\uff0c\u53ea\u4fdd\u7559\u5706\u5f62\u6c14\u6ce1\uff0c\u907f\u514d\u906e\u6321\u4fa7\u680f\u8be2\u76d8\u63d0\u4ea4\u6309\u94ae\u3002\n   \u6ce8\u610f\uff1aClick to Chat \u7684\u70b9\u51fb\u903b\u8f91\u662f\u300c\u95ee\u5019\u5361\u5143\u7d20\u5b58\u5728\u5c31\u4e0d\u8df3\u8f6c\u300d\uff0c\u53ea\u9760 CSS \u9690\u85cf\u4f1a\u8ba9\u6c14\u6ce1\u53d8\u6210\u6b7b\u94fe\u63a5\u3002\n   Code Snippets #9\u300cUPL single post: WhatsApp bubble jumps straight to chat\u300d\u8d1f\u8d23\u628a\u8be5\u8282\u70b9\u4ece DOM \u79fb\u9664\uff0c\n   \u4e0b\u9762\u8fd9\u6761 CSS \u53ea\u662f\u79fb\u9664\u524d\u7684\u89c6\u89c9\u515c\u5e95\u3002\u5220 #9 \u524d\u5fc5\u987b\u5148\u5220\u8fd9\u6761\u89c4\u5219\u3002 *\/\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\/thermoforming-food-trays.jpg\" alt=\"Stack of white multi-compartment thermoformed food trays with one turned over to show base ribs, a caliper on the bench\" width=\"1536\" height=\"909\"><figcaption>Nested PP food trays. The ribs in the base are what turn a thin wall into a tray that stacks and carries.<\/figcaption><\/figure>\n<div class=\"toc\"><\/div>\n<h2 id=\"line\">The tray is chosen on the filling line<\/h2>\n<p>A food tray is usually discussed as packaging, and it is actually a piece of process equipment. It has to survive the filling temperature, the sealing temperature, the top load in a pallet and the handling in a distribution centre, and it has to do that at a cost that is a few cents.<\/p>\n<p>Those requirements conflict. The material that takes the highest fill temperature, polypropylene, has a modest barrier. The material with the best barrier, PET, has a lower heat resistance. The material with the best sustainability story, PLA, has the lowest heat resistance of all.<\/p>\n<p>The order in which the requirements are considered decides the answer. Start with the fill temperature, then the barrier, then the top load, then the cost. A project that starts with the material has already made the decision before it has the requirements.<\/p>\n<h2 id=\"heat\">Heat resistance decides the material<\/h2>\n<p>Heat deflection temperature is a reasonable proxy for what a tray can take. Polypropylene sits at about 105 C, PET at 78, polystyrene at 75 and PLA at 55. A hot fill at 85 C is fine in PP and marginal in PET, and it will distort a PLA tray before it reaches the sealer.<\/p>\n<p>That is why PP dominates ready-meal trays and why PET dominates cold and chilled applications. It is not a preference; it is the fill temperature. A PLA tray in a hot-fill application is a design error that no amount of ribbing fixes.<\/p>\n<p>There is a second temperature that matters: the seal temperature. A lidding film seals at 140 to 180 C for a fraction of a second, and a tray that softens at that temperature will deform at the seal head even if it survived the fill. The seal is often the harder requirement.<\/p>\n<figure>\n<img decoding=\"async\" src=\"https:\/\/uplastech.com\/wp-content\/uploads\/2026\/10\/thermoforming-food-trays-chart.jpg\" alt=\"Heat deflection temperature for PP, PET, PS and PLA, and top load rising from 42 to 268 newtons with wall thickness\" width=\"1536\" height=\"909\"><figcaption>Left: heat deflection by material, 105 C for PP and 55 for PLA. Right: top load against wall thickness, 42 N at 0.4 mm and 268 N at 1.2.<\/figcaption><\/figure>\n<h2 id=\"load\">Wall thickness is what carries the load<\/h2>\n<p>Top load is the force a tray takes when it is stacked in a pallet, and it goes up steeply with wall thickness. At 0.4 mm a tray takes about 42 N, at 0.6 mm 88, at 0.8 mm 145, at 1.0 mm 205 and at 1.2 mm 268.<\/p>\n<p>That is a factor of six across the range, and it is the strongest argument against thinning a tray to save material. A tray that has been thinned from 0.8 to 0.6 mm saves a quarter of its material and loses 40 percent of its top load, and the failure appears in the pallet rather than in the plant.<\/p>\n<p>Ribs help, and they help differently from thickness. A rib increases the section's second moment of area without adding much material, so it improves stiffness more efficiently than a thicker wall. The base ribs in a tray are there for exactly this reason, and they are why a 0.6 mm ribbed tray can outperform a 0.8 mm flat one.<\/p>\n<h2 id=\"barrier\">Barrier is a separate decision<\/h2>\n<p>A single-material tray has the barrier of its material. PP is a good moisture barrier and a poor oxygen barrier; PET is better on oxygen and worse on moisture; PS is poor on both. For a product that needs an oxygen barrier, the tray is either multi-layer or it relies on the lidding film.<\/p>\n<p>Multi-layer trays are co-extruded sheet thermoformed into the same shape, with a barrier layer in the middle. They work, and they are difficult to recycle, which is why the market has moved towards mono-material trays with a barrier lidding film.<\/p>\n<p>The lidding film is often the cheapest place to put the barrier, because it is thin and it is discarded separately. A PP tray with an EVOH-containing lid gives a better total barrier than a mono PP tray with a plain lid, at a lower material cost than a barrier tray.<\/p>\n<table>\n<thead>\n<tr>\n<th>Materiaal<\/th>\n<th>Heat<\/th>\n<th>Oxygen barrier<\/th>\n<th>Geschikt voor<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>PP<\/td>\n<td>105 C<\/td>\n<td>Slecht<\/td>\n<td>Hot fill, ready meals<\/td>\n<\/tr>\n<tr>\n<td>PET<\/td>\n<td>78 C<\/td>\n<td>Goed<\/td>\n<td>Chilled, bakery, visible product<\/td>\n<\/tr>\n<tr>\n<td>PS<\/td>\n<td>75 C<\/td>\n<td>Slecht<\/td>\n<td>Cold, dry, low cost<\/td>\n<\/tr>\n<tr>\n<td>PLA<\/td>\n<td>55 C<\/td>\n<td>Matig<\/td>\n<td>Cold chain, compostable<\/td>\n<\/tr>\n<tr>\n<td>CPET<\/td>\n<td>200 C<\/td>\n<td>Goed<\/td>\n<td>Ovenable<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 1 \u2014 Tray materials and what each is good at<\/p>\n<h2 id=\"design\">Designing for the line, not the shelf<\/h2>\n<p>The stack height and the nesting ratio decide how many trays fit in a sleeve and on a pallet, and they are set by the side wall angle and the flange. A tray that nests too tightly jams in the denester; one that nests too loosely takes more space and costs more to ship.<\/p>\n<p>The flange width is set by the sealing head, not by the tray. A flange that is too narrow gives a weak seal; too wide wastes material and can interfere with the denester. The sealer supplier's dimension is the input, and it should be asked for before the tool is cut.<\/p>\n<p>The corner radius matters for the same reason as in any thermoformed part: it is the thinnest point after forming and the place where the tray cracks. A tight corner in a 0.6 mm tray is a crack waiting for a drop.<\/p>\n<table>\n<thead>\n<tr>\n<th>Functie<\/th>\n<th>Set by<\/th>\n<th>Typical<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Flange width<\/td>\n<td>Sealing head<\/td>\n<td>8-15 mm<\/td>\n<\/tr>\n<tr>\n<td>Side wall angle<\/td>\n<td>Nesting and draw<\/td>\n<td>5-10 degrees<\/td>\n<\/tr>\n<tr>\n<td>Base rib depth<\/td>\n<td>Top load<\/td>\n<td>2-4 mm<\/td>\n<\/tr>\n<tr>\n<td>Corner radius<\/td>\n<td>Forming and strength<\/td>\n<td>5 mm and up<\/td>\n<\/tr>\n<tr>\n<td>Wall<\/td>\n<td>Top load and cost<\/td>\n<td>0.6-1.0 mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 2 \u2014 Tray features and what actually sets them<\/p>\n<h2 id=\"sustain\">The recycling question, honestly<\/h2>\n<p>A mono-material PP tray is recyclable in a stream that accepts PP, and a multi-layer tray usually is not. That is the main reason the market has moved to mono-material with a barrier lid, and it is a real improvement rather than a marketing one.<\/p>\n<p>PLA is compostable in an industrial facility and not in a home compost heap, and it contaminates a PET recycling stream. A switch to PLA is a switch to a different waste route, not a free improvement, and it only works where that route exists.<\/p>\n<p>The most effective sustainability decision for a tray is usually thickness. A tray that uses 20 percent less material because it is properly ribbed saves more than a switch to a recycled grade, and it does not depend on infrastructure.<\/p>\n<div class=\"myth\">Myth: a compostable tray is always the greener choice. PLA needs an industrial composting stream, it cannot take a hot fill, and it contaminates PET recycling. Where the infrastructure is missing, it is a heavier landfill item with a better label.<\/div>\n<div class=\"faq\">\n<h3>What material should a hot-fill tray be?<\/h3>\n<p>Polypropylene, at about 105 C heat deflection. PET at 78 C is marginal for an 85 C fill, and PLA at 55 C will distort before it reaches the sealer.<\/p>\n<h3>How thick should a food tray wall be?<\/h3>\n<p>0.6 to 1.0 mm for most applications, set by the top load requirement. A 0.8 mm tray takes about 145 N; a 0.6 mm tray about 88 N, so thinning costs top load quickly.<\/p>\n<h3>Do ribs help more than thickness?<\/h3>\n<p>For stiffness, yes. A rib adds section without much material, so a ribbed 0.6 mm tray can outperform a flat 0.8 mm one. For puncture and impact, thickness still matters.<\/p>\n<h3>What is the seal temperature for a lidding film?<\/h3>\n<p>Usually 140 to 180 C for a fraction of a second. The tray has to survive that without deforming, and for some materials the seal is a harder requirement than the fill.<\/p>\n<h3>Can a PP tray be recycled?<\/h3>\n<p>Yes, as mono-material PP. A multi-layer tray with a barrier layer usually cannot be, which is why the market has moved to mono-material trays with a barrier lid.<\/p>\n<h3>Why does my tray jam in the denester?<\/h3>\n<p>Nesting ratio. A side wall angle that is too steep nests too tightly and the trays stick; too shallow and the stack is unstable. The angle and the flange are the two controls.<\/p>\n<\/div>\n<div class=\"cta\">\n<p class=\"cta-h\">A food tray that has to survive the line?<\/p>\n<p>Send the fill temperature, the seal condition and the pallet load. We will tell you the material and the wall, and where the tray will fail first.<\/p>\n<p><a class=\"btn\" href=\"https:\/\/uplastech.com\/nl\/custom-vacuum-forming\/\">Ask about food trays<\/a>\n<\/div>\n<div class=\"rel\">\n<h4>Continue reading<\/h4>\n<ul>\n<li><a href=\"https:\/\/uplastech.com\/nl\/sheet-thermoforming-grade\/\">Thermoforming Grade Sheet: What Separates It From General Purpose<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/nl\/thermoforming-mold-texture\/\">Thermoforming Mould Texture: Grain, Depth and Transfer<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/nl\/thermoforming-stacking-nesting\/\">Thermoforming Stacking and Nesting: The Geometry of a Stack<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/nl\/thermoforming-cnc-trimming\/\">Thermoforming CNC Trimming: The Last Millimetre<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/nl\/custom-vacuum-forming\/\">Custom Vacuum Forming: Tools, Tolerances and Volumes<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>A tray is chosen on the filling line, not on the shelf. PP holds 105 C and takes a hot fill; PET holds 78 and gives a barrier; PLA holds 55 and needs a cold chain. And the wall decides the top load, from 42 N at 0.4 mm to 268 N at 1.2.<\/p>","protected":false},"author":1,"featured_media":8205,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"class_list":["post-8207","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vacuum-forming"],"meta_box":{"post-to-quiz_to":[]},"_links":{"self":[{"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/posts\/8207","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/comments?post=8207"}],"version-history":[{"count":0,"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/posts\/8207\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/media\/8205"}],"wp:attachment":[{"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/media?parent=8207"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/categories?post=8207"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/uplastech.com\/nl\/wp-json\/wp\/v2\/tags?post=8207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}