{"id":7611,"date":"2026-10-27T01:14:41","date_gmt":"2026-10-27T01:14:41","guid":{"rendered":"https:\/\/uplastech.com\/pps-peek-injection-molding-guide\/"},"modified":"2026-10-27T01:14:41","modified_gmt":"2026-10-27T01:14:41","slug":"pps-peek-injection-molding-guide","status":"publish","type":"post","link":"https:\/\/uplastech.com\/ar\/pps-peek-injection-molding-guide\/","title":{"rendered":"PPS and PEEK Injection Molding: Hot Moulds and Crystallinity"},"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\/im-peek-part.jpg\" alt=\"Amber PEEK and black PPS injection moulded components on a high-temperature test bench beside a thermocouple readout\" width=\"1536\" height=\"909\"><figcaption>Amber PEEK and black glass-filled PPS parts. Both were moulded with a tool at 180 \u00b0C and a melt above 340 \u00b0C \u2014 which is why the machine, the oil heater and the tool steel all had to be specified together.<\/figcaption><\/figure>\n<div class=\"toc\"><\/div>\n<h2 id=\"why\">When the material costs more than the machine time<\/h2>\n<p>PPS (polyphenylene sulfide) and PEEK (polyether ether ketone) sit at the top of the engineering thermoplastics ladder. PPS holds its properties to 200 \u00b0C continuously and is inherently flame retardant. PEEK goes to 250 \u00b0C, has outstanding chemical resistance, and is one of the few polymers acceptable for repeated autoclave sterilisation and for direct contact with aggressive solvents.<\/p>\n<p>The economics are unlike any other material in this series. PEEK costs \u20ac70 \u2013 \u20ac120 per kilogram; PPS \u20ac12 \u2013 \u20ac25. A 20 g part in PEEK therefore carries \u20ac1.40 \u2013 \u20ac2.40 of material before any processing. At that ratio, the machine time and the tooling are almost irrelevant \u2014 what matters is yield. A 5 % scrap rate on a PEEK part can cost more than the moulding.<\/p>\n<div class=\"callout\">\n<p><strong>The number that governs both materials:<\/strong> mould temperature. PPS needs <strong>130 \u2013 150 \u00b0C<\/strong>; PEEK needs <strong>170 \u2013 200 \u00b0C<\/strong>. That is above the capability of water-based temperature control, so the tool must be designed for hot oil from the start \u2014 conformal cooling channels sized for oil flow, no water lines, high-temperature seals, and a manifold that can take 200 \u00b0C. A tool designed for water cannot be converted.<\/p>\n<\/div>\n<h2 id=\"compare\">PPS versus PEEK<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u0645\u0645\u062a\u0644\u0643\u0627\u062a<\/th>\n<th>PPS + 40 % GF<\/th>\n<th>PEEK + 30 % GF<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Continuous use temperature<\/td>\n<td>200 \u2013 220 \u00b0C<\/td>\n<td>250 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Melting point<\/td>\n<td>280 \u2013 285 \u00b0C<\/td>\n<td>340 \u2013 343 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Glass transition<\/td>\n<td>~90 \u00b0C<\/td>\n<td>~143 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Tensile strength, MPa<\/td>\n<td>150 \u2013 190<\/td>\n<td>180 \u2013 220<\/td>\n<\/tr>\n<tr>\n<td>Flexural modulus, GPa<\/td>\n<td>11 \u2013 14<\/td>\n<td>10 \u2013 13<\/td>\n<\/tr>\n<tr>\n<td>HDT at 1.82 MPa<\/td>\n<td>&gt; 260 \u00b0C<\/td>\n<td>&gt; 315 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Flame rating<\/td>\n<td>UL94 V-0 inherently, at 0.4 mm<\/td>\n<td>UL94 V-0 at 1.5 mm<\/td>\n<\/tr>\n<tr>\n<td>Chemical resistance<\/td>\n<td>Excellent; no known solvent below 200 \u00b0C<\/td>\n<td>Excellent; attacked by concentrated sulphuric acid only<\/td>\n<\/tr>\n<tr>\n<td>Water absorption<\/td>\n<td>0.02 \u2013 0.05 %<\/td>\n<td>0.1 \u2013 0.5 %<\/td>\n<\/tr>\n<tr>\n<td>Shrinkage, %<\/td>\n<td>0.2 \u2013 0.5<\/td>\n<td>0.3 \u2013 1.4 (grade dependent)<\/td>\n<\/tr>\n<tr>\n<td>\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u0630\u0648\u0628\u0627\u0646<\/td>\n<td>310 \u2013 340 \u00b0C<\/td>\n<td>360 \u2013 400 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Mould temperature<\/td>\n<td>130 \u2013 150 \u00b0C<\/td>\n<td>170 \u2013 200 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Relative material cost<\/td>\n<td>1\u00d7<\/td>\n<td>5 \u2013 8\u00d7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 1 \u2014 PPS and PEEK side by side. The cost difference is the reason PPS is used wherever it is good enough.<\/p>\n<p>The decision rule is straightforward: <strong>use PPS unless you need above 220 \u00b0C, autoclave sterilisation, or resistance to a specific aggressive chemical.<\/strong> PPS is inherently V-0 without additives, which is a significant advantage \u2014 flame-retardant PEEK grades exist but are more expensive and less robust. Most \"we need PEEK\" requirements turn out to be met by PPS at a fifth of the cost.<\/p>\n<h2 id=\"grades\">Grades<\/h2>\n<table>\n<thead>\n<tr>\n<th>Grade family<\/th>\n<th>\u0627\u0644\u0645\u0648\u0627\u062f<\/th>\n<th>Key property<\/th>\n<th>Used for<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>PPS + 40 % GF<\/td>\n<td>PPS<\/td>\n<td>Stiffest, most dimensionally stable<\/td>\n<td>Connectors, pump housings, under-bonnet<\/td>\n<\/tr>\n<tr>\n<td>PPS + 40 % GF + mineral<\/td>\n<td>PPS<\/td>\n<td>Low warp, good surface<\/td>\n<td>Flat parts, automotive<\/td>\n<\/tr>\n<tr>\n<td>PPS unfilled<\/td>\n<td>PPS<\/td>\n<td>Tough, low warpage<\/td>\n<td>Coatings, chemical parts<\/td>\n<\/tr>\n<tr>\n<td>PPS impact modified<\/td>\n<td>PPS<\/td>\n<td>Notched Izod 60 \u2013 90 J\/m<\/td>\n<td>Parts with snap fits<\/td>\n<\/tr>\n<tr>\n<td>PEEK unfilled<\/td>\n<td>\u0628\u064a\u0643<\/td>\n<td>Maximum toughness and elongation<\/td>\n<td>Seals, wear parts, medical<\/td>\n<\/tr>\n<tr>\n<td>PEEK + 30 % GF<\/td>\n<td>\u0628\u064a\u0643<\/td>\n<td>Stiffness plus high temperature<\/td>\n<td>Structural, aerospace<\/td>\n<\/tr>\n<tr>\n<td>PEEK + 30 % CF<\/td>\n<td>\u0628\u064a\u0643<\/td>\n<td>Highest stiffness, conductive<\/td>\n<td>Bearings, aircraft parts<\/td>\n<\/tr>\n<tr>\n<td>PEEK, bearing grade<\/td>\n<td>PEEK + PTFE + graphite<\/td>\n<td>\u00b5 0.10 \u2013 0.20<\/td>\n<td>Bearings, thrust washers<\/td>\n<\/tr>\n<tr>\n<td>PEEK, medical<\/td>\n<td>\u0628\u064a\u0643<\/td>\n<td>ISO 10993, implantable variants<\/td>\n<td>Instruments, implants<\/td>\n<\/tr>\n<tr>\n<td>PEI, PAI, PPSU<\/td>\n<td>Adjacent families<\/td>\n<td>Between PPS and PEEK<\/td>\n<td>Where PEEK is over-specified<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 2 \u2014 High-temperature grade families. PEI (Ultem) and PPSU are worth evaluating before jumping to PEEK.<\/p>\n<h2 id=\"machine\">The machine and the tool<\/h2>\n<p>PPS and PEEK cannot be run on a standard machine without modification. The requirements are specific and they are not negotiable.<\/p>\n<table>\n<thead>\n<tr>\n<th>Item<\/th>\n<th>Requirement<\/th>\n<th>Reason<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Barrel temperature capability<\/td>\n<td>400 \u2013 420 \u00b0C for PEEK<\/td>\n<td>Standard barrels are rated 350 \u2013 380 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Barrel and screw material<\/td>\n<td>Bimetallic or corrosion-resistant<\/td>\n<td>PPS releases corrosive volatiles at temperature<\/td>\n<\/tr>\n<tr>\n<td>Screw design<\/td>\n<td>Low-compression, wear resistant<\/td>\n<td>Glass-filled material is highly abrasive<\/td>\n<\/tr>\n<tr>\n<td>Nozzle<\/td>\n<td>Heated, with a positive shut-off<\/td>\n<td>Drool at 380 \u00b0C is a real problem<\/td>\n<\/tr>\n<tr>\n<td>Hot runner<\/td>\n<td>Rated 400 \u00b0C, with external heating<\/td>\n<td>Standard hot runners are rated 300 \u2013 350 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Mould temperature control<\/td>\n<td>Hot oil, 200 \u00b0C capability<\/td>\n<td>Water cannot reach 180 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Tool steel<\/td>\n<td>Hardened, 50 \u2013 54 HRC<\/td>\n<td>Abrasion plus high temperature<\/td>\n<\/tr>\n<tr>\n<td>Tool insulation<\/td>\n<td>Insulating plates between tool and platens<\/td>\n<td>Otherwise the press acts as a heat sink<\/td>\n<\/tr>\n<tr>\n<td>Seals and hoses<\/td>\n<td>High-temperature rated<\/td>\n<td>Standard hoses fail at 180 \u00b0C oil<\/td>\n<\/tr>\n<tr>\n<td>Venting<\/td>\n<td>0.01 \u2013 0.02 mm, generous<\/td>\n<td>Trapped gas at 380 \u00b0C burns the part<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 3 \u2014 Machine and tool requirements. Any one of these missing stops the job.<\/p>\n<p>The most common planning error is the mould temperature control. A tool quoted with \"hot oil capability\" but drilled with 8 mm channels sized for water flow will not deliver 180 \u00b0C uniformly \u2014 the oil flow rate is too low, the pressure drop too high, and the tool runs 30 \u00b0C cooler at the far end. Conformal cooling or generously sized channels (12 \u2013 14 mm) are needed, and the oil unit must be sized for the tool's heat load, not just its temperature.<\/p>\n<h2 id=\"processing\">Processing windows<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u0645\u0639\u0644\u0645\u0629<\/th>\n<th>PPS + GF<\/th>\n<th>PEEK + GF<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u0630\u0648\u0628\u0627\u0646<\/td>\n<td>310 \u2013 340 \u00b0C<\/td>\n<td>360 \u2013 400 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Barrel profile<\/td>\n<td>290 \/ 310 \/ 325 \/ 330 \u00b0C<\/td>\n<td>340 \/ 365 \/ 380 \/ 390 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Mould temperature<\/td>\n<td>130 \u2013 150 \u00b0C<\/td>\n<td>170 \u2013 200 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Injection pressure<\/td>\n<td>90 \u2013 140 MPa<\/td>\n<td>100 \u2013 160 MPa<\/td>\n<\/tr>\n<tr>\n<td>Injection speed<\/td>\n<td>\u0633\u0631\u064a\u0639<\/td>\n<td>Moderate \u2014 high shear degrades PEEK<\/td>\n<\/tr>\n<tr>\n<td>Hold pressure<\/td>\n<td>50 \u2013 70 % of injection<\/td>\n<td>50 \u2013 70 %<\/td>\n<\/tr>\n<tr>\n<td>Residence time<\/td>\n<td>&lt; 6 min<\/td>\n<td>&lt; 5 min<\/td>\n<\/tr>\n<tr>\n<td>Drying<\/td>\n<td>150 \u00b0C, 3 h<\/td>\n<td>150 \u2013 160 \u00b0C, 3 \u2013 4 h<\/td>\n<\/tr>\n<tr>\n<td>\u0627\u0644\u062a\u0644\u062f\u064a\u0646<\/td>\n<td>Rarely needed<\/td>\n<td>200 \u00b0C for 2 \u2013 4 h for maximum crystallinity<\/td>\n<\/tr>\n<tr>\n<td>Regrind<\/td>\n<td>Up to 15 %<\/td>\n<td>0 \u2013 10 % (property loss is significant)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 4 \u2014 Processing windows. PEEK's 400 \u00b0C melt is at the limit of most standard equipment.<\/p>\n<p>Drying is often overlooked because these materials absorb so little water \u2014 0.02 % for PPS. But at 380 \u00b0C even 0.05 % moisture causes visible splay and a measurable loss of molecular weight, and the part cost means the scrap is expensive. Dry at 150 \u00b0C for 3 hours regardless of what the datasheet implies.<\/p>\n<h2 id=\"crystallinity\">Crystallinity: the property you control with the tool<\/h2>\n<p>Both materials are semi-crystalline, and the degree of crystallinity determines strength, wear resistance, chemical resistance and dimensional stability. It is set by the mould temperature and the cooling rate, and it cannot be recovered afterwards except by annealing.<\/p>\n<table>\n<thead>\n<tr>\n<th>Mould temperature<\/th>\n<th>Crystallinity<\/th>\n<th>Result<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>PEEK at 120 \u00b0C<\/td>\n<td>15 \u2013 20 %<\/td>\n<td>Brittle, poor wear, poor chemical resistance, dimensionally unstable<\/td>\n<\/tr>\n<tr>\n<td>PEEK at 160 \u00b0C<\/td>\n<td>25 \u2013 30 %<\/td>\n<td>Acceptable for non-critical parts<\/td>\n<\/tr>\n<tr>\n<td>PEEK at 180 \u2013 200 \u00b0C<\/td>\n<td>30 \u2013 35 %<\/td>\n<td>Full properties as specified<\/td>\n<\/tr>\n<tr>\n<td>PPS at 100 \u00b0C<\/td>\n<td>\u0645\u0646\u062e\u0641\u0636\u0629<\/td>\n<td>Brittle; fails impact<\/td>\n<\/tr>\n<tr>\n<td>PPS at 140 \u2013 150 \u00b0C<\/td>\n<td>\u0639\u0627\u0644\u064a\u0629<\/td>\n<td>Full properties<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 5 \u2014 Crystallinity versus mould temperature. A cold tool produces a part that looks right and is not.<\/p>\n<p>This is the single most important thing to understand about high-temperature materials: a PEEK part moulded at 120 \u00b0C looks identical to one moulded at 190 \u00b0C, passes a dimensional check, and has roughly half the wear life and a fraction of the chemical resistance. If a supplier cannot tell you their mould temperature, they cannot tell you what they made.<\/p>\n<h2 id=\"design\">Design rules<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u0645\u064a\u0632\u0629<\/th>\n<th>Rule<\/th>\n<th>\u0644\u0645\u0627\u0630\u0627<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Wall thickness<\/td>\n<td>1.5 \u2013 4.0 mm<\/td>\n<td>Thin walls are hard to fill at high viscosity; thick walls are expensive material<\/td>\n<\/tr>\n<tr>\n<td>Wall uniformity<\/td>\n<td>Within 15 %<\/td>\n<td>Differential crystallinity causes warpage<\/td>\n<\/tr>\n<tr>\n<td>Internal radius<\/td>\n<td>\u2265 0.5 \u00d7 wall<\/td>\n<td>Notch sensitivity in glass-filled grades<\/td>\n<\/tr>\n<tr>\n<td>Draft<\/td>\n<td>1 \u2013 1.5\u00b0<\/td>\n<td>High shrinkage force, especially PEEK<\/td>\n<\/tr>\n<tr>\n<td>Gate<\/td>\n<td>Large; direct or edge<\/td>\n<td>High shear degrades the melt<\/td>\n<\/tr>\n<tr>\n<td>Snap fits<\/td>\n<td>Strain \u2264 1 % for glass-filled<\/td>\n<td>Elongation at break is 2 \u2013 3 %<\/td>\n<\/tr>\n<tr>\n<td>Threads<\/td>\n<td>Avoid; use inserts or a separate fastener<\/td>\n<td>Thread roots crack in brittle grades<\/td>\n<\/tr>\n<tr>\n<td>Material minimisation<\/td>\n<td>Core out every non-functional volume<\/td>\n<td>At \u20ac70 \u2013 \u20ac120\/kg, geometry is the biggest cost lever<\/td>\n<\/tr>\n<tr>\n<td>Tolerance<\/td>\n<td>&plusmn;0.05 mm achievable on small parts, &plusmn;0.1 mm typical<\/td>\n<td>High shrinkage and crystallinity variation limit it<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 6 \u2014 Design rules. The material-minimisation row is unique to this cost bracket.<\/p>\n<h2 id=\"cost\">Cost structure: where the money actually goes<\/h2>\n<table>\n<thead>\n<tr>\n<th>Cost element<\/th>\n<th>PPS part<\/th>\n<th>PEEK part<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0627\u0644\u0645\u0648\u0627\u062f<\/td>\n<td>45 \u2013 60 %<\/td>\n<td>70 \u2013 85 %<\/td>\n<\/tr>\n<tr>\n<td>Machine time (hot runner, slow cycle)<\/td>\n<td>15 \u2013 25 %<\/td>\n<td>8 \u2013 15 %<\/td>\n<\/tr>\n<tr>\n<td>Tooling amortisation<\/td>\n<td>10 \u2013 20 %<\/td>\n<td>3 \u2013 8 %<\/td>\n<\/tr>\n<tr>\n<td>Scrap and yield loss<\/td>\n<td>5 \u2013 10 %<\/td>\n<td>5 \u2013 15 %<\/td>\n<\/tr>\n<tr>\n<td>\u0627\u0644\u0641\u062d\u0635<\/td>\n<td>3 \u2013 8 %<\/td>\n<td>2 \u2013 5 %<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 7 \u2014 Cost structure. On PEEK, material is the price; on PPS, it is roughly half.<\/p>\n<p>The consequence for design is that a PEEK part should be designed like a machined part: minimise the envelope, core out everything, and accept a more complex tool if it removes material. A 20 % reduction in part volume is a 20 % reduction in the largest cost line, which usually beats any cycle-time improvement.<\/p>\n<h2 id=\"applications\">Where each material belongs<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u062a\u0637\u0628\u064a\u0642<\/th>\n<th>\u0627\u0644\u0645\u0648\u0627\u062f<\/th>\n<th>Reason<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Automotive under-bonnet connectors<\/td>\n<td>PPS + 40 % GF<\/td>\n<td>200 \u00b0C, chemical resistance, V-0 inherent<\/td>\n<\/tr>\n<tr>\n<td>Pump and valve housings<\/td>\n<td>PPS + GF<\/td>\n<td>Chemical resistance, dimensional stability<\/td>\n<\/tr>\n<tr>\n<td>LED reflector housings<\/td>\n<td>PPS or PEEK<\/td>\n<td>High temperature, low outgassing, white grades available<\/td>\n<\/tr>\n<tr>\n<td>Surgical instruments<\/td>\n<td>\u0628\u064a\u0643<\/td>\n<td>Repeated autoclave, ISO 10993<\/td>\n<\/tr>\n<tr>\n<td>Bearing cages, thrust washers<\/td>\n<td>PEEK + PTFE\/graphite<\/td>\n<td>Wear, temperature, chemical resistance<\/td>\n<\/tr>\n<tr>\n<td>Aerospace brackets<\/td>\n<td>PEEK + CF<\/td>\n<td>Specific strength, FST compliance<\/td>\n<\/tr>\n<tr>\n<td>Semiconductor wet benches<\/td>\n<td>PEEK or PPS<\/td>\n<td>Resistance to acids and solvents at temperature<\/td>\n<\/tr>\n<tr>\n<td>Downhole and oilfield parts<\/td>\n<td>\u0628\u064a\u0643<\/td>\n<td>Temperature plus H\u2082S and hydrocarbon resistance<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 8 \u2014 Application map. Most \"PEEK\" requirements are actually PPS requirements.<\/p>\n<h2 id=\"defects\">Defects and causes<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u0639\u064a\u0628<\/th>\n<th>\u0627\u0644\u0633\u0628\u0628<\/th>\n<th>Fix<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Brittle parts<\/td>\n<td>Low mould temperature \u2192 low crystallinity<\/td>\n<td>Raise mould to 140 \u00b0C (PPS) or 180 \u00b0C (PEEK)<\/td>\n<\/tr>\n<tr>\n<td>\u0648\u0627\u0631\u0628\u062c<\/td>\n<td>Differential crystallinity, fibre orientation<\/td>\n<td>Uniform mould temperature; symmetric gating<\/td>\n<\/tr>\n<tr>\n<td>Splay \/ streaks<\/td>\n<td>Moisture<\/td>\n<td>Dry at 150 \u00b0C for 3 \u2013 4 h<\/td>\n<\/tr>\n<tr>\n<td>Black specks<\/td>\n<td>Degraded material at 380 \u00b0C<\/td>\n<td>Purge; check hot-runner dead spots; reduce residence<\/td>\n<\/tr>\n<tr>\n<td>Short shots<\/td>\n<td>Cold tool, high viscosity<\/td>\n<td>Raise mould and melt temperature; increase speed<\/td>\n<\/tr>\n<tr>\n<td>Flash<\/td>\n<td>Low melt viscosity at high temperature<\/td>\n<td>Check clamp tonnage \u2014 high-temperature melts are thin<\/td>\n<\/tr>\n<tr>\n<td>\u0627\u0644\u0628\u062b\u0648\u0631<\/td>\n<td>Volatiles, or moisture<\/td>\n<td>Dry; add venting; check for degradation<\/td>\n<\/tr>\n<tr>\n<td>Dimensional drift after machining<\/td>\n<td>Incomplete crystallinity<\/td>\n<td>Anneal at 200 \u00b0C before machining<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 9 \u2014 Defects. Four of the eight trace back to mould temperature or moisture.<\/p>\n<h2 id=\"tool\">Designing a tool for a 200 \u00b0C mould<\/h2>\n<p>A high-temperature tool is a different design, not the same design with a bigger heater. The differences are structural and they have to be in the tool from the start.<\/p>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u0645\u064a\u0632\u0629<\/th>\n<th>Standard tool<\/th>\n<th>High-temperature tool<\/th>\n<th>\u0644\u0645\u0627\u0630\u0627<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Cooling channels<\/td>\n<td>8 \u2013 10 mm, water<\/td>\n<td>12 \u2013 14 mm, hot oil<\/td>\n<td>Oil needs 3 \u2013 5\u00d7 the flow for the same heat transfer<\/td>\n<\/tr>\n<tr>\n<td>Seals<\/td>\n<td>Nitrile O-rings<\/td>\n<td>Viton or PTFE<\/td>\n<td>Nitrile fails at 150 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Hoses<\/td>\n<td>Standard hydraulic<\/td>\n<td>High-temperature rated, insulated<\/td>\n<td>Standard hose degrades at 180 \u00b0C oil<\/td>\n<\/tr>\n<tr>\n<td>Insulation<\/td>\n<td>None<\/td>\n<td>Insulating plates to the platens<\/td>\n<td>Otherwise the press is a 20 kW heat sink<\/td>\n<\/tr>\n<tr>\n<td>Tool steel<\/td>\n<td>P20, 30 \u2013 34 HRC<\/td>\n<td>H13 or 1.2343, 50 \u2013 54 HRC<\/td>\n<td>Abrasion plus thermal cycling<\/td>\n<\/tr>\n<tr>\n<td>Ejector system<\/td>\n<td>Standard<\/td>\n<td>Clearanced for thermal expansion<\/td>\n<td>A 300 mm steel block grows 0.6 mm at 200 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Slides and lifters<\/td>\n<td>Standard fits<\/td>\n<td>Increased clearance, dry-film lubricant<\/td>\n<td>Grease carbonises at 200 \u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Venting<\/td>\n<td>0.02 mm<\/td>\n<td>0.01 \u2013 0.015 mm<\/td>\n<td>Thinner melt at temperature flashes more easily<\/td>\n<\/tr>\n<tr>\n<td>Hot runner<\/td>\n<td>300 \u2013 350 \u00b0C rated<\/td>\n<td>400 \u00b0C rated, external heat<\/td>\n<td>Internal-heat hot runners cannot reach 400 \u00b0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 9 \u2014 Standard versus high-temperature tooling. The insulation and the thermal expansion allowance are the two most often forgotten.<\/p>\n<p>Thermal expansion deserves a number: steel grows about 12 \u00d7 10\u207b\u2076 per kelvin. A 300 mm mould block taken from 20 \u00b0C to 200 \u00b0C grows 0.65 mm. If the ejector plate, the guide pins and the slides were fitted at room temperature with standard clearances, the tool will seize at operating temperature. High-temperature tools are assembled with the expansion allowance designed in, and often they are checked hot before the first shot.<\/p>\n<h2 id=\"anneal\">Annealing and machining PEEK<\/h2>\n<p>PEEK parts are frequently machined after moulding, and the sequence matters. Machining a part with incomplete crystallinity produces a part that changes dimension weeks later.<\/p>\n<table>\n<thead>\n<tr>\n<th>\u0627\u0644\u062e\u0637\u0648\u0629<\/th>\n<th>Condition<\/th>\n<th>\u0627\u0644\u063a\u0631\u0636<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1. Mould<\/td>\n<td>Mould at 180 \u2013 200 \u00b0C<\/td>\n<td>Achieve 30 \u2013 35 % crystallinity in the tool<\/td>\n<\/tr>\n<tr>\n<td>2. Anneal<\/td>\n<td>200 \u00b0C for 2 \u2013 4 h, cool at \u2264 20 \u00b0C\/h<\/td>\n<td>Complete crystallinity, relieve stress<\/td>\n<\/tr>\n<tr>\n<td>3. Machine<\/td>\n<td>Sharp carbide tooling, high speed, low feed<\/td>\n<td>PEEK machines like brass but is abrasive when filled<\/td>\n<\/tr>\n<tr>\n<td>4. Re-anneal (optional)<\/td>\n<td>200 \u00b0C for 1 \u2013 2 h<\/td>\n<td>Relieve machining stress for tight-tolerance parts<\/td>\n<\/tr>\n<tr>\n<td>5. Inspect<\/td>\n<td>After 24 h at 23 \u00b0C<\/td>\n<td>Let the part stabilise before final measurement<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 10 \u2014 The PEEK mould-anneal-machine sequence. Skipping step 2 causes dimensional drift after machining.<\/p>\n<p>For implantable or medical PEEK, annealing is also part of the validation: the crystallinity level affects the material's mechanical performance and must be documented. A supplier who cannot state the crystallinity of the parts they ship cannot support a medical submission.<\/p>\n<h2 id=\"supplier\">Qualifying a supplier for high-temperature moulding<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0633\u0624\u0627\u0644<\/th>\n<th>Why it matters<\/th>\n<th>Acceptable answer<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>What is your maximum barrel temperature?<\/td>\n<td>PEEK needs 400 \u00b0C<\/td>\n<td>A specific number, not \"high\"<\/td>\n<\/tr>\n<tr>\n<td>How do you control mould temperature?<\/td>\n<td>Water cannot reach 180 \u00b0C<\/td>\n<td>Hot oil, with the unit capacity stated<\/td>\n<\/tr>\n<tr>\n<td>What mould temperature will you run?<\/td>\n<td>Determines crystallinity<\/td>\n<td>180 \u2013 200 \u00b0C for PEEK, 140 \u00b0C for PPS<\/td>\n<\/tr>\n<tr>\n<td>How do you verify crystallinity?<\/td>\n<td>The part can look right and be wrong<\/td>\n<td>DSC, density, or a documented process window<\/td>\n<\/tr>\n<tr>\n<td>What is your dryer dew point?<\/td>\n<td>Moisture causes splay and hydrolysis<\/td>\n<td>\u221220 \u00b0C or lower, measured<\/td>\n<\/tr>\n<tr>\n<td>Is the hot runner rated for the melt temperature?<\/td>\n<td>Standard units fail above 350 \u00b0C<\/td>\n<td>A specific rating above the process temperature<\/td>\n<\/tr>\n<tr>\n<td>What is your regrind policy?<\/td>\n<td>Regrind reduces HDT and wear life<\/td>\n<td>Stated percentage, and tested<\/td>\n<\/tr>\n<tr>\n<td>Can you show a DSC trace?<\/td>\n<td>It is the only proof of crystallinity<\/td>\n<td>Yes, for the actual production parts<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"tablecap\">Table 11 \u2014 Supplier qualification questions. A supplier who cannot answer the crystallinity question should not be quoting PEEK.<\/p>\n<p>The crystallinity question is the one to press on, because it is where a cheap quote comes from. A moulder running PEEK at 140 \u00b0C mould temperature will produce parts faster and cheaper, and they will look identical. They will also have roughly half the wear life and a fraction of the chemical resistance \u2014 and the failure will appear in the customer's application, not in the incoming inspection.<\/p>\n<h2 id=\"faq\">Frequently asked questions<\/h2>\n<div class=\"faq\">\n<h3>Do I really need PEEK, or will PPS do?<\/h3>\n<p>PPS handles 200 \u2013 220 \u00b0C continuously, is inherently V-0, and resists almost every chemical. PEEK is needed above 220 \u00b0C, for autoclave sterilisation, for concentrated sulphuric acid, and for the highest wear applications. If none of those apply, PPS at a fifth of the cost is the right answer.<\/p>\n<h3>Can I mould PEEK on a standard machine?<\/h3>\n<p>Only if the barrel is rated for 400 \u00b0C and the tool can run at 180 \u2013 200 \u00b0C with hot oil. Most standard machines are rated 350 \u2013 380 \u00b0C and most standard tools are drilled for water. Both need to be specified for the material from the start.<\/p>\n<h3>Why is my PEEK part brittle?<\/h3>\n<p>Almost certainly low crystallinity from a cold mould. PEEK needs 170 \u2013 200 \u00b0C to crystallise fully; at 120 \u00b0C it is 15 \u2013 20 % crystalline instead of 30 \u2013 35 %. The part looks identical and has roughly half the wear life.<\/p>\n<h3>Does PPS need a hot runner?<\/h3>\n<p>It benefits from one, but the hot runner must be rated for 400 \u00b0C with external heating. A standard 300 \u00b0C hot runner will not hold PPS at 330 \u00b0C reliably and the tips will freeze or degrade the material.<\/p>\n<h3>How much does PEEK tooling cost?<\/h3>\n<p>1.3 \u2013 2\u00d7 an equivalent PBT tool, because of the hardened steel, the hot-oil cooling design and the high-temperature hot runner. The tooling is a small share of the project cost \u2014 the material dominates.<\/p>\n<h3>Can PEEK be sterilised repeatedly?<\/h3>\n<p>Yes \u2014 that is one of its defining advantages. PEEK withstands over 1,000 autoclave cycles at 134 \u00b0C, plus gamma and ethylene oxide sterilisation, without significant property loss. PPS is not suitable for repeated autoclave.<\/p>\n<h3>What is the shrinkage of PEEK?<\/h3>\n<p>0.3 \u2013 1.4 % depending on grade and flow direction \u2014 a very wide range. Unfilled PEEK is at the high end and is anisotropic; 30 % glass-filled is at the low end. This is why PEEK tools are usually cut, trialled and corrected rather than cut to a calculated shrinkage.<\/p>\n<h3>Is regrind acceptable?<\/h3>\n<p>Up to 10 \u2013 15 % for PPS, 0 \u2013 10 % for PEEK. The property loss is real and the material is expensive enough that regrind is tempting \u2014 but on a part that was specified for high-temperature performance, a 15 % regrind addition can drop the HDT below the requirement. Test it, do not assume.<\/p>\n<\/div>\n<div class=\"cta\">\n<p class=\"cta-h\">Specifying a high-temperature part? Check whether PPS is enough before you budget for PEEK<\/p>\n<p>Send the drawing, the continuous service temperature and the chemical environment. We will tell you which material actually meets it, and what the part costs in each.<\/p>\n<p><a class=\"btn\" href=\"https:\/\/uplastech.com\/ar\/pps-peek-injection-molding\/\">Talk to a high-temperature moulding engineer<\/a>\n<\/div>\n<div class=\"rel\">\n<h4>Continue reading<\/h4>\n<ul>\n<li><a href=\"https:\/\/uplastech.com\/ar\/pbt-pet-injection-molding-guide\/\">PBT and PET Injection Molding: Glass Fibre, Drying and Warpage<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/ar\/nylon-pa-injection-molding-guide\/\">Nylon (PA6 \/ PA66) Injection Molding: Moisture, Conditioning and Dimensions<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/ar\/injection-molding-material-selection\/\">Injection Molding Material Selection: 14 Plastics Compared<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/ar\/injection-molding-tolerances\/\">Injection Molding Tolerances: What Is Actually Achievable<\/a><\/li>\n<li><a href=\"https:\/\/uplastech.com\/ar\/custom-injection-molding-guide\/\">Custom Injection Molding Guide: Process, Cost &amp; Tolerances<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>High temperature moulding: PPS versus PEEK, the 200 \u00b0C mould requirement, machine and tooling specification, crystallinity, annealing and supplier qualification.<\/p>","protected":false},"author":1,"featured_media":7603,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"PPS & PEEK Injection Molding: Hot Moulds & Crystallinity","_seopress_titles_desc":"High temperature moulding: PPS versus PEEK, the 200 \u00b0C mould requirement, machine and tooling specification, crystallinity, annealing and supplier qualification.","_seopress_robots_index":"1","_seopress_robots_follow":"1","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"35","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"https:\/\/uplastech.com\/pps-peek-injection-molding-guide\/","_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":"pps peek injection molding","footnotes":""},"categories":[35],"tags":[],"class_list":["post-7611","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-injection-molding"],"meta_box":{"post-to-quiz_to":[]},"_links":{"self":[{"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/posts\/7611","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/comments?post=7611"}],"version-history":[{"count":0,"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/posts\/7611\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/media\/7603"}],"wp:attachment":[{"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/media?parent=7611"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/categories?post=7611"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/uplastech.com\/ar\/wp-json\/wp\/v2\/tags?post=7611"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}