# Thermoplastic Resin Processing Temperature and Shrinkage Reference > Source: https://netray.co/tools/thermoplastic-resin-processing-temperature-shrinkage-reference > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Typical processing windows, drying needs and shrinkage ranges for common injection molding resins, in a searchable table. ## Category manufacturing ## Industry Plastics and Injection Molding ## Audience - Process engineer - Molding engineer - Mold designer ## Tool **Kind:** worksheet **Mode:** reference **Columns:** #### Resin **Key:** resin **Type:** text #### Abbreviation **Key:** abbr **Type:** text #### Typical melt temp (F) **Key:** melt **Type:** text #### Typical mold temp (F) **Key:** mold **Type:** text #### Typical shrinkage (%) **Key:** shrink **Type:** text #### Drying before molding **Key:** dry **Type:** text #### Structure **Key:** family **Type:** text **Rows:** **Resin:** Polypropylene **Abbr:** PP **Melt:** 390-500 **Mold:** 70-140 **Shrink:** 1.0-2.5 **Dry:** Not normally required **Family:** Semi-crystalline **Resin:** High-density polyethylene **Abbr:** HDPE **Melt:** 400-500 **Mold:** 60-140 **Shrink:** 1.5-4.0 **Dry:** Not normally required **Family:** Semi-crystalline **Resin:** Low-density polyethylene **Abbr:** LDPE **Melt:** 330-450 **Mold:** 70-110 **Shrink:** 1.5-5.0 **Dry:** Not normally required **Family:** Semi-crystalline **Resin:** General purpose polystyrene **Abbr:** GPPS **Melt:** 360-480 **Mold:** 50-120 **Shrink:** 0.4-0.7 **Dry:** Not normally required **Family:** Amorphous **Resin:** High-impact polystyrene **Abbr:** HIPS **Melt:** 375-500 **Mold:** 50-130 **Shrink:** 0.4-0.8 **Dry:** Not normally required **Family:** Amorphous **Resin:** Acrylonitrile butadiene styrene **Abbr:** ABS **Melt:** 410-520 **Mold:** 100-180 **Shrink:** 0.4-0.7 **Dry:** About 180 F for 2-4 h **Family:** Amorphous **Resin:** Styrene acrylonitrile **Abbr:** SAN **Melt:** 400-500 **Mold:** 100-180 **Shrink:** 0.3-0.7 **Dry:** About 180 F for 2-3 h **Family:** Amorphous **Resin:** Polycarbonate **Abbr:** PC **Melt:** 520-620 **Mold:** 160-220 **Shrink:** 0.5-0.7 **Dry:** About 250 F for 3-4 h **Family:** Amorphous **Resin:** Polycarbonate / ABS blend **Abbr:** PC/ABS **Melt:** 450-550 **Mold:** 120-180 **Shrink:** 0.5-0.7 **Dry:** About 200-230 F for 3-4 h **Family:** Amorphous **Resin:** Polymethyl methacrylate (acrylic) **Abbr:** PMMA **Melt:** 400-500 **Mold:** 120-180 **Shrink:** 0.2-0.8 **Dry:** About 170-185 F for 3-4 h **Family:** Amorphous **Resin:** Nylon 6 **Abbr:** PA6 **Melt:** 480-540 **Mold:** 150-200 **Shrink:** 0.7-1.5 **Dry:** About 175 F for 4-6 h (dry as molded) **Family:** Semi-crystalline **Resin:** Nylon 66 **Abbr:** PA66 **Melt:** 520-570 **Mold:** 150-200 **Shrink:** 0.8-1.5 **Dry:** About 175 F for 4-6 h (dry as molded) **Family:** Semi-crystalline **Resin:** Polybutylene terephthalate **Abbr:** PBT **Melt:** 450-500 **Mold:** 120-180 **Shrink:** 1.2-2.0 **Dry:** About 250 F for 3-4 h **Family:** Semi-crystalline **Resin:** Polyethylene terephthalate **Abbr:** PET **Melt:** 500-550 **Mold:** Varies by grade and goal **Shrink:** 1.2-2.0 **Dry:** About 250-300 F for 4-6 h **Family:** Semi-crystalline **Resin:** Acetal copolymer **Abbr:** POM **Melt:** 360-440 **Mold:** 120-200 **Shrink:** 1.8-2.2 **Dry:** Usually not required, check supplier **Family:** Semi-crystalline **Resin:** Thermoplastic polyurethane **Abbr:** TPU **Melt:** 380-430 **Mold:** 70-120 **Shrink:** 0.5-1.5 **Dry:** About 180-200 F for 2-3 h **Family:** Elastomer **Resin:** Modified polyphenylene ether **Abbr:** PPE/PPO **Melt:** 480-600 **Mold:** 150-210 **Shrink:** 0.5-0.7 **Dry:** About 200-220 F for 2-4 h **Family:** Amorphous **Resin:** Polyphenylene sulfide **Abbr:** PPS **Melt:** 580-650 **Mold:** 275-325 **Shrink:** 0.2-1.0 **Dry:** About 300 F for 3 h **Family:** Semi-crystalline **Resin:** Polyether ether ketone **Abbr:** PEEK **Melt:** 700-750 **Mold:** 340-400 **Shrink:** 1.0-1.3 **Dry:** About 300 F for 3 h **Family:** Semi-crystalline **Resin:** Rigid polyvinyl chloride **Abbr:** PVC **Melt:** 340-400 **Mold:** 70-120 **Shrink:** 0.2-0.6 **Dry:** Not normally required, avoid long residence **Family:** Amorphous **Notes:** Values are typical ranges for unfilled general grades and are for planning only. Glass or mineral filled grades shrink less, and fiber orientation makes shrinkage different along and across flow. Always use the resin supplier's datasheet for the exact grade, and validate with a measured sample from your tool. ## Content **Intro:** Choosing starting settings for a new resin means knowing its typical melt temperature, mold temperature, drying requirement and shrinkage. This table puts those ranges for common thermoplastics in one searchable place so you can plan a trial or sanity check a setup. **Sections:** #### How to use these ranges **Body:** Find your resin by name or abbreviation and use the ranges as a starting window, not a recipe. Start in the middle of the melt range, set the mold temperature near the recommended value, and adjust from there during the trial. Check the drying column before the material goes near the press, since wet nylon, PC or PET produces splay and loses strength. The datasheet for your specific grade always has the final say, especially for flame retardant, glass filled or high flow grades. **Bullets:** - Start mid-range and adjust in small steps - Dry hygroscopic resins before molding, using a desiccant dryer with a dew point check - Record the actual settings in your process sheet for repeat runs #### Understanding shrinkage **Body:** Shrinkage is the difference between the cavity dimension and the cooled part, expressed as a percent. Semi-crystalline resins such as PP, HDPE, POM and PA shrink more than amorphous resins such as ABS, PC and PS because crystals pack more densely as they form. Shrinkage also rises with thicker walls, higher mold temperature and lower pack pressure, and varies with direction when fibers or flow orientation are present. Mold designers use the shrinkage value to size the cavity: cavity size is roughly part size divided by (1 minus shrinkage). #### Amorphous versus semi-crystalline **Body:** Amorphous resins soften gradually and are generally dimensionally stable with lower shrinkage. Semi-crystalline resins melt sharply, need enough heat to form crystals, and tend to be tougher and more chemically resistant but more prone to warpage. The distinction also affects mold temperature: higher mold temperature raises crystallinity, improves surface and stability, but lengthens cooling. Use the Structure column to remind yourself which behavior to expect. #### Common mistakes **Body:** Typical errors include using one shrinkage value for every direction and wall thickness, skipping drying because the bag looks sealed, and running the barrel at the top of the range with a long residence time. Degraded resin shows up as splay, black specks or brittle parts. Match shot size to barrel capacity so material does not sit too long, and purge when you change resins with incompatible temperature ranges. **Cta:** If you track resin lots, dryer settings and process parameters in your ERP or MES, Netray can help you connect them to scrap and quality results on-premises. **Faq:** #### Are these values exact for my resin grade? **Answer:** No. They are typical ranges for general unfilled grades. Filled, flame retardant and high-flow grades differ. Use the supplier datasheet for the exact melt temperature, mold temperature, drying and shrinkage of your grade. #### Why do semi-crystalline resins shrink more? **Answer:** As they cool, molecules arrange into crystals that pack more densely than the amorphous melt, which reduces volume. Amorphous resins lack this ordered structure, so they shrink less and are generally more stable. #### Do I need to dry polypropylene? **Answer:** Normally no. PP absorbs very little moisture. Hygroscopic resins like nylon, PC, PET, PBT and ABS do need drying. If the supplier states a moisture limit, measure it rather than guessing. #### How do I calculate cavity size from shrinkage? **Answer:** A common approximation is cavity dimension equals part dimension divided by (1 minus shrinkage as a fraction). For a 100 mm part with 1.5 percent shrinkage, the cavity is about 101.52 mm. Validate with a measured trial because real shrinkage depends on process. ## Search terms plastic melt temperature chart, mold temperature for abs pc pa66, plastic shrinkage rate table, resin processing temperature guide, injection molding material guide, polypropylene shrinkage rate, nylon drying temperature and time, thermoplastic processing parameters --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json