Process reference · Barrel temperature
Twin Screw Extruder Temperature Profile by Material: 16 Families, Zone by Zone
Zone 1, melt peak, metering and die ranges for sixteen material families — plus the eight ceilings that decide the profile before any setpoint is typed into the control panel. What follows is the reference temperature profile we start from at commissioning, material family by material family.
Quick answer
A twin screw extruder barrel temperature profile is not a ramp to the die. It is set by whichever limit is lower: the temperature the polymer needs in order to melt, or the temperature its most heat-sensitive additive will survive. In a review of 677 masterbatch and compounding patents, 54% of profiles rise to a plateau, 40% peak at zones 4–6 and then drop 10–20 °C, and 6% are flat. Use the tables below to find the governing limit first, then set the zones around it. Every temperature profile on this page is written as a ladder of zone setpoints, so it can be copied onto a control screen zone by zone.
The profile is capped by the weakest additive, not by the polymer
Every material has two temperature numbers that matter. The first is the melt window of the carrier resin. The second is the decomposition threshold of the additive that tolerates heat least — a flame retardant, a blowing agent, a biological active, a wood flour. The barrel profile has to satisfy both, and when they conflict, the additive wins.
| Carrier | Needs to melt at | Weakest additive | Ceiling | Which one governs |
|---|---|---|---|---|
| PP / PE | 160–190 °C | ATH (HFFR cable compound) | 200 °C | Additive — melt stays near 170 °C |
| PP / PA | 190–260 °C | Halogenated or P–N flame retardant | 220 °C | Additive — last zone capped at 220 °C |
| PE / starch blend | 140–175 °C | Starch (scorching) | 180 °C | Additive — whole barrel below 180 °C |
| PVC dry blend | 150–170 °C | PVC itself (HCl release) | 180 °C | Polymer — narrow 30 °C window |
| PE / PP | 160–200 °C | Organic antimicrobial | 240 °C | Polymer — additive is not the limit |
| PET | 260–285 °C | None — hydrolysis is the limit | — | Moisture, not temperature |
Ceilings are the published decomposition or processing limits of the additive class, not of a specific grade. Verify the grade datasheet before you lock a setpoint.
The practical consequence
When the additive ceiling sits below the polymer melt window, you cannot fix it with temperature. You fix it with geometry: a shorter L/D, a gentler kneading configuration, a later side-feeder entry, or a two-stage setup where the heat-sensitive component is added downstream. Raising the barrel temperature to improve dispersion is the single most common way to destroy a heat-sensitive formulation.
Temperature profiles for eight masterbatch families
The ranges below come from 677 Chinese compounding patents (2010–2020) that disclose zone-by-zone setpoints. They describe published patent practice — the lowest settings at which the inventors could make a saleable pellet — not optimised production values. Read the bottom of each range as a floor and the top as a ceiling.
| Material family | Zone 1 | Melt peak | Metering | Die | Curve | Governing limit |
|---|---|---|---|---|---|---|
| Filler masterbatch CaCO₃ or talc, 70–85% |
80–120 | 190–230 | 210–230 | 210–245 | Step | Feed-throat bridging — not melting |
| Color masterbatch PE carrier |
90–130 | 150–180 | 140–170 | 150–180 | Hump | Pigment dispersion vs carrier melt |
| Antimicrobial / functional masterbatch | 165–190 | 190–240 | 195–235 | 200–230 | Rise–plateau | Organic actives 240 °C, silver 230 °C |
| Flame-retardant PP / PA | 170–190 | 190–220 | 190–210 | 190–215 | Rise–plateau | FR decomposition above 220 °C |
| ABS / PC–ABS compound | 180–200 | 190–210 | 180–200 | 200–220 | Flat ±10 | PC flow below 230 °C; ABS degrades above 250 °C |
| Conductive masterbatch carbon black / CNT |
200–215 | 225–250 | 240–250 | 240–255 | Rise | Viscosity for network dispersion, low screw speed |
| Starch-based / biodegradable | 90–150 | 140–175 | 120–150 | 120–180 | Hump | Starch scorches above 180 °C |
| Anti-block / nucleating masterbatch PE carrier |
110–125 | 170–190 | 130–150 | 130–170 | Hump | Nucleating agent solubility; sharp cool-down after peak |
Scroll the table horizontally to see all columns.
All values in °C at the barrel wall. Measured melt temperature runs above the setpoint at high screw speed and high filler loading — confirm with a probe at the die, not with the HMI.
Seven more families: engineering plastics, cable, PET, TPE, WPC
These come from our application engineering files rather than the patent set, so they are wider ranges and should be treated as trial starting points.
| Material family | Zone 1 | Melt peak | Metering | Die | Governing limit |
|---|---|---|---|---|---|
| PA66 + 30% glass fibre | 240–260 | 260–280 | 255–275 | 250–270 | Moisture <0.1%; fibre attrition rises with residence time |
| PBT / PET compound | 235–250 | 245–265 | 240–260 | 245–260 | Hydrolysis — dry to <50 ppm before the hopper |
| PVC cable compound | 140–155 | 155–170 | 160–175 | 165–180 | HCl release above 180 °C; 30 °C total window |
| HFFR, ATH-filled | 140–155 | 155–170 | 160–175 | 160–175 | ATH dehydrates above 200 °C — voids and loss of FR |
| PET bottle flake / fibre black masterbatch | 260–270 | 275–285 | 278–285 | 275–285 | IV loss; short residence, L/D 40–48 with dedicated vacuum |
| TPE / TPV | 180–200 | 190–215 | 190–210 | 190–210 | TPV: stay inside the peroxide decomposition window |
| WPC, wood flour 40–60% | 160–175 | 175–185 | 170–180 | 175–185 | Wood scorches at 190 °C; flour dried to <2% moisture |
| Powder coating (no pelletizing) | 80–110 | 90–120 | 90–120 | 95–120 | Gelation at 120–130 °C — gel in the barrel means a teardown |
Why 40% of profiles are not a straight ramp
Of the 96 patent profiles with at least five zone setpoints, only 6% are flat. The rest split into two shapes — and the second one contradicts what most operators are taught.
| Shape | Share | What it looks like | When it is used |
|---|---|---|---|
| Rise–plateau | 54% | Zones climb, then hold flat to the die | Melt-stable systems: ABS, filled PP, functional masterbatch |
| Rise–peak–drop (hump) | 40% | Peak at zones 4–6, then −10 to −20 °C, die controlled separately | Heat-sensitive additives, high shear, high pigment or FR loading |
| Flat | 6% | All zones within ±10 °C | Short barrels, low-melting systems |
The mechanism is straightforward. Shear heating in the metering zone adds energy on top of the wall setpoint, so a flat or rising profile ends up hotter than intended at exactly the point where residence time is longest. Dropping the last zones compensates for that, and it also reduces the risk of gels and odour in ABS and PC blends.
One rule that survives every material
Die temperature = last barrel zone + 0 to 20 °C. Fifteen of the nineteen fully documented patent examples obey it. The die runs slightly hotter to cut viscosity at the pressure build-up point, but it is never the hottest part of the machine. If you find yourself setting the die 30 °C above the last zone, the screw configuration is not building pressure properly.
Three setpoint ladders you can start from
Barrel length and zone count are tied: our KTE barrels use 4:1 L/D per section, so L/D 40 is a ten-zone barrel, L/D 44 is eleven, L/D 48 is twelve. The ladders below are ten-zone examples derived from the ranges above. They are starting points for a trial, not production recipes — screw geometry, filler loading and screw speed all shift the result.
| Material | Z1 | Z2 | Z3 | Z4 | Z5 | Z6 | Z7 | Z8 | Z9 | Z10 | Die | Screw |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 75% CaCO₃ in PE L/D 44 | 95 | 150 | 195 | 215 | 220 | 220 | 218 | 215 | 215 | 215 | 225 | 325 rpm |
| PA66 + 30% GF L/D 40–44 | 245 | 255 | 265 | 270 | 275 | 275 | 272 | 268 | 265 | 262 | 265 | 300 rpm |
| PET bottle flake L/D 40–44 | 262 | 268 | 272 | 276 | 280 | 282 | 280 | 278 | 276 | 274 | 278 | low shear |
Screw speed is included because it changes the profile indirectly: each 100 rpm adds shear energy, which the wall setpoints then have to subtract. A profile is only valid at one speed band.
Eight hard ceilings
These are the numbers that separate a working profile from a wrecked barrel. Every one of them appears repeatedly in the patent set and in our own trial records.
| System | Ceiling | What happens above it |
|---|---|---|
| PVC dry blend | zone 1 ≤ 130–150 °C | HCl release, black specks, barrel corrosion, colour drift |
| Starch-based compound | 180 °C, all zones | Scorching, yellowing, burnt odour that no additive hides |
| Halogenated / P–N flame retardant | 220 °C, last zone | FR decomposition, gas evolution, loss of flame rating |
| ATH-filled HFFR | 200 °C, melt | ATH dehydration: voids, surface defects, FR failure |
| PET | 260 °C floor, short residence | Below 260 °C no melt; too long above 280 °C loses IV |
| Organic antimicrobial | 240 °C (silver: 230 °C) | Active burns off; the masterbatch tests clean and performs at zero |
| Filler masterbatch, zone 1 | 80–120 °C | Carrier softens in the feed throat, powder bridges, screws starve |
| Powder coating | 120 °C, melt | Gelation inside the barrel — a full teardown, not a setpoint change |
How to build a twin screw extruder temperature profile in five steps
- Find the polymer melt window. Use the datasheet or a DSC curve. This gives you the melt peak range and the minimum die temperature. For semi-crystalline resins the window is narrow; for amorphous resins it is wide and forgiving.
- Find the lowest additive ceiling and subtract 10–20 °C. That number caps your metering zone. If it is below the polymer melt requirement, stop: the formulation needs a different screw design, not a different setpoint.
- Set zone 1 from the feed, not from the melt. Powder-heavy feeds want 40–60% of the melt temperature in zone 1 — filler masterbatch at 80–120 °C, colour masterbatch at 90–130 °C. The purpose is to keep the carrier glassy so the powder does not bridge.
- Choose ramp or hump. Ramp to a plateau when the system is melt-stable. Use a hump when there is a heat-sensitive additive, a high pigment load, or a high-viscosity melt that will shear-heat in the metering zone.
- Set the die at last zone + 0–20 °C, then verify with a probe. Run at production screw speed for 15 minutes before taking the reading. If measured melt temperature exceeds the additive ceiling, lower the last two zones — not zone 1.
Three mistakes we see on start-up
1. Copying a profile from another machine
The same material on a 40:1 barrel and a 48:1 barrel needs different numbers, because residence time and shear history differ. A profile is a property of the material and the screw geometry. When a customer sends us a setpoint list from an old line, we treat it as a hypothesis and re-tune it on a trial run.
2. Ramping every zone up to the die
It looks tidy on the control screen and it over-heats the metering zone. The results are gels in ABS, odour in PP, and yellowing in anything with an organic additive. Forty per cent of the published profiles deliberately drop after the peak — that is not sloppiness, it is compensation for shear heat.
3. Setting zone 1 at melt temperature
With a 75% mineral fill, a hot feed throat softens the carrier before the screws can convey it. Output falls, torque fluctuates, and the operator adds more feeder speed, which makes the bridging worse. Zone 1 at 80–120 °C is the fix, and it is counter-intuitive enough that it is worth writing on the machine.
Five rules that survive a material change
When the formulation changes and there is no time for a trial, these five rules have kept more lines running than any table on this page. They are the short form of the twin screw extruder temperature profile logic above.
- Cap first, ramp second. Find the additive ceiling before typing a setpoint; the temperature profile is a consequence of that number, not an input.
- Zone 1 stays cold. 40–60% of melt temperature keeps the carrier glassy and the powder moving.
- Peak before metering, not at the die. In 40% of published cases the temperature profile drops 10–20 °C after zones 4–6 to limit shear heat.
- Die at last zone + 0–20 °C. Higher buys nothing except degradation and die drool.
- Verify with a probe at production speed. A temperature profile read at 150 rpm says nothing about the same profile at 500 rpm.
FAQ
How should a temperature profile be recorded for a new material?
Record the temperature profile as four columns: zone number, setpoint, measured barrel temperature and measured melt temperature, taken at production screw speed after 15 minutes. Add the screw speed and feeder rate beside it. A temperature profile without those two numbers cannot be reproduced, which is why the parameter sheet we hand over at commissioning carries all four columns plus the process settings — see the service page for what ships with a line.
What is a typical temperature profile for a twin screw extruder?
For a 40:1 barrel running a filled PP compound, a typical profile rises from 90–120 °C in zone 1 to a melt peak of 190–220 °C around zones 4–6, holds 210–225 °C through metering, and sets the die 10–20 °C above the last zone. There is no single universal profile: the range is set by the polymer melt window and capped by the most heat-sensitive additive.
Why is zone 1 colder than the rest of the barrel?
Zone 1 is a conveying zone, not a melting zone. Keeping it at 40–60% of melt temperature stops the carrier from softening in the feed throat, which is what causes powder bridging and starved screws. In filler masterbatch the first zone typically runs at 80–120 °C while the melt peak is 190–230 °C — a gap of up to 150 °C inside one barrel.
Should barrel temperature always increase toward the die?
No. In our review of 96 patent profiles, 40% peak at zones 4–6 and then drop 10–20 °C before the die. The drop reduces melt viscosity and limits shear-heat accumulation where residence time is longest. Only the die itself sits slightly above the last barrel zone, typically by 0–20 °C.
What temperature should I use for 80% CaCO₃ masterbatch?
Zone 1 at 80–120 °C, melt peak 190–230 °C, metering 210–230 °C, die 210–245 °C, with screw speed around 300–500 rpm. Above 85% loading the melt viscosity rises sharply and a two-stage line becomes the better choice, because mixing and pressure build-up compete for the same shaft.
How do I set the profile for glass-filled PA66?
Barrel 240–280 °C with the peak in the melting and mixing zones, die slightly below the maximum melt temperature. The controlling variables are moisture and residence time, not the setpoint: PA66 must be dried to below 0.1% moisture, and every extra metre of L/D costs fibre length. Keep strong kneading blocks downstream of the glass entry to a minimum.
Does the profile change with L/D or gearbox type?
Yes, indirectly. Longer L/D means longer residence time, so the same setpoints produce more degradation and more IV loss in PET. Higher torque gearboxes let you run more filler at lower speed, which lowers shear heat and lets you raise wall temperature slightly. The setpoint table stays the same; the speed band and the last two zones change.
Why does measured melt temperature differ from the setpoint?
Because shear heating adds energy that the wall heaters did not supply. The gap grows with screw speed, filler loading and melt viscosity. It is the reason a profile validated at 300 rpm can overheat at 500 rpm without a single setpoint changing. Always take a melt-probe reading at the die at production speed.
How this data was built
The eight masterbatch profiles and the shape distribution come from a structured extraction of 2,839 Chinese compounding patents, of which 771 describe extrusion pelletizing and 677 disclose machine-parseable process parameters: 237 give zone-by-zone temperatures, 379 give screw speed, 175 give L/D, 192 mention vacuum devolatilization. The extraction is automated, so single data points should be checked against the original before being used in a quotation.
Every twin screw extruder temperature profile reproduced here was published with a stated material, and the material is the condition that travels with it. Published patent ranges describe the minimum settings at which an invention could be worked. They are not optimised production values, and they are not a substitute for a material trial on your own screw geometry. Treat every number here as a starting hypothesis with a stated condition attached.
A 3–7 day trial on our barrels returns a setpoint ladder, a pellet sample and a report — before you commit to a machine.
Reference: Google Patents — the patent corpus behind these profiles