1Why POM and Nylon need tight changeover control
Switching into POM and Nylon never ends when fresh material exits the nozzle. Old resin, old color or compound may still sit in screw channels, nozzles, runners and mold cavities. Slight leftovers can hit engineering parts strength, dimensions and surfaces.
Great flow but heat-handling sensitive
POM melt viscosity runs low, so it may flow past some held material without carrying it all out. Avoid raising temperature or soaking past the resin maker terms.
Good-looking skin does not mean clean inside
Nylon may blend with held material into normal-looking skins, and moisture must still be controlled per each PA type spec before judging purge results
2Standard order before POM production
Use the order below as a site-trial baseline, adding shots on real evidence. Never conclude purging from shot counts alone.
3Standard order before Nylon (PA) production
Confirm PA type and drying terms first. Moisture disturbs both part quality and purge-result reading. Then follow the POM order with extra weight on part-property checks, never surface looks alone.
4Match ASACLEAN grades to resin and flow path
Asahi Kasei grade pages list POM, PA6 and PA66 among RU and GL3 supported resins, while RE stresses low residue and supports POM with PA6. Real picks still weigh temperature, residue severity, Hot Runner and clearance together.
| Grade | Fits the task | Temperature range | Hot Runner and limits |
|---|---|---|---|
| RU Sold in Thailand | General color and material change, supports POM, PA6 and PA66 | 180–330°C | Hot Runner and sealing supported. Clearance at least 0.5 mm. |
| GL3 All-purpose | Color, material and routine cleaning, supports POM, PA6 and PA66 | 180–330°C | Hot Runner and sealing supported. Clearance at least 0.5 mm. |
| RE Sold in Thailand | Low residue, transparent and light-color jobs, and switching into POM or PA6 at low temps | 160–300°C | Hot Runner and sealing supported. Grade page states no minimum clearance. |
| RX* Not yet available in Thailand | Manufacturer data for heavy carbon, Glass Fiber | 180–330°C | Barrel-only, no sealing, no barrel residence at any temperature |
Key: RX* only explains manufacturer product data. Not yet available in Thailand. Never judge Hot Runner systems by grade name alone. Verify geometry and clearance before every trial.
5Conditional HDPE transition material on hard rinse-out
Transition material flow
Use when needed: Fits long nozzles, complex flow paths, or stubborn compound additives. Verify HDPE fits that temperature range and process, discarding all transition material.
6Release gates before counting good parts
7FAQ
Are 4–5 free shots enough for every machine?
Not guaranteed figures. Use as a starting point, then verify real discharge. With old color, specks or compound remaining, continue and log passing counts as that machine standard.
Can every ASACLEAN grade pass Hot Runner?
No. RU and GL3 qualify with at least 0.5 mm clearance, while RE supports Hot Runner but needs real-geometry checks. RX is barrel-only with no sealing.
Why does Nylon need more than surface checks?
Nylon may blend with held material into normal-looking skins. Check color, specks, weight, dimensions and job-specific property metrics together.
RU, GL3 or RE. Which to pick?
Pick from old resin, new resin, temperature, residue level, Hot Runner and residue goals, never material names alone. CSC can plan Controlled Trials on real machines.
Maker sources
Want trial planning before switching to POM or Nylon?
Send resin type, temperature, machine size, Hot Runner system and current problems for technician trial-order assessment