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Science of Purging

What Is Purging Compound: Understanding ASACLEAN Mechanical Purging

Mechanical Purging physics diagram showing viscosity, pressure, flow reversal and resin compatibility
Key Mechanical Purging mechanisms: viscosity, shear and pressure, flow-direction change and resin compatibility

Understand Rheology, Shear Force and Cleaning Agent That make Purging Compound work differently from new-resin purging, plus measuring time, material, scrap and cleanliness on real machines

Updated 15 June 2026 8-min read ASACLEAN Thailand technical team

1What Purging Compound means

Purging Compound Or screw purging pellets and injection-machine purging pellets. A specialty material built to Clean screw barrels and screws Of injection, blow and extrusion machines. Removing old resin, color and carbon residue for contamination-free material, color and job changes.

Purging Compound is not idle plastic pellets. It is an engineered polymer formulated for properties Opposite to general resin Where it matters

23 main Purging Compound types

TypeWorking principlePros and cons
Chemical PurgingFormula reaction or expansion helps split residueVerify temperature, dwell time, odor, fumes and each formula maker limits
Abrasive PurgingAdditive-boosted mechanical scrubbingVerify fitness for screws, flow paths and fine-clearance parts
Mechanical PurgingFlow properties and shear carry residue outASACLEAN sits here, but grade and steps must match machine and resin

ASACLEAN is a Mechanical Purging Compound with some Glass Fiber-blended grades for extra mechanical cleaning. GF grades serve only manual-listed systems, barred from Hot Runner or fine flow paths the maker has not cleared.

3How Mechanical Purging works — 3 principles

ASACLEAN runs 3 simultaneous mechanisms:

  1. Rheology Control: ASACLEAN matrix designed for high Melt Viscosity. Tacky-thick flow drags residue out
  2. Shear Cleaning: Rotating screws shear ASACLEAN matrix against metal, sweeping stuck residue
  3. Encapsulation: In-pellet Cleaning Agent wraps released residue against re-sticking, carrying it out with discharged pellets
Plain version Think water vs cleansing gel. Water flows past dirt without pulling it, but thick gel drags dirt out. ASACLEAN works like gel at molecular scale.

4Rheology: why viscosity matters

Rheology Is the science of material flow and deformation. In molten plastics the key rheology is Melt Viscosity (η) at melt temperature

Common units Pa·s or Poise. Viscosity shifts with resin type, temperature and shear rate. Never substitute one range for every material. Grade choice should cite the grade manual temperature range and terms.

When viscosity runs high:

5Shear Force and unreachable zones

Natural low-shear points inside screw barrels:

These are Dead Spots standard resin flows past unswept. ASACLEAN uses rheology plus glass fiber (in GF grades) to reach these zones beyond plain resin.

6What Cleaning Agent in ASACLEAN does

Cleaning Agent is the ASACLEAN-pellet mix that:

Why new-resin purging fails this. No Cleaning Agent.

7ASACLEAN vs new-resin purging

Logged criterionBaseline: new-resin purgingControlled trial: ASACLEAN
Material usedWeigh resin to QA passWeigh ASACLEAN plus rinse resin combined
Color and material timeClock old-job-stop to good partsSame start and approval gates as baseline
Startup scrapLog reject kg or countsSame units and collection windows
ContaminantsCount Black Specks and streaks to QA gatesCompare many rounds, never conclude from one trial
Cost per jobTotal material, scrap, labor, downtimeCalculate from real results net of purging-compound cost

Results depend on machine, resin, color, build-up and operating steps. Trial controlled for at least several rounds, then use ROI calculator With real plant data

Trial ASACLEAN free on your machine

Starting from free samples plus step advice from the CSC technical team

8When to use Mechanical Purging

9FAQ

Is ASACLEAN safe for Hot Runner?

Use Glass-fiber-free (Non-GF) formulas in maker-listed Hot Runner grades such as RU, RE, SL or PF. Glass-fiber grades such as newEX and RX are barred from Hot Runner. Other Non-GF formulas still need manual and system-limit verification first. (RX: Not yet available in Thailand) Hot Runner purging guide

Which grade to start first use with?

For general non-Hot-Runner injection, start from GL3 Or newEX Broad-coverage grades. Ask technicians to pick for your machine and resin.

How much per use?

No single amount fits every machine. Start from grade advice and Shot Size or Barrel Capacity data, then tune to discharge cleanliness. Real amounts belong in the post-trial SOP.

How long does ASACLEAN keep?

Check production date, lot number, shelf life and storage terms on the pack or grade documents. Keep bags sealed against moisture. Oven-dry only where the grade manual states.

Key references

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