Examples for improvement on black dots defects

Introducing an example for improving black dots defects by using ecomaru, a high-cleaning purging pellet (cleaning agent) .

Examples for improvement on black dots defects

Air conditioning related parts modling

Molding machine 30 units (owned)
Molding machine tonnage (t) : 30-650t
Countermeasures against black dots defects
Waste reduction
  • Reduction by 10 to 20% was confirmed for all of machines compared to by using the conventional purging agent mixing GF.
  • Especially for larger molding machines, The results are clearer and the amount of purging pellet (cleaning agent) containing glass can be reduced by up to 50%.
  • Rinsing (washing twice) by using glass [GF] has been stopped.

Reduction impact

Reduction impact

Black dots defects

black dots failure

Automobile parts molding

Grade: GWS
Molding machine capacity: 100 tons
Temperature: 270 ℃
Resin change / color change
Resin type: ABS (black) → PC-ABS (natural)

Cleaning status

  • Purging was carried out using other companies’ surface-active type cleaning agent conventionally used. Immediately it turned white and the purging was ended.
  • When started purging by switching to ecomaru, gray and black dots appeared, so purging was continued untill its completion and eventually total 3kg was used.

Customer evaluation

It has been continuously defective before when black dots appeared. However, by purging using ecomaru, the quality has significantly improved and black dots defects are dramatically reduced.

Staff in charge of modling
I was impressed with cleaning power of ecomaru.
Was told by a sales person before purging there are some chances “phenomenon of waking up a sleeping child” might occur by using ecomaru for the first time.
“Waking up a sleeping child” was likened to “something remained and was not able to be removed before can be getting rid of by ecomaru and some chances for using more than the standard usage volume” and that is exactly the case.

Reduction impact [Defect rate reduction]

Reduction impact
Reduction of black dots defects

Molding with PP flame retardant

Cost reduction
Environment improvement
Grade: GWP
Molding machine capacity: 1300 ton
Resin type: PP
Color change and reduction of black dots defects

Customer evaluation

  • A big cost advantage is washing twice to discharge glass was eliminated.
    We think PP-based cleaning agents mixing glass have good matching for post-material replacement. Since PP molding (color change) is mainly used.
  • The defect rate has been reduced.
  • Productivity has significantly improved.

Reduction impact [Reduction of cleaning cost]

Reduction impact [Reduction of cleaning cost]
Reduction impact [Reduction of cleaning cost]
As a result of QMS (TQM) activity, the number of adoption is increasing.
Scroll to Top