Nanodax

Reducing black dots defects! Features of the purging pellet “ecomaru”

High cleaning purging pellet preventing black dots defects,
Make great contributions to quality improvement!

black dots failure

ecomaru is purging pellet specially developed and made for cleaning the inside of cylinders for injection molding machine. Highly mixing with GW (glass wool), the highest priority is on black dots removal performance. It makes great contributions to quality improvement by removing and preventing resin deterioration (burning and black dots) in cylinder that was not able to be completely removed by GF (glass fiber) and reducing the foreign material defect rate such as black dots defects.

About ecomaru, high-cleaning purging pellet

What is cleaning agent (purging pellet) for injection molding machines?

Cleaning agent for injection molding machines (purging agent) iscleaning pellet used for color change, resin change, reduction on appearance defect rate and prevention of foreign materials generation. “Cleaning” for injection molding machine is to discharge molding material, burnt carbide and dirt left in cylinder. There are purging agents such as glass filler , surfactant type and foaming type, etc. and are used property in accordance with usages.

With glass filler

Purging pellet mixing glass wool cleans with strong frictional force. Best fitted for cleaning carbides stuck to screws and cylinders.

Surfactant type

Purging agents containing surfactants improve discharging performance by controlling interfacial tension between prior material (subsequent material) and metal surface.

Foam type

Foaming type purging agent is to extrude by removing stickings on screw wall using foamability resin.

First in the world! Purging pellet using GW (cotton like glass wool)

Glass fiber used in cleaning agent (purging agent) mixing glass filler is generally GF (glass fiber). However, GW (glass wool) which has finer fibers than GF is used and mixing for “ecomaru” and high cleaning is achieved. It scrapes off unnecessary materials very effectively with countless glass fiber angles and overwhelming specific surface area. Since glass wool’s fiber length is shorter, its fiber diameter is thinner and it is soft.

Conventional cleaning agent

ecomaru

Role of purging agent

Color change and resin type change, etc. for shortening the setup time have impacts on productivity. The advantage on “shortening the setup time” needs to be confirmed by comparing the shortening the setup time and its potential cost reduction to purging agent cost. Since purging agent cost is relatively higher as material cost. On the other hand, prevention and improvement of foreign materials defects such as black dots leads to quality improvement.

“ecomaru” is high cleaning type having great impacts on removing carbides and black dots .

High cleaning purging pellet (cleaning agent)
Please try testing and evaluating "ecomaru."

Features of ecomaru

High cleaning purging pellet (cleaning agent) being realized washing never seen before.
Improving black dots defects and making great contributions to reducing the defect rate.

Please take a look at test samples from major electric manufacturer. Showing comparison on cleaning for each shot when ABS (black) is purged. By looking at the 5th shot, ecomaru’s result showing darker black. There are chances ecomaru’s having darker black colors than those from the other purging agents when compared by the same number of shots. That is becuase fine glass wools in ecomaru clean all corners of dirts left and accumulated in modling machines before, though it also suject to the dirtiness level of modling machines.

Hitting 10 and 15 shots without intervals. Cleaning was completed earlier by ecomaru, and when compared at the 15th shot, black materials are still seen and remained by other companies’ purging agents. It certifies and has confirmed showing very big differences in cleaning capability.

60% recycled material for new material GW is used.
Eco-friendly upcycling product.

Glass wool (glass fiber) is made by melting glass at high temperature and making it into fine(thin) fibers in cotton-like shape. It has excellent heat insulation, sound absorption and vibration isolation characteristics, and has been used to block heat/cold, noise, and vibration.

We are the first company in the world to develop “purging pellet (cleaning agent) using glass wool as its material” making use of glass wool scraps usually using as heat insulation material. It is a material friendly to global environment and higher cleaning capability than that of conventional purging agents mixing glass fiber is achieved.

Difference at the number of shots during injection molding

Excellent in subsequent resin replacement,
Preventing "purging agent residue" molding defects.

Injection molding machine and purging pellet

Subsequent resin replaceability is the property how quickly and reliably purging agent is discharged and switched to next resin when succeeding resin is added after cleaning by purging agent. It is important that purging agent has high cleaning capability and needs to be discharged completely as well after cleaning. It seems likely especially puring agents mixing glass filler are showing hesitation to be used due to concerns on glass residues and “cleaning twice” is performing at molding production sites? When purging agents are not discharged and are left over, those will be “purging agent residues” and purging agent which should be preventing black dots defects causes molding defects, which will end up being overwhelming situation and getting priorities wrong truely.

ecomaru is purging agent having high cleaning capability as well as exhibiting excellent replaceability. For verification, red ABS resin was purged by ecomaru (using glass wool) and purging agent mixing glass fiber. The upper row of the photo in the below is for ecomaru and the cleaning was completed at 8 shots, and the amount of resin discharged was 360g. (The photo showing the resin discharged in order from upper left to right. One lump is for one shot.) On the other hand, the lower row is the case of purging by purging agent mixing glass fiber and cleaning is completed at 10 shots. The amount discharged up to here was 400g. This is showing and certifing the high detergency of ecomaru. And this is showing the high substitutability of ecomaru.

Comparison on resin amount
Subsequent resin substitution property

After cleaning, when “AS transparent” was used as subsequent resin, switching from purging agent was verified. Replacement was completed at 3 shots for ecomaru and 5 shots required for company A’s purging agent (Furthermore, you are able to see that the red color appears again on the resin cleaned by company A’s despite of its completion of cleaning).

No need to clean twice.
Making great contributions to shortening lead time and reducing costs.

Purging pellet ecomaru

ecomaru is “cleaning agent mixing glass filler”, however, does not need to be cleaning twice. * However, subject to the resin used, there are chances cleaning twice might have better result.
Cleaning twice is to be cleaning by purging agent mixing glass filler and cleaning again by purging agent not mixing glass filler or inexpensive pellets so that glass is not left over in the subsequent resin. Usually ecomaru does not need to be cleaning twice, because one glass fiber is thin and short and ecomaru has excellent discharging capability (good subsequent replacement) even at narrow tunnels (nozzle part, etc.).

<Evaluation on molding with PP flame retardant>

At the molding production site in the below, after cleaning by GF mixing purging agent at 8kg, cleaning twice by PP-based detergent (at 5 kg). By using ecomaru (GWP grade), the cleaning agent amount usage has been reduced from 8kg to 7kg and eliminating the secondary cleaning.

Pre-resin: PP flame retardant
Molding machine used: 1300 ton injection molding machine
Replacement resin: PP natural

Purging pellet grade selection guideline

By eliminating the need for cleaning twice and reducing the amount of purging agent used, the cost was reduced by approx. 46%.

Customer evaluation

Compatible with a wide range of resins in 2 grades.
It can be used under simple conditions at production sites.

Corresponding temperature table

GWP…Priority on glass discharge, for color change / resin change. High cleaning and excellent subsequent resin replacement (material: PP + GW)
GWS: Priority on carbide removal. Priority on balance over a wide range of applicable resin and temperature range (material: AS + GW)

Purging pellet grade selection guideline
Please take a look at ” Cleaning Method Recommendations ” for purging method recommendations.

Problem-solving cases

Case studyDefect rate reduction
Verification conditions◇ Grade: GWP
◇ Resin used: PP (main), nylon
TaskThe biggest problem is causing black dots when changing resin from PP to nylon.
evaluationCompared with the current purging agent, the detergency was greatly improved and the defect rate was significantly reduced.
Case studyDrastic reduction for black dots defects rate
Verification conditions◇ Grade: GWS
◇ Molding machine capacity: 100 tons
◇ Temperature: 270 ℃ ◇ Evaluation content: Resin change / color change
◇ Resin type: ABS (black) → PC-ABS (natural)
TaskUntil now, when black dots appeared, suffering from same defects continuously
evaluation[Inspector]
After purging by ecomaru, black dots defects were dramatically reduced and quality was significantly improved.
[Molding production staff]
Was very impressed with the cleaning power of ecomaru. Sales person told me in advance, "using more cleaning agents than usual when using it for the first time, however, keep cleaning until it gets clean completely." It is a phenomenon that materials was not able to be taken until now can be removed by ecomaru. After it gets clean completely, the defect rate is going down. That's exactly what I was told and explained.
Defect rate reduction
Defective rate
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