wearing and cutting rate table

How we test the wearing and cutting rate

1.   Below is the step that we do wearing and cutting the media:

Use exactly 20Kg (on a precise scale) of RKM 15 mm pyramid. Measure 5 random media samples for length per side (see the picture).

 

plastic media weight to the right size
plastic media weight to 20kg weight

 

Fill CD50 with 20 Kg of media, previously weighted to exactly 20Kg.

 

Put metal cylinder in the machine
Put metal cylinder in the machine

 

The machine has to be feed with 60L of water per hour of test – one L per minute. You can use any plastic friendly compound that you produce, (similar to KFL or FC230 with PH from 7.5 to 8.5) and feed to the machine in the ratio of 0.5%.

Testing in centrifugal disc finishing machine
Testing in the centrifugal disc finishing machine

Set the timer for one hour exactly and run CD50 at speed 180RPM

 

The control panel of centrifugal disc finishing machine
The control panel of the centrifugal disc finishing machine

 

When machine stop, wait for 10 min for water to set on the bottom of the disk. Run machine without water for 2 min.

 

Water and compound flow through the processing barrel
Water and compound flow through the processing barrel

 

details of compound flow through
details of compound flow through

 

When 60 min cycle time is finished, empty machine, (take media out, in the bag or previously weighted container/Tare), and measure the weight of the media (media will be wet, and plastic will absorb some weight from water). This weight test should be completed immediately after you run 2 min cycle to drain excess water from the machine.

Record the weight after 1 hour cycle time as outlined above (and an additional 2 min cycle). Measure random 5 media samples for length per side (see the picture) and record the results. Calculate percentage ratio for media wear per hour.

 

2.   Metal Coupons for the test

  • Hot rolled steel bar cylinder 10X34 1018/1020
  • Aluminum bar cylinder 10X34 2024 or 7075
  • Brass 10X34 cylinder

 

Metal Cylinder Coupon Before Test
Metal Cylinder Coupon Before Test

 

They all need to be of the same size in all aspects, and the same weight. Weight also needs to be recorded before and after.

 

metal cylinder after testing
metal cylinder after testing

 

We did not reuse coupons. They stay finished as they are, as a benchmark for the future referral.

 

3. Measurement of wearing and cutting

M%=(M1-M2)/M1

Where M1 is media weight before test and M2 is media weight after the test
M% means the wearing rate of media per hour

 

C%=(C1-C2)/C1

Where C1 is cylinder weight before test and C2 is the cylinder weight after the test
C% means the metal cutting off rate in one hour

 

4. Conclusion

This article informs the most popular way of wear rate and cutting rate testing method for mass finishing media. Some companies also use centrifugal barrel machine to test tumbling media.

Three types of metal cylinder coupons are used to represent most common parts material.

Finally, we give the equation to get the media to wear rate and cylinder coupons cutting rate. Therefore, tumbling media from different manufacturers can be compared in the same standard.