Millers-Xtra: Oil Filtration for Injection Moulding Machines

Why filter hydraulic oil?

Even new oil isn’t always clean enough for the plastics industry. Injection moulding equipment is designed to be highly sensitive, in order to manufacture plastic components with maximum precision. If the particle count of the oil in the system isn’t controlled, it can lead to wear, damage and blockages that bring production grinding to a halt.

Where do particles come from?

  • Environmental dust and debris
  • Metal wear particles from the machine
  • Degraded oil

What happens if you don’t filter particles?

Even though particles in the oil are tiny (smaller than red blood cells!), when pumped through the system at the high pressures required for injection moulding, they crash into the walls of the system with a huge amount of force. This results in accelerated component wear, blockages of the small clearances and ultimately costly break-downs.

How do you measure the number of particles?

The ISO standard 4406/1999 is a way of measuring the solids contamination in hydraulic oil, by counting the number of particles per 100 ml of oil. The ISO class is a logarithmic scale, i.e. when the particle count doubles, the ISO code increases by one.

ISO Class

Number of particles per 100 ml

More than

Up to and including

24

8,000,000

16,000,000

23

4,000,000

8,000,000

22

2,000,000

4,000,000

21

1,000,000

2,000,000

20

500,000

1,000,000

19

250,000

500,000

18

130,000

250,000

17

64,000

130,000

16

32,000

64,000

15

16,000

32,000

14

8,000

16,000

13

4,000

8,000

12

2,000

4,000

11

1,000

2,000

10

500

1,000

9

250

500

8

130

250

7

64

130

6

32

64

 

The ISO code that Millers-Xtra Technicians work to is 17/14/11 or better, which is also used by many of the injection moulding original equipment manufacturers and is recommended where system sensitivity is critical. It means that the allowed particle count is ISO 17 for particles larger than 4 μm, ISO 14 for particles larger than 6 μm and ISO 11 for particles larger than 14 μm. Some of the standard suggested acceptable contamination levels are listed below.

 

ISO suggested acceptable contamination levels

ISO code numbers

Type of system

Typical components

Sensitivity

23/21/17

Low pressure systems with large clearances

Ram pumps

Low

20/18/15

Low pressure heavy industrial systems or applications where long-life is critical

Flow control valves

Cylinders

Average

19/17/14

General machinery and mobile systems. Medium pressure, medium capacity.

Gear pumps/ motors

Important

18/16/13

World Wide Fuel Charter cleanliness standard for diesel fuel delivered from the filling station nozzle

Valve and piston pumps/ motors

Very important

17/15/12

Highly sophisticated systems and hydrostatic transmissions

Proportional valves

Critical

16/14/11

Performance servo and high pressure long life systems

Industrial servovalves

Critical

15/13/09

Silt sensitive control system with very high reliability

Laboratory or aerospace

High performance servovalves

Super critical

 

How does filtration work?

A Millers-Xtra Fluid Management Technician arrives on site with the filtration equipment. The rig is regularly calibrated for guaranteed accuracy, and portable and so it can be pushed through the tight confines of a factory to each machine. The equipment pumps approximately 40 L of oil per minute through a 1 μm filter, and the integrated particle counter means that results can be e-mailed directly to our customer from the rig – all while the machine is still in operation!

The end result is clean hydraulic oil with particle count of 17/14/11 or better, for maximum power transfer with the precision required for manufacturing even the most sophisticated plastic components.

SERVICES QUICK CONTACT