Lasercut Mesh filter products: PET Filters, Polyamid (Nylon) Filters, Filter Dispenser


1. Cleanliness
Orignally filters were produced for filtration,so cleanliness of the membrane itself was no issue, and filter manufacturer did not care for remaining particles on filter membranes.
ISO 16232 and VDA Vol.19 give clear instructions about the blank value, which is the limit of contaminaion of the cleanliness analysis equipment itself. Filters are of course part of the analysis equipment and thus contribute to the blank value.
In cleanliness analysis, filter cleanliness is of importance and should be specified.
JOMESA met this challenge since 2015 by cleaning, lasercutting and packing the filters in a cleanroom class 7 (ISO 14644).



JOMESA controls cleanliness of filter production with a dedicated optical (JOMESA HFD) and SEM (JOMESA PSE) systems.




Optical Quality Control


SEM Quality Control


2. Porosity
SEM images of typical filter membranes







Foamed membrane: Cellulose 0.8µm poresize

Closed Mesh Filter

Open Mesh Filter, 20µm poresize


Open mesh filters (> 15µm poresize) can be easily measured by image analysis.They can be used to separate different particle sizes:
Mesh filters with 20µm holes (pores) size mesh will allow all particles smaller than 20µm to pass and hold back all particles larger.



Pore sizes of foamed filters are conventionally measured by liquid stream and bubble point techniques.

Poresizes in foamed (Cellulose) filters, how are they defined and measured ?

JOMESA measurements with these methods for closed cesh filters yielded values which corresponds approximately to a foamed 8µm filter. This shows that the methods are not appropriate for the measurement of closed mesh filters, because measured value is too close to measurement uncertainty.


In fact, filters with high filtration speed (= large porosity) have key advantages in the cleanliness analysis business.


Different closed mesh fabrics, defined by their weaving pattern (Binding key) and filament diameters are often misleading called 1µm, 5µm and 10µm or similar.







1µm“
Binding key:30-01 07-01-03

5µm“
Binding key:20-04 04-01-01

10µm“
Binding key:20-03 03-01-01


JOMESA definition and test of closed mesh filtration



A defined amount of dirt liquid is poured through a closed mesh filter.

The mesh filter is analyzed how many particles in the range from 5 to 15µm is on the filter (how many the mesh filter hold back).

The filtered liquid is poured through a Cellulose 0.8µm poresize filter.

The Cellulose filter is analyzed how many particles in the range from 5 to 15µm is on the filter (how many particles the mesh filter let pass).




Weaving pattern and filament diameter have no significant influence on filtration.
The ration of heldback/pass through depents on filtration condition (pressure)
.

Filtration capabilities of closed mesh filters in detail


3. Chemistry and Mechanical Properties.
ISO 16232:2018 (see page 138) and VDA 19.1 (see page 132) classifiy filters for microscopic filter analysis in 2 classes: Foamed and Mesh Filters



Filter material

Medium (test or final rinsing liquid)

Aqueous neutral cleaner

Isopropanol

Ethanol (spirit)

Aliphatic hydrocarbons (cold cleaners)

Ketones (Acetone)


Foamed membrane

Cellulose nitrate

+

-

-

+

-

Cellulose acetate

+

+

-

+

-

Polyamide/Nylon

+

+

+

+

+

Mesh

Polyester

+

+

+

+

+

Polyamide/Nylon

+

+

+

+

+

+ suitable, - unsuitable


Because of their chemical stability (see above table), PET and Polyamide filters are suitable for all rinsing liquids used.
Because of quicker filtration processes, mesh filters are preferred against foamed filters.

Polymer

Melting Temperature

Moisture Regain (20 deg C, 65%rel.Hum.)

Recommended drying temperature

Polyamide 6.6 (Nylon)

approx. 240 deg C

4.5%

70 deg C

Polyester PET

approx. 250 deg C

0.2%

90 deg C


Because of hygroscopic and thermal advantages PET filters are mostly used in cleanliness analysis applications.


From the woven fabric, filtermembranes can be produced in two ways:

Cold stamped
Cold-stamping is a process, where particlulate contamination cannot be avoided.



Laser cut

Due to cleanliness requirements and to avoid entangling with environment, JOMESA offers only Laser cut filtermembranes.




4. JOMESA Filter Membrane Program



Nylon (Polyamid) Filter Membranes, Laser cut
Polyester (PET) Filter Membranes, Laser cut

Ordering Code:
PE-
YYL-ZZ for PET Filters
NY-
YYL-ZZ for Polyamide Filtes
where
YY is diameter in mm
where
ZZ is poresize in µm if poresize is >= 15µm
where
ZZ is binding code abbreviation for closed mesh filters

Standard fabrics: see below
Special fabrics are available on request.

Filter prices are volume dependent
For price information contact JOMESA:
info@jomesa.com


Closed Mesh Filters, Laser Cut

Article Code

SEM Image

Binding key

Filtration Specification

Cleanliness Specification

NY-47L-1



30-01 07-01-03

50% (+-25%) of particles 5 to 15µm are held back by the mesh filter

80% (+-20%) of particles larger 15µm are held back by the mesh filter

No metallic particles

No particle > 200µm

Max 2 particles between 50 and 200 µm

Max. 100 particles between 5 and 50 µm

PE-47L-5
NY-47L-5



20-04 04-01-01

PE-47L-10



20-03 03-01-01


Open Mesh Filter, Laser Cut

Article Code

SEM Image

Binding key

Pore Size Specification

Cleanliness Specification

PE-47L-15



20-02 02-01-03

15µm x 15µm +- 5µm

No metallic particle

No particle > 200µm

Max 2 particles between 50 and 200 µm

Max. 100 particles between 15 and 50 µm

PE-47L-20



20-02 02-01-01

20µm x 20µm +- 7µm

No metallic particle

No particle > 200µm

Max 2 particles between 50 and 200 µm

Max. 50 particles between 25 and 50 µm

PE-47L-50

20-02 02-01-01

50µm x 50µm +- 10µm

No metallic particle

No particle > 200 µm

Max. 20 particles > 50µm

PE-47L-100

20-02 02-01-01

100µm x 100µm +- 15µm

No metallic particle

Max. 5 particles > 100µm

PE-47L-150

20-02 02-01-01

150µm x 150µm +- 15µm

No metallic particle

Max. 5 particles > 150µm

PE-47L-200

20-02 02-01-01

200µm x 200µm +- 10µm

No metallic particle

Max. 5 particles > 200µm

(All product specifications are subject to modifications without prior notice)

5. Ergonomics: JOMESA Filter Dispenser

Pulling out an individual filter from a stacked pack can be a fiddly work.

The JOMESA Filter-Dispenser provides an user-friendly, safe and easy way to remove individual filters out of a cartridge.
The cartridges are assembled in a cleanroom. After assembly there is no way of pollution the filters until dispensing.







The avantages are evident:

Easy grab 1 filter
No pollution danger for the rest of the pack, when removing one filter
Save and clean storage of filter until dispensed


Cassettes are available with 100 and 500 filtermembranes.