vdma specification 24364 · vdma specification 24364 testing for paint wetting impairment...
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VDMA SPECIFICATION 24364 Testing for paint wetting impairment substances (PWIS/LABS-conformity)
Simone FrickProfessional Forum parts2clean 24 October, 2019
www.seals-and-finishing.com
Consulting and training Technical cleanliness and PWIS (LABS)-
free condition of technical components Surface technology like coatings, marking,
assembly facilitation, maximize friction characteristics, plasma treatment
Special field elastomers and seals
TECHNICAL CONSULTING TRAINING COPYWRITER
For further information: www.seals-and-finishing.com
Copywriter Author for technical publications,
professional articles etc. to support content marketing
Copywriter for catalogues, brochures and websites, technical focus
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364 2
SPECIAL CLEANLINESSPaint-Wetting Impairment Substances
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364 3
SPECIAL CLEANLINESS
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Contamination through paint wetting impairment substances impair the uniform paint application lead to blemishes and so-called craters
LABS is the German acronym for LAckBenetzungsstörende Substanzen PWIS is the equivalent English acronym for Paint-Wetting Impairment Substances
Components for varnishing applications
PWISLacquer
Substrate
PAINT-WETTING IMPAIRMENT
Total wetting: Requires the lacquer’s surface tension to be lower than that of the substrate
<
Disturbed wetting: The lacquer’s surface tension is higher than that of PWIS
> The lacquer will retreat from the substrate at the contaminated spots PWIS contaminated surfaces cannot be wetted flawlessly with paint This leads to blemishes and craters
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364 5
Cause and effect through contamination with PWIS
<
>
total wetting
disturbedwetting
FAILURE MODE
Craters are punctual cavities in the lacquer coat Partly surrounded by a bulging margin Size, shape and characteristic can be quite diverse
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364 6
Images: APO GmbH Industrielackierung
PWIS EFFECTS
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Consequences of paint wetting impairments
PWIS disturb the look and the function of the lacquer coat, e.g. corrosion protection Deficiently painted components have to be scraped
or reworked extensively which leads to additional expenses High rework effort Additional expenses Image: APO GmbH Industrielackierung
Image: APO GmbH Industrielackierung
DEFICIENT DEFINITION
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Silicone-free Silicones were initially mainly noticed as substances that interfere
with paint wetting The term „freedom from silicones “ is mistakenly still used today Not all PWIS contain silicones
Free of oil and grease Not all PWIS are oils and greases Not all oils and greases interfere with paint wetting
PWIS-free PWIS is no definable group of substances or contaminants
Silicone-free Free of oil and grease PWIS-free
Paint wetting impairment effects depend on the contaminants’ interaction with The paint system The substrate The ambient conditions
A general listing of all PWIS is not possible
When does a contaminant cause paint wetting disturbance?
PAINT-WETTING IMPAIRMENT SUBSTANCES
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SOURCES OF CONTAMINATION
In the production Lubricants Residues of drawing and release agents Sealing compounds Plasticizers from polymer components Contamination distributed via the room air technology, process
air technology or the compressed air system Carry-overs from other production areas Operating and auxiliary materials
Cleaning agents Polishing agents Gloves, work clothes, etc.
And more…
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364
PWIS are pervasive
10
SOURCES OF CONTAMINATION
Person-related sources Cosmetics, skin and hair care products Eyeglass cleaner Clothing (e.g. impregnation and shoe care products) Food and beverages
Fatty acid esters such as butter, fats Drinking cups from coffee machines (mould release agents)
Plastic bracelets or jewellery, fitness tracker, smartphone cases
And more…
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364
PWIS are pervasive
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PWIS TESTING
Sample taking Dissolving/extraction of PWIS through suitable media-
adequate method Collecting of PWIS on a suitable substrate Drying
Painting the substrate Analysis of the paintwork
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General principle of testing procedures
DEGREE OF CLEANLINESS REQUIRED?
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PWIS testing of elastomeric components Example: Insertion of a component in solvents
Dissolution of substances out of an elastomeric component PWIS containing Nowhere usable? Also not in air-ducting applications?
No Dissolution of substances out of a PTFE component PWIS-free Unrestricted use? Also with abrasion?
PWIS testing procedures can be too severe or too weak or simply not suitable Rejection of suitable components Admission of unsuitable components
Inspection severity for adequate cleanliness
VDMA SPECIFICATION 24364
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ADEQUATE CLEANLINESS
Established by the VDMA* Working Group LABS Experts concerning PWIS from German Industries
Based on PWIS-free requirements from automotive industries Participating companies
ABB, AUDI, DFO, Dürr, Systems, Eisenmann, Festo, Fraunhofer IPA, Freudenberg Filtration Technologies, GSR Ventiltechnik, IngenieurbüroFischer, iLF, KAESER Kompressoren, Krautzberger, Parker Hannifin, Phoenix Contact, plasma technology, SATA, Schmalz, SICK, Siemens, SMC Deutschland, Trelleborg Sealing Solutions, VDMA, Volkswagen, Wildeboer Bauteile, Wörwag (und seals‘n‘finishing)
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364
VDMA specification 24364
15
*VDMA = German engineering federation
VDMA SPECIFICATION 24364
For evaluation of the PWIS relevance For the definition of the test requirements for products and substances Distribution of a painting production in three zones*
Critical Zone Areas of pre-treatment, painting and drying Surfaces which are exposed to media
Zone with low PWIS relevance Located within the painting production Outside of the critical zone
Zone with no PWIS relevance Located outside the painting production line
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Practical Relevance Zones and Product Groups
*simplified description following VDMA 24364
VDMA SPECIFICATION 24364
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Product group A Components with direct contact to the lacquer, solvent or to the substrate, normally zone I
Product group B Components with only indirect contact to the lacquer, solvent or to the substrate, normally zone II
Product group C Components which cannot be classified into A or B, e.g. control system, air duct, normally zone II
Product group S Products which cannot be classified into A, B or C Substances which can be transferred to zone I or II or which are applied on the substrate (liquid,
paste, powder, grease, …)
Product group T Products which are used at higher temperatures
Practical Relevance Product Groups*
*abstract from VDMA 24364 definitions
Images: APO GmbH Industrielackierung
VDMA SPECIFICATION 24364
10/2019 - SF PWIS/LABS conformity in accordance with VDMA 24364
Practical Relevance Test Classes*
Classification synonymous to the product group designation Selection of the appropriate sample taking has to be
adjusted to the actual use of the component Combination of test classes possible Differentiation of test classes through the method of
sample taking
18Image: APO GmbH Industrielackierung
VDMA SPECIFICATION 24364
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Practical Relevance Test Classes* The test class and sample taking shall be selected on the basis of the
exposure when the product is used as intended Test class A
Solvent defined Sample taking through
A1: Rinse off with solvent A2: Rubbing off with solvent A3: Immerse in solvent
Test class B Solvent choice (SHALL – MAY) Sample taking through
B1: Blow off B2: Rinse off with solvent (SHALL for zone I)
*abstract from VDMA 24364 definitions
VDMA SPECIFICATION 24364
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Test class C Sample taking through
C1: Dry rubbing off C2: Blow off
Test class S Sample taking through
SHALL: Direct application of the substance onto the test plate in a very thin layer
Dry rubbing off of the hardened substance Test class T
Sample taking through Outgassing Only in conjunction with another testing
Practical Relevance Test Classes*
*abstract from VDMA 24364 definitions
VDMA SPECIFICATION 24364
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Practical relevance of PWIS testing to the intended use of a product Especially for polymer components any rejection of suitable
materials through high inspection severity can be avoided Basis for
the standardisation of PWIS-conformity requirements for products the definition of the PWIS-conformity for standard products the prevention of redundant and unnecessary testing economical and ecologically meaningful adjustments of cleaning
processes
Practical Relevance Benefit
Image: APO GmbH Industrielackierung
THE VDMA PWIS MANUAL
Gives information on the topic of PWIS Explains the handling of VDMA 24364 Gives examples for the selection of test classes Explains the different sample taking methods
Illustrated with pictures Gives support for the evaluation of test results
Illustrated with pictures Gives information concerning preventive measures in the
production Free of charge
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A practical guide
Cover picture of the VDMA PWIS guide
SOURCES AND CONTACTS
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VDMA specification 24364 Via www.beuth.de
VDMA LABS guide Download via VDMA website https://ot.vdma.org/en/viewer/-/v2article/render/26327354
Contact the VDMA* Working Group LABS via VDMA, department surface technology https://ot.vdma.org/en/
Consulting and training concerning PWIS conformity and VDMA 24364 www.seals-and-finishing.com
Documents Working Group Consulting
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