Upload
lamliem
View
264
Download
0
Embed Size (px)
Citation preview
Color and Appearance Standardization
Jeff Alspach, Axalta Coating Systems, Mt. Clemens, MI
Nick Lena, GTI Lighting, NY
Allan Rodrigues, Bloomfield Hills, MI
2AXALTA COATING SYSTEMS
Presentation Purpose
• Todays talks…
• 3 Speakers with 100 years combined standards participation
• Inform industry peers on key standards and organizations
• Share some history of what has been done and needs done
• Continue to communicate with members about ongoing work
• Open collaboration and the need for volunteers/resources
• Our Education class(s) on color and appearance
3AXALTA COATING SYSTEMS
Presentation Outline
Standards Organizations For Color and Appearance
Description of Key Standards Organizations
Objectives
Various key committees
Relationships with each other
Current work
Key SAE Industry standard
J1545
Previous work/Current Work/Next Update
J361 details of latest revisions
Other standards activity
ASTM (E12.11) D1729 latest revisions
Work of AATCC and CIE on new standard illuminants for 2017
AATCC new role on developing weighting functions for Standard Illuminants
AATCC Adoption of CIE DE 2000 for textile (CMC)
Lighting changes, developments and trends,( LED's and daylight LED's)
DOE and IES TM30-15 Metric for evaluation and review to replace CRI
AATCC LED Lighting Conference May 2017
J1545… Current Work/Future Work
Sparkle and Graininess Study
Combined color and Appearance difference equations
Future standards committee work
Education…Metallics Class
4AXALTA COATING SYSTEMS
What is an Industry Standard…
Long answer…. Posted 27th January 2013 by Jason Yip (http://jchyip.blogspot.com/2013/01/what-does-industry-standard-actually.html )
What does "industry standard" actually mean?
Many times I encounter decisions that imply people have what I'll call the naive understanding of "industry standard":
"industry standard" means that this is best practice across the industry and doing this will ensure that we have the best chance of achieving our outcomes.
"industry standard" doesn't even mean that it will work. Many industry standards are decided by a committee, what is known as a de jure standard. Actual practice in the field tends to at most influence the standard; it's not usually a straight copy. In other words, until it's been around for a while, a standard approach is not necessarily a proven approach.
"industry standard" doesn't mean all the significant players in the industry were involved. For various reasons (political, technical disagreement, whatever), not everyone will want to play in standardization efforts. It is entirely possibly that a significant player will ignore or compete with the standard, which means it's quite possible that the standard ends up going nowhere.
The "industry standard" is almost always not the best technical solution... it's the one that could be agreed on... so unless the standard is about some kind of interoperability that you actually have to care about, don't bother.
What are we actually trying to do?
In priority order, we're trying to design and build something that:
works
acknowledges the likely direction of change in the industry to avoid unnecessary change later
An "industry standard" presumably gives us guidance on industry direction. However, until we are confident that a design actually works, I wouldn't worry too much about industry direction. It's a reasonable assumption that things that don't work are highly unlikely to be the eventual direction of an industry.
Short answer…. Standard = disambiguation (wiki)
5AXALTA COATING SYSTEMS
Benefits and Challenges of Industry Standards…
"industry standard" means that this is best practice across the industry and doing this will ensure that we have the best chance of achieving our outcomes.
1 “industry standard” means we should all be following the same practice and if we do that can lead to…
Results similar
Efficiency
Not following “industry” standards can lead to…
Multiple standards
Many different implementations
Dissimilar results
No efficiency
SAE standards reference both ASTM and CIE
Stipulate methodology…
Recommend color equations but allow for different color equations (worked out by customer/supplier)
Do not specify the actual color tolerance (worked out by customer/supplier)
Benefit
Challenge
6AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations…
SAE
Description - SAE International is a global association of more than 128,000 engineers and related technical experts in the aerospace, automotive and commercial-vehicle industries. Standards from SAE International are used to advance mobility engineering throughout the world. The SAE Technical Standards Development Program is now-and has been for nearly a century-among the organization's primary provisions to those mobility industries it serves: aerospace, automotive, and commercial vehicle. Today's SAE standards product line includes almost 10,000 documents created through consensus standards development by more than 240 SAE Technical Committees with 450+ subcommittees and task groups. These works are authorized, revised, and maintained by the volunteer efforts of more than 9,000 engineers, and other qualified professionals from around the world. Additionally, SAE has 60 US Technical Advisory Group (USTAG's) to ISO Committees.
Objective – To advance aerospace, automotive and commercial-vehicle industries in a neutral forum for the benefit of society. SAE International strives to be a leader in connecting and educating engineers/technical experts while promoting, developing and advancing aerospace, commercial vehicle, and automotive engineering.
ASTM
Description - Over 12,000 ASTM standards operate globally. Defined and set by us, they improve the lives of millions every day.Combined with our innovative business services, ASTM standards enhance performance and help everyone have confidence in the things they buy and use – from the toy in a child’s hand to the aircraft overhead. Working across borders, disciplines and industries we harness the expertise of over 30,000 members to create consensus and improve performance in manufacturing and materials, products and processes, systems and services. Understanding commercial needs and consumer priorities, we touch every part of everyday life: helping our world work better.
Objective - Beyond standards development, ASTM offers certification and declaration through our subsidiary, the Safety Equipment Institute, as well as technical training programs and proficiency testing. All of our programs complement our standards development activities and provide enterprise solutions for companies, government agencies, researchers and laboratories worldwide.
7AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations…
CIE
Description - The International Commission on Illumination - also known as the CIE from its French title, the Commission Internationale de l´Eclairage - is devoted to worldwide cooperation and the exchange of information on all matters relating to the science and art of light, lighting, colour, vision, photobiology and image technology.With strong technical, scientific and cultural foundations, the CIE is an independent, non-profit organization that serves member countries on a voluntary basis. Since its inception in 1913, the CIE has become a professional organization and has been accepted as representing the best authority on the subject and as such is recognized by ISO as an international standardization body.
Objective – Advancing knowledge and providing standardization to improve the lighted environment
DIN
Description - DIN is a privately organized non-profit provider of standardization services with nearly 100 years' experience. More than 32,000 external experts from industry, research, consumer protection and the public sector come together at DIN to develop market-oriented standards and specifications that promote global trade and innovations, assure efficiency and quality, and help protect the environment and society as a whole.
Objective - Standards are developed with full consensus, that is, they are developed by experts with the aim of arriving at a common standpoint, taking the state of the art into consideration.
8AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations…
AATCC
Description - Founded as the American Association of Textile Chemists and Colorists (AATCC), the Association continues to evolve to meet the needs of those in the ever-changing textile and materials industries. AATCC has served textile professionals since 1921. AATCC is the world’s leading not-for-profit association serving textile professionals. AATCC provides test method development, quality control materials, and professional networking for thousands of members in 60 countries throughout the world.
Objective –Today, the Association provides test method development, quality control materials, education, and professional networking for a global audience.
9AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations Committee’s…ASTM (courtesy of Larry Steenhoek)
ASTM…2 Key active committee’s
E12.12 on Metallic and Pearlescent Colors
Scope: This committee will study the color measurement of metallics and pearlescents looking at quality control aspects, not colorant formulation and shading.
E12.14 on Multidimensional Characterization of Appearance
Scope: Develop standards for visual and instrumental assessment of appearance to address:
The multiple dimensions of appearance
Numerical scales to describe the above as observed and quantifications of the interactions between them
Many standards however the Key standards are…
ASTM E2175 Standard Practice for Specifying the Geometry of Multi-angle Spectrophotometers
ASTM E2194-14 Standard Test Method for Multiangle Color Measurement of Metal Flake Pigmented Materials
ASTM E2539-14 Standard Test Method for Multiangle Color Measurement of Interference Pigments
ASTM E284 Standard Terminology of Appearance
10AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations Committee’s…CIE(courtesy of Ellen Carter)
CIE…
A newly formed Division 2 Technical Committee (TC) (2.85) with Gael Obein as chair.
The title is Recommendation on the geometrical parameters for the measurement of the bidirectional reflectance distribution function (BRDF).
They are also defining terms and their work areas which included graininess and sparkle. The TC relates to the XReflect program in Europe... Including gloss and multi-angle measurements.
There are two TCs in Division 1 of CIE nearing their finish...
TC1-63
Chair: Klaus Richter on Validity of the Range of CIEDE2000
TC1-81
Chair: Klaus Richter on "Validity of Formulae for Predicting Small Colour Differences"
11AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations Committee’s…DIN(courtesy of Ellen Carter)
DIN 5033-1 “BASIC TERMS OF COLORIMETRY”…German translation of DIN EN ISO 11664 is misleading and currently this goes together with the fact that a lot of translations over the years for phrases and terms have become very faulty or misleading, and that the committee is currently revising the complete list of technical terminology.
DIN 5033 “BASIC TERMS OF COLORIMETRY”
Part 1 is undergoing revision as some terms are no longer accurate or need more info
Part 6 was accidentally canceled and will be reinstated this month as it should have been kept active
Part 8 will be canceled as there is no more interest in the procedure
Part 9 will undergo revision as some members aren’t satisfied with the current description of the traceability and calibration of white standards; apart from this, part 9 mentions also black standards and color standards – it was agreed that none of these should be mentioned in part 9 “white standards” but rather be revised into…
Part 10 – black and white standards for color measurement; especially Orion Engineered Carbons (former Degussa) has a high interest in this matter as they measure on the complete bottom of the scale and need repeatable results or reliable recommendations
DIN 55600 TESTING OF PIGMENTS - DETERMINATION OF THE SIGNIFICANCE OF COLOUR DIFFERENCES OF SURFACE COLOURS ACCORDING TO THE CIELAB-FORMULA
Statistical evaluation and significance of color measurements…There have been several improvements on statistics since the old standard for the statistical significance of color difference measurements DIN 55600 was released.
New metrics (e.g. Mahalanobis distance calculation) and tools should be covered in the latest revision; a technical report on the evaluation and statistical significance of color measurements is currently prepared by the university of applied sciences in Esslingen (Dr. Meichsner/Hiesgen et. Al. (T. Dauser, P.Emmel, S.Gauss, T.Kantimm) to explain the matter in detail.
DIN 6172 “Metamerism” was translated into English and handed over to ISO to officially become part of ISO 18314 as part 4
12AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations Committee’s…DIN(courtesy of Ellen Carter)
DIN 6175-1 and DIN 6175-2 “Tolerances for Automotive Paints”
The main task is to modify the current standards (part 1 being based on DIN99 for solid paints and part 2 on a modified AUDI95 for effect paints) to use the latest AUDI2000 method as decided last year.
Some of the participants opted to change the meaning of the standard, as the old goal “presenting a tool and tolerances for automotive repair finishing” was never really successful and now is no longer sufficient. Apart from that, Repair Finishing is dependent on many parameters that need control, so the question remains “what do I need the color measurement for?”
In addition, some participants believe it is not our job to write tolerance specifications into a standard – this is the job of the automotive manufacturers in correspondence with their suppliers.
For this, the title of the revised DIN 6175 will be changed into “Color difference metric for evaluation of automotive coatings”, and use the old DIN 6175 as appendices. Apart from the new formula used, it is important to note that the change will also mean that 3 angle instruments are no longer usable for DIN 6175 as the new AUDI2000 formula needs 5 or 6 angles to work.
13AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations Relationships…DCC/SAE
PURPOSE: The Detroit Colour Council is a non-profit Michigan corporation. All Officers and Directors serve on a voluntary basis. Our purpose is: a) to develop and carry out programs that contribute to communication among personnel involved in producing, using, designing, or specifying colored and/or decorative materials with emphasis on the automotive industry; b) to study and recommend practices intended to improve the quality of colored and decorative materials; and c) to provide opportunities for color education.
SCOPE: All matters relating to color and appearance developments and requirements regarding styling, compounding, color matching, production and acceptability of automotive components and raw materials.
DCC Endorse…
Open industry collaboration
SAE color and appearance committees
Which work mainly on SAE J1545 and SAE J361
Overall committee – Strive to have a representative from each OEM and tier 1 suppliers. This group serves as bi-directional communication channel back to their organizations and provide feedback to the working committee.
Working committee –
Strategically have people that are also members of ASTM/CIE/DIN.
Design experiments, collect data, do analysis, and present findings.
Update and review standards as necessary
14AXALTA COATING SYSTEMS
SAE standards for Color and Appearance
Textile and Flexible Plastics Committee
About 80 standards (includes weathering/materials testing that impacts color and/or appearance)
Prior to 2009…
This group had over 100 active members
SAE contracted someone from IFAI to administer the group (Industrial Fabrics Association International)
IFAI formed the AMA (Automotive Materials Association) board members sponsor standards
Each member of the Textile and Flexible Plastics Committee had to pay $1200.00 annually
Rely on our committee to keep standards updated
Slow arduous process to get a standard update approved and published
After 2011
No more IFAI
No more AMA
No more fee
Fewer active members
Those few are actual sponsors of the standards
Standard update process is more streamlined
Rely on our committee to keep standards updated (reviewed every 5 years)
15AXALTA COATING SYSTEMS
Key Color and Appearance Standards Organizations Committee’s…
DCC/SAE
Current Committee’s
J1545
Previous work…
• Major Update 2005
• Color Center Process
• Dark Color Study
Current work…
• Sparkle and Graininess
Next update…
• Add section(s) on Sparkle and Graininess
• Need ASTM standard for Instrument Geometry for Sparkle and Graininess
J361
Current work
• Recent update just published
Next update
• Gonio-viewer for color specifications
• Gonio-viewer for Sparkle and Graininess
16AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
J1545 - Instrumental Color Difference Measurement for Exterior Finishes, Textiles, and Colored Trim
What is J1545…
Recommended Engineering practice to:
1) Aid in the determination of color difference
2) Numerical communication of color difference
3) Resolution of acceptance or rejection compared to numerical difference
Main Goals…
Do a general update and extend the standard to include multi-angle measurements for gonio-apparent materials.
Completed
What was Next?
Formed a working group to look at…
Tolerancing for Metallics/Pearlescents
Devise and run experiments to determine a standard color tolerance method that best fits visual and instrumental assessments for gonio-chromatic material containing flake.
• The “Challenge”... No Data Set Exists
• The Answer... Create One...
17AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
The working group tasks…
Design The Experiments
Create The Color Centers
Evaluate The Colors Instrumentally and Visually
Publish The Data
Analyze The Data
Make The Recommendation
18AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
Axalta hired 2 students... Objectives…
First Student
In metallic shades, as lightness increases, larger dL are visually acceptable
CIE94 color equation has SL=1.0 for solid colors. This led to study of dark colors to investigate whether SL for dark colors is less than 1
The study was inconclusive
The study did help define the standard methodologies we used for our next study
19AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
Axalta hired 2 students... Objectives…
Second Student
Procedure For Creating Color Center
• Formula Variation Method
• Culling For Color And Appearance
Procedure For Evaluating Color Center
• Visual (Gray Anchor vs. Acceptability)
• Instrumental
Procedure For Analyzing The data
Goal…Complete 1 Color Center By End Of Summer
20AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
The Big “Challenge”... The Color Center Creation (no panel sets available) Color Difference Not To Big Not To Small Linear Steps on all 3 Axis In Both Directions At All 5 Angles This Is Done For Each Pigment In The FormulaFor 7 Pigment Formula
• 1 Pigment x 1 Axis x 6 Steps = 6• 7 Pigments x 6 Steps = 42 Color Difference Pairs To Observe At 5 Angles
Will Use More Than 1 Standard for panel pairs
21AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
(0°)
(45°)
(-45°)0°
15°
25°
45°
75°
110°
The Next “Challenge”... Visual to Instrumental Angles
The Solution... a Gonio-Viewer
22AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
Create “Color Centers”…
Cull For Appearance and Color• Start with 1 Large Panel• Measured Instrumentally(10/Panel)• End up with ~5 Standards for 42 pairs
Observers…• Some Color Experience• Anonymity• Screened• Randomize• Keep Observation Time Controlled
Appraisal Methods...• Acceptability…“Would you accept this match if you saw it on your car?”• Gray Anchor Pair
Determine Which is the Best
23AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
Analysis...
Raw Observer Data Are Usually Noisy
Observer Data Is Filtered Using Berns Filtering Technique
• Reduces Intra-observer Uncertainty While Retaining Inter-observer Differences
Look for R Squares ~ .80 for Visual Data
Then Plotted Using Logit Analysis
• Logit is a mathematical expression given by:
• Logit = Log10(f/1-f)
• Where f is the frequency of rejection or percentage of observers seeing the color difference in a sample pair.
24AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work
Logit Analysis…The center region is of most importance and needs to be amplified.Logit is very effective at estimating the slope of this sigmoidal curve and linearizes the
center portion as shown below on right hand side graph.Logit doesn’t work for unanimous decisions by the observers as for unanimous decision
Logit = infinite value.Logit requires some confusion among observer decision.Logit analysis is recommended by CIE.
Variation in frequency response with Color difference (dE) Variation in Logit with color difference
25AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work Summary
Summary…
Establish preferred experimental procedure
Acceptability vs. Grey Anchor Pair
• It took 4 to 5 days to get all 30 observers through the acceptability method and that time would increase using the gray anchor pair method.
Study a variety of current automotive colors
• It took a year to make 1 color center (Blue Metallic), get the observations, measurements and make the analysis
Establish an observer database for gonio apparent colors
• With the established process and if there are sources for panel pairs the work can be done quicker
Test existing color difference equations...Modify if necessary
• We tested 5 different equations…there was no clear winner
26AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Previous Work Summary
• Summary…Output of the work…
Methodology for Creating a Metallic Color Center
Procedure for formulation variation to cover all color axis robustly at all angles
Procedure for culling color panels for appearance as well as color difference
Methodology for Evaluating the Color Center
Procedure to visually appraise at all five angles
Determined that Acceptability Method was sufficient and time capable vs. Gray Anchor Pair Method
Procedure to instrumentally measure at all five angles
Method for Analyzing the data
27AXALTA COATING SYSTEMS
DCC/SAE Color Committee…Current and Future Work
Current and Future Work…Sparkle and Graininess…
Examine new instrumental measurement development for industry
Share knowledge and educate industry on the topic
Standardize terminology
Standardize geometry for equipment
28AXALTA COATING SYSTEMS
DCC/SAE Color Committee
J361 - Procedure for Visual Evaluation of Interior and Exterior Automotive Trim
Purpose:
• To precisely specify procedures for the visual evaluation of appearance of interior and exterior colored materials or parts incorporated in the manufacture of vehicles. The document provides a consistent engineering practice for the determination of visual color difference between materials or parts of the same or like materials. A suitable fixture providing daylight, fluorescent, and horizon lighting conditions is necessary for this evaluation.
Current work• Recent update just published• 5 year review…made key updates and introduced a section for Goniochromatism
Next update Gonio-viewer for color specifications Gonio-viewer for Sparkle and Graininess
Need geometry and lighting
specification
29AXALTA COATING SYSTEMS
Where to get Standards…
http://www.sae.org/technical/standards/J361_201611
http://www.sae.org/technical/standards/j1545_201410
https://www.astm.org/COMMITTEE/E12.htm
http://www.cie.co.at/
http://www.din.de/en/getting-involved/standards-committees/fnf/standards/wdc-beuth:din21:36796413
30AXALTA COATING SYSTEMS
Acknowledgements
Members of the DCC Committee
DCC for their endorsement
Participants from automotive companies and suppliers in on-going experiments
Allan Rodrigues and Nick Lena
AXALTA COATING SYSTEMS
Thank You!
Any Questions?