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“When you can measure what you arespeaking about, and express it in numbers,you know something about it.When you cannot express it in numbers,your knowledge is of a meager andunsatisfactory kind.It may be the beginning of knowledge, butyou have scarcely, in your thoughtsadvanced to the stage of science.”William Thomson, 1st Baron KelvinInventor of the Absolute (Kelvin) Temperature Scale5 December 3M 2017 . All Rights Reserved. 3M Confidential.“In God we trust;all others must bring data.”W. Edwards Deming1
The goal of weathering is toPredict the FutureHow long will this product last?5 December 3M 2017 . All Rights Reserved. 3M Confidential.2
The goal of weathering is toPredict the FutureusingWhat is the probability/technical risk of in-service failureas a function of time and end-use environment?5 December 3M 2017 . All Rights Reserved. 3M Confidential.3
Applying Weathering Science to Predict the Future– The Reliable Approach toEstimating Product Service LifeDavid M. BurnsWeathering Research Center3M Corporate ResearchLaboratorySt. Paul MN USA
Weathering ScienceWeathering Science (polymer systems) - The multi-disciplinary field focused onunderstanding the sources, processes and pathways resulting in degradation of the functionalproperties of materials & systems in outdoor applications.Photochemistry Polymer ChemistryMaterials EngineeringReaction KineticsAnalytical SciencesMetrologyData Analytics & StatisticsClimatologyScienceWhy?Weathering Technology - The tools (equipment and protocols)for conducting systematic experiments in weathering science.Practical ApplicationTechnologyHow to test?5 December 3M 2017 . All Rights Reserved. 3M Confidential.5
The Science of WeatheringWeathering (polymeric systems) – changes in material properties resulting predominantly fromexposure to solar radiation in combination with heat and water, in its various states.Discussion— Solar radiation, heat and water are the primary stress factors in the natural environment. Secondary stress factors specific to aclimate or location include temperature cycling, wind born particulates and chemicals in the atmosphere.SunlightP h P*HeatdP/dt Ae-Ea/RT WaterDegradationdP/dt k[H2O]nSP [H2O]/[P] P iMH2ORTWeathering is the response to stress;Weathering is not the stress applied.5 December 3M 2017 . All Rights Reserved. 3M Confidential.6
NOTE! Light is NOT always a factor in degradationSunlightHeat WaterDegradationPET film(oC/%RH)Kanuga, IEEE PVSC 2011increased IV Drop decreased Molecular Weight5 December 3M 2017 . All Rights Reserved. 3M Confidential.7
Weathering Science focuses on quantifying the material’s response to stress rather than justrelating property changes to exposure duration.“ The new concept of exposure parameters to describe the mode of dependence of properties onexposure variables, and to simplify the mathematical treatment of the data can be used for the prediction ofoutdoor weathering characteristics of a variety of plastic materials with surprisingly good agreement such ashift in objective would require basic changes in methodology and analytical procedures ”Musa R. Kamal (1966) Polymer Engineering & Science, v.6 (4) 333-340tFP(t)-P(0) ( I n* e-Ea/RTs* [RH]m) dt0Quantitative Degradation Modeling is the key to Reliable Service Life Prediction5 December 3M 2017 . All Rights Reserved. 3M Confidential.8
19661996200420145 December 3M 2017 . All Rights Reserved. 3M Confidential.9
How long will this product last?HighEnd User Reduce RiskDesigner Increase ConfidenceService LifeConfidenceDurabilityRiskLowTechnologyUser5 December 3M 2017 . All Rights Reserved. 3M Confidential.HighLowUnderstanding of Degradation(sources, processes and pathways)WeatheringScientist10
Applying Weathering Science to Predict the Future– The Reliable Approach toEstimating Product Service LifeDavid M. BurnsWeathering Research Center3M Corporate ResearchLaboratorySt. Paul MN USAThank you
Jan 09, 2018 · “When you can measure what you are speaking about, and express it in numbers, you know something about it. When you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind. It may be the beginning of knowledge, but you have scarcely, in your thoughts
