1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULDecember 20, 20071SUBJECT 5703OUTLINE OF INVESTIGATIONFORDETERMINATION OF THE MAXIMUM OPERATING TEMPERATURE RATINGOF PHOTOVOLTAIC (PV) BACKSHEET MATERIALSIssue Number: 1DECEMBER 20, 2007Summary o
2、f TopicsThis is the first issue of the Outline of Investigation for Determination ofthe Maximum Operating Temperature Rating of Photovoltaic (PV)Backsheet Materials.The UL Foreword is no longer located within the UL Outline of Investigation. Forinformation concerning the use and application of the r
3、equirements contained inthis Outline of Investigation, the current version of the UL Foreword is located onULStandardsInfoNet at: http:/ 2007 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULDECEMBER 20, 2007SUBJEC
4、T 57032No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTS1 Scope .42 Glossary .43 Supplementary Test Procedures 54 General 55 Maximum Operating Temperature - Based Upon Historical Record 56 Apparatus - Ovens 77 Scope
5、of Test Programs - Selection of Test Properties 78 Property Evaluation Tests 78.1 Choice of end-point .78.2 Selection of oven temperatures 89 Selection of Control Material .910 Specimens 911 Full Thermal Aging (Long Term Thermal Aging) .1012 End-of-Life 1112.1 Primary properties 1112.2 Secondary pro
6、perties .1113 Proof Testing .1114 Analysis and Evaluation .1115 Abbreviated Thermal Aging One Temperature Aging and Two Temperature Aging 1215.1 General .1215.2 One temperature aging .1315.3 Two temperature aging .14DECEMBER 20, 2007 SUBJECT 5703 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER R
7、EPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL1 Scope1.1 These requirements cover long-term test procedures to be used for the evaluation of photovoltaicbacksheet materials used for parts intended for specific applications in end products.2 Glossary2.1 For the purpose of these requirements, t
8、he following definitions apply.2.2 ADHESIVE A gelatinous substance such as glue or cement used to join, bond, or fastenindividual photovoltaic backsheet layer materials together to form a laminate.2.3 AS-RECEIVED Specimens or samples in an unconditioned state, prior to being subject toconditioning,
9、or without a history of conditioning.2.4 COATING A non-metallic substance applied to the surface of the photovoltaic backsheetmaterial.2.5 CONSTRUCTION A term which refers to photovoltaic backsheet material that can be either ahomogeneous material or more commonly a laminated assembly of film materi
10、als, typically including anexterior layer, core layer and/or interior layer, adhesive layers, and surface coatings.2.6 CONDITIONING Exposure of test samples to an environment for a period of time, prior to, orafter testing and prior to evaluation.2.7 DELAMINATION A planar separation of materials (i.
11、e., separation between adjacent photovoltaicbacksheet layers).2.8 END PRODUCT An individual part or assembly in its final completed state.2.9 FILM A sheet material having a nominal thickness not greater than 0.25 mm (0.010 in).2.10 GRADE A designation arbitrarily assigned to a material by the fabric
12、ator.2.11 LAMINATE The product of bonding two or more layers of material.2.12 MAXIMUM OPERATING TEMPERATURE (MOT) The maximum continuous use temperaturethat the material may be exposed to under normal operating conditions.2.13 RELATIVE THERMAL INDEX (RTI) Maximum service temperature for a specified
13、criticalproperty which will not be unacceptably compromised through chemical thermal degradation, over thereasonable life of an electrical product, relative to a reference material having a confirmed, acceptablecorresponding performance-defined RTI.2.14 SAMPLE A test vehicle which may be a productio
14、n material, or a portion thereof, or a coupon.DECEMBER 20, 2007SUBJECT 57034UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL3 Supplementary Test Procedures3.1 The Standard for Polymeric Materials - Short Term Property Evaluations, UL 746A, con
15、tainsshort-term test procedures to be used for the evaluation of materials used for parts intended for specificapplications in electrical end products. The Standard for Polymeric Materials - Long Term PropertyEvaluations, UL 746B, contains long-term test procedures for the thermal evaluations of mat
16、erials forspecific applications in electrical end products. The Standard Test Method for Peel Resistance ofAdhesives (T-Peel Test), ASTM D 1876-01, contains short-term test procedures to characterize the peelresistance between film materials used for parts intended for specific applications in elect
17、rical endproducts.4 General4.1 The maximum operating temperature (MOT) is an indication of the materials ability to retain criticalproperties when exposed to elevated temperatures for an extended period of time.5 Maximum Operating Temperature - Based Upon Historical Record5.1 Table 5.1 presents a li
18、st of material ratings derived from Table 7.1 of the Standard for PolymericMaterials - Long Term Property Evaluations, UL 746B, each of which is assigned a maximum operatingtemperature based upon acceptable service experience, the chemical structure of the material, and aknowledge of the performance
19、 of the material in tests of insulating systems and electrical equipment. Theassigned maximum operating temperature is applicable to each member of the generic material class.5.2 Unless otherwise indicated in Table 5.1, the generic maximum operating temperature of a material isto be considered 50C (
20、122F).5.3 Unless otherwise indicated in Table 5.1, the generic maximum operating temperature of a material isindependent of thickness and pigmentation.Table 5.1Maximum operating temperatures based upon UL 746B generic relative thermal indices basedupon past field-test performance and chemical struct
21、ureaMaterial ISO designationMaximum operatingtemperature based on UL746B generic thermal indexCPolyamide (Type 6, 11, 12, 66, 610, or 612 nylon)b(PA) 65Polycarbonateb(PC) 80Polyethylene terephthalate - (PET)molding resinb75Film ( 0.010 in, 0.25 mm) (PET) 105Polybutylene (polytetramethylene) terephth
22、alateb(PBT) 75Polyphenylene oxidej(PPE - PS) 65Polypropyleneb,h(PP) 65Polyetherimideg 105Polyphenylene sulfideb(PPS) 130Polyimide film (0.25 mm, 0.010 in max) (PI) 130Molded phenolicc(PF) 150Molded melaminec,dand Molded melamine/phenolicc,d-specific gravity 1.55 130DECEMBER 20, 2007 SUBJECT 5703 5Ta
23、ble 5.1 Continued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 5.1 ContinuedMaterial ISO designationMaximum operatingtemperature based on UL746B generic thermal indexCspecific gravity 1.55 150Polytetrafluoroethylene (PTFEI
24、) 180Polychlorotrifluoroethylene (PCTFE) 150Fluorinated ethylene propylene (FEP) 150Urea Formaldehydec(UF) 100Acrylonitrile - butadiene - styreneb(ABS) 60Silicone - molding resinc,d 150Silicone rubber -molding resin (SIR) 150room-temperature vulcanizingor heat-cured paste(RTV) 105Epoxy - molding res
25、inc,d130powder coating materials 105casting or potting resinb,i(EP) 90Molded diallyl phthalatec,d 130Molded unsaturated polyesterc,d(UP)alkyd (AMC), bulk (BMC),dough (DMC), sheet (SMC),thick (TMC), and pultrusionmolding compounds(electrical) 105e(mechanical) 130Liquid crystalline thermotropic aromat
26、ic polyesterf(LCP) 130Ligno-cellulose laminate 60Vulcanized fiber 90Cold-molded phenolic, melamine or melamine-phenoliccompoundsd-specific gravity 1.55 130specific gravity 1.55 150Cold-molded inorganic (hydraulic-cement, etc.) compounds 200Integrated mica, resin-bonded - epoxy, alkyd or polyesterbin
27、der130phenolic binder 150silicone binder 200aGeneric thermal index is for homopolymer resins only unless a specific copolymer or blend is indicated. In the case of alloys,the lowest generic index of any component shall be assigned to the composite.bIncludes glass-fiber reinforcement and/or talc, asb
28、estos, mineral, calcium carbonate, and other inorganic fillers.cIncludes only compounds molded by high-temperature and high-pressure processes such as injection, compression,pultrusion, and transfer molding and match-metal die molding; excludes compounds molded by open-mold or low-pressuremolding pr
29、ocesses such as hand lay-up spray-up, contact bag, filament winding, rotational molding, and powder coating(fluidized bed, electrostatic spray, hot dip, flow coating).dIncludes materials having filler systems of fibrous (other than synthetic organic) types but excludes fiber reinforcementsystems usi
30、ng resins that are applied in liquid form. Synthetic organic fillers are to be considered acceptable at temperaturesnot greater than 105C.eExcept 130C generic thermal index if the material retains at least 50 percent of its unaged dielectric strength after a 504-hexposure at 180C in an air circulati
31、ng oven. Specimens are to be tested in a dry, as molded, condition. Specimens that areremoved from the oven are to be cooled over desiccant for at least 2 h prior to testing.DECEMBER 20, 2007SUBJECT 57036Table 5.1 Continued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION
32、ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 5.1 ContinuedMaterial ISO designationMaximum operatingtemperature based on UL746B generic thermal indexCfIncludes only wholly aromatic liquid crystalline thermotropic polyesters; wholly aromatic polyester/amides and wholly aromaticpolyester/ethers; excl
33、uding amorphous, lyotropic and liquid crystalline aliphatic-aromatic polyesters which are aliphatic in thebackbone chain or main chain, and substituted aromatic polyesters (except for methyl or aromatic).gIncludes only polyetherimide molding resin.hIncludes polypropylene copolymers containing not mo
34、re than 25 percent ethylene comonomer, by weight.iMulti-part liquid epoxy materials incorporating acid anhydride or aromatic amine curing agents receive a 130C generic thermalindex.jIncludes only those polyphenylene oxide materials in which the PPO component is not less than 30 percent of the totalc
35、omposition by weight and that have a heat deflection temperature of at least 70C at a load (fiber stress) of 1.80 M Pa (264psi).6 Apparatus - Ovens6.1 The thermal-aging ovens that are used in the aging program shall comply with the respective ovenrequirements in Section 9.1 of the Standard for Polym
36、eric Materials - Long Term Property Evaluations, UL746B.7 Scope of Test Programs - Selection of Test Properties7.1 The specific properties to be evaluated in the thermal-aging program shall be tensile strength, peelstrength, and dielectric strength. If a construction contains more than one combinati
37、on ofadhesive/substrate bond interfaces, each critical interface is to be evaluated for peel strength.8 Property Evaluation Tests8.1 Choice of end-point8.1.1 The maximum operating temperature determination is based on the assumption that a factor ofsafety exists in the applicable physical and electr
38、ical property requirements. It is not expected that a50-percent loss of property due to thermal degradation results in premature risk of electric shock, fire, orpersonal injury. The considerations have led to the decision to report the end-of-life at each agingtemperature as the time at which a prop
39、erty value has decreased to 50 percent of its un-aged level wherequantitative evaluation test methods are available.DECEMBER 20, 2007 SUBJECT 5703 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL8.2 Selection of oven temperatures8.2.1 At leas
40、t four oven temperatures are to be selected for conditioning.Exception: A photovoltaic backsheet laminate construction may be evaluated at a minimum of twotemperatures in accordance with 15.3.3 if each individual material comprising the laminate construction(with the exception of adhesives and coati
41、ngs) has been previously evaluated for Relative Thermal Indices(RTIs) in accordance with the Standard for Polymeric Materials - Long Term Property Evaluations, UL746B, (including those generic ratings based on historical record).8.2.2 The lowest temperature selected is to produce an anticipated end-
42、of-life of the material at thistemperature at approximately9-12months. The next higher temperature selected is to produce ananticipated end-of-life of the material at this temperature at approximately 6 months. The third and fourthtemperatures are to produce end-of-life of the material at approximat
43、ely 3 months and 2 months,respectively. See Table 8.1.8.2.3 Degradation is a function of the aging characteristics of the particular polymer or laminateconstruction. Specific aging temperatures cannot therefore be recommended since the test temperaturescan differ for each construction tested.8.2.4 S
44、hort-time screening tests at various temperatures can be used to estimate the anticipatedend-of-life.Table 8.1Selection of oven temperaturesTest temperature(C) t1a(highest) t2 t3 t4b(lowest)Approximate Life,Months136912Hours 720 2160 4320 6480 8640Cycle Period,cDays 3 7 14 28at1 is not to result in
45、end-of-life in less than 500 h.bt4 is not to result in end-of-life in less than 5000 h.cSee 14.2.8.2.5 The spread between aging temperatures is to be enough to overcome the small errors in measuringand controlling temperatures, generally at least 10C (18F).8.2.6 The reason for these test-temperature
46、 limitations is to provide accurate data so that extrapolation todetermine the acceptable operating temperature for life can be reasonably predicted.DECEMBER 20, 2007SUBJECT 57038UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL9 Selection of C
47、ontrol Material9.1 A control material is to be selected and tested in the thermal-aging test program in the same manneras the material under investigation.Exception: A photovoltaic backsheet laminate construction may be evaluated without the use of a controlin accordance with 15.3.3 if each individu
48、al material comprising the laminate construction (with theexception of adhesives and coatings) has been previously evaluated for Relative Thermal Indices (RTIs)in accordance with the Standard for Polymeric Materials - Long Term Property Evaluations, UL 746B,(including those generic ratings based on
49、historical record).9.2 The control material is to be a material that has an established relative thermal index determined inaccordance with the Standard for Polymeric Materials - Long Term Property Evaluations, UL 746B.Preferably, the material is to be one with a record of good field service at its rated temperature. If possibleit is to be of the same generic type as the candidate material, is to be tested in the same thickness, andis to have a relative thermal index as
