1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared and published by Underwriters Laboratories Inc.(UL). It is normative for the a
2、pplicable UL Product Certification Program(s); however, it is currently notpart of the UL Standard(s) referenced below.Product Category (CCN): QMFZ2, QMFZ3, QMFZ8, QMTR2, QMTR8, OCDT2, OCDT3,OCDT8, QMTS2, QMTS3, QMTS8, QIHE2, QIHE3Standard Number: UL 746AEdition Date: September 6, 2012Edition Number
3、 6Section / Paragraph Reference: Section 9.9Subject: Specialized Analysis of Polymer VariationsDECISION:9.9.7 As an alternative to the Long Term Thermal Aging tests per UL 746B that are normally requiredwhen the test program in Table 9.1 is identified by Code D, the following equivalent high-temper
4、atureaging program can instead be conducted:a) An analysis of available chemical, analytical, and high temperature performance data for thecompound being tested on the known formulation (the control) and the known formulation withingredient variations (the candidate), andb) An elevated temperature a
5、ging analysis of property retention data at 500 hours, 1000 hoursand 2000 hours on the control formulation and the candidate formulation. The agingtemperatures are to be chosen based on (a).9.9.8 If an analysis of variance of the retention property values between the candidate and controlformulation
6、s in the as-received condition (0-hour), the 500-hour, 1000-hour, and 2000-hour time intervalsis found to be statistically not significant (p-value 0.05), the same Relative Thermal Indices (RTIs) ofthe control formulation are to be assigned to the candidate formulation.RATIONALE FOR DECISION:Chemica
7、l compound formulations that can be molded, cast or extruded for use in consumer products arecomprised of a number of ingredients that contribute to the overall performance of the plastic partproduced. Having intimate knowledge of the chemical formulation of the compound, a robustunderstanding of th
8、e chemical interactions of the ingredients in the compound, and analytical and hightemperature performance data, allows a testing laboratory to predict, with a high level of confidence, thepossible deterioration of the compounds performance when ingredient changes are made. A confirmationof the comp
9、ounds performance through heat aging at elevated temperatures, and a statistical comparisonof the property retention levels for the candidate versus the control formulation, at specific time periodscan help in gauging with a high degree of confidence whether specific chemical ingredient changes to t
10、heknown formulation will or will not affect the expected high temperature performance of the modifiedformulation (the candidate).Copyright 2013 Underwriters Laboratories Inc.UL, in performing its functions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certificati
11、on Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certification Requirement Decisions are the opinion of Underwriters Laboratories Inc. inpractically applying the requirements of the standard. They do not represent formal interpretations of theUL COPYRIGHTED
12、MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULstandard under American National Standards Institute (ANSI) processes. UL shall not be responsible toanyone for the use of or reliance upon Certification Requirement Decisions by anyone. UL shall not incurany o
13、bligation or liability for damages, including consequential damages, arising out of or in connectionwith the use or reliance upon Certification Requirement Decisions. The electronic version of theCertification Requirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 746A -2-
