1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOctober 26, 20051SUBJECT 2321OUTLINE OF INVESTIGATIONFORPLATE WARMERSIssue No. 1October 26, 2005Summary of TopicsThis is the First issue of the Outline of Investigation for Plate Warmers.This out
2、line covers plate warmers intended primarily for use with aspecific manufacturers unitized base dispenser.COPYRIGHT 2005 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 26, 2005SUBJECT 23212No Text on This
3、 PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .4CONSTRUCTION2 General 4PERFORMANCE3 General 44 Resistance to Impact Test .45 Direct Flame Test .5MARKINGS6 Details .7OCTOBER 26, 2005 SUBJECT 2321 3UL COPYRIGHT
4、ED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These requirements apply to plate warmers intended primarily for use with a specific manufacturersunitized base dispenser. The plate warmers contain a medium that has thermal storage p
5、roperties to keepinstitutional food plates warm.1.2 These requirements do not cover the unitized base dispenser or other heat source.CONSTRUCTION2 General2.1 The plate warmer thermal storage media container shall be formed and assembled so that it will havethe thermal properties, strength and rigidi
6、ty required to resist the abuses to which it is subject.2.2 If deterioration of the container could result in a risk of personal injury due to expulsion of heatedmedia, the container shall be of a material that is resistant to deterioration by the media intended to beused therein.2.3 The media emplo
7、yed in the plate warmer shall be food grade, complying with applicable direct orindirect food additive requirements of the US FDA. Compliance shall be determined via formulation reviewof media ingredients.PERFORMANCE3 General3.1 When the performance tests described in 4.1 5.4 are conducted on the in
8、dicated number ofsamples of the plate warmers there shall be no evidence of leakage of the media from the container.4 Resistance to Impact Test4.1 The plate warmer shall be subjected to the drop impact test described in a) and b).a) Each of two samples of the plate warmer is to be conditioned in an
9、air circulating oven for a3 hour period at a temperature of 300F (149C). The plate warmers shall then be removedfrom the oven and are to be immediately dropped from a height of 5 ft (152.4 cm) onto aconcrete floor; andb) Each of two different samples of the plate warmer shall be conditioned for a 3
10、hour period ata temperature of 0F (-18C). The plate warmers shall then be removed from the oven andimmediately dropped from a height of 5 ft (152.4 cm) onto a concrete floor. If the manufactureragrees, the same samples of a) may be used for b).OCTOBER 26, 2005SUBJECT 23214UL COPYRIGHTED MATERIAL NOT
11、 AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL4.2 The conditions for acceptable results for each test are as indicated in 3.1.5 Direct Flame Test5.1 A sample of the plate warmer shall be subjected to this test. The test sample is to be preconditionedin a full draft ci
12、rculating air oven for 3 hours at 1200F (649C). Immediately following the conditioning, adirect flame of 5 inches (127 mm) with a 1-1/2 inch (38.1 mm) inner cone shall be applied to the undersideof the plate for a period of 1/2 hour. The laboratory burner and flame shall be as specified in 5.2 and 5
13、.3respectively.5.2 The burner shall have a tube with a length of 100 10 mm (3.94 0.39 inch) and an inside diameterof 9.5 0.3 mm (0.374 0.012 inch). The barrel shall not be equipped with an end attachment, such as astabilizer. The burner shall be adjustable to produce a flame as specified. The burner
14、 shall be incompliance with ASTM D5025, Standard Specification for Laboratory Burner Used for Small-ScaleBurning Tests on Plastic Materials.5.3 A supply of technical-grade methane gas (minimum 98 percent pure) shall be used with a regulatorand meter for uniform gas flow. The methane gas supply to th
15、e burner shall be arranged as in Figure 5.1and adjusted to produce a gas flow rate of 965 ml/min with a back pressure of 125 25 mm water column.See ASTM D5207, Standard Practice for Confirmation of 20-mm (50-W) and 125-mm (500-W) TestFlames for Small-Scale Burning Tests on Plastic Materials. The flo
16、w meter shall be a rotameter calibratedin accordance with ASTM D3195, Standard Practice for Rotameter Calibration, with correlation curvesappropriate for the gas, or a mass flow meter with 2 percent accuracy.Exception: Natural gas having a heat content of approximately 37 MJ/m3(1000 Btu/ft3) at 23C
17、(73.4F)has been found to provide similar results; however, technical grade methane shall be used in case ofdispute.This is generated text for figtxt.OCTOBER 26, 2005 SUBJECT 2321 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFigure 5.1Burne
18、r supply arrangementOCTOBER 26, 2005SUBJECT 23216UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL5.4 At the conclusion of the test, the unit shall be examined for compliance with 3.1.MARKINGS6 Details6.1 A plate warmer shall be legibly and per
19、manently marked where readily visible with:a) The manufacturers name, trade name, trademark, or other descriptive marking by which theorganization responsible for the product is capable of being identified;b) A distinctive catalog, model number, series number or the equivalent; andc) The date or oth
20、er dating period of manufacture not exceeding any three consecutive months.Exception No. 1: Providing the manufacturers identification in a traceable code meets the intent of therequirement if the product is identified by the brand or trademark owned by a private labeler.Exception No. 2: Abbreviatio
21、n of the date of manufacture, or provision in a nationally acceptedconventional code or in a code affirmed by the manufacturer, meets the intent of the requirement in theevent that the code does not repeat in less than 10 years and does not require reference to the productionrecords of the manufactu
22、rer to determine when the appliance was manufactured.6.2 Markings affixed to the product shall be of such nature as to resist the deleterious effects oftemperature, handling, cleaning agents and the like, expected in the intended use of the appliance.6.3 Pressure-sensitive labels are not considered
23、to provide the degree of attachment required unless aninvestigation shows that the nature and method of application are such as to comply with the Standard forMarking and Labeling Systems, UL 969, with regard to permanency and legibility.6.4 Surfaces to which labels are attached shall be assumed to
24、achieve up to 300F (140.9C).6.5 When a manufacturer produces or assembles products at more than one factory, each finishedcontainer or smallest unit package shall have a distinctive marking to identify it as the product of aparticular factory.6.6 Block lettering shall be used for the marked words CA
25、UTION and for the nature of hazard wordingthat follows.6.7 A plate warmer shall be marked in letters no less than 7/64 inch (2.8 mm) high with “CAUTION HOTDo not puncture or heat over 300F (140.9C). Not for use in microwave oven.” The marking shall belocated where readily visible during heating.OCTOBER 26, 2005 SUBJECT 2321 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 26, 2005SUBJECT 23218No Text on This Page
