1、Designation: C1607 12Standard Test Method forDetermination of “Microwave Safe for Reheating” forCeramicware1This standard is issued under the fixed designation C1607; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method determines the suitability of ceram-icware for use in microwave re-heating applications. Micro-wave ovens
3、 are mainly used for reheating and defrosting frozenfoods. Severe thermal conditions can occur while reheatingfoods. Typical reheating of foods requires one to five min. inthe microwave at the highest power settings. Longer periodsthan five minutes are considered cooking. Cooking test meth-ods and s
4、tandards are not addressed in this test method. Mostceramicware is minimally absorbing of the microwave energyand will not heat up significantly. Unfortunately there are someproducts that absorb microwave energy to a greater extent andcan become very hot in the microwave and pose a serioushazard. Ad
5、ditionally, the nature of microwave heating intro-duces radiation in a non-uniform manner producing tempera-ture differentials in the food being cooked as well as theceramic container holding it. The differential may becomegreat enough to thermal shock the ware and create dangerousconditions.1.2 Thi
6、s standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Document
7、s2.1 ASTM Standards:2C554 Test Method for Crazing Resistance of Fired GlazedCeramic Whitewares by a Thermal Shock Method3. Terminology3.1 Definition:3.1.1 microwave safe for re-heatingceramic products thatcan be used in a microwave oven without any degradation,such as by deformation, fracturing, cra
8、zing, or heating up toexcessive temperatures.4. Summary of Test Method4.1 This method can be used to determine if a product issafe to use for reheating foods in a microwave oven. The testemulates typical microwave use conditions. Temperature maxi-mums and temperature differentials of products are de
9、terminedafter being subjected to microwave re-heating conditions.5. Significance and Use5.1 This test is for evaluating ceramic products that areintended for reheating in a Consumer based microwave oven.It is not intended for evaluating products that will be used incommercial type microwaves.5.2 Thi
10、s test method is not intended to evaluate metallic orpolymeric based products.5.3 Ceramic products intended for microwave use must alsobe evaluated for thermal shock resistance and pass the 325Fcriteria as described in Test Method C554, before being testedfor microwave safety. This would include spe
11、cific tests fordinnerware, cookware, drinkware and ancillary items intendedfor use with hot foods, such as gravy boats or any productintended for microwave use.5.4 Dishes having a metallic glaze, decoration or paintshould not be used in this test or microwave ovens unless it isspecifically designed
12、for and marked as microwave safe.6. Interferences6.1 Test samples must be free from any obvious physicaldefects.7. Apparatus7.1 The microwave oven chosen for testing is based on itspower level and being close to a mid-sized consumer product.This is to provide a relatively high power density, whichcr
13、eates conditions that are slightly harsher than conditionsfound in the average microwave oven. The main differencebetween microwave ovens is the power of the magnetron,which generates the microwaves. Midsize and large ovens are1This test method is under the jurisdiction ofASTM Committee C21 on Ceram
14、icWhitewares and Related Products and is the direct responsibility of SubcommitteeC21.03 on Methods for Whitewares and Environmental Concerns.Current edition approved April 1, 2012. Published April 2012. Originallyapproved in 2006. Last previous edition approved in 2006 as C160706. DOI:10.1520/C1607
15、-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO
16、Box C700, West Conshohocken, PA 19428-2959, United States.typically rated at 900 to 1300 watts and compact ovens haveabout 600 to 800 watts of output.7.1.1 Greater wattage for a given space heats food morequickly. The microwave oven chosen for this method is basedon having the greatest power output
17、per volume. This providesworse case conditions for microwaves available in the midsizerange while allowing for a greater range of sample sizes.Microwaves with greater power outputs of 1400 and 1600watts that were once available are no longer in production.7.1.2 Microwave Oven, (1350 Watts) with an i
18、nternal ovencavity volume of approximately 0.045 M3(1.58 ft3) dimen-sions of 228 by 418 by 470 mm (9 by 16716 by 1812 in.) androtating glass platter.7.2 Fast Reading Contact Surface Thermocouple Probe,orsuitable surface temperature reading device.7.3 Scale, capable of reading 1200 6 0.5 g.8. Reagent
19、s and Materials8.1 Tap Water.8.2 Plastic Beakers, 1 L, 500 mL; Graduate cylinder 250mL.8.3 Eye Protection.8.4 Insulated Gloves or Oven Mitts, preferably waterproof.8.5 Permanent Marker.8.6 Boiling Stones.9. Hazards9.1 Thermal shock is possible during the testing of theproduct. Care should be taken w
20、hile handling ware and beprepared for unexpected failure of the ware.9.2 Whenever heating water in a microwave there is thepossibility of super heating the water. Do not use distilledwater, as it is more likely to superheat than tap water. If thewater is super heated it is possible that it will spon
21、taneouslyerupt splashing boiling hot water, which could potentiallycause burns and injury. Always use boiling stones in the watercontainer when boiling water.9.3 People with Pacemakers or any other life sustainingdevices should not perform this test and should also not be inthe area when the test is
22、 performed.9.4 While performing the test maintain a distance of at least20 in. from the microwave oven when it is heating. This willreduce any possible leakage of radiation 100 times. The moredistance from the microwave the greater the reduction in anyexposure.9.5 Do not operate an oven that is dama
23、ged or suspected ofbeing physically damaged.9.6 If there is any damage to the door, hinges or door sealshave the oven repaired and tested for microwave leakage.9.7 Look for holes created by electrical arcing inside theoven and on the door and door frame.9.8 Wear oven mitts or insulated gloves when h
24、andling hotsamples. Always test the piece before handling as there is thepossibility that the product attained temperatures that willquickly burn through insulated oven mitts.10. Sampling, Test Specimens, and Test Units10.1 Representative sample(s) of the process generating theproducts should be use
25、d. Check ware before testing for anyphysical damage resulting from shipping or handling thatwould not represent the process.11. Preparation of Apparatus11.1 Only microwave models fulfilling the description in7.1 of this method should be used for testing. It is critical tohave the same power level of
26、 emitted microwaves in the samevolume of space to achieve correlation between test sites.12. Calibration and Standardization12.1 Measure and log the available power for heating beforeperforming tests. This should be performed one time at thebeginning of tests to determine that the microwave unit isp
27、roducing consistent power levels. It is important that themicrowave does not have residual heat in it from previoustesting so that this test starts from room temperature. Thedetermination of power output is accomplished by measuringthe temperature rise in 1 kg of water exposed to microwaveradiation
28、for a two-minute period of time. The analyst canrelate power in watts to the power setting of the microwave.12.1.1 Program the microwave for 2 minutes at maximumpower and leave the door open.12.1.2 Record the weight of the plastic beaker.12.1.3 Add 1.0 kg (1000.0 6 0.5 g) of tap water into aplastic
29、beaker. Equilibrate the water to room temperature 23 62C (73 6 4F) measure to 6 0.1C (0.2F).12.1.4 Place the beaker in the center of the glass platterclose the door and press start on the microwave.12.1.5 When the microwave finishes the 2-minute cycle, thebeaker is removed and the water vigorously s
30、tirred with aplastic spoon for 10 seconds. Then immerse the temperaturereading device into the water and slowly stir.12.1.6 Record the maximum temperature within the first 10seconds to 6 0.1C (0.2F). Use a new sample for eachadditional measurement. Do not reuse the water, even aftercooling, as it ma
31、y be more prone to create dangerous super-heating conditions.12.1.7 The absorbed power is determined by the followingrelationship:P 5KCpmDT!t(1)where:P = the apparent power absorbed by the sample in watts(W) (W = joule/s),K = the conversion factor for thermochemical calories/s towatts (= 4.184 joule
32、/cal),Cp = the heat capacity, thermal capacity, or specific heat(cal/g C) of water,m = the mass of the water sample in grams (g),DT = the final temperature minus the initial temperature(C), andt = the time in seconds (s).12.1.8 Using 2 minutes and 1 kg of distilled water (heatcapacity at 25C is 0.99
33、828 cal/g C) the calibration equationsimplifies to:P 5 DT! 3 34.86! (2)12.1.9 Calculate and record the power absorption.C1607 12212.1.10 Maintain a record of the power absorption forreference and determination of any degradation of the energyoutput.13. Conditioning13.1 Porous product must be precond
34、itioned before testing.Preconditioning is performed by heating the test samples to163C (325F) in a test oven for one hour then submerse thepiece in cold tap water overnight. This is done to allow waterto migrate into the piece to emulate what will happen once theitem is in use. The product can then
35、be used in the followingprocedure.14. Procedure14.1 Microwave Safe for ReheatingThere are two proce-dures for testing flatware. The first emulates short time periodof 1 minute that is typically used to reheat small quantities offood. The second method is to simulate defrosting or heatinglarger quant
36、ities of food for 5 minutes. The ware must passboth procedures, as well as the thermal shock requirements, tobe considered “Microwave Safe.”14.1.1 One-minute Microwave Cycle for FlatwarePlace250 mL of 16C (60F) tap water in a 500 mL beaker in theback left corner of the microwave for each test run. T
37、his is usedfor protecting the magnetron.14.1.2 FlatwareMark test points on ware to be tested in 3positions (120 angles) around the outer rim near the edge ofthe ware for flatware shapes. Turn the ware over and mark the4th position in the center of the back of the ware.14.1.3 The temperature of the w
38、are must be at roomtemperature to initiate the test.14.1.4 Check temperature of glass platter that is part of themicrowave and chill in water if over 38C (100F). Dry andplace the glass platter in the microwave.14.1.5 Place test item in the center of the rotating glassplatter in the microwave.14.1.6
39、Set Power Level to maximum and time for 1 minutethen start the cycle.14.1.7 Remove the ware from the microwave when heatingis completed.14.1.8 Within 15 seconds measure and record temperaturesat the indicated areas. Front or inside first, then back or outsideof product second.14.1.9 Scan over the su
40、rface of product slowly and find themax temperature on product and record.14.1.10 If more samples are to be tested repeat procedurefrom 14.1.1 by replacing the 250 mL of water with 16C (60F)tap water.14.1.11 Five-minute Cycle for FlatwarePlace 500 mL of16C (60F) tap water in a 1.0-L beaker.14.1.12 M
41、ark test points on ware to be tested (see 14.1.2).14.1.13 Check temperature of microwave glass platter andchill in water if over 38C (100F).14.1.14 Place plastic beaker of water in the center of theware being tested. Center ware and beaker on the rotating glassplatter in the microwave. The water is
42、used to simulate food forreheating.14.1.15 Set Power Level to maximum and time for 5 minutethen start the cycle.14.1.16 Remove the beaker and then the ware from micro-wave at end of cycle.14.1.17 Within 15 s measure and record temperatures at theindicated areas. Front or insides first then back or o
43、utside ofproduct second.14.1.18 Two-minute Cycle for CupsConsists of measuringtemperatures of the handle area and the body area.14.1.19 Measure the internal volume of the cup or mug. Fillthe cup or mug half full with tap water.14.1.20 Mark test points on the vessel to be tested in 3positions (120 an
44、gles) around the outer rim of the lip-rim area.Also mark test points on the top and bottom surface of thehandle where it attaches to the body of the vessel as well as thecenter outside surface of the handle.14.1.21 Place in the center of the microwave oven.14.1.22 Set Power level to maximum, time fo
45、r 2 min. andstart cycle.14.1.23 Remove from microwave at end of cycle and pourout water.14.1.24 Within 25 s test and record the three test pointpositions around the vessel handle, then measure the three testpoints in the lip-rim area.14.1.25 Turn the ware over and with the surface temperatureprobe m
46、easure and record the maximum reading by sliding theprobe around the surface of the cup or mug while observing thetemperature readings.14.2 Record results.15. Calculation or Interpretation of Results15.1 To be considered Microwave Safe for Reheating theproduct must pass the following criteria:15.1.1
47、 If there is any degradation of the ware, for examplecrazing, cracking, deformation, or discoloration, the ware failsthe test.15.1.2 The One-minute Microwave Cycle for Flatware re-sults must be 71C (160F) or less.15.1.3 The Five-minute Microwave Cycle for Flatwareresults must be 163C (325F) or less.
48、15.1.4 The Two-minute Microwave Cycle for Cups andMugs result must have handle temperatures of 60C (140F) orless and all body temperature measurements of 121C (250F)or less.16. Report16.1 The results are reported by identification of the prod-uct, date, the temperatures measured, any failures of the
49、product such as cracking or crazing of the glaze etc. and theconditions when the failure occurred. Additionally, the powerabsorption, the thermal shock results and date of testing are tobe included in the test results.17. Precision and Bias17.1 No information is presented for the precision or bias ofTest Method C1607 because the test result is non-quantitative.18. Keywords18.1 ceramicware; dinnerware; drinkware; microwave safe;mugs; safetyC1607 123ASTM International takes no position respecting the validity of any patent rights asserted i
