1、Designation: D 4321 04Standard Test Method forPackage Yield of Plastic Film1This standard is issued under the fixed designation D 4321; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthe
2、ses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of yield (areaper unit mass) of plastic film.1.2 Also described in this test method is the means forcalculati
3、ng nominal yield, given values for nominal density,and nominal thickness. This is needed since, in materialspecifications, limits for yield are normally stated in terms ofthe percent deviation of actual yield from nominal yield.1.3 The values stated in SI units are to be regarded as thestandard. The
4、 values given in brackets are for information only.1.4 This 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
5、regulatory limitations prior to use.NOTE 1This test method is not equivalent to ISO 4591.2. Referenced Documents2.1 ASTM Standards:2D 374 Test Methods for Thickness of Solid Electrical Insu-lationD 1505 Test Method for Density of Plastics by the Density-Gradient TechniqueE 252 Test Method for Thickn
6、ess of Thin Foil and Film byWeighingE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 density, apparentthe weight in air of a unit volumeof a material.3.1.2 yieldthe area per unit mass of a material.3.2 Definitions of
7、 Terms Specific to This Standard:3.2.1 measured densitythe density of the fabricated filmas determined by actual measurement.3.2.1.1 DiscussionThe measured density is not the valueused to classify the material in accordance with a standardmaterial specification. The measured value will depend on the
8、manufacturing process of the film.3.2.2 measured thicknessthe thickness of the fabricatedfilm as determined by actual measurement.3.2.3 nominal densityan estimated value of density offilm as agreed upon between the user and the supplier.3.2.4 nominal thicknessthe target value of film thicknessas agr
9、eed upon between the user and the supplier.3.2.5 nominal yieldthe target value of yield as agreedupon between the user and the supplier.3.2.6 package yieldthe calculated value of yield as deter-mined by this test method.4. Significance and Use4.1 Actual yield is important to the film converter as th
10、isdetermines the actual number of units or packages that he canderive in a particular conversion from any given mass of film.5. Apparatus5.1 Means for preparing test specimens of accurately knownarea and weighing at least 1 g.5.1.1 When film width and thickness are such that aspecimen weighing at le
11、ast 1 g will be produced, a rectangularmetal template, nominally 100-mm 4-in. wide, having alength greater than the width of the film from which thespecimens are to be taken and having accurately parallel edgesin the length direction, is to be used for preparing specimens.The width is to be accurate
12、ly measured for subsequent use incalculating the specimen area. If slippage of film beneath thetemplate during the cutting operation is a problem, cement athin layer of cork, felt, or other suitable material onto thecontact face of the template.5.1.2 For narrower, thinner films for which the abovete
13、mplate would not produce a specimen weighing at least 1 g,a steel straightedge may be used. Using the steel straightedge,make cuts as far apart as necessary to produce a specimenweighing at least 1 g.5.2 Horizontal Flat Surface, of a size large enough toaccommodate film samples from which test speci
14、mens are tobe cut.5.3 Sharp Utility Knife or Razor Blade, or equivalent.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.Current edition approved July 1, 2004. Published July 2004. Originally app
15、rovedin 1983. Last previous edition approved in 1999 as D 4321 - 99.2For 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 w
16、ebsite.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 Analytical Balance having a resolution of at least 0.001gram.5.5 Steel Tape Measure having a resolution of a
17、t least 0.001metre (0.040 inch).6. Sampling6.1 For a lot or a commercial shipment, sample as directedin the appropriate film standard or specification. In the absenceof a reference standard or specification, the sampling frequencyshall be agreed upon between the supplier and user.6.2 If results are
18、to be obtained for only a single roll, obtaina sample with a length sufficient for three test specimens.Usually, a length of 3 m 10 ft is sufficient.6.3 In obtaining a sample from a roll, unwind and discard atleast two turns before taking the sample. In obtaining a sample,cut across the full width o
19、f the film perpendicular to its length.7. Procedure7.1 Smooth out the sample onto a flat surface. If the sampleis a flat tubular film, the test specimen shall be taken in doublethickness. If the sample is gusseted or multi-folded, spread outthe gussets or folds until the sample is a sheet or flat tu
20、be.7.2 Measure the sample width to the nearest 0.001 m 0.040in. using a steel tape measure. Record this as the test specimenwidth, Wa, in metres inches, for single thickness film. For flattubular film, multiply the measured width value by 2 andrecord as Wa.7.3 Cut out a specimen weighing at least1gb
21、yoneofthefollowing techniques.7.3.1 Lay the template across the full width of the film withthe length of the template perpendicular to the edge of the film.Press down on the top of the template in the area where the cutis being made. Cut across the entire film width on both sides ofthe template. Ret
22、rieve the cutout specimen. Record the pre-measured width of the template as the length, La, in metresinches of the test specimen.7.3.2 Lay the steel straightedge across the film widthperpendicular to the edges of the film. Make one cut across thefilm width along the straightedge. Pick up the straigh
23、tedge andreposition it at an appropriate distance from the first cut. Againcut across the film width with the straightedge. Measure thelength of the test specimen using a steel tape measure to thenearest 0.001 m 0.040 in. Record this as the length, La,inmetres inches of the test specimen.7.4 If yiel
24、d of a single roll is being measured, obtain twomore specimens from the roll. These specimens must be at least1 m 3 ft apart in accordance with 7.3. Discard the scrapbetween where the specimens are taken. If yield of a lot orshipment is being determined, obtain one specimen from eachsampling unit fr
25、om the lot or shipment.7.5 Weigh each test specimen and record its mass, Ma,inkilograms to the nearest 0.001 g.8. Calculation8.1 Calculate the measured yield for each specimen asfollows:Ya5 Wa3 La!/Ma! (1)where:Ya= measured yield, m2/kg in.2/lb,Wa= measured specimen width, m in.,La= measured specime
26、n length, m in., andMa= measured specimen mass, kg lb.8.2 For reporting on the measured yield of a specific roll,average the three values obtained of Yafor the roll. Forreporting on the measured yield of a lot or shipment, averagethe n values of Yaobtained for the n samples from the lot.8.3 Calculat
27、e nominal yield for the roll, lot, or shipment asfollows:Yn5 C!/dt! (2)where:Yn= nominal yield, m2/kg in.2/lb,C = constant,d = nominal density, andt = nominal thickness.8.3.1 When d is in kg/m3and t is in m, the value of C is 106in order to give Ynin m2/kg.8.3.2 When d is in g/cm3and t is in inches,
28、 the value of Cis 27.68 in order to give Ynin in.2/lb.8.4 Calculate the percent deviation D of measured yieldfrom nominal yield as follows:D 5 Ya2 Yn!/Yn! 3 100 (3)where Yaand Ynare as found in 8.2 and calculated in 8.3.NOTE 2If needed, calculate the length of film per roll, per lot, or pershipment
29、can be found as follows:L 5 Ya3 M!/Wa! (4)where:L = length, m in., per roll or shipment,M = net mass, kg lb, of film on the roll or in thelot or shipment, andYaand Wa= are as previously defined.NOTE 3If the value of D found in 8.4 is deemed to be too large, thecause(s) can be that measured density d
30、eviates too much from nominaldensity or that measured thickness deviates too much from nominalthickness, or both. As a further check, measured density can be measuredby Test Method D 1505 and measured thickness can be measured by TestMethods D 374 or by Test Method E 252.9. Report9.1 Report the foll
31、owing information:9.1.1 Complete identification of the roll of film or of the lotor shipment, including nominal density, nominal thickness, andnominal yield.9.1.2 For one roll, the (mean) measured yield and the rangeof the three replicates for measured yield.9.1.3 For a lot or shipment, the (mean) m
32、easured yield forthe number of samples tested and the range of determinationsof measured yield.9.1.4 Percent deviation of measured yield from nominalyield for the roll, lot, or shipment.9.1.5 Operator and date of test.D432104210. Precision and Bias10.1 An interlaboratory evaluation3was carried out i
33、nwhich six laboratories tested four materials in accordance withthe recommendations of Practice E 691. In this study, consid-ering a test result to be the average value of actual yield derivedfrom testing three specimens of a material in a short time span,all six laboratories obtained one test resul
34、t for each material byuse of templates, and four of the six obtained one test result foreach material by use of straightedges.10.2 For the four materials employed in this study, indexesof precision, as defined in Practice E 691, were found to be asshown in Table 1.NOTE 4Repeatability, Vr, %: When co
35、mparing two test results for thesame material obtained by the same operator using the same equipment,the two test results should be judged not equivalent if they differ by morethan the r value for that material.NOTE 5Reproducibility, VR, %: When comparing two test results forthe same material obtain
36、ed by different operators using different equip-ment in different laboratories, the two test results should be judged notequivalent if they differ by more than the R value for that material.11. Keywords11.1 nominal yield; package yield; plastic filmSUMMARY OF CHANGESThis section identifies the locat
37、ion of selected changes to this test method. For the convenience of the user,Committee D20 has highlighted those changes that impact the use of this test method. This section also includesdescriptions of the changes or reasons for the changes, or both.D 4321 - 04:(1) In Section 5, resolutions for we
38、ight and length measure-ment apparatus have been specified.(2) In Section 7, resolution for length measurements has beenspecified.(3) Removed permissive language in Sections 5 and 7, andNote 2.(4) Reworded Section 6 for clarity.D 4321 - 99:(1) In Note 1, editorial change.(2) In Footnote 1, deleted s
39、entence referring to previouslyapproved changes to the standard.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any suc
40、h patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invite
41、d either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a
42、fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this
43、standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).3Supporting data are available from ASTM Headquarters. Request RR:D20-1103.TABLE 1 Indices of Precision for a Test Result of Actual YieldMaterialMean,in.2/lbRepeat-ability,Vr,%Reproduci-bility,VR,%TypeThick-ness, milPE 2.5 12994 1.0 2.4PP 2.0 14913 0.9 1.2PET 0.5 43398 0.7 1.2PET 2.0 9849 0.6 1.0D4321043
