1、Designation: D4321 09D4321 15Standard Test Method forPackage Yield of Plastic Film1This standard is issued under the fixed designation D4321; 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 pa
2、rentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of yield (area per unit mass) of plastic film.1.2 Also described in this test method is the means for ca
3、lculating nominal yield, given values for nominal density, and nominalthickness. This is needed since, in material specifications, limits for yield are normally stated in terms of the percent deviation ofactual yield from nominal yield.1.3 The values stated in SI units are to be regarded as the stan
4、dard. The values given in brackets are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabi
5、lity of regulatorylimitations prior to use.NOTE 1This test method standard and ISO 4591 address the same subject matter, but differ in technical content.2. Referenced Documents2.1 ASTM Standards:2D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD883 Te
6、rminology Relating to PlasticsD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD4883 Test Method for Density of Polyethylene by the Ultrasound TechniqueD6988 Guide for Determination of Thickness of Plastic Film Test SpecimensE691 Practice for Conducting an Interlaboratory S
7、tudy to Determine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 density, apparentthe weight in air of a unit volume of a material.3.1.2 yieldthe area per unit mass of a material.3.2 Definitions of Terms Specific to This Standard:3.2.1 measured densitythe density of the fabricated
8、 film as determined by actual measurement.3.2.1.1 DiscussionThe measured density is not the value used to classify the material in accordance with a standard material specification. Themeasured value will depend on the manufacturing process of the film.3.2.2 measured thicknessthe thickness of the fa
9、bricated film as determined by actual measurement.3.2.3 nominal densityan estimated value of density of film as agreed upon between the user and the supplier.3.2.4 nominal thicknessthe target value of film thickness as agreed upon between the user and the supplier.3.2.5 nominal yieldthe target value
10、 of yield as agreed upon between the user and the supplier.1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.19 on Film, Sheeting, and MoldedProducts.Current edition approved Feb. 1, 2009May 1, 2015. Published February
11、 2009June 2015. Originally approved in 1983. Last previous edition approved in 20042009 asD4321 - 04.D4321 - 09. DOI: 10.1520/D4321-09.10.1520/D4321-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Sta
12、ndardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possibl
13、e to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyri
14、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.6 package yieldthe calculated value of yield as determined by this test method.4. Significance and Use4.1 Actual yield is important to the film converter as this determines the actual numb
15、er of units or packages that he can derivein a particular conversion from any given mass of film.5. Apparatus5.1 Means for preparing test specimens of accurately known area and weighing at least 1 g.5.1.1 When film width and thickness are such that a specimen weighing at least 1 g will be produced,
16、a rectangular metaltemplate, nominally 100-mm 4-in.(4-in.) wide, having a length greater than the width of the film from which the specimens areto be taken and having accurately parallel edges in the length direction, is to be used for preparing specimens. The width is to beaccurately measured for s
17、ubsequent use in calculating the specimen area. If slippage of film beneath the template during the cuttingoperation is a problem, cement a thin layer of cork, felt, or other suitable material onto the contact face of the template.5.1.2 For narrower, thinner films for which the above template would
18、not produce a specimen weighing at least 1 g, a steelstraightedge may be used.is an option. 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 to accommodate film samples from which test spe
19、cimens are to be cut.5.3 Sharp Utility Knife or Razor Blade, or equivalent.5.4 Analytical Balance having a resolution of at least 0.001 gram.5.5 Steel Tape Measure having a resolution of at least 0.001 metre (0.040 inch).6. Sampling6.1 For a lot or a commercial shipment, sample as directed in the ap
20、propriate film standard or specification. In the absence ofa reference standard or specification, the sampling frequency shall be agreed upon between the supplier and user.6.2 If results are to be obtained for only a single roll, obtain a sample with a length sufficient for three test specimens. Usu
21、ally,a length of 3 m 10 ft(10 ft) is sufficient.6.3 In obtaining a sample from a roll, unwind and discard at least two turns before taking the sample. In obtaining a sample,cut across the full width of the film perpendicular to its length.7. Procedure7.1 Smooth out the sample onto a flat surface. If
22、 the sample is a flat tubular film, the test specimen shall be taken in doublethickness. If the sample is gusseted or multi-folded, spread out the gussets or folds until the sample is a sheet or flat tube.7.2 Measure the sample width to the nearest 0.001 m 0.040 in.(0.040 in.) using a steel tape mea
23、sure. Record this as the testspecimen width, Wa, in metres inches,(inches), for single thickness film. For flat tubular film, multiply the measured width valueby 2 and record as Wa.7.3 Cut out a specimen weighing at least 1 g by one of the following techniques.7.3.1 Lay the template across the full
24、width of the film with the length of the template perpendicular to the edge of the film.Press down on the top of the template in the area where the cut is being made. Cut across the entire film width on both sides ofthe template. Retrieve the cutout specimen. Record the premeasured width of the temp
25、late as the length, La, in metres inches ofthe test specimen.7.3.2 Lay the steel straightedge across the film width perpendicular to the edges of the film. Make one cut across the film widthalong the straightedge. Pick up the straightedge and reposition it at an appropriate distance from the first c
26、ut. Again cut across thefilm width with the straightedge. Measure the length of the test specimen using a steel tape measure to the nearest 0.001 m 0.040in.(0.040 in.). Record this as the length, La, in metres inches of the test specimen.7.4 If yield of a single roll is being measured, obtain two mo
27、re specimens from the roll. These specimens must be at least 1m 3 ft(3 ft) apart in accordance with 7.3. Discard the scrap between where the specimens are taken. If yield of a lot or shipmentis being determined, obtain one specimen from each sampling unit from the lot or shipment.7.5 Weigh each test
28、 specimen and record its mass, Ma, in kilograms to the nearest 0.001 g.8. Calculation8.1 Calculate the measured yield for each specimen as follows:Ya 5Wa 3La!/Ma! (1)where:Ya = measured yield, m2 /kg in.2 /lb,D4321 152Wa = measured specimen width, m in.,La = measured specimen length, m in., andMa =
29、measured specimen mass, kg lb.Ya = measured yield, m2 /kg (in.2 /lb),Wa = measured specimen width, m (in.),La = measured specimen 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 Ya for the roll.
30、 For reporting onthe measured yield of a lot or shipment, average the n values of Ya obtained for the n samples from the lot.8.3 Calculate nominal yield for the roll, lot, or shipment as follows:Yn 5C!/dt! (2)where:Yn = nominal yield, m2/kg in.2 /lb,Yn = nominal yield, m2/kg (in.2 /lb),C = constant,
31、d = nominal density, andt = nominal thickness.8.3.1 When d is in kg/m3 and t is in m, the value of C is 106 in order to give Yn in m2/kg.8.3.2 When d is in g/cm3 and t is in inches, the value of C is 27.68 in order to give Yn in in.2/lb.8.4 Calculate the percent deviation D of measured yield from no
32、minal yield as follows:D 5Ya 2Yn!/Yn! 3100 (3)where Ya and Yn are as found in 8.2 and calculated in 8.3.NOTE 2If needed, calculate the length of film per roll, per lot, or per shipment can be found as follows:L 5Ya 3M!/Wa! (4)where:L = length, m in., per roll or shipment,L = length, m (in.), per rol
33、l or shipment,M = net mass, kg lb, of film on the roll or in the lot or shipment, andM = net mass, kg (lb), of film on the roll or in the lot or shipment, andYa and Wa = are as previously defined.NOTE 3High values of D found in 8.4 are attributable to deviations between the measured density and the
34、nominal density or deviations betweenthe measured thickness and the nominal thickness, or both. This requires confirmation of the measured density by Test Method D1505 (Test Method D792is also acceptable as is D4883 provided instrument calibration is traceable to D792 or D1505) and confirmation of t
35、he measured thickness by GuideD6988.9. Report9.1 Report the following information:9.1.1 Complete identification of the roll of film or of the lot or shipment, including nominal density, nominal thickness, andnominal yield.9.1.2 For one roll, the (mean) measured yield and the range of the three repli
36、cates for measured yield.9.1.3 For a lot or shipment, the (mean) measured yield for the number of samples tested and the range of determinations ofmeasured yield.9.1.4 Percent deviation of measured yield from nominal yield for the roll, lot, or shipment.9.1.5 Operator and date of test.10. Precision
37、and Bias310.1 AnTable 1 interlaboratory evaluationis based was carried out in which six laboratories tested four materials in accordancewith the recommendations of on a round robin conducted in accordance with Practice E691. , involving four materials tested bysix laboratories. In this study, consid
38、ering a test result to be the average value of actual yield derived from testing three specimensof a material in a short time span, all six laboratories obtained one test result for each material by use of templates, and four ofthe six obtained one test result for each material by use of straightedg
39、es. For the four materials employed in this study, indexesof precision, as defined in Practice E691, were found to be as shown in Table 1.3 Supporting data are available from ASTM Headquarters. Request RR:D20-1103.D4321 153NOTE 4The following explanations of “r” and “R” (10.2 10.2.3) are only intend
40、ed to present a meaningful way of considering the approximateprecision of this test method. The data in Table 1 should not be rigorously applied to acceptance or rejection of material, as those data are specific to theround robin and may not be representative of other lots, conditions, materials, or
41、 laboratories. Users of this test method should apply the principlesoutlined in Practice E691 to generate data specific to their laboratory and materials, or between specific laboratories. The principles of 10.2 10.2.3 wouldthen be valid for such data.)10.2 Concept of r and R in Table 1For theIf Sr
42、four materialsand SR employed in this study, indexes of precision, as definedin Practicehave been calculated from a large enough body of data, and for test results E691, were found to be as shown inthat werethe result of testing ten specimens Table 1.for each test result then:10.2.1 RepeatabilityTwo
43、 results obtained within one laboratory shall be judged not equivalent if they differ by more than the“r” value for that material. “r” is the interval representing the critical difference between two test results for the same material,obtained by the same operator using the same equipment on the sam
44、e day in the same laboratory.10.2.2 ReproducibilityTwo test results obtained by different laboratories shall be judged not equivalent if they differ by morethan the “R” value for that material. “R” is the interval representing the critical difference between two test results for the samematerial, ob
45、tained by different operators using different equipment in different laboratories.10.2.3 Any judgment in accordance with 10.2.1 or 10.2.2 would have an approximate 95 % (0.95) probability of being correct.NOTE 4Repeatability, Vr, %: When comparing two test results for the same material obtained by t
46、he same operator using the same equipment, thetwo test results should be judged not equivalent if they differ by more than the r value for that material.10.3 There are no recognized standards by which to estimate of this method.NOTE 5Reproducibility, VR, %: When comparing two test results for the sa
47、me material obtained by different operators using different equipment indifferent laboratories, the two test results should be judged not equivalent if they differ by more than the R value for that material.11. Keywords11.1 nominal yield; package yield; plastic filmSUMMARY OF CHANGESCommittee D20 ha
48、s identified the location of selected changes to this standard since the last issue(D4321 - 04D4321 - 09) that may impact the use of this standard. (February (May 1, 20151, 2009)(1) In Section 2 and NoteUpdated ISO equivalency statement (Note 1 3, deleted reference to ) in accordance D374 and E252 a
49、ndreplaced with D6988 for thickness measurement.Guide D4968 (the revision guide).(2) In Section 2, addedEdited permissive language in 5.1.2reference to .D883 for Terminology.(3) Alternate Density methods Revised precision D792and D4883 were addedbias section (Section 10to Section 2 and Note 3.) toreflect language in Guide D4968.(4) In Note 3 the permissive language was removed and reworded for clarity.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item me
