ASTM_D_4321_-_15.pdf

Designation:D432115Standard 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 parentheses 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(areaper unit mass)of plastic film.1.2 Also described in this test method is the means forcalculating 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 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 regulatory limitations prior to use.NOTE1This 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(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD4883 Test Method for Density of Polyethylene by theUltrasound TechniqueD6988 Guide for Determination of Thickness of Plastic FilmTest SpecimensE691 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 Terms Specific to This Standard:3.2.1 measured densitythe density of the fabricated film asdetermined 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 themanufacturing 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 of filmas agreed upon between the user and the supplier.3.2.4 nominal thicknessthe target value of film thicknessas agreed 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 thisdetermines 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 least 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 accurately 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 abovetemplate would not produce a specimen weighing at least 1 g,1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film,Sheeting,andMolded Products.Current edition approved May 1,2015.Published June 2015.Originallyapproved in 1983.Last previous edition approved in 2009 as D4321-09.DOI:10.1520/D4321-15.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 a steel straightedge 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 toaccommodate film samples from which test specimens are tobe cut.5.3 Sharp Utility Knife or Razor Blade,or equivalent.5.4 Analytical Balance having a resolution of at least 0.001gram.5.5 Steel Tape Measure having a resolution of at least 0.001metre(0.040 inch).6.