1、Designation: D3981 09a (Reapproved 2016)Standard Specification forPolyethylene Films Made from Medium-Density Polyethylenefor General Use and Packaging Applications1This standard is issued under the fixed designation D3981; the number immediately following the designation indicates the year oforigin
2、al 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. Scope1.1 This specification covers unpigmented, unsupported,sheet or tubul
3、ar, medium-density polyethylene films (hereafterreferred to as film or films) from resins having densities in therange from 926.0 to 938.0 kg/m3(0.926 to 0.938 g/cm3),inclusive, as measured on molded plaques.1.2 This specification is applicable to homopolymer poly-ethylene but is not restricted to i
4、t.1.3 This specification is also applicable to films made fromcopolymer polyethylene commonly referred to in industry aslow-pressure polyethylene.1.4 This specification is also applicable to films made fromblends of homopolymers and copolymers, including ethylene/vinyl-acetate copolymers.1.5 This sp
5、ecification allows for the use of recycled poly-ethylene film or resin as feedstock, in whole or in part, as longas all the requirements of this specification are met and as longas any specific requirements as governed by the producer andend user are also met (see Note 1).NOTE 1Guide D7209 contains
6、terminology and definitions relating torecycled plastics.1.6 Special care must be exercised if this specification isapplied to colored or pigmented films. This specification doesnot address specific problems associated with coloring, such as,quantity and quality of pigment dispersion, optical proper
7、ties,and increase in density. These and other areas must be takeninto account by mutual agreement between the supplier and thepurchaser.1.7 The thickness of the films covered by this specificationrange from 25 to 100 m (0.001 to 0.004 in.), inclusive. Themaximum width of the sheet or lay-flat is 3.0
8、5 m (120 in.).1.8 This specification does not cover oriented heat-shrinkable films.1.9 This specification defines the levels of various physicalproperties from which specifications for specific films are to bedescribed. The levels of physical properties required by a filmfor a given application are
9、selected from Section 6 and thecorresponding tables. However, Sections 7.2 7.5 relating totolerances shall apply without change to all film falling withinthe scope indicated by the title and 1.1 1.4.1.10 This specification covers dimensional tolerances,classification, intrinsic quality requirements,
10、 and test methods.The dimensional tolerances include thickness, width, andlength or yield. Classification defines types, classes, surfaces,and finishes. The intrinsic quality requirements include density,workmanship, impact strength, tensile strength, heatsealability, and odor, as well as the classi
11、fication properties forstiffness, coefficient of friction, optical properties, and surfacetreatment. A sampling method is included.1.11 The values stated in SI units are to be regarded asstandard. The values in parentheses are given for informationonly.1.12 The following precautionary caveat pertain
12、s only to thetest methods portion, Section 10, of this specification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applic
13、ability of regulatory limita-tions prior to use.NOTE 2There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD882 Test Method for Tensile Properties of Thin Plastic
14、SheetingD883 Terminology Relating to PlasticsD1003 Test Method for Haze and Luminous Transmittance1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.19 on Film, Sheeting,and Molded Products.Current edition approved May
15、1, 2016. Published May 2016. Originallyapproved in 1981. Last previous edition approved in 2009 as D3981 09a. DOI:10.1520/D3981-09AR16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inf
16、ormation, 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 States1of Transparent PlasticsD1505 Test Method for De
17、nsity of Plastics by the Density-Gradient TechniqueD1709 Test Methods for Impact Resistance of Plastic Filmby the Free-Falling Dart MethodD1894 Test Method for Static and Kinetic Coefficients ofFriction of Plastic Film and SheetingD1898 Practice for Sampling of Plastics (Withdrawn 1998)3D2103 Specif
18、ication for Polyethylene Film and SheetingD2457 Test Method for Specular Gloss of Plastic Films andSolid PlasticsD2578 Test Method for Wetting Tension of Polyethylene andPolypropylene FilmsD4321 Test Method for Package Yield of Plastic FilmD4703 Practice for Compression Molding ThermoplasticMaterial
19、s into Test Specimens, Plaques, or SheetsD4883 Test Method for Density of Polyethylene by theUltrasound TechniqueD4976 Specification for Polyethylene Plastics Molding andExtrusion MaterialsD6988 Guide for Determination of Thickness of Plastic FilmTest SpecimensD7209 Guide for Waste Reduction, Resour
20、ce Recovery, andUse of Recycled Polymeric Materials and Products (With-drawn 2015)3E1870 Test Method for Odor and Taste Transfer fromPolymeric Packaging FilmNOTE 3Relevant government regulations also apply to this specifica-tion.NOTE 4If this product is intended for packaging foods, medicines,drugs,
21、 and cosmetics it is subject to applicable regulations of the Food andDrug Administration or the Department of Agriculture and must complywith such regulations. If it is necessary to comply with regulations of othergovernment agencies, such as the Consumer Product Safety Commission,Environmental Pro
22、tection Agency, Department of Transportation, FederalTrade Commission, etc., such compliance shall be arranged between thepurchaser and the seller prior to placing an order.F88 Test Method for Seal Strength of Flexible BarrierMaterials3. Terminology3.1 Unless otherwise indicated the terminology used
23、 in thisspecification is in accordance with definitions given in Termi-nology D883.4. Classification4.1 The medium-density film is, by this specification, clas-sified by Types: 0, 1, 2, and 3; Surfaces: 0, 1, 2, and 3; Classes:0, 1, 2, and 3; and Finishes: 1, 2, 3, and 4. These classificationsare de
24、scribed in detail in 6.1.5. Materials5.1 The film shall be made from a homopolymerpolyethylene, copolymer polyethylene (see Note 5), or blendsof homopolymers or copolymers, or both, so that it meets thedensity and other film requirements listed herein.NOTE 5From a polyethylene, polyethylene plastic,
25、 or an ethyleneplastic as defined in Terminology D883.5.2 The film shall be made from resins having a densitybetween 926.0 and 938.0 kg/m3(0.926 and 0.938 g/cm3),inclusive.5.3 The film shall be natural in color (essentially colorless)unless a color has been agreed upon between the supplier andthe pu
26、rchaser. If colored, the quality and uniformity of coloringshall be by agreement between the supplier and the purchaser.Also, if added colorants or pigments are used in an amountsuch that some film properties are affected, this shall be takeninto account by mutual agreement between the supplier and
27、thepurchaser.6. Physical Requirements6.1 Classification Properties:6.1.1 TypeThe 1 % secant modulus for all thicknesses offilm shall be as specified in Table 1 for Types 0, 1, 2, and 3.6.1.2 SurfaceThe kinetic coefficient of friction shall be asspecified in Table 2 for Surfaces 0, 1, 2, and 3.6.1.3
28、ClassThe optical properties shall be as specified inTable 3 of Classes 0, 1, 2, and 3. The three optical propertiesof clarity, gloss, and haze do not always correlate. Theparticular property of most importance for the specific appli-cation shall be established and the value for this property shallth
29、en govern, in case of any inconsistency.6.1.4 FinishThe surface treatment level of the film shallbe as specified in Table 4 for Finishes 1, 2, 3, and 4.6.2 Other Physical Properties:6.2.1 Impact ResistanceImpact resistance of the film shallbe established by mutual agreement between the supplier andt
30、he purchaser if this property is required.NOTE 6Dart-impact resistance of medium-density polyethylene filmscan be substantially less than that of low-density polyethylene films.6.2.2 Tensile PropertiesThe tensile strength and elonga-tion at break for all thicknesses shall be as specified in Table 5.
31、6.2.3 Heat SealabilityThe minimum ratio of heat-sealstrength to the film strength in the two principal directions shallbe as specified in Table 6.6.2.4 OdorThe odor level of the film shall average nomore than a 3.5 rating level.7. Dimensions7.1 SizeThe nominal thickness, width, length per roll orrol
32、l diameter, and yield of the film shall be established bymutual agreement between the purchaser and the supplier.7.2 Thickness ToleranceThe average thickness and thethickness variation across the film shall be within the toler-ances given in Table 7.3The last approved version of this historical stan
33、dard is referenced onwww.astm.org.TABLE 1 Classification for TypeType 1 % Secant Modulus, MPa (psi)0 170 (25 000) or less1 170 to 240 (25 000 to 35 000)2 240 to 345 (35 000 to 50 000)3 greater than 345 (50 000)D3981 09a (2016)27.3 Width ToleranceThe width shall be within the toler-ances given in Tab
34、le 8.7.4 Yield ToleranceThe deviation of the actual yield fromnominal yield shall be within the tolerances given in Table 9.7.5 FlatnessThe flatness of the film shall be within limitsas mutually agreed upon between the purchaser and thesupplier.8. Workmanship, Finish, and Appearance8.1 FilmThe film
35、shall have workmanship qualities con-forming to good commercial practice. The quality of film withregard to gels, streaks, pinholes, particles of foreign matter,undispersed raw materials, holes, tears, and blisters shall bemutually established between the purchaser and the supplier.8.2 Roll Formatio
36、n:8.2.1 The diameter of cores upon which film is wound shallbe established by mutual agreement between the purchaser andthe supplier. Cores upon which film is wound must not berecessed at either edge of the roll and shall not extend morethan6mm(14 in.) beyond either edge of the roll.8.2.2 Ridges and
37、 soft spots that result in bagginess andlooseness of the unwound film are grounds for rejection by thepurchaser on a roll-to-roll basis if the conditions contribute topoor performance of the film and end-use application.8.2.3 The edges of the roll must be free of nicks and cuts,and the general condi
38、tion of roll edges must not interfere withthe unwinding of the rolls.8.2.4 The type and number of splices and flaggings ofsplices or breaks (if unspliced) in rolls of more than one pieceshall be established by mutual agreement between the supplierand the purchaser.9. Sampling9.1 Statistically based
39、sampling plans that are appropriatefor each particular product or quantity shall be used to obtainsamples for use in determining compliance with this specifi-cation. Refer to Practice D1898 for guidance.9.2 For the purposes of developing supplier or purchaserspecifications a lot size generally refer
40、s to the number of rollsin a lot. Sampling units are those rolls selected by randomnumbers from the lot. A unit sample is the sample of film takenfrom the roll. Take care in taking unit samples. Unwind anddiscard several turns from the roll and then take more thanenough sample to run all specified t
41、ests. Do not allow thesample to become soiled. Ensure that the sample is not foldedor creased excessively.10. Test Methods10.1 ConditioningCondition the test specimens at 23 62C (73.4 6 3.6F) for not less than 40 h prior to test inaccordance with Specification D4976 or as otherwise specifiedby agree
42、ment. In cases of disagreement, the tolerances shall be61C (61.8F)10.2 Test ConditionsConduct tests at 23 6 2C (73.4 63.6F) in accordance with Specification D4976 or as otherwisespecified by agreement. In cases of disagreement, the toler-ances shall be 61C (61.8F).10.3 In addition, for films contain
43、ing hydrophilic fillers,co-monomers, pigments or other modifiers, conditioning andtesting shall be done at 50 6 10 % relative humidity. In casesof disagreement, the tolerance shall be 65 % relative humidity.10.4 WidthMeasure the width with a metal rule capable ofmeasuring to an accuracy of 61mm(or11
44、6 in.).10.5 ThicknessMeasure the thickness in accordance withGuide D6988. The specimen shall be taken as a 50-mm (2-in.)strip across the web and measured at intervals of not more than50 mm (2 in.).10.6 YieldMeasure by Test Method D4321.10.7 FlatnessMeasure the flatness using a method mutu-ally agree
45、d upon between the purchaser and the seller.TABLE 2 Classification for SurfaceSurface Coefficient of Friction0 greater than 0.71 0.4to0.72 0.2to0.43 0.2 or lessTABLE 3 Classification for ClassClass ClarityAGloss Units Haze %0 30 or less greater than 251 low 30 to 50 10 to 252 moderate 50 to 70 5 to
46、103 high greater than 70 0 to 5AAs yet undefined but refers to degree of see-through visual acuity.TABLE 4 Classification for FinishFinish Wetting Tension, dynes/cm1 32, 33, 342 35, 36, 373 38, 39, 404 41 and overTABLE 5 Tensile PropertiesProperty Units Machine DirectionTransverseDirectionMinimum te
47、nsilestrengthMPa (psi) 14.1 (2000) 10.5 (1500)Minimumelongation% 100 300TABLE 6 Heat SealabilityFinish of Contact SurfacesAMinimum Ratio of Heat SealStrengthsB2to2 0.601to2 0.601to1 0.75AHeat sealability is not applicable to films with finish greater than 2.BThe ratio is:average stress sforce/unit w
48、idthd for seal breakaverage stress sforce/unit widthd for film breakin the same film orientation.Care shall be taken that the film samples for the ratio measurement are repre-sentative of each other.D3981 09a (2016)310.8 DensityThe density of resins from which the film ismade shall be measured in ac
49、cordance with Test MethodD1505 (alternatively acceptable methods are D792 andD4883). Density specimens shall be prepared in accordancewith Practice D4703, Annex A1, Procedure C.10.9 StiffnessMeasure the secant modulus in accordancewith Test Methods D882 at the 1 % strain point of thespecimen.10.10 Coeffcient of FrictionMeasure the kinetic coeffi-cient of friction in accordance with Test Method D1894.10.11 Optical Properties:10.11.1 ClarityDetermine the clarity of the film by visualor instrumented means, as agreed upon between the pur
