1、Designation: D 3981 09aStandard Specification forPolyethylene Films Made from Medium-Density Polyethylenefor General Use and Packaging Applications1This standard is issued under the fixed designation D 3981; the number immediately following the designation indicates the year oforiginal adoption or,
2、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 specification covers unpigmented, unsupported,sheet or tubular, medium-dens
3、ity 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 it.1.3 This spec
4、ification 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 specification all
5、ows 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 D 7209 contains terminology an
6、d definitions relatingto recycled 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 properties,and incre
7、ase 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 3.05 m (120 in.).
8、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 selected from
9、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, clas-sification, intrinsic quality requirements, and test me
10、thods. Thedimensional tolerances include thickness, width, and length oryield. Classification defines types, classes, surfaces, and fin-ishes. The intrinsic quality requirements include density, work-manship, impact strength, tensile strength, heat sealability, andodor, as well as the classification
11、 properties for stiffness,coefficient of friction, optical properties, and surface treatment.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 pertains only t
12、o 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 applicability
13、of regulatory limita-tions prior to use.NOTE 2There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D 792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 882 Test Method for Tensile Properties of Thin PlasticSheeti
14、ngD 883 Terminology Relating to PlasticsD 1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD 1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD 1709 Test Methods for Impact Resistance of Plastic Filmby the Free-Falling Dart MethodD 1894 Test Method
15、for Static and Kinetic Coefficients of1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.19 on Film andSheeting.Current edition approved May 1, 2009. Published June 2009. Originallyapproved in 1981. Last previous editio
16、n approved in 2008 as D 3981 09.2For 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.1*A Summary of Changes sectio
17、n appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Friction of Plastic Film and SheetingD 1898 Practice for Sampling of Plastics3D 2103 Specification for Polyethylene Film and SheetingD 2457 Test Met
18、hod for Specular Gloss of Plastic Films andSolid PlasticsD 2578 Test Method for Wetting Tension of Polyethyleneand Polypropylene FilmsD 4321 Test Method for Package Yield of Plastic FilmD 4703 Practice for Compression Molding ThermoplasticMaterials into Test Specimens, Plaques, or SheetsD 4883 Test
19、Method for Density of Polyethylene by theUltrasound TechniqueD 4976 Specification for Polyethylene Plastics Molding andExtrusion MaterialsD 6988 Guide for Determination of Thickness of PlasticFilm Test SpecimensD 7209 Guide for Waste Reduction, Resource Recovery,and Use of Recycled Polymeric Materia
20、ls and ProductsE 1870 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, and cosmetics it is subject to applicable regulations of the Food
21、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 Protection Agency, Department of Transportation, FederalTrade Commissi
22、on, 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 in thisspecification is in accordance with definitions given in Te
23、rmi-nology D 883.4. 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 described in detail in 6.1.5. Materials5.1 The film shall be made fr
24、om a homopolymer polyeth-ylene, copolymer polyethylene (see Note 5), or blends ofhomopolymers or copolymers, or both, so that it meets thedensity and other film requirements listed herein.NOTE 5From a polyethylene, polyethylene plastic, or an ethyleneplastic as defined in Terminology D 883.5.2 The f
25、ilm 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 purchaser. If colored, the quality and uniformity of coloringshal
26、l 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 thepurchaser.6. Physical RequirementsPhysical Requirements6.1 C
27、lassification 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 ClassThe optical properties shall be as sp
28、ecified 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 shallthen govern, in case of any inconsistency.6.
29、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 andthe purchaser if this property is required.
30、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 5.6.2.3 Heat SealabilityThe minimum ratio of
31、 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 orroll diameter, and yield of the film shall be
32、 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 7.7.3 Width ToleranceThe width shall be within the toler-ances given in Table 8.7.4 Yield Tole
33、ranceThe 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.3Withdrawn. The last approved version of this historical standard is refer
34、encedon www.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)D 3981 09a28. Workmanship, Finish, and Appearance8.1 FilmThe film shall have workmanship qualities con-
35、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 Formation:8.2.1 The diameter of cores upon wh
36、ich 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 soft spots that result in bagginess
37、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 condition of roll edges must not interfere
38、 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 sampling plans that are appropriatefo
39、r each particular product or quantity shall be used to obtainsamples for use in determining compliance with this specifi-cation. Refer to Practice D 1898 for guidance.9.2 For the purposes of developing supplier or purchaserspecifications a lot size generally refers to the number of rollsin a lot. Sa
40、mpling 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 tests. Do not allow thesample to beco
41、me 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 D 4976 or as otherwise specifiedby agreement. In cases of disagreement, the
42、 tolerances shall be61C (61.8F)10.2 Test ConditionsConduct tests at 23 6 2C (73.4 63.6F) in accordance with Specification D 4976 or as otherwisespecified by agreement. In cases of disagreement, the toler-ances shall be 61C (61.8F).10.3 In addition, for films containing hydrophilic fillers,co-monomer
43、s, 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(or116 in.).10.5 ThicknessMeasure the t
44、hickness in accordance withGuide D 6988. 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 D 4321.10.7 FlatnessMeasure the flatness using a method mutu-ally agreed upon between the purchaser and
45、 the seller.10.8 DensityThe density of resins from which the film ismade shall be measured in accordance with Test MethodD 1505 (alternatively acceptable methods are D 792 andD 4883). Density specimens shall be prepared in accordancewith Practice D 4703, Annex A1, Procedure C.10.9 StiffnessMeasure t
46、he secant modulus in accordancewith Test Methods D 882 at the 1 % strain point of thespecimen.10.10 Coeffcient of FrictionMeasure the kinetic coeffi-cient of friction in accordance with Test Method D 1894.10.11 Optical Properties:TABLE 2 Classification for SurfaceSurface Coefficient of Friction0 gre
47、ater 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 103 high greater than 70 0 to 5AAs yet undefined but refers to degree of see-through visual acuity.TABLE 4 Classif
48、ication for FinishFinish Wetting Tension, dynes/cm1 32, 33, 342 35, 36, 373 38, 39, 404 41 and overTABLE 5 Tensile PropertiesProperty Units Machine DirectionTransverseDirectionMinimum tensilestrengthMPa (psi) 14.1 (2000) 10.5 (1500)Minimumelongation% 100 300TABLE 6 Heat SealabilityFinish of Contact
49、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 force/unit width! for seal breakaverage stress force/unit width! for film breakin the same film orientation.Care shall be taken that the film samples for the ratio measurement arerepresentative of each other.D 3981 09a310.11.1 ClarityDetermine the clarity of the film by visualor instrumented means, as agreed upon between the purchaserand the supplier.10.11.2 Gloss
