【astm標(biāo)準(zhǔn)】d 3981 - 09a

1、Designation: D3981 ? 09aStandard Specification for Polyethylene Films Made from Medium-Density Polyethylene for General Use and Packaging Applications1This standard is issued under the fixed designation D3981; the number

2、 immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon

3、(´) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers unpigmented, unsupported, sheet or tubular, medium-density polyethylene films (hereafter referred to as

4、film or films) from resins having densities in the range 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 i

5、s not restricted to it.1.3 This specification is also applicable to films made from copolymer polyethylene commonly referred to in industry as low-pressure polyethylene.1.4 This specification is also applicable to films

6、made from blends of homopolymers and copolymers, including ethylene/ vinyl-acetate copolymers.1.5 This specification allows for the use of recycled poly- ethylene film or resin as feedstock, in whole or in part, as long

7、as all the requirements of this specification are met and as long as any specific requirements as governed by the producer and end user are also met (see Note 1).NOTE 1—Guide D7209 contains terminology and definitions re

8、lating to recycled plastics.1.6 Special care must be exercised if this specification is applied to colored or pigmented films. This specification does not address specific problems associated with coloring, such as, quan

9、tity and quality of pigment dispersion, optical properties, and increase in density. These and other areas must be taken into account by mutual agreement between the supplier and the purchaser.1.7 The thickness of the fi

10、lms covered by this specification range from 25 to 100 µm (0.001 to 0.004 in.), inclusive. The maximum width of the sheet or lay-flat is 3.05 m (120 in.).1.8 This specification does not cover oriented heat- shrinkab

11、le films.1.9 This specification defines the levels of various physical properties from which specifications for specific films are to be described. The levels of physical properties required by a film for a given applica

12、tion are selected from Section 6 and the corresponding tables. However, Sections 7.2 – 7.5 relating to tolerances shall apply without change to all film falling within the scope indicated by the title and 1.1 – 1.4.1.10

13、This specification covers dimensional tolerances, classification, intrinsic quality requirements, and test methods. The dimensional tolerances include thickness, width, and length or yield. Classification defines types,

14、classes, surfaces, and finishes. The intrinsic quality requirements include density, workmanship, impact strength, tensile strength, heat sealability, and odor, as well as the classification properties for stiffness, coe

15、fficient of friction, optical properties, and surface treatment. A sampling method is included.1.11 The values stated in SI units are to be regarded as standard. The values in parentheses are given for information only.1

16、.12 The following precautionary caveat pertains only to the test methods portion, Section 10, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use.

17、It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limita- tions prior to use.NOTE 2—There is no known ISO equivalent

18、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 Sheet

19、ingD883 Terminology Relating to Plastics D1003 Test Method for Haze and Luminous Transmittance1 This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommit

20、tee D20.19 on Film, Sheeting, and Molded Products. Current edition approved May 1, 2009. Published June 2009. Originally approved in 1981. Last previous edition approved in 2008 as D3981 – 09. DOI: 10.1520/D3981-09A.2 Fo

21、r referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page

22、 on the 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 States17.3 Width Tol

23、erance—The width shall be within the toler- ances given in Table 8.7.4 Yield Tolerance—The deviation of the actual yield from nominal yield shall be within the tolerances given in Table 9.7.5 Flatness—The flatness of the

24、 film shall be within limits as mutually agreed upon between the purchaser and the supplier.8. Workmanship, Finish, and Appearance8.1 Film—The film shall have workmanship qualities con- forming to good commercial practic

25、e. The quality of film with regard to gels, streaks, pinholes, particles of foreign matter, undispersed raw materials, holes, tears, and blisters shall be mutually established between the purchaser and the supplier.8.2 R

26、oll Formation: 8.2.1 The diameter of cores upon which film is wound shall be established by mutual agreement between the purchaser and the supplier. Cores upon which film is wound must not be recessed at either edge of t

27、he roll and shall not extend more than 6 mm (1?4 in.) beyond either edge of the roll. 8.2.2 Ridges and soft spots that result in bagginess and looseness of the unwound film are grounds for rejection by the purchaser on a

28、 roll-to-roll basis if the conditions contribute to poor 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 inter

29、fere with the unwinding of the rolls. 8.2.4 The type and number of splices and flaggings of splices or breaks (if unspliced) in rolls of more than one piece shall be established by mutual agreement between the supplier a

30、nd the purchaser.9. Sampling9.1 Statistically based sampling plans that are appropriate for each particular product or quantity shall be used to obtain samples for use in determining compliance with this specifi- cation.

31、 Refer to Practice D1898 for guidance.9.2 For the purposes of developing supplier or purchaser specifications a lot size generally refers to the number of rolls in a lot. Sampling units are those rolls selected by random

32、 numbers from the lot. A unit sample is the sample of film taken from the roll. Take care in taking unit samples. Unwind and discard several turns from the roll and then take more than enough sample to run all specified

33、tests. Do not allow the sample to become soiled. Ensure that the sample is not folded or creased excessively.10. Test Methods10.1 Conditioning—Condition the test specimens at 23 6 2°C (73.4 6 3.6°F) for not les

34、s than 40 h prior to test in accordance with Specification D4976 or as otherwise specified by agreement. In cases of disagreement, the tolerances shall be 61°C (61.8°F)10.2 Test Conditions—Conduct tests at 23 6

35、 2°C (73.4 6 3.6°F) in accordance with Specification D4976 or as otherwise specified by agreement. In cases of disagreement, the toler- ances shall be 61°C (61.8°F).10.3 In addition, for films contain

36、ing hydrophilic fillers, co-monomers, pigments or other modifiers, conditioning and testing shall be done at 50 6 10 % relative humidity. In cases of disagreement, the tolerance shall be 65 % relative humidity.10.4 Width

37、—Measure the width with a metal rule capable of measuring to an accuracy of 61 mm (or 1?16 in.).10.5 Thickness—Measure the thickness in accordance with Guide D6988. The specimen shall be taken as a 50-mm (2-in.) strip ac

38、ross the web and measured at intervals of not more than 50 mm (2 in.).10.6 Yield—Measure by Test Method D4321.10.7 Flatness—Measure the flatness using a method mutu- ally agreed upon between the purchaser and the seller.

39、TABLE 2 Classification for SurfaceSurface Coefficient of Friction0 greater than 0.7 1 >0.4 to 0.7 2 >0.2 to 0.4 3 0.2 or lessTABLE 3 Classification for ClassClass ClarityA Gloss Units Haze %0 — 30 or less greater t

40、han 25 1 low >30 to 50 >10 to 25 2 moderate >50 to 70 >5 to 10 3 high greater than 70 0 to 5A As yet undefined but refers to degree of see-through visual acuity.TABLE 4 Classification for FinishFinish Wetting

41、 Tension, dynes/cm1 32, 33, 34 2 35, 36, 37 3 38, 39, 40 4 41 and overTABLE 5 Tensile PropertiesProperty Units Machine Direction Transverse Direction Minimum tensile strength MPa (psi) 14.1 (2000) 10.5 (1500)Minimum elon

42、gation % 100 300TABLE 6 Heat SealabilityFinish of Contact SurfacesA Minimum Ratio of Heat Seal StrengthsB2 to 2 0.60 1 to 2 0.60 1 to 1 0.75A Heat sealability is not applicable to films with finish greater than 2. B The

43、ratio is:average stress sforce/unit widthd 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-sentativ