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W�r�field `�, 10 Designation: 0 1709 — 75 (ReaPProved 1980) r--77.7 �1 StandardFER[Aft /SERVICES Test Methods IMPACT RESISTANCE OF POLYETHYLENE THE FREE -FALLING DART METHOD' .this Standard is issued under the fixed designation D 1709: the number immediately following the designation indicates the �f original adoption orin the case of revision. the year of last revision. A number in parentheses indicates the year of Last ie=PPpval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 1, Scope 1,1 These methods cover the determination of the energy that causes polyethylene film to fail under specified conditions 'of impact of a free -falling dart. This energy is expressed in terms of the weight (mass) of the missile falling from a specified height which would result in ;p , failure of specimens tested. 1.3 Two methods of test are described: 1.3.1 .Method A employs a dart with a 3S.mm (1.3 -in.) diameter hemispherical head dropped from a height of 0.66 m (26 in.). This method may be used for films whose impact resistances require masses of about 50 g or less to about '- ke to fracture them. 1.3.3 Method 8 employs a dart with a ;t -mm (2 -in.) diameter hemispherical head dropped from a height of 1.52 m (60 in.). Its range of applicability is from about 0.3 kg to about '- kg. 1.3 T%%o testing techniques are described: 1.3.1 The standard technique is the staircase method. B% this technique. a uniform missile %fight increment is employed during test and ,he mis.ile weight -i, decreased or increased by the uniform increment after test of each speci- men. depending upon the result (fail or not fail) observed for the specimen. 1.3.3 The alternative technique provides for :eating specimen; in successive groups of ten. One mis.ile height i, employed for each group and missile weight is vaned in uniform incre- ments from group to group. 1.3.3 The staircase technique and the alter- native technique give equivalent results both as to the values of impact failure weight which are W nNeid Corp. 9'47 C e San 1619) obtained and as to the precisions with which they are determined. L Applicable Documents 2.1 ASTM Standards. D 374 Test for Thickness of Solid Electrical Insulation2 D 618 Conditioning Plastics and Electrical Insulating Materials for Testmg2 D 1248 Specification for Polyethylene Plas- tics Molding and Extrusion Materials2 E 177 Recommended Practice for Use of the Terms Precision and Accuracy as Applied to Measurement of a Property of a Mate- rial3 3. Significance 3.1 Methods A and B are used to establish the weight of the dart when 50 'c of he specimens fail under the conditions specified. Data obtained by one method cannot be cum - pared directly with the other method nor with those obtained from tests employing different conditions of missile velocity. impinging sur- face diameter. effective specimen diameter. and thickness. The values obtained I these test variables are highly dependent on the method of film fabrication as well as the ty pe and grade of polyethylene resin (see Specification D 1248). 87 ' These methods are under the jurisdiction of ASTM Committee D-20 on Plastics and are the direct responsibih y of Subcommittee D20.19 on Meeting. Current edition approved Jan. 24. 1975. Published March 19'+5. Originally published as D 1709 - 59 T. Last previous edition D 1709 - 67 11972). 1983 Annual Book of AST.W Standards. Vol 08.01. 1983 Annual Book of AST:N Standards. Vol 14.02.