1、Designation:D78718Standard Specification forEthyl Cellulose Molding and Extrusion Compounds1This standard is issued under the fixed designation D787;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number i
2、n parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This specification covers requirements for plasticizedethyl c
3、ellulose thermoplastic compounds suitable for injectionmolding and extrusion.It does not include special materialscompounded for special applications.1.2 The values stated in SI units are to be regarded asstandard.The English values given are for information only.1.3 The following precautionary stat
4、ement pertains only tothe Test Methods portion,Section 9 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,health,andenvironmental practices and
5、 determine the applicability ofregulatory limitations prior to use.NOTE1There is no known ISO equivalent to this specification.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the
6、Development of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD570 Test Method for Water Abso
7、rption of PlasticsD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionD785 Test Method for Rockwell Hardness of Plastics andElectrical Insulating Mater
8、ialsD792 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 TechniqueD3641 Practice for Injection Molding Test Specimens ofThermoplastic Molding and Extrusio
9、n MaterialsD3892 Practice for Packaging/Packing of Plastics3.Terminology3.1 Terms in this specification are in accordance withTerminology D883.4.Classification4.1 This specification covers two types and eleven grades ofethyl cellulose molding and extrusion compounds as classifiedin accordance with T
10、able 1.Type I materials are generalpurpose and Type II are characterized by improved resistanceto impact,especially at low temperatures.The grades areclassified in accordance with their physical properties asspecified in Table 1.4.1.1 A typical call out of material covered by this specifi-cation wou
11、ld contain the number of this specification and therequired type and grade chosen from Table 1,for example,D787 Type 1,Grade 1.5.Materials and Manufacture5.1 Materials supplied under this specification shall be ethylcellulose plastics in the form of pellets unless otherwisespecified.5.2 Material sup
12、plied shall be as uniform in compositionand size and as free of contamination as can be achieved bygood manufacturing practice.5.3 These materials possibly contain colorants in the nomi-nal amounts ordinarily employed.Only those materials of thiskind that meet the properties specified are covered by
13、 thisstandard.5.4 The color and transparency or opacity of items fabri-cated under the conditions recommended by the manufacturer1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current ed
14、ition approved April 1,2018.Published April 2018.Originallyapproved in 1944.Last previous edition approved in 2012 as D787 12.DOI:10.1520/D0787-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards vo
15、lume 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 StatesThis international standard was developed in a
16、ccordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 of the material shall be comparable within commercial matchtolerances to the color and transparency or opacity of samplessubmitted by the manufacturer.6.Physical Requirements6.1 Test specimens of the material shall conform to ther
