1、Designation: D 787 96 (Reapproved 2003)Standard Specification forEthyl Cellulose Molding and Extrusion Compounds1This standard is issued under the fixed designation D 787; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers requirements for plasticizedethyl cellulose thermoplastic compounds suitable for injection
3、molding and extrusion. It does not include special materialscompounded for special applications.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 The following precautionary statement pertains only tothe Test Methods port
4、ion, 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 of regulatory limita-ti
5、ons prior to use.NOTE 1There is no equivalent or similar ISO standard.2. Referenced Documents2.1 ASTM Standards:D 256 Test Methods for Determining the Pedulum ImpactResistance of Notched Specimens of Plastics2D 569 Test Method for Measuring the Flow Properties ofThermoplastic Molding Materials2D 570
6、 Test Method for Water Absorption of Plastics2D 618 Practice for Conditioning Plastics for Testing2D 638 Test Method for Tensile Properties of Plastics2D 648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load2D 759 Practice for Conducting Physical Property Tests ofPlastics at Subn
7、ormal and Supernormal Temperatures3D 785 Test Method for Rockwell Hardness of Plastics andElectrical Insulating Materials2D 792 Test Methods for Specific Gravity (Relative Density)and Density of Plastics by Displacement2D 883 Terminology Relating to Plastics2D 1505 Test Method for Density of Plastic
8、s by the Density-Gradient Technique2D 1897 Practice for Injection Molding Test Specimens ofThermoplastic Molding and Extrusion Materials2D 1898 Practice for Sampling of Plastics2D 3892 Practice for Packaging/Packing of Plastics43. Terminology3.1 Terms in this specification are in accordance withTerm
9、inology D 883.4. Classification4.1 This specification covers two types and eleven grades ofethyl cellulose molding and extrusion compounds as classifiedin accordance with Table 1. Type I materials are generalpurpose and Type II are characterized by improved resistanceto impact, especially at low tem
10、peratures. The grades areclassified in accordance with their physical properties asspecified in Table 1.5. Ordering Information5.1 Purchase orders for, or inquiries about, the materialsdescribed in this specification shall identify the following:5.1.1 The number of this specification and the require
11、d typeand grade chosen from Table 1, for example, D 787 Type 1,Grade 1.5.1.2 Supplementary requirements in accordance with thisspecification if necessary.5.1.3 Color and opacity within the limits defined in 6.4.5.1.4 Particle form and size if choice is available.5.1.5 Such other requirements as may
12、be agreed between theseller and the purchaser.6. Materials and Manufacture6.1 Materials supplied under this specification shall be ethylcellulose plastics in the form of pellets unless otherwisespecified.1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct
13、 responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved July 10, 2003. Published September 2003. Originallyapproved in 1944. Last previous edition approved in 1996 as D 787 96.This edition includes the addition of an ISO equivalency statement and aKeywords section,
14、the elimination of superfluous references to user/seller agree-ments, and the removal of specific requirements relating to Federal/Militaryprocurement. Some references to specimens were changed to samples in keepingwith normal usage within ASTM materials standards.2Annual Book of ASTM Standards, Vol
15、 08.01.3Discontinued, see 1982 Annual Book of ASTM Standards, Vol 08.01.4Annual Book of ASTM Standards, Vol 08.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Material supplied in these forms shall be as uniform incomposition
16、and size and as free of contamination as can beachieved by good manufacturing practice.6.3 These materials may contain colorants in the nominalamounts ordinarily employed, but such additives shall not alterthe ability of the materials to meet the specified properties.6.4 The color and transparency o
17、r opacity of items fabri-cated under the conditions recommended by the manufacturerof the material shall be comparable within commercial matchtolerances to the color and transparency or opacity of samplessubmitted in advance by the manufacturer and approved by thepurchaser.7. Physical Requirements7.
18、1 Test specimens of the material shall conform to therequirements prescribed in Table 1.7.2 Molded specimens for those tests requiring them shallbe prepared as described in Section 10.7.3 Flow temperature of a given compound shall be within65C of the flow temperature designated in the contract orord
19、er.7.4 Conformance to the requirements of this specificationshall be determined by means of the tests identified in Section11 unless otherwise specified.8. Sampling8.1 The material shall be sampled in accordance withSections 9 to 12 of Practice D 1898. Adequate statisticalsampling prior to packaging
20、 shall be considered an acceptablealternative.8.2 For sampling purposes, a batch or lot shall be considereda unit of manufacture as prepared for shipment and may consistof a blend of two or more production runs of material.9. Number of Tests9.1 Routine testing of each batch or lot shall be limited t
21、oproperties designated in Table 1 of this specification.9.2 One set of samples for those tests that are designated(Section 11), shall be considered sufficient for testing the batchor lot. The average results of those samples shall comply withthe requirements prescribed in this specification.10. Spec
22、imen Preparation10.1 Requirements in Table 1 are based on injection moldedspecimens 3.2 mm 18 in. thick. Machined specimens fromcompression-molded blanks or extruded strips may be usedprovided it can be shown that the results are comparable.10.2 Prior to molding ethyl cellulose, the material should
23、bedried to a moisture content of 0.2 % or less. Material spread ina tray to a maximum depth of 51 mm 2 in. and exposed in acirculating-air oven at 76.5 to 88C 170 to 190F for 3 hshould be satisfactory. Control the injection molding conditionon cycle in accordance with Practice D 1897, using a materi
24、altemperature of 10 to 25C 13 to 45F below the level thatcauses discoloration of the plastic. Mold temperatures of 48 to71C 120 to 160F have been found desirable. As a rule, thinsection molding and the higher flow temperature compoundsrequire the higher mold temperature.TABLE 1 Detailed Requirements
25、 for Molded Test SpecimensNOTE 1ftlbf/in. 3 53.3378660 = joules per metre. Megapascals (MPa) = newtons 3 106per metre squared.PropertyType I Type IITestMethodsGrade1Grade2Grade3Grade4Grade5Grade6Grade7Grade8Grade9Grade10Grade11Specific gravity, unpigmented, max at 23/23C 73.4/73.4F1.13 1.13 1.12 1.1
26、2 1.11 1.10 1.12 1.12 1.11 1.11 1.10 D 792Hardness (Rockwell) R scale, min 110 110 105 105 100 95 105 80 75 75 50 D 785Tensile strength at 23C, min:MPapsi44.8650041.4600038.1540033.0480031.0450024.2380027.6400024.1350020.7300020.0330015.92900D 638Impact strength (Izod), minat 23C 73.4F:J/m of notchf
27、tlbf/in. of notch90.71.790.71.7106.72.0106.72.0117.32.2149.52.8186.73.5213.54.0293.45.5213.54.0320.36.0D 256at 40C 40F:J/m of notchftlbf/in. of notch26.70.526.70.526.70.526.70.526.70.526.70.553.41.064.11.280.11.553.41.080.11.5D 758Deflection temperature, min:at 1820-kPa 264-psi fiber stress:CF821807
28、7170711606615060140491206615077170711606014049120D 648at 455-kPa 66-psi fiber stress:CF94200881908218077170711606615082180821808218077170Water absorption (24-h immersion), max % 1.7 1.5 1.4 1.2 1.1 1.0 1.3 1.5 1.5 1.5 1.5 D 570Weight loss on heating (72 h at 82C), max % 0.3 0.4 0.6 0.8 1.5 1.8 2.0 1
29、.2 2.0 2.0 2.0 D 787D 787 96 (2003)211. Test Methods11.1 Determine the properties defined by this specificationin accordance with the following methods:11.1.1 Unless otherwise specified, all tests shall be per-formed in the standard laboratory atmosphere as defined byPractice D 618.11.1.2 Unless oth
30、erwise specified, molded test specimensshall be conditioned in accordance with Procedure A ofPractice D 618.11.1.3 Flow TemperatureProcedure A of Test MethodD 569.11.1.4 Rockwell HardnessProcedure A of Test MethodD 785.11.1.5 Specific GravityMethod A of Test Methods D 792,or Test Method D 1505.11.1.
31、6 Tensile StrengthTest Method D 638, Type I testspecimen, 5.0-mm 0.2-in./min testing speed.11.1.7 Impact Strength (Izod)Method A of Test MethodsD 256, and Practice D 759. Specimen size: 63.5 mm 212 in.long, by 12.7 mm 12 in. wide, by 3.2 mm 18 in. thick.11.1.8 Deflection TemperatureTest Method D 648
32、. Con-dition test specimens in accordance with Procedure B ofPractice D 618.11.1.9 Water AbsorptionTest Method D 570, 2424-h im-mersion. Condition in accordance with Test Method D 570.11.1.10 Weight Loss on HeatingCondition test specimens,50.8 mm 2 in. in diameter or 50.8 mm wide by 63.5 mm 212in. l
33、ong by 3.2 mm 18 in. thick, for 48 h over anhydrouscalcium chloride at 23 6 1C 73.4 6 1.8F. Weigh threespecimens and then place them in a circulating-air oven for 72hat826 1C 180 6 1.8F. Support the specimens flatwiseon a screen in the oven. Upon removal from the oven, cool thespecimens in a desicca
34、tor over anhydrous calcium chloride to23 6 1C 73.4 6 1.8F. Then weigh the specimens andcalculate the percentage weight loss on heating on the basis ofthe conditioned weight.12. Inspection12.1 Inspection of the material shall be as described inSections 7 and 8.13. Rejection13.1 If any failure occurs,
35、 the materials may not be certifiedto this specification.14. Packaging and Package Marking14.1 PackagingThe material shall be packaged in stan-dard commercial containers, so constructed as to ensureacceptance by common or other carriers for safe transportationto the point of delivery.14.2 Package Ma
36、rkingShipping containers shall identifythe material and its supplier, the batch or lot number, its type,and the quantity contained.14.3 All packing, packaging, and marking provisions ofPractice D 3892 shall apply to this specification.15. Keywords15.1 cellulose; ethylcellulose; extrusion; molding; p
37、lasti-cized; specificationASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infrin
38、gement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard
39、 or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views
40、 known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 787 96 (2003)3
