1、Designation: D787 12D787 18Standard 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 revisio
2、n. A number in 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
3、plasticized ethyl cellulose thermoplastic compounds suitable for injectionmolding and extrusion. It does not include special materials compounded for special applications.1.2 The values stated in SI units are to be regarded as standard. The English values given are for information only.1.3 The follo
4、wing precautionary statement pertains only to the Test Methods portion, Section 109 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 safety
5、, health, and healthenvironmental practices and determine the applicabilityof regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this specification.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationesta
6、blished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod Pendulum Impact Res
7、istance of PlasticsD570 Test Method for Water Absorption of PlasticsD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD648 Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise PositionD785 Test Method for Rockwell
8、Hardness of Plastics and Electrical Insulating MaterialsD792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD3641 Practice for Injection Moldin
9、g Test Specimens of Thermoplastic Molding and Extrusion MaterialsD3892 Practice for Packaging/Packing of Plastics3. Terminology3.1 Terms in this specification are in accordance with Terminology D883.4. Classification4.1 This specification covers two types and eleven grades of ethyl cellulose molding
10、 and extrusion compounds as classified inaccordance with Table 1. Type I materials are general purpose and Type II are characterized by improved resistance to impact,especially at low temperatures. The grades are classified in accordance with their physical properties as specified in Table 1.4.1.1 A
11、typical call out of material covered by this specification would contain the number of this specification and the requiredtype and grade chosen from Table 1, for example, D787 Type 1, Grade 1.1 This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsib
12、ility of Subcommittee D20.15 on Thermoplastic Materials.Current edition approved Aug. 1, 2012April 1, 2018. Published August 2012April 2018. Originally approved in 1944. Last previous edition approved in 20092012 asD787 09.12. DOI: 10.1520/D0787-12.10.1520/D0787-18.2 For referencedASTM standards, vi
13、sit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM stand
14、ard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM
15、 is to be considered the official document.*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 States15. Ordering Information5.1 Purchase orders for, or inquiries about, the materi
16、als described in this specification shall identify the following:5.1.1 The number of this specification and the required type and grade chosen from Table 1, for example, D787 Type 1, Grade1.5.1.2 Supplementary requirements in accordance with this specification if necessary.5.1.3 Color and opacity wi
17、thin 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 be agreed between the seller and the purchaser.5. Materials and Manufacture5.1 Materials supplied under this specification shall be ethyl cellulose plastics in the form of pellets
18、unless otherwise specified.5.2 Material supplied in these forms shall be as uniform in composition and size and as free of contamination as can be achievedby good manufacturing practice.5.3 These materials maypossibly contain colorants in the nominal amounts ordinarily employed, but such additives s
19、hall notalter the ability of the materials to meet the specified properties.employed. Only those materials of this kind that meet the propertiesspecified are covered by this standard.5.4 The color and transparency or opacity of items fabricated under the conditions recommended by the manufacturer of
20、 thematerial shall be comparable within commercial match tolerances to the color and transparency or opacity of samples submittedin advance by the manufacturer and approved by the purchaser. by the manufacturer.6. Physical Requirements6.1 Test specimens of the material shall conform to the requireme
21、nts prescribed in Table 1.6.2 Molded specimens for those tests requiring them shall be prepared as described in Section 109.7.3 Flow temperature of a given compound shall be within 65C of the flow temperature designated in the contract or order.6.3 Conformance to the requirements of this specificati
22、on shall be determined by means of the tests identified in Section 1110unless otherwise specifiedTABLE 1 Detailed Requirements for Molded Test SpecimensNOTE 1ftlbf/in. 53.3378660 = joules per metre. Megapascals (MPa) = newtons 106 per metre squared.PropertyType I Type II TestMethodsGrade1 Grade2 Gra
23、de3 Grade4 Grade5 Grade6 Grade7 Grade8 Grade9 Grade10 Grade11Specific gravity, unpigmented, max at 23/23C (73.4/73.4F)1.13 1.13 1.12 1.12 1.11 1.10 1.12 1.12 1.11 1.11 1.10 D792Hardness (Rockwell) R scale, min 110 110 105 105 100 95 105 80 75 75 50 D785Tensile strength at 23C, min:MPapsi44.8650041.4
24、600038.1540033.0480031.0450024.2380027.6400024.1350020.7300020.0330015.92900D638Impact strength (Izod), minat 23C (73.4F):J/m of notchftlbf/in. of notch90.71.790.71.7106.72.0106.72.0117.32.2149.52.8186.73.5213.54.0293.45.5213.54.0320.36.0D256at 40C (40F):J/m of notchftlbf/in. of notch26.70.526.70.52
25、6.70.526.70.526.70.526.70.553.41.064.11.280.11.553.41.080.11.5D256Deflection temperature, min:at 1820-kPa (264-psi) fiber stress:CF8218077170711606615060140491206615077170711606014049120D648at 455-kPa (66-psi) fiber stress:CF94200881908218077170711606615082180821808218077170D648Water absorption (24-
26、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 D570Weight loss on heating (72 h at 82C), max % 0.3 0.4 0.6 0.8 1.5 1.8 2.0 1.2 2.0 2.0 2.0D787 1827. Sampling7.1 Sampling shall be statistically adequate to satisfy the requirements of 12.411.4.7.2 For sampling purposes, a batch or lot
27、 shall be considered a unit of manufacture as prepared for shipment and maycan consistof a blend of two or more production runs of material.8. Number of Tests8.1 Routine testing of each batch or lot shall be limited to properties designated in Table 1 of this specification.9. Specimen Preparation9.1
28、 Requirements in Table 1 are based on injection molded specimens 3.2 mm (18 in.) thick. Machined specimens fromcompression-molded blanks or extruded strips maycan be used providedif it can be shown that the results are comparable.9.2 Prior to molding ethyl cellulose, dry the material should be dried
29、 to a moisture content of 0.2 % or less. Material spread ina tray A recommended procedure is to keep the material, spread to a maximum depth of 51 mm (2 in.) and exposed in a tray, ina circulating-air oven at 76.5 to 88C (170 to 190F) for 3 h should be satisfactory. hours. Control the injection mold
30、ing conditionon cycle in accordance with Practice D3641, using a material temperature of 10 to 25C (13 to 45F) below the level that causesdiscoloration of the plastic. Mold temperatures of 48 to 71C (120 to 160F) have been found desirable. As a rule, thin sectionmolding and the higher molecular weig
31、ht compounds require the higher mold temperature.10. Test Methods10.1 Determine the properties defined by this specification in accordance with the following methods:10.1.1 Unless otherwise specified, all tests shall be performed in the standard laboratory atmosphere as defined by PracticeD618.10.1.
32、2 Unless otherwise specified, molded test specimens shall be conditioned in accordance with Procedure A of PracticeD618.10.1.3 Rockwell HardnessProcedure A of Test Method D785.10.1.4 Specific GravityMethod A of Test Methods D792, or Test Method D1505.10.1.5 Tensile StrengthTest Method D638, Type I t
33、est specimen, 5.0-mm (0.2-in.)/min testing speed.10.1.6 Impact Strength (Izod)Method A of Test Method D256. Specimen size: 63.5 mm (212 in.) long, by 12.710.7 mm (12in.) wide, by 3.2 mm (18 in.) thick.10.1.7 Deflection TemperatureTest Method D648. Condition test specimens in accordance with Procedur
34、e B of Practice D618.10.1.8 Water AbsorptionTest Method D570, 24-h immersion. Condition in accordance with Test Method D570.10.1.9 Weight Loss on HeatingCondition test specimens, 50.8 mm (2 in.) in diameter or 50.8 mm wide by 63.5 mm (212 in.)long by 3.2 mm (18 in.) thick, for 48 h over anhydrous ca
35、lcium chloride at 23 6 1C (73.4 6 1.8F). Weigh three specimens andthen place them in a circulating-air oven for 72 h at 82 6 1C (180 6 1.8F). Support the specimens flatwise on a screen in theoven. Upon removal from the oven, cool the specimens in a desiccator over anhydrous calcium chloride to 23 6
36、1C (73.4 61.8F). Then weigh the specimens and calculate the percentage weight loss on heating on the basis of the conditioned weight.11. Inspection and Certification11.1 Inspection and certification of the material supplied with reference to a specification based on this classification systemshall b
37、e for conformance to the requirements specified herein.11.2 Lot-acceptance inspection shall be the basis on which acceptance or rejection of the lot is made. The lot-acceptanceinspection shall consist of the tests listed as they apply:(1) Tensile Strength(2) Izod Impact Strength(3) Deflection Temper
38、ature11.3 Periodic-check inspection with reference to a specification based upon this classification system shall consist of the testsspecified for all requirements of the material under this classification system. Inspection frequency shall be adequate to ensure thematerial is certifiable in accord
39、ance with 12.411.4.11.4 Certification shall be that the material was manufactured by a process in statistical control, sampled, tested, and inspectedin accordance with this classification system and that the average values for the lot meet the requirements of the specification (linecallout).11.5 A r
40、eport of the test results shall be furnished when requested. The report shall consist of results of the lot acceptanceinspection for the shipment and the results of the most recent periodic-check inspection.D787 183NOTE 2The ASTM publication Manual on Presentation of Data and Control Chart Analysis,
41、 7th Edition, stock number MNL7A,3 provides detailedinformation about statistical process control.12. Rejection12.1 If any failure occurs, the materials may not cannot be certified to this specification.13. Packaging and Package Marking13.1 PackagingThe material shall be packaged in standard commerc
42、ial containers, so constructed as to ensure acceptance bycommon or other carriers for safe transportation to the point of delivery.13.2 Package MarkingShipping containers shall identify the material and its supplier, the batch or lot number, its type, andthe quantity contained.13.3 All packing, pack
43、aging, and marking provisions of Practice D3892 shall apply to this specification.14. Keywords14.1 cellulose; ethylcellulose; extrusion; molding; plasticized; specificationSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D787 - 09D
44、787 - 12) that may impact the use of this standard. (August(April 1, 2012)2018)(1) Replaced the termAdded 4.1.1 to flow temperatureillustrate callouts with the term using this standard.molecular weight in 10.2.(2) Eliminated Section 5 as unnecessary and of little value. Renumbered subsequent section
45、s.(3) Eliminated purchaser in 6.4 (now 5.4) as unnecessary to the standard.(4) Eliminated former 7.3; flow temperature is not defined.(5) Replaced permissive words and language in 5.2, 5.3, 6.3, 7.2, 9.1, 9.2, and 12.1.ASTM International takes no position respecting the validity of any patent rights
46、 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 infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any ti
47、me 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 or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will r
48、eceive 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 known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM I
49、nternational, 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ Avai
