ASTM_D_3015_-_95.pdf

Designation:D 3015 95An American National StandardStandard Practice forMicroscopical Examination of PigmentDispersion in Plastic Compounds1This standard is issued under the fixed designation D 3015;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of 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 practice describes microscopical examination ofplastic compounds to check quality of pigment dispersion.Thin sections of polymers are prepared for observation withtransmitted light.Microscopical examination is normally madefor grading or classification by comparison against observa-tional standards.1.2 Operations are listed for practice generally applicable tomany thermoplastic compounds.Details specific to wire-andcable-grade Type I polyethylene is given in Appendix X1.NOTE1There is no similar or equivalent ISO standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2D 1238 Test Method for Flow Rates of Thermoplastics byExtrusion Plastometer2F 412 Terminology Relating to Plastic Piping Systems33.Terminology3.1 DefinitionsTerms applicable to this practice are de-fined in Terminologies D 883 and F 412.4.Significance and Use4.1 Examination is made because of the general relationshipbetween observed quality on the microscopical scale andoverall serviceability,and to some extent the appearance,of theplastic compound.The method may be employed to measuredegree of dispersion of pigments,presence of foreign matter,spots of unpigmented resin,and resin degradation.Serviceabil-ity of a compounded plastic can be quite sensitive to the qualityof pigment dispersion.Black,weather-resistant polyethyleneserves as a good example where quality of the dispersion isindicative of weatherability which is achieved by effectivescreening of ultraviolet light by the carbon black.4.2 The test is directly applicable to plastic compounds thatare translucent in thin(microscopical)sections.Up to 5%carbon black-filled polyethylene,for example,could be soexamined for dispersion.The test may also be employedindirectly with opaque samples or pigment concentrates.Con-centrates(which are extended in use)may be diluted with baseresin to their final pigment level,as for example,by rollmilling,such that examination of test specimens may be madewith transmitted light.As such processing can effect improveddispersion,dilution must not be employed without regard toend use of the material being sampled.4.3 Examination and report are normally made with respectto observational standards which are not included in thispractice(see Section 7).5.Apparatus5.1 Microscope,100-power(103 eyepiece,103 objective),unless otherwise agreed.5.2 Eyepiece Micrometer(optional),calibrated for magni-fication employed.A stage micrometer(standard calibratingslide),such as one having a 2-mm scale divided into units of0.01 mm(10 m),may be employed to calibrate the eyepiecescale.5.3 Light Source,suitable for the microscope.5.4 Microscope Slides,nominal 25 by 75 by 1 mm(1 by 3by 0.040 in.)NOTE2Aliquid mixture of approximately the composition by volumegiven as follows has been found suitable for cleaning microscope slides.After being cleaned,the slides shall be wiped dry with lint-free cleansingtissue.Ethyl alcohol(any grade)85%Methyl alcohol(reagent grade)10%Concentrated ammonium hydroxide(stock solution)5%5.5 Hot Plate,capable of maintaining temperature appropri-ate for press-out of samples.5.6 Lens-Cleaning Paper.5.7 Pyrometer,or other suitable device capable of measur-ing surface temperatures of hot plate.5.8 Metal Shimstock,Brass,Aluminum,or Other MetalTwo pieces 3.8 cm by 7.9 mm(1.5 by516in.),to control1This practice is under the jurisdiction of ASTM Committee D-20 on Plasticsand is the direct responsibility of Subcommittee D20.40 on Optical Properties.Current edition approved Sept.10,1995.Published November 1995.Originallypublished as D 3015 72.Last previous edition D 3015 72(1990).This revision includes additions of an ISO equivalency statement,a Terminologysection,and a Keywords section.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standards,Vol 08.04.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.thickness in pressing test specimens.Shimstock of 25-m(0.001-in.)thickness has been found us