ASTM_D_7711_-_11_2015.pdf

Designation:D771111(Reapproved 2015)Standard Guide forDescription of Polymer Pellet Defects1This standard is issued under the fixed designation D7711;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide is a compilation of terms used to describedefects of polymeric pellets.Terms that are generally under-stood or defined adequately in Terminology D883 or in otherreadily available sources are not included.1.2 Not every term is applicable to every type of pellet.Terms which apply to transparent pellets,for example,do notalways apply to translucent or opaque pellets.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.NOTE1There is no known ISO equivalent to this guide.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to Plastics3.Terminology and Definitions3.1 Pellet Color Defects and Terms:NOTE2Not all color defect terminology is applicable to all pellettypes.3.1.1 discoloration,nof a pellet,any deviation from theproducts normal color.3.1.2 opaque center pellet,npellet that is translucent orslightly translucent and has a less clear/more opaque center bycomparison to the remainder of the pellet.3.1.3 striped pellet,npellet containing a stripe of adifferent color than the remainder of the pellet.3.2 Pellet Contamination Defects and Terms:3.2.1 die pearls,nnon-degraded particles that build upand break off of the die.3.2.2 droolssee die pearls3.2.3 fines,nvery small particles,dust,or unattachedtails.3.2.4 foreign material contamination,nof pellets,anymaterial in,on,or around the pellets that emanates from anexternal source and has a composition different than that of thepellet;also known as trash if it can be picked up separately.3.2.5 oxidized pellet,npellet with a deep yellow,brown,red,or black particle present.3.2.6 polymer cross-contamination,nof pellets,unin-tentional mixture of two or more dissimilar resins or com-pounds;generally apparent by comparing key properties suchas pellet geometry,color,opacity,or hardness.3.2.7 speck contamination on/in,nof a pellet,smallpinpoint particles of discolored matter,internal or external,which can sometimes rub off;includes,but is not limited to:black,brown,yellow,or white specks.3.3 Pellet Size and Shape Defects and Terms:NOTE3Polymeric pellets are of many shapes.These include cylinders(formed by a strand pelletizer),spheres(underwater-face cut),andsliver-like pieces(hot-face cut).3.3.1 agglomerates,nof pellets,thoroughly fused accu-mulation of pellets.3.3.2 angel hair,nthin,fiber or thread-like strands ofpolymer.3.3.3 clumpssee agglomerates3.3.4 clusters,nof pellets,three or more pellets fusedtogether;only referred to as triples when there are three distinctpellets.3.3.5 daisy chains,nof pellets,two or more pellets joinedtogether“chain-like”by strands of polymer;can be separatedto form pellets with tails.3.3.6 doublessee marriages3.3.7 globssee agglomerates3.3.8 marriages,nof pellets,two pellets fused together.3.3.9 pellet non-uniformity,npellets that deviate fromnormal size-range and shape;for example,undersized oroversized,over-length,not round,flattened on one or bothends,or smashed.3.3.10 snake skins,nlong,thin,film-like pieces ofpolymer,or a build-up that looks like a shed snake skin whenit comes free.3.3.11 streamerssee snake skins1This guide is under the jurisdiction of ASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.92 on Terminology.Current edition approved Sept.1,2015.Published September 2015.Originallyapproved in 2011.Last previous edition approved in 2011 as D7711-111.DOI:10.1520/D7711-11R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.3.12 tail,non a pellet,a small thin extension attached toa pellet;usually exceeds half the length of a normal pellet.3.3.13 triplessee clusters3.3.14 twinssee marriages3.3.15 walnutssee agglomerates3.4 Pellet Integrity Defects and Terms:3.4.1 cracks,nin a pellet,breaks,splits,or separationswithin the pellet that are visible to the unaided eye.3.4.2 foamed pellet,npellet that contain voids due toentrapped water,volatiles,or other substances;typically whitein appearance and sometimes larger than normal-sized pellets.3.4.3 foamy pellet,nsee foamed pellet3.4.4 puffy pellet,nsee foamed pellet4.Signific