ASTM_D_7310_-_11.pdf

Designation:D731011Standard Guide forDefect Detection and Rating of Plastic Films Using OpticalSensors1This standard is issued under the fixed designation D7310;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 intended to provide suggested approachesand criteria for the observation and reporting of defects invarious types of plastic film,by means of an optical scanningsystem.1.2 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 standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to Plastics3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 defectfor the purpose of this guide any entity in thefilm that is large enough to be detected by an optical sensor andis either polymeric in nature or caused by degradation,externalcontamination,undispersed additives or pigments,or similarsources.4.Significance and Use4.1 Defects in film are not acceptable to the end-user asthere is a reduction in the fitness-for-use in many applications.This document is intended to be a guide to assist users in theinspection and observation of defects.4.2 This guide is applicable in a laboratory environment asa quality control or as a research tool.It is also appropriate foruse in any commercial process used to produce film includingcalendering and solvent casting.4.3 This guide is also suitable for use as an evaluation orscreening tool for materials intended to be used in otherprocesses where defects of this nature are also critical,such asfiber spinning and non-wovens.4.4 The individual user must establish the relationshipbetween the criteria and acceptance for fitness-for-use and theobserved defects,as it varies by polymer and application.Thisis attained by the collection of data over a time-period toestablish acceptable control limits.5.Apparatus5.1 ExtruderAdevice for melting polymer that produces aflat or blown(tubular)film with sizes varying from lab-scale toproduction-scale.NOTE2Although this technique is utilized for many different pro-cesses used for producing films,the extrusion systems described in thefollowing section represent the more prevalent process used.This is not toimply that the guidance provided for utilizing this type of instrumentationcannot be applied to other processes or other applications.5.1.1 Flat Film ExtrusionAn extrusion system that pro-duces a flat film that is quenched immediately after extrusionby means of one or more cooling devices such as an air knife,chill roll or water bath.5.1.2 Blown or tubular extrusion An extrusion system thatproduces a tubular“bubble”of film from a circular die,usuallyequipped with an air-ring to cool the polymer.5.2 Screen PackAlthough commonly used in commercialor semi-commercial environments,screen packs are not gen-erally used in laboratory units intended for research or qualityfunctions.5.3 Defect Detection SystemAn optical scanning systemwith a light source,an analog or digital camera,and an imageprocessor.The optical characteristics of the camera are criticalfor detecting small(30 m)defects and it is important that theinstrument manufacturer be informed of the detection needswhen choosing a system.NOTE3Other types of detection systems than the ones described inthis guide are available,but are outside the scope of the guide and are notdefined.1This guide is under the jurisdiction of ASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.19 on Film,Sheeting,and MoldedProducts.Current edition approved Dec.1,2011.Published January 2012.Originallyapproved in 2007.Last previous edition approved in 2007 as D7310-07.DOI:10.1520/D7310-11.2For 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 5.3.1 Transmission Mode(Transparent or Translucent FilmConfiguration)The camera is located directly across from thelight source with the film passing between them.With thissystem,the film is illuminated and the camera captures imagesof the defects and sends them automatically to the imageprocessor,which measures the size and frequency of thedefects.Fig.1 is a basic outline of this setup.5.3.2 Reflection Mode(Opaque Film Configuration)Thelight source and camera are both located above and at equalangles,t