Pneumatic Clean Series

153 How to Use Clean SeriesThe position of the pneumatic equipment in relation to the workpiece is determined by the degree of particle generation.The grade number of the pneumatic equipmentor moreThe grade number of the particle density around the workpieceClassification of particlegeneration gradesSelection procedureqParticle density(particles/ft 3 )10 410 310 21010.1Particle density(particles/m 3 )10 510 410 310 210(Equivalent to Class 1000)Grade 4(Equivalent to Class 100)Grade 3Grade 2(Equivalent to Class10)Grade 1(Equivalent to Class 1)10.1 0.5 1Particle diameter (µm)∗ The grading in the left figure is based on SMCoriginal representation. The grade numberdecreases with the amount of particle generation.(For particle generation measurement method,please refer to Item 4 particle generationmeasurement method.)What is the cleanliness of the clean room? Class10 or Class100 or Class1000 ?wHow does the air currents to theworkpiece flow? (Refer to Diagram 1.)Diagram 1 Condition of air currentsWorkpiece AThe air current is blockedbefore the workpiece.Workpiece BConvection currents are frequentlygenerated around the workpiece.eWhere is the pneumatic equipmentused? (Refer to Diagram 2.)Workpiece CThe air current flows freely.Workpiece DThe air is suctioned forcedlybelow the workpiece.rFrom the above 3 items, decide thegrade number of the particle densityaround the workpiece (Table 1).Diagram 2 Point of useCurrentAbove the workpieceWorkpieceUnstable areaBelow the workpiecerSelect the equipment to be usedfrom Table 2.Stable areaTable 1 Grades of particle density around the workpiecew Workpiece A, B Ce Position of the equipmentto be usedUpstream tothe workpieceDownstream to the workpieceUnstable area Stable areaUpstream tothe workpieceDownstream to the workpieceUnstable area Stable areaUpstream tothe workpieceDDownstream to the workpieceUnstable area Stable areaClass 10Grade 1Grade 2 Grade 1 Grade 2q CleanlinessClass 100Grade 2 Grade 3Grade 3Class 1000Grade 1 Grade 2 Grade 3 Grade 2Grade 3 Grade 4Grade 2Grade 3 Grade 4The cleanliness of Class 10 and 1000 is not available for the sections indicated withbecause of dust accumulation and flotation.Front matter 14