Defining the End-Use Requirements.
The most important first step in designing a plastic part is to define properly and completely the environment in which the part will operate.Properties of plastic materials are substantially altered by temperature changes, chemicals and applied stress. These environmental effects must be defined on the basis of both short and long term, depending of course on the
application.
The following checklist can be used as a guide.
Part Name ___________________________________________________________________________
Company ___________________________________________________________________________
Print No. ___________________________________________________________________________
Job No. ___________________________________________________________________________
A.PART FUNCTION _______________________________________________________________________
B.OPERATING CONDITIONS Normal Max. Min.
Operating temperature _____________ _____________ _____________
Service life (HRS) _____________ _____________ _____________
Applied load (lb, torque, etc.— _____________ _____________ _____________
Describe fully
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Time on _____________ _____________ _____________
Duration of load
Time off _____________ _____________ _____________
Other (Impact, Shock, Stall, etc.) ___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
C.ENVIRONMENT
Chemical _____________________ Moisture ___________________________
Ambient temp. while device not operating _______
Sunlight direct _______ Indirect _______
D.DESIGN REQUIREMENTS
Factor of safety ________________________
Max. Deflection/Sag ___________________________
Tolerances ____________________________ Assembly method _____________________________
Finish/Decorating ______________________
Agency/Code approvals ________________________
E. PERFORMANCE TESTING—If there is an existing performance specification for the part and/or device, include copy. If not, describe any known requirements not covered above.
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
F. OTHER—Describe here and , any additional information which will assist in understanding completely the function of the part, the conditions under which it must operate and the mechanical and environmental stresses and abuse the part must withstand.
Also add any comments which will help to clarify the above information.
___________________________________________________________________________
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___________________________________________________________________________
___________________________________________________________________________
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Walsh's Plastic consulting. 