Patent ID: 6517754
Filing Date: 2003-02-11
Classification: B29C,G05B,Y02P

Abstract:
A method for evaluating injection-molded parts, produced in an injection-molding machine, as a good molding or a bad molding, said method comprising:determining a respective curve of a first parameter (y), which curve indicates changes in the first parameter (y) as a function of a prescribed second parameter (x), said determining operation being performed during a plurality of injection-molding operations wherein non-defective good moldings are produced, to form a group of curves; averaging the group of curves to form a mean value curve (M2, M3), which mean value curve indicates a mean value of the curves of the first parameter (y) for each value of the second parameter (x); calculating and determining a standard deviation in dependence on at least one parameter; setting a permissible range (T) of the at least one parameter along the mean value curve (M2, M3) on the basis of the determined standard deviation; effecting an actual value assessment of the at least one parameter, which is produced during an actual production of a molding, to check whether the actual value falls within the permissible range (T); and assessing a molding as a good molding when the actual value lies substantially within the permissible range (T), or respectively as a bad molding when the actual value does not lie within the permissible range, wherein, to set the permissible range (T), the standard deviation is calculated in dependence on the second parameter (x).