Pyramid's Quality Assurance Inspection Procedures
There are two tests performed on every line item of every order prior to shipment. The quantity of items checked from each line depends on the total line quantity. These tests are the tensile strength test and quality assurance (QA) check.
Tensile Strength Tests
Tensile strength tests are performed on belts which are complete and ready for shipment. When belts for an order have been counted in the shipping area, the appropriate number of sample belts are set aside from each line item for testing. This number of samples varies by the quantity of the line item from as few as one to fifteen or more.
A tensile strength test is a destructive test performed to determine the strength of the weld or body of the finished belt. One end of the belt is looped over an apparatus that is hooked to a load cell which measures the amount of force being generated while the other end is looped over a pin on a motor shaft which is turning at a certain pre-defined speed. Because the weld is the weakest point, it is purposely made vulnerable during this procedure. (We also perform tests in the body of the belt to determine the tensile strength of the base material as necessary.) As the belt stretches, the load cell measures the tension on the belt and calculates the force being placed on the belt while a meter logs the peak tension. When the belt reaches the point of failure, the final reading is left on the meter and this number is entered into our custom-designed software to calculate the pounds of pressure per square inch (PSI) at which the belt finally broke as well as to collect other relevant information about the belt and the order to which it belongs. This information is stored in a database for further examination and analysis. Minimum tensile strength levels have been established for each Pyrathane material based upon many years of historical performance tests and field reports.
Tensile test results will fall into one of three categories: acceptable, warning and unacceptable.
A “warning” result is one that falls below our target but is still above our minimum. This warning result requires a supervisor be notified who must then enter their password into the computer for further tests to be performed. If the tensile strength of the belt falls below the minimum tensile level, top management must be notified. This “failure” result requires that the top management representative enter their password into the computer. The quality inspector cannot enter further test results until a password has been entered into the data collection interface, thereby assuring that the appropriate level of management will be involved when belts fall below our target tensile strengths.
In either of the above cases, five more belts must be tested to determine if the warning or failure was a fluke or if there is a greater problem with the belts from this order. Based upon the information available, the appropriate person will make a determination on the status of the quality of the belts. The result of this could be anywhere from releasing the order if the warning or failure was a fluke to quarantining the belts for further testing to scrapping the order completely and remaking the entire order.
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