Injection Molding_B

Revision B
SVP Procedure for Critical Process Control
-Injection Molding-
I.PURPOSE
This procedure identifies the injection molding parameters that must be measured, analyzed, controlled, and appropriately acted upon, under the auspices of the Safety Verification Process (SVP). Any control methods used must be proven effective via empirical study, and the data made available in the SVP database.
II.PROCEDURE
For each design and program, the HK/China based team will set up a control plan identifying which parameters will be controlled, and how they will be controlled. At a minimum, the following parameters must always be monitored and controlled in any injection molding process used in SVP: Cycle time, barrel temperature, injection pressure and regrind levels.
A processing window* for each of these setting parameters will be set utilizing data from the machine manufacturer, material manufacturer, designed experiment or other empirical source.
For each of these parameters, and any other machine parameters estab lished by the control plan, the actual readings from each molding machine and regrind levels will be checked, at a minimum, every 4 hours by factory staff.
Regrind level data will be sent to the agency and lab, every day.
For the rest of the parameters listed above, records of the readings taken shall be maintained by the factory staff at the factory, and will be available to agency and laboratory staff, upon request. These records need not be sent the agency or lab, unless a machine operates outside its processing window* or unless specifically requested by the agency or lab. In addition, if molded parts are trimmed or treated in any way after molding, work instructions will be written to describe the proper method of trimming or treatment. Proper performance of work instructions will be checked at each molding machine every 4 hours by factory staff.
If a machine operates for any period of time outside the processing window*, the following will occur:
The factory QC staff will quarantine the affected parts
The factory QC staff will notify the agency of the problem via email
2.6.3The factory, agency and lab staff team will create a CAP identifying what
went wrong, what should be done with the produced parts (re-work, scrap,
sort, other..) and what will be done in future to prevent the event from re-
occurring. Consideration should be given to heightened QC checks, in
Revision B order to detect the problem, should it re-occur. Agency and lab QC staff
will check to see that these procedures are followed during their in process
audits at factories.
2.7 The Control Plan will establish some critical dimensions and tolerances on the
product. Such critical dimensions will be those that, if they excessively will result in an unsafe condition on the final product.
2.8Factory staff will measure and record these critical dimensions on, at a minimum,
5 randomly selected samples from each molding machine, every four hours. Such
records will be available to McDonald’s, the labs and the agency 24 hours of
when the data is collected.
2.9If parts are found that do not comply with set tolerance limits, the following will
occur:
2.9.1 The factory QC staff will quarantine the affected parts
2.9.2 The factory QC staff will notify the agency of the problem via email
2.9.3 The factory, agency and lab staff team will create a CAP identifying what
went wrong, what should be done with the produced parts (re-work, scrap,
sort, other..) and what will be done in future to prevent the event from re-
occurring. Consideration should be given to heightened QC checks, in order
to detect the problem, should it re-occur. Agency and lab QC staff will
check to see that these procedures are followed during their in process audits
at factories.
2.9.4 The CAP will be made available to McDonald’s, the a gency and both labs
for reference.。