FORD W-IMMS PDF

GENERAL DESCRIPTION

This standard defines the requirements for the control of plastic injection molding processes. These requirements reflect the following manufacturing concepts:

• Robust part and mold designs lay the oundation of a robust injection molding process.

• Process consistency, shot to shot and run to run, is the first step towards producing quality injection molded parts.

• Startup verification plays an important role in preventing injection molding process mean shift over time.

• In-process machine and process status monitoring is necessary to provide an early warning for potential quality deviations.

• Effective machine and mold preventive maintenance contributes to process consistency in long term production.

• Proper verifications are necessary when changes in process, part, mold, or machine take place.

The manufacturing standard and its appendices include methods and criteria for assessing the robustness of part design, mold design and fabrication, and molding process, as well as methods and frequencies of inprocess monitoring. Below is a list of the methods:

• Evaluating the robustness of the design of an injection molded plastic part

• Evaluating the robustness of a production tool

• Evaluating robustness of a production process

• Establishing injection molding process window

• Injection molding process monitoring

• Injection molding machine status monitoring

• Detecting emerging mold maintenance needs

• Establishing instructions for first and last piece inspection

Appendix A: “Part, Mold, Machine, and Process Robustness Assessment” lists the recommended evaluation methods and robustness criteria. If a production process fails to meet robustness criteria, the molder should increase process monitoring frequency and sample size to ensure product quality.

When a plastic part quality issue arises, the Critical Response List is recommended to Ford suppliers as a reference for proper actions during problem solving.

Appendix E: “W-IMMS Compliance Checklist” provides a tool for the molder to assess whether its injection molding system meets the requirements in W-IMMS. The molder should always refer to the main text of this standard for details and clarification of each requirement. To facilitate the assessment, a workbook of the checklist in Excel format (also known as Ford Specific CQI-23 Assessment) has been developed and the document is available to Ford suppliers.

APPLICATIONS AND LIMITATIONS

This standard applies to all plastic injection molded production and service parts manufactured by tier 1 and sub-tier suppliers to Ford Motor Company. Exceptions to the standard shall be reviewed and concurred by Ford Supplier Technical Assistance (STA).

The intent of this standard is to deploy specific plastic molding best practices and lessons learned that are proven effective in the development and control of injection molding processes, as well as in the prevention of recurrence of quality issues. For plastic molding general quality practices, molding suppliers to Ford Motor Company are required to conduct self-assessment by using AIAG CQI-23: Special Process: Molding System Assessment.

This standard uses key items in injection molded part design, mold design, and mold construction as design for manufacturing indicators, defines assessment methods, and sets part and mold robustness criteria based on benchmark data. However this standard should not be interpreted as a part design standard or a tooling standard for injection molded parts. Whenever a conflict between this standard and an applicable engineering specification or between this standard and an applicable tooling specification arises, final decision shall be made by a team consisting of Ford Engineering, Ford STA, and the supplier or the suppliers.

In this standard, the word “shall” indicates a requirement. Suppliers need to take immediate actions to address areas that fail to meet the requirements. The word “should” indicates a recommendation. Where the term “such as” is used, suggestions given are for guidance only.