GMW15424 - Procedure For Evaluating Parting Lines - 2007-11

Procedure For Evaluating Parting Lines

? Copyright 2007 General Motors Corporation All Rights Reserved

November 2007 Originating Department: North American Engineering Standards

Page 1 of 2

1 Scope

Note: Nothing in this standard supersedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

This standard covers the evaluation method for determining the acceptability of parting lines on visible or customer contact plastic parts. 1.1 Purpose. Part approval process. 1.2 Forward. Not applicable.

1.3 Applicability. All visible or customer contact plastic parts.

2 References

Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications.

None

3 Resources

3.1 Facilities. Not applicable.

3.2 Equipment. Molded parts from production

tooling (not the tool or cold pour impressions from tooling).

3.3 Test Vehicle/Test Piece. Minimum of two samples.

3.4 Test Time. Not applicable.

3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills. Not applicable.

4 Procedure

4.1 Preparation. Parts should be installed in vehicle or buck; if property is not available, the part is held in approximate installed position. 4.2 Conditions.

4.2.1 Environmental Conditions. Not applicable.

4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc.

4.3 Instructions.

4.3.1 Evaluate parting line; visual and tactile (perceptible to the touch).

4.3.2 Visually and tactilely inspect parts for parting line execution.

4.3.3 Test Sample Preparation. Tool Mismatch – Parting Line core to cavity; Parting Line at edge of part. (See Figure 1 and Figure 2.) 4.3.4 Maximum 0.05 mm mismatch, unless otherwise specified, or designed as an offset. 4.3.5 Texture execution stops at 0.25 mm minimum to 0.50 mm maximum to protect parting line appearance.

Figure 1: Tool Mismatch and Parting Line

Texture Execution

GMW15424 GM WORLDWIDE

ENGINEERING STANDARDS

? Copyright 2007 General Motors Corporation All Rights Reserved

Page 2 of 2 November 2007

Figure 2: Edge of Part Texture Execution 4.3.6 Seamless Execution Parting Line. See Figure 3.

4.3.7 No Tool Mismatch Allowed. Applies to:

4.3.7.1 Parting Line on A-Surface (Lifter/Slide to cavity).

4.3.7.2

Core to cavity on Tactile parts (handles, knobs, switches, etc.).

4.3.8 Texture execution stops at 0.10 mm minimum to 0.20 mm maximum to protect parting line appearance.

Figure 3: Seamless Execution Requirements Lifter/Slide Parting Line and Tactile Surface

Parting Line 4.3.9 The part submission and evaluation

procedure is repeated until all issues are in agreement.

5 Data

5.1 Calculations. Not applicable.

5.2 Interpretation of Results. Not applicable .

5.3 Test Documentation. Global Pre-texture Instruction Form (GIF), Appearance Approval Report (AAR).

6 Safety

This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

7 Notes

7.1 Glossary.

Appearance Approval Report (AAR) Form: Used to document parting line non-compliance at the time of Production Part Approval Process (PPAP) apearance submission.

Global Pre-Texture Instruction Form (GIF): Used to document parting line non-compliance at the time of Surface Quality Evaluation.

7.2 Acronyms, Abbreviations, and Symbols. AAR Appearance Approval Report GIF Global Pre-Texture Instruction Form PPAP Production Part Approval Process 7.3 Figures are not to scale.

8 Coding System

This standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW15424

9 Release and Revisions

9.1 Release. This standard originated in August 2006, replacing GM9684P. It was first approved by Global Appearance Quality in October 2007. It was first published in November 2007.