1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW15703 Two-Component Urethane Clearcoat Over Exterior Exposed Carbon Fiber Copyright 2013 General Motors Company All Rights Reserved January 2013 Originating Department: North American Engineering Standards Page 1 of 4 1 Scope This specificat
2、ion covers the qualification and performance requirements of two-component, high solids (40 to 55% volume solids as sprayed), urethane clearcoats direct over carbon fiber substrate. These clearcoats may require the addition of pigmentation to maintain “neutral” clearcoat color due to the inherent co
3、lor of the Ultraviolet (UV) stabilizers needed to maintain durability in UV visible range. 1.1 Material Description. Clearcoat (CC) is a rigid, two-component urethane or urethane blends. 1.1.1 Color Description. Color coding WAXXXX, supplier code and batch number used for testing. 1.2 Symbols. Not a
4、pplicable. 1.3 Typical Applications. These clearcoats are designed to be applied directly to GM approved carbon fiber substrates. Parts coated in this manner are typically used on the exterior of the vehicle and are designed to meet exterior durability performance requirements. 1.4 Remarks. Not appl
5、icable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ISO 2808 SAE J2527 2.2 GM Standards/Specifications. 9984801 GMW15433 GMW3005 GMW15545 GMW3059 GMW15777 GMW14124 GMW15931 GMW14865 GMW15932 GMW14873 2.3 Addi
6、tional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Submission. Submission requirements per GMW3005 must be completed prior to approval of the product. The supplier must clearly define the usage target. 3.2 Durability Performance. Materials app
7、roved to this specification must meet all minimum requirements of GMW3005, Class 1, Type B. 3.3 Etch Resistance. Minimum etch rating is 5 per Jacksonville rating system, or equal to typical Original Equipment Manufacturer (OEM) body system control for a given exposure test. 3.4 Scratch Resistance (G
8、MW14865). Control to be used is a typical OEM body topcoat system. 3.5 Processing Requirements. The general processability must be demonstrated to be production capable and documented in the submission per GMW3005. Documentation of panel preparation must include all sanding procedures. The baseline
9、process contains the following elements. 3.5.1 Carbon fiber substrate material must be sanded before painting. 3.5.2 Substrate material must be cleaned prior to painting. Power washing per 9984801 is required. 3.5.3 To achieve minimum film build requirements, the clearcoat will require at least two
10、separate clearcoat applications of 40 m to 45 m (1.6 mil to 1.8 mil) with bake and sanding to de-gloss the clearcoat between each application layer. 3.5.4 Flash. Flash is typically 1 to 2 minutes between wet coats of clearcoat. Flash prior to oven is typically 8 to 10 minutes. 3.5.5 Bake. Paints tha
11、t are approved to this specification have a typical bake range of 60 C to 135 C (140 F to 275 F). Time at substrate temperature typically varies from 20 to 90 minutes. 3.5.6 Reprocess. One additional recoat is allowed (three (3) applications and three (3) bake cycles), with sanding required prior to
12、 the recoat application. Evaluation of recoats beyond what is allowed requires additional testing per agreement with the responsible paint engineer. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without
13、 license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15703 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 2 of 4 3.5.7 Chemical Requirements. All reducers must be urethane grade or equivalent. 3.5.8 Special Handling. Clearcoat may require a dry nitrogen blanket to
14、 prevent the entry of moist air. Isocyanate materials in the activator components will react with water, alcohols and certain other materials; therefore, precautions must be taken to ensure that none of these are present or introduced into storage containers or circulating systems containing materia
15、ls noted. 3.6 Panel Preparation. Panels are to be prepared using Type B carbon fiber materials and processing. Carbon fiber substrates typically include materials approved to GMW15931 or GMW15932, provided that the basis for the paintability approval includes application of this clearcoat directly t
16、o the substrate and weathering test results meet requirements described in paragraph 3.14. Additional controls may be required per agreement with the responsible paint engineer. 3.7 Compatibility. Compatibility with associated materials is evaluated for Type B usage per GMW3005. 3.8 Film Build (ISO
17、2808). The clearcoat must meet all specified appearance and durability requirements at a minimum total film of 75 m (3.0 mil) applied in two (2) 37.5 m (1.5 mil) clearcoat applications, with bake and sanding between clearcoat layers. 3.9 Ultraviolet/Visible Transmission Through Cured Paint Film (GMW
18、15545). Panels must be prepared per the conditions in Table 1 at required clearcoat film builds. Report data as specified in GMW15545 for CC Only at Target Bake conditions. Requirements are as specified in Table 1. Table 1: Sample Preparation and Performance for Ultraviolet Transmission Note 1 Layer
19、 Film Build Bake Criteria CC Only 62.5 m (2.5 mil) (info only) 20 minutes at Target Bake a, b and c CC Only 75 m (3.0 mil) 20 minutes at Target Bake a, b and c Note 1: a = 0.1% transmission from 290 nm to 360 nm b = 0.5% transmission at 400 nm c = 12% transmission at 420 nm 3.10 Film Build Latitude.
20、 The specific clearcoat film build range for individual technologies must be established by Designed Experiment or a matrix ranging from 60 m (2.4 mil) to 125 m (5.0 mil) applied in two (2) coats of 30 m (1.2 mil) to 62.5 m (2.5 mil), with bake and sanding between clearcoat layers. Performance crite
21、ria are Xenon weatherometer, Florida exposure, initial adhesion, humidity and adhesion, and chip resistance as outlined in GMW3005. 3.11 Appearance. The material must meet or exceed company specifications for gloss, Distinctness Of Image (DOI), orange peel, and uniformity as designated in GMW15777.
22、3.12 Film Build Zones. Film build requirements for Zone D or any deviations to Zones A thru C will be specified on individual part drawings. 3.13 Bake Window. Cure charts must be developed as specified in GMW3005 to define technology limits for each product. Once developed and approved, the bake cha
23、rt is signed by Vehicle Systems Engineering and is the only acceptable document for defining cure. 3.14 Color. All new clearcoat colors shall require pigmentation documentation, establishment of manufacturing standards, demonstration of UV transmission, and visual yellowing assessment per GMW15433 a
24、cross the film build range and bake range defined by this specification, as required by the responsible paint engineer. Additionally, durability testing, including accelerated weathering per SAE J2527 to 4500 kJ and natural weathering per GMW14873 to 24 months, shall be required to document color sh
25、ift and performance characteristics over specified carbon fiber substrate. Exposure assessment characteristics, interim frequency, controls, and post-exposure testing shall be per agreement with the responsible paint engineer. 3.15 Appearance. Change with environmental cycling (information only). Me
26、asure orange peel in “X” (cross-weave) and “Y” (with weave) directions prior to exposure and after every cycle per GMW15777. Contrast to control over steel. These measurements are to be taken for two (2) different environmental cycling conditions as described below. 3.15.1 Conduct 15 cycles of Cycle
27、 I per GMW14124. Record measured appearance and note any other appearance changes. 3.15.2 Conduct 10 cycles of Cycle O per GMW14124. Record measured appearance and any other appearance changes.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo
28、reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15703 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 3 of 4 4 Manufacturing Process All shipments of material or parts under contract or purchase order manufactured to
29、 this specification shall be equivalent in every respect to the initial samples approved by engineering. There shall be no changes in either formulation or manufacturing processes permitted without prior notification and approval by engineering. Lack of notification by the supplier constitutes groun
30、ds for rejection of any shipment. While samples may be taken from incoming shipments and checked for conformance to this specification, the supplier shall accept the responsibility for incoming shipments meeting this specification without dependence upon purchasers inspection. 4.1 Initial Source App
31、roval. No shipment shall be made by any supplier until representative initial production samples have been approved by engineering as meeting the requirements of this specification and the Bulk Material Interim Approval Requirements as documented in the current edition of Production Part Approval Pr
32、ocess (PPAP) for GM. 4.2 Incoming Material Approval. No shipment shall be made by any supplier until it is demonstrated that each shipment or batch complies with acceptance criteria established during PPAP for a minimum of identified attributes per agreement with the regional paint engineer. Supplie
33、r shall submit a Certificate of Analysis providing supplier name, supplier material code, manufacturing date and batch number for every shipment, including actual values for each attribute compared against the established range of that attribute and at an agreed frequency. Table 2 provides an exampl
34、e of attributes and frequencies which may be required. Table 2: Certificate of Analysis for Incoming Material 4.3 Source Shipment Responsibility. It will be the responsibility of the supplier to ensure that the material is not exposed to temperatures or other environmental factors during shipment wh
35、ich would cause the material to fail to meet any of the requirements of this specification. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS
36、GMW15703 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 4 of 4 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between
37、the English and domestic language, the English language shall take precedence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requirements of this material specification and approved by the responsible
38、Engineering department prior to commencement of delivery of bulk supplies. A new approval must be received for any changes, e.g., properties, manufacturing process, location of manufacture, etc. If not otherwise agreed, all testing and documentation normally required for initial release must be comp
39、leted. It is the responsibility of the supplier to inform the customer in a timely manner, without solicitation, and to include documentation of all modifications of materials and/or processes and to apply for a new release. If not otherwise agreed, all release tests shall be repeated and documented
40、 by the supplier prior to commencement of delivery of non-conforming bulk supplies. In individual cases, a shorter test can be agreed to between the responsible Engineering department and the supplier. 5.4 Material Safety Data Sheets/Safety Data Sheets (MSDS/SDS). For new product submissions, or whe
41、n a change in chemical composition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/Safety Data Sheet must be submitted in compliance with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) requirements or other country-specific MSD
42、S/SDS requirements. In addition, product MSDS/SDS submissions must be in compliance with specific country General Motors TMC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.5 All materials supplied to this standard must comply with the requirements of GMW3059, R
43、estricted and Reportable Substances for Parts. 6 Approved Sources Materials supplied to this specification must be approved by General Motors. A list of approved materials can be found in MATSPC, This GM Material File is provided to third parties to reduce redundant testing of materials. If approved
44、 material already listed is used, the part supplier can use GM Material File reference for Production Part Approval Process material approval. If the decision is made to use a not yet approved material, contact Vehicle Systems Engineering for detail on the approval process. The material approval pro
45、cess must be completed prior to PPAP start date of the part supplied to General Motors. 7 Notes 7.1 Glossary. MATSPC: Global repository of GM approved materials for corresponding GM Engineering Standards. 7.2 Acronyms, Abbreviations, and Symbols. CC Clearcoat DOI Distinctness of Image GHS Globally H
46、armonized System of Classification and Labeling of Chemicals MSDS Material Safety Data Sheet OEM Original Equipment Manufacturer PPAP Production Part Approval Process SDS Safety Data Sheet UV Ultraviolet 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows
47、: Material per GMW15703 9 Release and Revisions This standard was originated in October 2007. It was first approved by the Global Paint & Polymers Center in November 2007. It was first published in November 2007. Issue Publication Date Description (Organization) 1 NOV 2007 Initial publication. 2 JAN 2013 Five-year refresh. Updated references. (Vehicle Systems-Paint Materials and Facilities) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
