GMW GMW16 PDF

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

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

Purpose/Material Description.

This specification describes material types of high molecular weight, High-Density Polyethylene (HDPE), which are used in blow molded or injection molded forms for plastic parts in the fuel system. The described material types shall possess high impact and excellent Environmental Stress Cracking Resistance (ESCR).

Symbols.

The material abbreviation per ISO 11469 is >PE-HD<.

Applicability.

Blow molded fuel filler pipes, fuel tanks and their injection molded components.

Remarks.

The classification into types is according to the different melt flow rates (MFR)s. If no type is specified on the drawing, the default is Type 1 (T1) per the following:

• T1: Low fractional melt 3.0 to 9.0 for layers used in multilayer and some monolayer fuel tank designs. Resins to Type 1 will only be given full approval in the GM Material Approved Source List (GMMASL) after a fuel tank has been validated for a GM program.

• T2: Medium fractional melt 7.0 to 11.5 for monolayer fuel tank and windshield washer containers under high stress conditions, injection molded components compatible for welding to HDPE fuel tanks.

• T3: High fractional melt 10.0 to 17.0 for injection molded components compatible for welding to HDPE fuel tanks.