GM 7452M-1991 外部塑料部件性能要求.pdf

90ロbヨ79 30001839?ヨ?
GENERAL MOTORS ENGINEERING STANDARDS
Materials and Processes-plastics
PERFORMANCE REQUIREMENTS FOR EXTERIOR PLASTIC PARTS
7459M
1 SCOPE. This specification covers the performance re- 3.2.3 Ths test is not applicable to parts when the wo
quirements of unpainted or clearcoated plastic parts used in except xenon are appended to the specification number
exterior automotive applications. The parts may be functional the
drawing.
within themselves or they may be a subassembly of, or
attached to, metallic, decorative or functional parts
3.3 Humidity. Parts shall not show any surface deteriora
tion, objectionable shrinkage, or noticeable color or gloss
1.1 learcoated parts must meet the requirments of change after 7 days exposure er GM4465P. Evaluation of
GM4350M, Class AO, in addition to meeting the require- the parts shal be made after 24 h ambient exposure.
ments of this specification
3.4 Oven Aging Parts shall not show any surface deteriora
1. 2 Requirements for parts painted body color should be tion, objectionable shrinkage or noticeable color or gloss
specid r GM4 M las AO, not y this speciaton. change after days exposure at 80 C in an air-circulating
1.3 Parts which require gasoline resistance will be designat
3.5 Dimensional Stability Test
applicable to pa
hich incorporate more than one
of material in their
Example of fuel filler door: GM7452M-G
construction. Parts shall not show any crazing, discoloration,
cloudiness, blistering, objectionable shrinkage, deformation,
2 REFERENCED STANDARDS.
or loss of adhesion to the subsrate or between layers of the
composite at any point within the follow
Clic sequence
GM4350M
GM9508P
GM4465P
GM99OOP
GM4476P
SA:J1545
3 h min at-30±2C
GM9125P
SAE J1960
15 minutes min at 25 +5C
GM9501P
3 h min at82±1.5°C
15 minutes mn at25±5°c
17 h humidity min per GM4465P
3 REQUIREMENTS, Unless otherwise specified, parts
shall meet the following requirements and shall be tested Evaluate for detrimental effects.
under standard conditions, 22 * 3C and 50 t 5% RH:
3.6 Gasoline Resistance(G-sufiix only), GM9501P. Im
3.1 Raw Material Specifcation Conformance. The compo mere the pa for 10s in a fuel consisting of 45%by lume
nents of the assembly must meet the individual mate
toluene (9981729 )and 55% VM&P naphtha (998 1062)and
reifications shown on the engineering drawing in addition
folow with a 20s
iod. Repeat the cycle 10
to meeting the r mens of this p ommance spc on. times There shall be no color change loss of bond, material
tackie
following the la
st 20 s
3. 2 Xenon Weatherometer. Exposed parts shall not exhibit perod
any indications of surface tackiness or embrittlement, change
如? the famet on o mea ane of the oat. ol n
3.7 Cleaning Solvent Resistance. Parts must be rated satis
factory when clean
GM9900P
ge shall not exceed a AE of 3.0 units when measured
SAEJ1545(CAB color pace 1 see, m a 3. D R i T h c onbe
D65, specular component included). Visual color change color or gloss change, loss of bond or shrinkage of the
which is considered objectionable shall overide the A ma erial when a sample is immersed for 24 h at 23* in
measurement. Part must not exhibi