RAL9003 White Plastic Injection Molding Products , Round Base
Washer Shim 5 X 50 mm
Round body base washer shim is made of POM plastic injection molded
for application on household appliances . Base washer shim is a
plate with holes that spread on , these holes are supporting fixing
place to other objects so that base washer protect components are
not be scratched .
One side of plastic injection molded base washer shim with socket
holes which can be inserted into groove in object for fixing base
washer .
Material
Base washer plastic injection molded is made of POM that with good
characteristics for household appliances
High mechanical strength
Tensile strength can be up 50.5MPa . close to metal properties .
and only a tiny change on mechanical strength even working
temperature has a large change .
High stiffness
The maximum specific stiffness for POM can be up to 2650MP
Good wear resistant
Wear resistant strength still keeps 35MPa or so even item is put 10
J variable load . it is best compared to items that with
PA,ABS,HPVC,PS,PC
Resistant impact
POM has good impact resistance but inferior to ABS and PC , Impact
performance will be down 90% or so if there is breaking on or in
product .
Self-lubricant
POM parts with F4 , C ,MoS2 ,PE and lubricant elements that improve
self-lubricant performance .
Stability in dimensions
POM part with good tensile strength and hardness that not easy to
be deformed and broken .
Resistant Organic solvent
POM parts are resistant for hydrocarbon ,alcohol ,ether ,aldehyde ,
gasoline ,lubricant and Weak Alkalis .
Small creep properties
Creep property rate is 2.3% or so in 20℃,21MPa,3000h . and nearly
not be effected by temperature
Good insulation
POM items nearly not be effected by temperature and humidity on
insulation . insulation is related with the thickness of items , eg
when thickness is 0.127mm insulation is 82.7kV/mm,thickness is
1.88mmi insulation is 23.6kV/mm
Low water absorption
Specification
POM injection molded base washer shim parts are customized
according to requests of fittings .
Outside diameter : 55 mm
Thickness : 1.5 mm
Tolerances
Normally , basics tolerances for POM injection molded base washer
shim parts based on level MT 7, and unspecified tolerance based on
ISO 2768M .
| Basic Sizes | Tolerance Level |
| MT7 |
| A | B |
| 0-3 | 0.38 | 0.58 |
| 3-6 | 0.46 | 0.66 |
| 6-10 | 0.56 | 0.76 |
| 10-14 | 0.66 | 0.86 |
| 14-18 | 0.76 | 0.96 |
| 18-24 | 0.86 | 1.06 |
| 24-30 | 0.98 | 1.18 |
| 30-40 | 1.12 | 1.32 |
| 40-50 | 1.32 | 1.52 |
| 50-65 | 1.54 | 1.74 |
Normal sizes tolerances
| Basic Sizes | Level |
| MT7 |
| A | B |
| 0-3 | 0.19 | 0.29 |
| 3-6 | 0.23 | 0.33 |
| 6-10 | 0.28 | 0.38 |
| 10-14 | 0.33 | 0.43 |
| 14-18 | 0.38 | 0.48 |
| 18-24 | 0.43 | 0.53 |
| 24-30 | 0.49 | 0.59 |
| 30-40 | 0.56 | 0.66 |
| 40-50 | 0.66 | 0.76 |
| 50-65 | 0.77 | 0.87 |
Unspecified tolerance ISO 2768-M
Physical Performance
| Density | 1.43 |
| Water absorption % | 2.5 |
| Shrinkage % | 1.5～3 |
Mechanical Property
| Tensile strength MPa | 70 |
| Elongation at break % | 40 |
| Bending strength MPa | 90 |
| Modulus of elasticity for tension MPa | 3160 |
| modulus of elasticity for bending MPa | 2880 |
| Compressive strength MPa | 127 |
| Shearing strength MPa | 67 |
| Notched Impact Strength(J/m) | 76 |
| HR hardness | 94 |
| Friction | — |
| Fatigue MPa | 35 |
Thermal Performance
| Heat distortion Temperature(1.82MPa)℃ | 110 |
| Normal working temperature ℃ | 80 |
| Working temperature arrange ℃ | -40℃～90℃ |
| Coefficient of linear expansion (×10K) | 7.5 |
| Heat conduction W/(m·K) | 0.23 |
| Specific volume resistance Ω·cm | 10 |
| Specific inductive capacity(10Hz) | 3.8 |
| Dielectric loss tangent (10Hz) | 0.005 |
| Dielectric strength(kV/mm) | 20 |
| Arc-resistances | 220 |
Tips for use
POM injection molded base washer shim parts are easy to be cracked
and pulverized outside long-term .
Don’t put POM injection molded base washer shim parts under
temperature over 100℃
Don’t put POM injection molded base washer shim parts under
circumstance with alkali and oxidant .
