SAE J1474 pdf download

SAE J1474 pdf download.Heavy-Duty Nonmetallic Engine Cooling Fans—Material,Manufacturing, and Test Considerations.
The In-Vehicle Testing section lists factors which should be considered in addition to those covered by Section 4 of SAE J1390.
The Laboratory Testing section addresses some test considerations and methods for nonmetallic fans which differ from those used with metallic fans or which were not included in Section 5 of SAE J1390.
1.1 Purpose—This report exists to identify general methodology which addresses the areas of evaluation listed previously for injection.molded nylon fans. It is envisioned that those working with other processes and/or matenals can use SAE J1390 and this document as starting points In the development of structural analysis methodology pertinent to their particular combination(s).
2. References
2.1 Applicable Publications—The following publications form a pail of this specification to the extent specified herein. Unless otherwise indicted the latest revision of SAE publications shall apply.
2.1.1 SAE PuBLIcAn0N—Available from SAE, 400 Commonwealth Drive. Warrendale. PA 15096-0001. SAE JI 390—Engine Cooling Fan Structural Analysis Recommended Practice
2.1.2 ASTM PL,eucA’rlo.i—Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. ASTM D 61 8—Method for Conditioning Plastics and Electrical Insulating Materials for Testing
3. Definitions—The following terms relating to injection molding of plastics are used:
3.1 Barrel, Liner and Screw—Components of the plasticizing cylinder of an injection-molding machine in which the material is melted and moved forward to the injection nozzle.
3.2 Weld or Knit-Line—The area of a molded plastic part, formed by the union of two or more streams of plastic flowing together.
3.3 Cold Slug Flow—Condition where insufficient heating of plasticizing cylinder results in unmetted pellets appearing in the molded part.
3.4 Flash—The excess plastic material that is forced from a mold cavity during the molding operation, Flash may also occur between worn mold sections.
3.5 Gate-An orifice or opening through which the melted plastic material enters the cavity.
3.6 Surface Drag—Skidding of plastic resin along surface of mold due to improper mold temperatures, injection pressure, or injection speed.
I3.7 Stress Whitening—An effect noted in nylon (crystalline materials) under stress loading occurring as a result of molecular orientation visibfe as a white area due to the change in the refraction index of the material.
4.1 All materials classified as nylons share certain basic charactenslcs. However, even within the seemingly limited realm of glass-fiber reinforced nylons, many levels and combinations of physical, thermal.
and environmental resistance properties are available. These properties result from such factors as the following:
a. Type of nylon (6. 6/6. 6/10, 6/12, etc.)
b. Percentage (by we4ghl) of glass fibers
c. Diameter and length of glass fibers
d. Wetting agent used to promote adhesion between resin and fibers (if present)
e. Heat stabilizer (if present)
f. Impact modifier (if present)
g. Pigmentation (if present)
In order to select a material with appropriate characteristics, the prospective manufacturer and end user should investigate the proposed application thoroughly, and maintain open communication with the various material suppliers.
4.2 Application Factors—Evaluate the following characteristics, as applicable, for all materials used in the fan assembly:
4.2.1 Temperature extremes—highest and lowest
4.2.2 Relative humidity (relative to material moisture content)
4.2.3 PHYsICAL PROPERTES
4.2.3.1 TensIle strength
4.2.3.2 Tensile fatigue strength
4.2.3.3 Tensile modulus
4.2.3.4 Flexural fatigue strength
4.2.3.5 Flexural modulus
4.2.3.6 Low-temperature impact resistance
42.3.7 Ignition temperature
4.2.3.8 Noncombustibility or self-extinguishing
4.2.3.9 Flame propagation
4.2.3. 10 Any other depending on application
4.2.4 THERMAL PROPERTIES
4.2.4.1 Heat distortion temperature
4.2,4.2 Expansion characteristic.