Injection-molding

Molding conditions

Both CM1026 and CM3006 can be molded using the same conditions as standard grades.
In terms of resin temperature, use a 230-260°C molding temperature for CM1026 and 260-290°C for CM3006. A mold temperature of about 60-80°C is appropriate for both CM1026 and CM3006.
Regarding flowability, spiral flow-length tests show about L/T200 works well for both CM1026 and CM3006.
If master color pellets will be mixed into the pellets to add colors such as black, use a screw type injection-molding machine.
For more detailed data on injection molding, refer to Toray’s injection-molding guide.

Mold design

Mold shrinkage is influenced by a complex combination of factors—product shape and thickness, molding temperature, mold temperature and pressure, among others. See Figure 32 for an example using CM3006. The data was generated using a flat plate-shaped product. Cylindrical products have a mold shrinkage rate that is about 70% that of flat plate-shaped products.
A draft angle of about 1° to 1.5° is appropriate for the inside surface of a cylindrical product, where a larger draft angle is required, in particular.
A mold temperature within the range of 60-80°C is appropriate, and it is important to keep the temperature as uniform as possible.

Figure 32: Molding conditions and mold shrinkage (%)

Pellet water absorption

Nylon is water-absorbent. To avoid bubbles, silver streaking and other quality issues caused by water absorption, dry the pellets to about 0.2% water content or less before molding. Coming off the manufacturing line, the nylon pellets have been dried to a level no higher than 0.1% water content, so there is no need to dry the pellets if used immediately after opening. However, leaving the pellets inside the hopper for extended periods of time will allow gradual water absorption that could lead to quality issues.
To assess the water absorption speed of CM3006, change in weight under various humidity conditions was measured. See Figure 33 for the test results. Assuming an allowable water content of no higher than 0.2%, the pellets can be left out in the open for no more than 20 hours at 40% RH and about one hour at 80% RH.

Figure 33 Nylon 66 pellets speed of water absorption

Material: nylon 66 (CM3001N and CM3006)
Pellet shape: 3.0 × 3.0 × 3.0mm
Temperature: 23±1°C
Humidity: 40-80±3%RH