Toray C740
Toray C740 is a cyanate ester resin system for cures at 135°C (275°F), pre-impregnated into high performance fibers such as carbon, glass and aramid. The system is capable of withstanding very high temperatures and is inherently flame-retardant. After a suitable post cure the glass transition temperature can be increased to as high as 325°C (617°F).
Properties
- Physical Form
- Prepreg
Product families
- Thermoset Prepregs
Other characteristics
- End Uses
- Motorsport, Tanks
- Functions
- Prepreg
- Polymer Name
- Cyanate Ester Resin
- Processing Methods
Out of Autoclave Prepreg, Prepreg Processing, Vacuum Bagging
- Markets
- Automotive & Transportation
- Industrial
- Exotherm
In certain circumstances, such as the production of thick section laminates rapid heat-up rates or highly insulating masters, Toray C740 can undergo exothermic heating leading to rapid temperature rise and component degradation in extreme cases. Where this is likely, a cure incorporating an intermediate dwell is recommended in order to minimize the ris
- Technology
- Composite Materials
- Moisture Effects
Under certain conditions moisture will react with cyanate ester functional groups to produce carbon dioxide gas, and at elevated temperatures trapped gas will expand and may cause the laminate to blister. Care must be taken when defrosting the prepreg to minimize any condensation. All tooling and any molded inserts should be dried prior to use to ensure any absorbed moisture is removed. It is recommended that the post cure takes place immediately after the cure is completed.
- Processing Method
Following removal from refrigerated storage, allow the prepreg to reach room temperature before opening the polythene bag, to avoid moisture condensation. Typically, the thaw time for a full roll of material will be 4 to 6 hours. Cut patterns to size and lay-up the laminate in line with design instructions taking care not to distort the prepreg. If necessary, the tack of the prepreg may be increased by gentle warming with hot air. The lay-up should be vacuum debulked at regular intervals using a P3 (pin pricked) release film on the prepreg surface; vacuum of 980 mbar (29 in Hg) is applied for 20 minutes. For autoclave cures, use of a nonperforated release film on the prepreg surface trimmed to within 25–30 mm of the prepreg edge is recommended for the cure cycle and a vacuum bag should be installed using standard techniques.
- Composites End Use
- Motorsport
- Tanks
- HIGHLIGHTS
Excellent drapeability—complex shapes easily formed; Good electric properties; 30 days shelf life at ambient temperature; Inherently flame retardant with low toxic gas and smoke generation; Good dimensional stability and thermal durability up to 250°C (482°F) after post cure; Excellent surface finish; Maximum Tg of 325°C (617°F); Low volatile content—no solvents used during processing
- Recommended Cure Cycle
Increase autoclave pressure to 1.4 bar (20 psi) with vacuum applied (29 in; Vent to atmosphere and raise pressure to 6.2 bar (90 psi) (or max allowed by the core material); Increase air temperature at 1.5°C (2.7°F)/min and hold for 2 hours at 135°C (275°F.); Allow to cool to 60°C (140°F) before removal of pressure; To obtain the maximum Tg, it is essential that a suitable post cure is carried out; E.g. for Tg 325°C (617°F), ramp from initial cure temperature to 280°C (536°F) at 0.5°C (0.8°F)/min and hold for 2 hours minimum. Cool to 60°C at 3.0°C (4.8°F)/min.
- Recommended Applications
- Motorsport & Formula 1
- Automotive
- Industrial
- aerospace
- Composite Materials Functions
- Prepreg
Technical data
Table 1 of 2
2 rows| Characteristic | Value | Unit |
|---|---|---|
| Tg (DMTA) 2 hours at 280°C (536°F) Onset | 325 (617) | °C (°F) |
| Tg (DMTA) 2 hours at 280°C (536°F) Peak tan δ | 415 (779) | °C (°F) |
Table 2 of 2
1 row| Characteristic | Value | Unit |
|---|---|---|
| Density (23°C (73.4°F)) | 1.27 (79.3) | g/cm³(lbs./ft³) |
