Toray TC250

Toray Advanced Composites recommends that cyanate ester composite parts bagged for cure should be performed as follows:

• Release the tool surface
• Lay-up part using standard debulking procedure
• Dam the edges of the part for cur
• Place one ply of porous Teflon® or perforated Teflon® onto the bag surface of the part
• Place bleeder layers over the porous Teflon® material and trim to the part periphery
• Place a non-porous layer of Teflon® over the part
• Utilize a breather cloth to facilitate vacuum draw
• Install vacuum bag on the tool for cure
• Follow the provided Toray Advanced Composites cure cycle for the particular resin system

Toray Advanced Composites recommends that any composite or adhesive lay-up be performed in a clean area visibly free from dust. Any work surfaces should likewise be free of residue, dust, or debris. No eating or smoking shall be allowed in the shop area. For radome materials, conductive materials shall not be allowed in the process area. The processing shop area should be maintained between 16–32°C (60–90°F) with a relative humidity of no greater than 70% RH.

• Out Life: Up to 30 days at ambient
• Frozen Storage Life: 12 months at -18°C (< 0°F)

Out life is the maximum time allowed at ambient temperature before cure. *Ambient is 18–22°C (65–72°F)

The following guidelines are provided to our customer to assure that all customers are aware of the procedures to attain the best possible results from Toray Advanced Composites epoxy products. These resin systems will provide sound composite hardware and structures if some simple procedures are followed. Keep in mind that these procedures are good practice for all composite prepreg and adhesive materials and should be used whenever possible.

• FREEZER STORAGE: Epoxy resin materials have good shelf life at room temperature; however, the life and performance of the material is best preserved with the following basic guidelines. Refer to the shelf life included in the product certificates. The epoxy material should be sealed in an airtight bag and kept frozen below -18°C (0°F) when not being used for longest life and most consistent performance. A good safety measure is to have a bag of desiccant (silica moisture absorber) in the core of the prepreg roll just in case a pinhole in the bag or other problem occurs

• MOISTURE ABSORPTION AND SENSITIVITY: While very resistant to moisture absorption after cure, epoxies can be adversely affected by moisture uptake prior to cure. For this reason, all materials must be “thoroughly thawed” to room temperature prior to opening the sealed bag to avoid condensation on the material. Also, it is good practice to keep prepreg and in-process hardware in a sealed bag or vacuum bag if to be exposed to the atmosphere for long periods of time.

• HANDLING OF MATERIALS: When handling any prepreg materials, one should always be wearing clean, powder-free latex gloves. This will assure that no hand oils are transferred to the prepreg and/or composite during processing. The presence of oils in the part could lead to problems in both mechanical and electrical performance of the part. This also guards against any dermatitis that could occur with certain users

• NONMETALLIC HONEYCOMB AND FOAM CORE USE: When using nonmetallic honeycomb and foam core materials for sandwich structures, the materials should always be dried in an oven prior to lay-up to drive off any moisture that may be in the core. The material should then be cooled in the presence of a desiccant, to avoid any moisture uptake. Following this procedure, it is always a good idea to use the material as soon as possible to avoid rehydration. Recommended Core Dry Time/Temp: 121°C (250°F) for 3–4 Hours.