FEATURE / FAST-CURE RESIN SYSTEM Resin G85* G85** Rc % by weight 42% 37.5% FAW g/m2 204 190 T300B-3K / 2X2 Twill T700S-60E Fiber / Fabric weave Property Unit Method DMA Tg °C ASTM D7028 177 177 0° TS MPa ASTM D3039 606 2680 0° TM GPa ASTM D3039 57 130 90° TS MPa ASTM D3039 600 - 90° TM GPa ASTM D3039 57 - 0° CS MPa ASTM D695 - 1667 0° CM GPa ASTM D695 - 112 V-notch IPS MPa ASTM D5379 90 - ILSS MPa ASTM D2344 12 - Flex. Mod. GPa ASTM D790 83 - Poisson's Ratio -- ASTM D3039 0.05 - *Values Normalized to Vf = 49% ** Values Normalized to Vf = 54% Table 2. Mechanical test results of T300 fabric vs. T700 unidirectional prepreg. Figure 4. Mechanical performance of G83C vs. G85. Figure 5. Surface Finish of the epoxy snap cure resin with T300 2x2 Twill (no clear coat used). An example part using G85/T300B 2x2 Twill is shown in Figure 5. With proper layup techniques and tool preparation the part can maintain a class "A" finish without sacrificing distinctness of image or telegraphing of the fabric from the resin shrinkage due in part to the design characteristics of the epoxy snap cure resin matrix. 14 | SAMPE JOURNAL | J U LY/AU G U S T 2 0 1 9 w w w. s a m p e . o r ghttp://www.sampe.org