Autoclave Processing 145 Tensioner 三目 Feeding Comb Resin Heater Take up creels spreader bath roll FIGURE 4.3 Schematic of a prepregging machine. Resins are usually thermosets such as epoxies,although recently prepregs made of vinyl ester resins have also been available.The par- tially cured resin has about 30%of the crosslinks already formed.With the incorporation of fibers(such as carbon,glass or Kevlar at about 60% by volume),prepregs are flexible sheets of fibers about 150 mm thick. This is similar to a sheet of wallpaper except that it is sticky on both sides. Figure 4.4 shows a roll and a sheet of the carbon/epoxy prepreg. FIGURE 4.4 A roll and a sheet of carbon/epoxy prepreg.Resins are usually thermosets such as epoxies, although recently prepregs made of vinyl ester resins have also been available. The par￾tially cured resin has about 30% of the crosslinks already formed. With the incorporation of fibers (such as carbon, glass or Kevlar at about 60% by volume), prepregs are flexible sheets of fibers about 150 mm thick. This is similar to a sheet of wallpaper except that it is sticky on both sides. Figure 4.4 shows a roll and a sheet of the carbon/epoxy prepreg. Autoclave Processing 145 FIGURE 4.4 A roll and a sheet of carbon/epoxy prepreg. FIGURE 4.3 Schematic of a prepregging machine