Resin sections autoclaving

ANTIGEN RETRIEVAL ON THIN RESIN SECTIONS USING AUTOCLAVING... 

Standard test for hydrolytic stability. The hydrolytic stability of the chlorinated resins was determined by the following test procedure. An acid digestion autoclave having a volume of 125 ml is charged with 40 ml of resin and 28 ml of deionized water. The bomb is sealed and transferred into an oven, pre-heated to 200 °C. The test is continued for 24 hours. The bomb is removed and cooled to ambient temperature. The liquid is separated from the resin and the chlorine content analyzed while the resin is washed thoroughly and its acid capacity is determined as described in section 5. The test results are shown in Table 2. 

In this section a specialized set of equations governing transport of mass, momentum, and energy in resin transfer molding, injected pultrusion, and autoclave processing are obtained from the general balance equations presented in Section 5.3. This involves eliminating unimportant terms in the general balance equations based on the specific nature of the process. 

The chapter is divided into a section on development of process cycles or plans and a section on in-process control. The tools to be discussed include design of experiments, expert systems, models, neural networks, and a variety of combinations of these techniques. The processes to be discussed include injection molding, resin transfer molding, autoclave curing, and prepreg manufacturing. The relative cost and difficulty of developing tools for these applications will be discussed where data is available. 

Thermoset based composite laminates are generally produced bj Autoclave/Vacuum Degassing Lamination Process (38, 39). The characteristics of this inocess are shown in Fig. IS. In this process, pr eg plies of desired shape are laid up in a prescribed orientation to form a laminate. The laminate is covered with successive layers of an absorbent material (glass bleeder fabric), a fluminated film to prevent sticking, and, finally, with a vacuum bag. The mitire system is placed upon a smooth metal tool surface into an autoclave, vacuum is a Ued to the bag and the temperature is increased at a constant rate in order to promote the resin flow and polymerization. The autoclave process will be used along this section as a case study to describe the influence of the matrix characteristics on the processing behavior of hi performance conqmsites. 

Compared to BMI adhesives, the nadimide-terminated resins discussed in Section 4.3.4.2 exhibit a better thermal-oxidative resistance, but they require a complex cure schedule in autoclaves. Condensation and imidisation of the monomer reactants is performed at 205°C under partial vacuum to remove methyl alcohol and water. Addition polymerisation of the norbomene rings is then conducted under full vacuum at 290°C with an applied air pressure of 0.7 MPa. PMR adhesives have been successfully tested for bonding parts of cruise missiles, space shuttle, and YF-12 aircraft. The lap shear strength data indicate an excellent adhesion after a long-term ageing at 232°C and approximately 200 h at 316°C. 

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