Minimum thermosetting temperature

Figure 11.5 Effect of water content on the Tg and minimum thermosetting temperature (TJ for wheat gluten proteins [163]. Hoseney and co-workers [163] (0), Kalichevski and co-workers [164] ( ), Nicholls and co-workers (O), Cherian and Chinachoti [154] (A), and Pouplin and co-workers [187] (X) the thermosetting temperature ( ) was determined for wheat glutenins [166]...

Thermoplastically processable starch Thermoplastic starch Minimum thermosetting temperature Total solid(s)... 

Figure 1 Effect of water content on the glass transition temperature (Tf and on minimum thermosetting temperature (Tr) for wheat gluten proteins (10).

The cure cycle is the temperature vs time schedule used to polymerize the thermoset precursors. The selection of an adequate cure cycle has several purposes. What is desired is to obtain the final part without strains exceeding design tolerances, with a uniform conversion (usually close to the maximum possible conversion), without degradation produced by the high temperatures attained during the cure, with convenient morphologies (in the case of heterogeneous materials), and all this, must be achieved in the minimum possible time for economic reasons. 

Acetal Copolymer (CELCON ) Two types of non-solvent adhesives are used, structural and non-structural. Most structural adhesives are based on thermoset resins and require the use of a catalyst and/or heat to cure. This type of adhesive is normally used in applications which require maximum bond strength and minimum creep of the adhesive joint under sustained loading. Many structural adhesives can be used continuously at temperatures up to 350 F, which is higher than the... 

Molding index n. A practical measure of the difficulty of molding of thermosetting compound. A calculated weight of the candidate molding powder, is placed into a flash-type cup mold that has been preheated to the temperature prescribed for the material. The mold is closed and the total minimum force required to close it is reported as the molding index of the compound. 

Various optimization studies on thermosetting as well as thermoplastic pultrusion parameters were conducted (Chew, 2004 Joshi et al, 2003 Kyaw, 2003 Li, 2001 Tat, 2006 Zaw, 2003) using the same FE/NCV method developed by Joshi and Lam (2001). Chew (2004) worked on cooling optimization in thermoplastic pultrusion whereas Tat (2006) studied the impact of mounting locations for the feedback thermocouples controlling heater temperatures. It was observed that if the thermocouples sense either the maximum or the minimum temperature on a hot die surface, the power input to the heater will be rather uneven and the process may not completely optimize. Joshi et al. (2003) looked for improved pultudate quality with the... 

In the 0 to 212°F range, a broad selection of materials is available. Low temperature considerations may eliminate many of the thermoplastics. Polyphenylene oxide can be used at temperatures as low as -275°F. Thermosetting materials exhibit minimum embritdement at low temperature. 

Commercial latexes are supplied both as thermoplastic and thermosetting types. Thermoplastic acrylic (and vinyl) latexes are very commonly used as binders for architectural paints and some specialty coatings. Such coatings are required to dry under ambient conditions without any chemical cross-linking and hence are designed to precise T and minimum film formation temperature. 

Pressure, describes how to test individual pipe specimens and is applicable to both thermoplastic and reinforced thermosetting/resin pipe materials. ASTM D2837 requires that a minimum of 18 failure points as well as a specific distribution of failure points be obtained to develop a full hydrostatic stress rupture curve for a material at a specific temperature. This distribution is shown in Table 32.1. 

Major requirements for book binding adhesives beyond adequate adhesion to the various substrates in the book include flexibility and die abihty to perform at cold and hot temperatures. The process of binding books is highly automated except in the case of special limited volume editions. New adhesives must therefor be adaptable to use on existing equipment, or new equipment must be developed for their use. New products such as thermoset polyurethane hot melts provide excellent adhesion and flexibility but new application technology is required for their use in high volume apphcadons with minimum equipment down time. 

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