Curing under

When the surface conditions are acidic or the ambient humidity is low enough to affect the cure significantly, a surface accelerator may be used to promote the reaction. Available from most manufacturers, these basic solutions may be dip, wipe, or spray appHed. Recentiy, new additive chemistry has been developed that accelerates the cure under adverse conditions without the need for a separate accelerator. 

Binders and Resins. The choice of binder is the most important ingredient choice in the formulation process because the binder affects the performance properties of a paint more than any other single ingredient (3). The physical properties of binders required for paints include the abiHty to dry or cure under various ambient conditions, good adhesion to various substrates, abrasion resistance, washabiHty, flexibiHty, water resistance, and ultraviolet light resistance. The balance of these required properties is mosdy dependent on whether the paint is being developed for interior or exterior appHcations. 

The decorative plastic laminates widely used for countertops and cabinets are based on melamine—formaldehyde resin (see Laminates). Several layers of phenohc-saturated kraft paper are placed in a press and a sheet of a-ceUulose paper printed with the desired design and impregnated with melamine—formaldehyde resin is placed over them. Then a clear a-ceUulose sheet, similarly impregnated with the resin, is placed on top to form a clear, protective surface over the decorative sheet. The assembly is cured under heat and pressure up to 138°C and 10 MPa (1450 psi). A similar process is used to make wall paneling, but because the surfaces need not be as resistant to abrasion and wear, laminates for wall panels are cured under lower pressure, about 2 MPa (290 psi). 

Murray remarks that ester-cured phenolics do not produce the strength seen in some other systems. This could be due to several factors. First it may be due to incompleteness of cure under the conditions provided. We have noticed that... 

The plates are dried and cured under controlled temperature and humidity conditions producing no wastewater or particulate emissions. Cured plates are sent to a three-process operation that involves manual separation of the plates, stacking them with non-conducting separators, and the welding on of metallic lead battery leads (pronounced leeds ) and lead terminals. The plates are then assembled Into battery cases. 

Insulation formed by slurry casting or heat curing under pressure in molds in a number of insulation types. Most common moldings are preformed bends, valve boxes and flange covers. 

Concrete structures should be constructed in accordance with BS 5337 or BS 8110 as appropriate. The concrete must be properly cured under shuttering, or a curing membrane, for seven days followed by at least 28 days open curing prior to the commencement of lining. Surfaces have to be free from voids and projections and are often screeded to give a satisfactory finish. 

The laminated (RP) fabric, bonded with phenolic plastic incorporating antifriction ingredients and cured under heat and pressure, gives excellent service when properly applied in various applications. This group of bearings has a low coefficient of friction, antiscoring properties, and adequate strength for use in steel mills and other heavy-duty applications and is well established in the industry. 

Quartz fine aggregate and normal Portland cement were used to prepare mortar with a w/c of 0.5. A cylindrical specimen, 43 mm in diameter and 50 mm long, was cast and cured under sealed conditions for 3 days at 23 °C. The specimen was then oven dried at 105 °C for 1 day prior to exposure to lithium nitrate solution. The specimen was then placed such that the bottom of the cylinder was submerged approximately 1-2 mm into a lithium nitrate solution with Teflon tape applied to the curved surface. 

Cure the organosilane-modified substrate by incubation at 110°C for 30 minutes or at room temperature in a low humidity environment. Curing under vacuum also will aid in the removal of water and the formation of siloxane bonds. 

The ability to apply a planarizing, optically transparent, thermally stable polymer system that cures under relatively mild conditions has recently been demonstrated to have utility in the fabrication of multilayer devices such as advanced color liquid-crystal display31,32 The ability to apply this material as a dielectric or optical coating for thin-film electronics devices has also recently been demonstrated with the fabrication of an optical wave guiding device.33... 

Fig. 5.35 Calcium chloride does not affect the long-term strength development of dense concrete cured under laboratory conditions, or with outside exposure (Blenkinsop). 

The effects on other properties of both plastic and hardened mortar or concrete have not been investigated. Furthermore, since the studies have been done on a laboratory scale, no information pertaining to effects of placing and curing under normal or varied environmental conditions is available. 

Cement hydration and epoxy polymerization occur simultaneously to form a structure that is similar to the latex-modified cementitious system. Epoxy systems develop high strength, adhesion and have low permeability, good water resistance and chemical resistance. A major advantage of this system is that it can be cured under moist or wet conditions. According to a recent study, the epoxy-modified mortars can be made without the hardeners with superior properties to those obtained with conventional epoxy mortars [89, 90]. 

Dignum M, Kerler J, Verpoorte R (2002) Vanilla curing under laboratory conditions. Food Chem 79 165-171... 

Materials. The materials are described in detail in the studies summarized in Table I. Most of these results are based on kraft lignin. The NCO/OH ratio of all of these networks were high greater than 1.5. All of the networks were prepared from homogeneous solutions of the lignin-based polyol, added (soft segment) polyol, and diisocyanate. Films were cast and cured under mild conditions with a controlled loss of solvent. The films were post-cured to insure complete reaction (25). 

The second important feature of the reaction mechanism of the epoxy compound curing under the action of amines (primary, secondary and tertiary) and their mixtures consists in formation of various hetero-, auto-, inter- and intramolecular donor-acceptor complexes between the components of the reaction system — the starting substances and reaction products. Consideration of this complex formation can adequately explain the reaction kinetics. 

Figure 15.21. Final curing temperature vs. in-plane birefringence of six kinds of polyimides cured under a constant load.

Figure 15.22. Temperature profile and elongation of PMDA/TFDB poly(amic acid) film cured under a constant load.

Soft rubber - A term used for rubber which cures under 70 durometer "A" scale. 

Thermosetting - Capable of being changed into a substantially infusible or insoluble product when cured under application of heat or chemical means. Vulcanization is a type of thermosetting. 

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