Casting and Molding

Fig. 2. Influence of concentration (C) and diameter (D) of carbon microspheres on the fluidity (1, relative units) and the apparent density (2) of epoxy syntactic foams401. The A and B regions are the cast and molding compositions, respectively...

Gallagher Corporation. "Cast and Molded Components of Polyurethane Elastomers— Design and Application Guide." Trade Paper (1994) 35. 

Shot metal Pb, 99 As, 1 Harder than Pb yet readily fusible Bullets and shot (cast and molded)... 

One of the earliest commercial plastics was Bakelite , formed by the reaction of phenol with a little more than one equivalent of formaldehyde under acidic or basic conditions. Baeyer first discovered this reaction in 1872, and practical methods for casting and molding Bakelite were developed around 1909. Phenol-formaldehyde plastics and resins (also called phenolics) are highly cross-linked because each phenol ring has three sites (two ortho and one para) that can be linked by condensation with formaldehyde. Suggest a general structure for a phenol-formaldehyde resin, and propose a mechanism for its formation under acidic conditions. (Hint Condensation of phenol with formaldehyde resembles the condensation of phenol with acetone, used in Problem 26-17, to make bisphenol A.)... 

One essential difference between casting and molding processes is that pressure need not be used in casting (although large-volume, complex parts can be made by low pressure and/or vacuum casting methods). Another difference is that the starting material is usually in liquid form rather than the usual solid plastic used in other processes. There is also the difference that the liquid could be a monomer rather than the plastic used in most other processes and in turn the monomer is converted to a polymer/plastic (Chapter 1). 

Salt casts and molds, in the form of cubic and hopper-shaped voids, impressions, and fillings in rocks, are evidence of the former presence of salt in the rock. These features are fairly common in each of the study areas and are best seen in the dolomite beds that are capable of retaining the delicate impressions of the salt crystals. The quantity of salt removed from such casts and molds is small in comparison to that which can be removed from bedded rock salt. 

The polycocyclotrimers of isocyanates of variable crosslink density were prepared by polycocyclotrimerization of difunctional isocyanate (HDI) with monofunctional isocyanate (BuNCO) and by polycocyclotrimerization of difunctional isocyanates of variable chain length using casting and molding techniques. 

Ease Release. [Gecnge Mann] Rdease agent for casting and molding systems. 

MAJOR USES Solvent in the manufacture of pharmaceuticals used for spinning fibers, casting and molding plastic materials used in lithium batteries used in the extraction of fatty acids from animal and vegetable oils used in chemical laboratories for the detection of materials such as pesticide residues. 

OTHER COMIVIENTS used for creating casts and moldings used in tiles, stucco, wall plaster, and wallboard present in dental casting materials can be formed by heating gypsum. 

Acetonitrile is used as a solvent for polymers, spinning fibers, casting and molding plastics, and HPLC analyses for extraction of butadiene and other olefins from hydrocarbon streams in dyeing and coating textiles and as a stabilizer for chlorinated solvents. It occurs in coal tar and forms as a by-product when acrylonitrile is made. 

Casts and Molds Polymerizations may also be carried out in molds or casts. In this process, the monomer is added to a mold and allowed to heat up to the point of selfpolymerization. The resultant polymer product is removed from the pans and cooled. While this more manual process appears slightly archaic, its simplicity allows the production of a number of specialty products still in commercialization today. 

Boljanovic, Vukota. Metal Shaping Processes Casting and Molding, Particulate Processing, Deformation Processes, and Metal Removal. New York Industrial Press, 2010. Describes the fundamentals of how metal is shaped into products. 

Figure 5 A representation of dynamic combinatorial libraries nnder template control, casting and molding, with all the possible ontcomes of the 4-1-4 macrocycLic prodnct (with other macrocycles and catenanes possible hypothetically) shown in between the templated prodncts and the components.

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