End-use applications

Recent pigment technology has yielded a wide range of products which ate much mote specialized for individual end use applications. New polymers have been combined with improved dyestuffs to yield fluorescent pigments with better performance properties and economics, and more desirable environmental characteristics. 

According to the end use application, PEs are processed by various techniques, which include injection moulding, blow moulding, rotomoulding, and film extrusion. However, since the bulk of the processed material is used as film in the area of packaging, the discussion in this chapter focuses mainly on processing behavior and the ultimate properties of tubular blown film. 

In addition, there is the difficulty of controlling the grafted side chains in molecular weight distribution. In the context of this chapter, the authors hope to give a systematic, comprehensive, up-to-date review on the various methods of grafting, the methods used for characterization of grafted substrates, and their possible end use applications. 

Predicting end use applications Water immersion Vacuum or space conditions Pipe burst... 

Plastics product design engineering handbook , Sidney Levy and T. Harry DuBois Van Nostrand Reinhold, (Kluwer Academic Publishers) (1977) ASIN 0412005115. A classic design course converted to book format that provides a very good introduction to a multitude of basic design features and environments focused on specific examples and end use application areas. 

The reinforcement of rubbers using nylon, rayon, vinyl, and polyester fibers was reported by various authors [10,58,73-75]. Because of the design flexibility and suitable end-use applications, high-performance fibers such as glass, carbon, and aramid also find extensive applications in short fiber-reinforced mbbers. A brief description of some of the major high-performance fibers commonly used in short fiber-rubber composites is given below ... 

From an engineering perspective, recycled materials should be used in such a manner that the expected performance of the product will not be compromised. Waste and byproduct materials, however, differ vastly in their types and properties and, as a result, in the end-use applications for which they may be suited. Experience and knowledge regarding the use of these materials vary from material to material as well as from facility to facility. To recover these materials for potential use, engineers, researchers, generators, and regulators need to be aware of the properties of the materials, how they can be used, and what limitations may be associated with their use. 

Some end-use applications may prefer the characteristics of foundry solid waste. For instance, spent foundry sand is a uniformly graded fine aggregate containing chemically active iron and organics. Spent foundry sand can be superior to other types of granular materials, such as compacted soils or clays, for hydraulic barriers. In this case, spent foundry sand provides better performance at lower cost. 

The stabilizer or stabilization system used depends on the heat and shear likely to be experienced by the polymer during processing, the end use application requirements, such as clarity or color, and the health concerns. A major health issue has been identified with the lead salts and soaps, because of their relative solubility and their corresponding potential to leach into water. For this reason, lead stabilizers currently find use only when other stabilizer systems do not provide the necessary stabilization or end use properties. Wire and cable sheathing is the only remaining application where the use of the lead stabilizer systems is widespread. Since most humans do not chew on wires (though mice, rats, and squirrels do) and lead-based stabilizers provide superior electrical properties, lead salts persist in this application. 

In the literature it is easy to obsetve that different types of fatigue tests rank materials in different orders. Thus, to predict a material s behavior for specific long-term end-use application, it is important to select the correct fatigue test. 

The use of carrier films is thus an effective way to enable the transfer printing of assemblages of nanoscale materials elements. In addition to SWNTs, this carrier film approach may aid in the transfer of arrays of small inorganic nanoparticles or perhaps even small molecules that for whatever reason must be synthesized or processed on the surface of a substrate that is not suitable for the end-use application. 

A profile of methylene chloride is presented including US production capacities, demand, growth rate, price, uses, strength, weakness and outlook. Paint stripping and removal accounts for 30% of MeC by end-use application, adhesives 20%, metal cleaning 10%, aerosols 10%, pharmaceuticals 10%, chemical processing 10% and flexible PU foams 5%. Because of occupational concerns, users of MeC are under pressure to limit use, restrict... 

In stationary end-use applications, hydrogen is used in remote locations and island grids... 

Physical characterization of polymers is a common activity that research and development technologists at the Dow Chemical Company perform. A material property evaluation that is critical for most polymer systems is a tensile test. Many instruments such as an Instron test frame can perform a tensile test and, by using specialized software, can acquire and process data. Use of an extensometer eliminates calibration errors and allows the console to display strain and deformation in engineering units. Some common results from a tensile test are modulus, percent elongation, stress at break, and strain at yield. These data are then used to better understand the capabilities of the polymer system and in what end-use applications it may be used. 

CHDM is thus a highly versatile monomer for producing polyesters that can be tailored to achieve a wide range of physical properties for a broad range of end-use applications. 

However, there remain numerous end-use applications which require significant improvements in the properties PET has to offer. These include higher tensile strength and modulus for tyre reinforcement yams and monofilament applications, higher temperature resistance for hot-fill containers and films, and greater gaseous barrier for longer shelf-life requirements (e.g. fruit juice and beer markets). 

When the full improved property potential of PEN compared to PET is not needed for an end-use application, copolyesters may be considered. Common available comonomers which may be used include terephthalic acid and isoph-thalic acid (IPA), DEG and cyclohexane dimethanol glycols. 

End-use applications for naphthalate-based polyester resins depend on optimizing the balance of properties desired in a specific application. Usually this involves optimizing the orientation process (uni- or bi-axial) with its accompanying crystallinity development. Subsequent heat setting may be included when additional improvements in thermal stability are needed. 

Developments in monldable particle PP foams are described, nsing the BASF product range as a basis. The monlding process is detailed, physical properties of monldings prodnced from Neopolen P at densities of 20 to 60 kg/cn.m. are detailed and major end-use applications are indicated. The monlding sequence is also illustrated. 

Isocyanates can also be advanced into a variety of intermediate products that contain different forms of condensation oligomers. These advanced products are typically used in applications where the reactivity or the viscosity of the isocyanate is modified for specific requirements in an end-use application. 

Polymerization of the oxiranes is typically propagated from a starter molecule that is chosen to define the functionality if) of the final polyol. The functionality and the molecular weight of polyols are the main design features that define the polyurethane properties in the end-use applications. Additionally, the balance of EO and PO in the polyether polyols, mainly for flexible foam polyols, is tailored to enhance the compatibility of formulations and the processability of the foam products. The exact composition of the polyols defines the crucial performance features of the final polyurethane product. Even seemingly small differences in polyol composition can result in changes to polyol processabihty and polyurethane performance. This becomes a crucial issue when replacing conventional petrochemical polyols with polyols from different feedstocks. To demonstrate the sensitivity of commercial formulations to changes in feedstocks, a simple example is offered below. 

The hydroxymethyl-substituted methyl esters can then be transesterified with any number of different initiator types to tailor the structure of the polyol to the end-use application, and all from a single raw material source. The stoichiometry of the polyol is adjustable, to produce polyols of any molecular weight. This synthetic strategy was developed by The Dow Chemical Company as the Renuva polyols. 

An interesting effect that has to be taken into account in assessing the potential of a new process or product is the distinction between performance (or speciality ) and commodity (or bulk ) chemicals. The former tend to be more expensive and are assessed principally on the basis of the value of their functionality in specific end-use applications. The later tend to be cheaper and to be valued in terms of their chemical specification, such as composition and purity etc., and tend to have a wide range of uses,... 

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