Originally Published MDDI July 2001
Larger, machinable ceramic plates available. A machinable ceramic is now supplied for jobs requiring material as long as 20 in. Rescor 914 is readily machinable on conventional equipment with standard cutting tools, and custom machining services are available upon request. Cotronics Corp. (Brooklyn, NY; 718/646-7996) offers Rescor 914 as a substitute for Macor glass ceramic, alumina, and alumina silicate when larger sizes are needed. Temperatures may not exceed 1000°F. This ceramic is dense, vacuum-tight, inert to oxidizing and reducing atmospheres, and has low thermal conductivity. It offers good mechanical and electrical properties and requires no postmachining heat treatments. The material's dielectric strength is 480 V/mil, and it is ideal for vacuum feed-throughs and all electrical and vacuum parts. Rescor 914 can be metallized and soldered. It is also available as 914 HT, suitable for temperatures up to 1100°F.
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Sample Polymers Prepared at High Temperatures
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The high-temperature polymer characterization market is served by a gel permeation chromatography sample preparation system from Polymer Laboratories Inc. (Amherst, MA; 413/253-9554). Hot polymer solutions are easily prepared and filtered by the system. Filtration occurs with 0.5-, 2-, 5-, and 10-µm stainless-steel frits or nominal 1-µm glass-fiber filters. The PL-SP 260 agitates samples with accurate temperature and shaker control and can handle a wide range of polymers with dissolution temperatures from ambient to 260°C. Vials in 2-, 4-, and 20-ml sizes are accommodated by interchangeable hot blocks. The lid of the PL-SP 260 creates an oven environment which can be extracted for bench operations or purged with nitrogen for an oxygen-free dissolution environment. The machine's top surface may be used as a work surface.Compounds are flexible after curing. Potting compounds and encapsulants are available with fast curing times at room temperature and minimal air entrapment. Electronics, wiring, and other components are protected from moisture, temperature extremes or cycling, and shock or vibration with the use of these materials from Devcon (Danvers, MA; 978/777-1100). Flexane compounds are known for their elasticity and flexibility after curing. The Flexane line comprises two-component liquid urethanes with demolding times of 5–10 hours. All of these compounds are castable and nonshrinking, mix and pour easily, and cure at room temperature. Syon Tru-Cast 101/901 is part of the Syon epoxy compound family, which is made up of black and clear encapsulants, electrically and thermally conductive potting compounds, and high-density, high-temperature potting compounds. Tru-Cast 101/901 is appropriate for packaging and protection of delicate systems. It is a silica-filled, 4000-cps potting and casting resin which may be used as a UL Class B insulating compound. Syon Tru-Cast 100M/928 has good thermal shock resistance and may be cured in small masses at 250°F. This clear epoxy displays no signs of discoloration or striations when cured at room temperature in large masses. Syon Tru-Cast 111M is a high-density resin filled with aluminum oxide, offering good thermal conductivity and heat resistance.
Company divides plants into subgroups. Two regional extrusion groups and a components and assemblies group have been formed from a six-plant network. On April 1, 2001, Hydro Aluminum Wells (Baltimore, MD; 410/494-4500) initiated its reorganization to increase flexibility and entrepreneurship; it will provide the new units with higher-quality business development, human resources, information technology, and financial planning. Hydro Aluminum Wells East includes the Belton, SC, and Moultrie, GA, extrusion, fabrication, and finishing operations. Hydro Aluminum Wells Midwest is composed of the Monett, MO, and North Liberty, IN, extrusion, fabrication, and finishing plants. A remelt unit with an aluminum billet cast house was also created within the Monett/Cassville, MO, plant. The components and assemblies group provides complex, multistep, manufacturing operations for the production of major subassemblies. This group includes the Kalamazoo, MI, and Sidney, OH, operations.
Fiber reinforces thermoplastics. A new line of continuous-fiber thermoplastics (CFTs) combines the strength of fiber-reinforced materials with good design flexibility. All of the fibers are continually connected throughout the material, resulting in processing and product advantages over other fiber-reinforced composites. Features of the CFTs include impact tolerance, toughness, the ability to be postformed, secondary attachment capacity, joining capability, the ability to be recycled, light weight, corrosion resistance, and good insulating qualities. Suitable for medical tubing, the CFTs offer chemical resistance without conductivity and high strength and flared ends, if desired. The CFT line is from Polygon Co. (Walkerton, IN; 800/918-9261).
TPEs produce soft, colorable film. New film grades have expanded the Monprene line of compounds, processable in conventional blown- or cast-film extrusion systems. These thermoplastic elastomer (TPE) compounds produce film that has good colorability and processability, and a soft, dry touch like latex. Teknor Apex (Thermoplastic Elastomer Div.; Pawtucket, RI; 401/725-8000) produced the compounds to solve the problem of allergenic reactions caused by latex products. The compounds are presently used for bands and straps in physical therapy and are also suitable for hygiene products. Higher production rates than latex are possible, and the ease of coloring aids in product differentiation or color coding.
Copyright ©2001 Medical Device & Diagnostic Industry
