Tapes and Belts

PEN him is like PET film, but superior in various properties, and is finding wide applicahon for magnehc tapes. Weick and Bhushan have compared the dynamic mechanical properties and wear/abrasion properties of PEN- and PET-based magnehc tapes. The PEN tapes have better dimensional stability, elastic moduli and coating thickness. They also have higher storage moduli 

The use of specialty substrates for labels have been driven by the market looking for materials with greater dimensional stability at higher temperature, improved mechanical performance under harsh environments, and resistance to scratching and tearing. Up until now, PET-based labels have been used where conditions are moderate, while polyimide-based labels have been employed in the most extreme environments. PEN films offer a unique performance advantage over PET and a considerable cost saving when compared to polyimide films. 

PEN is a good candidate for labels where temperature tolerance is required, such as multi-layer labels for automobile bodies when being painted and dried at high temperatures. PEN is ideally suited for bar code labels where dimensional stability and registration are required at elevated temperatures. PEN labels have dimensional-excellence performance on printed circuit boards, in solvent- and aqueous-based painting operations, and in under-the-hood applications. PEN labels also provide substantially improved performance over PET or vinyl labels when the label must survive in harsh chemical environments. PEN performs extremely well in applications where the label must be in contact with organic solvents, such as acetone, ethers, toluene and phenol, as well as strong bases (30 % NaOH) and moderate acids. 

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For planar sensors manufactured by multilayer technology, the recently developed ceramic tape casting process was improved further [17, 18]. ZrOz powder is mixed into an organic matrix of binders, plasticizers, and solvents and is tape cast onto a Mylar supporting tape or a steel belt After drying, the ceramic tape is separated from the support tape and the flexible green tape can be punched to form individual substrates. 

Typical products are automotive exterior trim, fascia components, spoilers, window track tapes, boots, bellows, underhood wire covering, connectors, hose, and belts appliance seals, power tool components, ski boots, and camping equipment. ... 

A significant use of acetylene black is in dry cell batteries where it contributes low electrical resistance and high capacity. In rubber it gives electrically conductive properties to heater pads, tapes, antistatic belt drives, conveyor belts, and shoe soles. It is also useful in electrically conductive plastics such as electrical magnetic interference (EMI) shielding enclosures. Its contribution to thermal conductivity has been useful in rubber curing bags for tire manufacture. 

The casting onto polymer carriers was first described by Park in 1961 [26]. Tapes are cast in uniform thicknesses, typically based on English units. For example, tapes as thin as about 0.002 in. and as thick as 0.025 in. are in commercial production. Thicker tapes, for example, 0.040 in., have also been demonstrated, although it is difficult to punch and laminate multilayer structures with such tape. In the casting process, control of tape thickness, belt speed, temperature, and drying atmosphere is critical [27]. 

PETs are extensively used in such products as bottles and films. Stretched-injection blow-molded bottles are used for nearly all two-liter carbonated beverage containers. PET is also used for packaging foods, cosmetics, and household chemicals (see Figs. 6-7 and 6-8). With changes in formulation, surface treatment, and processing— from unoriented to bioriented— PET films can produce variations in optical, mechanical, physical, and surface properties. They are used in liquid-crystal displays, metalized photocopier belts, motor and wire insulation, for holographic reproduction, in magnetic tapes and discs, and other uses. Aluminized PET film with nylon fabric set the world s record for altitude in a manned hot-air balloon at 59,500 m (65,(KX) ft.), in 1988. 

Finally, there is a way to achieve effective adult incontinence protection without compromising dignity. Protective underwear is a stretchable, disposable, low-profile undergarment that offers superior containment and fit. Less bulky and without the tapes or belts of traditional adult briefs and undergarments, it slips on and off just like ordinary underwear for easier and more dignified and discrete use. 

Natural mbber latex is also used in adhesives for tape, packaging, envelopes, and in the footwear industry. It is used in the carpet industry as a binder for backing compounds, but this is another area in which synthetic SBR latex has competed effectively. There are a number of relatively small and specialized appHcations for natural mbber latex including mbberized coir or hair and cast products such as toys. Latex sheeting which is used in dental dams and for numerous other purposes can be made by dipping or casting onto a continuous belt. 

Tape can be cast on a stainless steel table or belt, glass plate, or a Mylar, Teflon, or ceUulose acetate film carrier. The tape should adhere to the carrier sufficiently to prevent curling, but should be easily removable. In a continuous casting process, the tape is dried by air flowing 1—2 m/min counter to the casting direction. A typical dry green tape contains approximately 35 vol % organics, 50% ceramic powder, and 15% porosity. 

In an attempt to simplify the geometiy of the tape casting machine, the zone between the bottom of the flat tape casting blade and the moving belt surface is isolated for analysis. In this zone, shown in Figure 13.8(b), a momentum balance is performed, giving... 

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