Window seals

Nag and Haidar reported the purification of vegetable oil extracted from the seeds of Pongamia glabra and its ability to substitute commercially available factices [33]. Factices are usually used for mastication of NR during production of tubing, automobile parts, and window seals. The authors reported improvement in thermal stability of the NR vulcanizate after the factice was added. 

Wire and cable applications and extrusion profiles, e.g., window seals and car door seals, probably form the major applications for EPM and EPDM rubber, although they are also used in a wide variety of other extrusion and moulding applications. Washing machine door seals moulded from EPDM are starting to replace NR as washer/dryers are becoming more common. 

Rack and pinion boots. .. Weather-stripping, window seals. .. 

The U.S. rubber processing industry encompasses a wide variety of production activities ranging from polymerization reactions closely aligned with the chemical processing industry to the extrusion of automotive window sealing strips. The industry is regulated by seven Standard Industrial Classification (SIC) codes [1] ... 

We have already described the design of our miniature reactors, the overall concept and the details of the window seals (1,10). Briefly, the cell has a small volume, ca. 2ml, on grounds of both safety and cost (when using scXe ). It is constructed from stainless steel and can be filled from an external syr—- K ... 

Probes can be engineered for almost any environment, but these requirements must be clearly defined before probes are built. No probe can survive all environments so there may be some design trade-offs. Many immersion probes have a second window as a safety backup to ensure the process remains contained in the event of a window seal failure. Probes have been designed with motorized focus adjustments, automatic solvent or steam washes or air jets to keep the window clear, and sealed in water- and pressure-safe containers. Three commercial probes, two immersion and one non-contact, are pictured in Figure 5.4. Different optics can be attached to the face of the non-contact probe, much like conventional cameras using different lenses. 

As a result of its saturated polymer backbone, EPDM is more resistant to oxygen, ozone, UV and heat than the low-cost commodity polydiene rubbers, such as natural rubber (NR), polybutadiene rubber (BR) and styrene-butadiene rubber (SBR). Therefore, the main use of EPD(M) is in outdoor applications, such as automotive sealing systems, window seals and roof sheeting, and in under-the-hood applications, such as coolant hoses. The main drawback of EPDM is its poor resistance to swelling in apolar fluids such as oil, making it inferior to high-performance elastomers, such as fluoro, acrylate and silicone elastomers in that respect. Over the last decade thermoplastic vulcanisates, produced via dynamic vulcanisation of blends of polypropylene (PP) and EPDM, have been commercialised, combining thermoplastic processability with rubber elasticity [8, 9]. 

A) X-ray transparent window (B) window seal (C) sample holder (D) gas connections. Reprinted with permission from (Weiher et al, 2005). Copyright 2005 Wiley-Blackwell. 

Low modulus elastomers are materials that have found wide use in the automobile industry for fascia, bumper covers, and trim parts. Other applications include integral window seals and a wide variety of applications where it is replacing molded rubber. Most of these materials are not pure polyurethane, but polyurethane/polyurea hybrids with improved processing and properties when compared with the earlier allurethane systems. 

Spectra.—The infrared spectrum was recorded with the material sublimed on to cold potassium bromide windows sealed to a gas-tight glass cell with an epoxy resin. The deposit could not be sublimed from the windows without some attack on the bromide and thus it is possible that spurious peaks may be present in the spectrum. The observed peaks are 631vs, 680w, 725vw, and 1308w cm.. ... 

EPRs and EPDMs have excellent resistance to oxidation and ozone, compared to NR and SBR, and a relatively low cost. Their most important applications are in the manufacture of window sealing strips and in the automobile industry. 

A specific type of proportional counter that is used for accurate counting of a and P activity on smear samples, is the gas flow proportional counter. In some types of gas flow proportional counters, the sample is put inside the detector for greater sensitivity—there is no structural material to absorb the radiation before it can be detected. Figure 5.24 shows a diagram of the detector of such a gas flow proportional counter. Other gas flow proportional counters have very thin Mylar windows sealing off the detector s gas chamber. During counting, samples are positioned very close to the window. 

FIGURE 6.22 A HGA used for the atom spectrometric determination of trace elements in solid or dissolved samples. The graphite tube is connected as resistor between two graphite contact cylinders. Quartz window seals are attached to both ends of the primary beam plane, and the entire unit is water cooled. 

The ideal situation for a process analyzer is to have the detector/electrical components in an area physically isolated from the sample stream and any liquid components required for calibration or instrument operation (e.g., solvents for liquid chromatography or gel-permeation chromatography). In this arrangement, isolation of the electrical components ensures that a spark source or hot surface (such as a spectroscopic light source) will not cause a problem with flammable components (both sample stream components and solvents). Also, this isolation wiU limit instrument damage in case of a sample system leak or solvent leak. Although the ideal situation is often not realized in a practical application, one should make every effort to protect the delicate sections of the instrument. In one application of the authors, a fiber optic probe having a quartz window sealed on the end of the probe was installed in the reactor of a process that contained... 

The cell used in this physical adsorption was a simple glass cylinder with CaF2 windows sealed on the ends and with a side tube for admission of gases. The path length in the cell was reduced to 4 mm. by inserting salt plates, and about half of this space was filled with Cab-o-sil. 

Fig. 15.17a) for automotive and molded products like grommet (Fig. 15.17b) and washing machine gasket (Fig. 15.17c). These products typically use 100% EPDM, hence, the inclusion of a certain percentage of NR would reduce the products cost without affecting the products quality and performance. NR EPDM with a ratio of 60 40 is also widely used for making extruded profile weather strip shown in Fig. 15.17a. Examples of such extruded profiles are door liners of car and back window seal of a van. 

The dynamic runs of the actual window and seals were made in an apparatus shown in Fig. 4. With this apparatus, both parts of the double window seals remained tight throughout. At nitrogen temperature, the expander was pulsed for a total of 2 million pulses during several separate cool-downs. On only one occasion was there a small leak in one of the seals during this series of tests. 

The window seals described here should have a wide range of uses in other types of cryogenic apparatus. The use of plastics in the cryogenic engineering of bubble chambers, refrigerators, storage dewars, and experimental devices of all kinds can become more flexible. Several of the features of this seal may be useful for other cases in which differential... 

Figure 1 Matrix apparatus as used in Nottingham (1) valve power supply, (2) helium pressure connections to compressor, (3) silicon diode and heater lead-through, (4) pump-out port, (5) gas inlet port, (6) cold station, (7) heater and thermocouple wires, (8) stainless steel tube, (9) silicon diode, (10) very cold station and heater sleeve, (11) cell, (12) photolysis and spectroscopic windows, for an experiment the cell is turned by 90° towards the windows, (13) vacuum shroud, (14) large half of cell, (15) small half of cell, (16) IR optical windows, (17) lead seal, (18) indium window seal, (19) circlip retainer groove, (20) bolt, (21) steel washer, (22) spring washer, (23) nut, (24) femal-femal union, (25) steel tubing, (26) to very cold station, (27) threaded copper stud, (28) threaded hole in large half of cell to receive stud, (29) indium joints, (30) circlip, which fits in groove and retains windows.

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