Sealing compounds

Seal face material Sealing compounds Sealing rings Sealings Seals... 

Dibutyltin and dioctyltin diacetate, dilaurate, and di-(2-ethylhexanoate) are used as catalysts for the curing of room-temperature-vulcanized (RTV) sihcone elastomers to produce flexible siUcone mbbers used as sealing compounds, insulators, and in a wide variety of other appHcations. Diorganotin carboxylates also catalyze the curing of thermosetting siHcone resins, which are widely used in paper-release coatings. 

They are used extensively to react with epoxy or phenoHc resins, yielding adhesives that are useful in casting and laminating, in stmctural work, for patching and sealing compounds, and for protective coatings. The amount used in epoxy appHcations far exceeds the use with phenoHc resins. 

Berners lor sealing compound easily insiailea atier dams are made and beiore compound IS poured Body may be installed With either cOAduil hub up... 

Splices. Splices and taps may not be made in sealing fittings. Most sealing compounds are poor insulators, and electrical shorts could occur. 

Verguss, m. pouring, casting, filling, seal, -harz, n. casting resin, -masse, /. sealing compound, filler,... 

Some crevice attack upon titanium can also occur in the presence of gaseous chlorine gas at temperatures below 100°C, but this is mainly confined to crevices formed between titanium and organic sealing compounds. Here again, the Ti-0- 15Pd alloy is less prone to attack. 

At first, the program which investigated the packaging of irradiation-- processed foods, concentrated on the most advanced type of container, the tinplate can. It had performed successfully for a century as a container for thermoprocessed foods. However, as a container for the irradiation-processed foods, its physical, chemical, and protective characteristics had to be evaluated, including the effects of radiation on enamels and end-sealing compounds. This container was satisfactory for packaging foods that were irradiation sterilized while unfrozen (1, 2). 

A screening study for evaluating and selecting components of the tinplate container—tinplate, enamel, end-sealing compound, and side-seam solder—which were irradiated at designated doses and temperatures... 

End-Sealing Compounds. The commercial end-sealing compounds used in this study were ... 

End-Sealing Compounds. The qualitative cohesion testing of the three end-sealing compounds with the dissecting needle showed that... 

The three irradiated end-sealing compounds had good adhesion to all the enamels except Enamel 5, the epoxy-wax enamel with aluminum... 

Table III. Effect of Irradiation on Cracking and Adhesion of End-Sealing Compounds"...

Table IV shows the data on rigidity changes of the end-sealing compounds at two dose levels. Rigidity was determined by torsional braid analysis (5). These data indicate that the blend of cured and uncured isobutylene-isoprene copolymer was softened most by the irradiation treatment, the blend of polychloroprene and butadiene-styrene copolymer softened the least, and the blend of polychloroprene and the uncured isobutylene-isoprene copolymer was intermediate. Increasing the irradiation dose from 3-4 Mrad to 6-7.5 Mrad decreased the rigidity of the three end-sealing compounds. The irradiation temperature did not significantly influence rigidity.

Table IV. Rigidity of End-Sealing Compounds After the Irradiation...

Table V. Relative Rigidity of Unirradiated End-Sealing Compounds...

Production Test. In a small-scale production test, tinplate containers with two commercially available enamels and two end-sealing compounds, which were selected from the results of this study, performed satisfactorily when packed with beef and ham. Beef was irradiated with 4.5-5.6 Mrad at 5, —30, and —90°C ham was irradiated with 3-4 Mrad and 6-7.5 Mrad at —30°C. For this production test, beef and ham were packaged in round tinplate containers and ham in Pullman tinplate containers, frozen and refrigerated products were shipped 1,200 miles by truck, and were gamma irradiated at various doses and temperatures. Irradiated products were shipped 1,200 miles in a non-refrigerated truck and stored at selected temperatures and humidities. The integrity of the cans was evaluated after storage for 10 days, 3 months, and 6 months. 

The production test showed that the epoxy phenolic enamel was the preferred enamel for coating tinplate containers used in packaging irradiation-sterilized ham and beef. The preferred end-sealing compound for the same application was the blend of cured and uncured isobutylene-isoprene copolymer. 

The evaluation of the components of the tinplate container showed that the preferred enamel for irradiation processing was the epoxy phenolic the preferred end-sealing compound was the blend of cured and uncured isobutylene—isoprene copolymer. Component testing of tinplate and solder for possible changes in mechanical properties, microstructure, and corrosion resistance indicated that the radiation caused... 

Adhesion of end-sealing compounds Alcohol permeability of acrylonitrile-styrene copolymers. .. Alcoholic beverages stored in... 

The weather conditions also added headaches. In winter the temperature sometimes gets below -50°F (-45°C) and may remain at -30°F (-35°C) for sustained periods. It is so cold that certain buildings need air locks to prevent excessive heat losses when people enter or leave. Many ordinary construction materials cannot withstand the temperature. The usual mastic sealing compound has to be replaced by an expensive silicone sealant. In addition to this the region has high winds and is earthquake-prone. 2... 

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