Moisture problem

Microbial deterioration of plastics is intimately involved with the moisture problem, especially with regard to plastics in electronic equipment. For this reason much of the literature treats the two problems together. Furthermore, there is often confusion between the deterioration of the electrical properties of plastics, more often than not a moisture phenomenon, and actual deterioration of the substance of the polymer. 

A surprisingly low concentration of water can reduce the viscosity such that reclaimed PET cannot be used for the blow molding of bottles with acceptable physical properties. The established solution to the moisture problem is to dry the recycled PET in special dryers prior to use. However, the drying process is both time and energy intensive. Paper labels can cause problems in PET recycling if they decompose during washing and removal. The paper fibers formed can produce cellulose fibers that are difficult to remove from the reprocessed PET.1... 

Nontransparent containers (e.g., dairy cups) account for the remaining 40% of the European market. If toughness requirements are not met by PEA, Ecovio compounds can be used for the extmsion of rigid containers. They have an adequate viscosity and can be recycled if the moisture problem is solved by drying the recycled material (like virgin PEA, to a moisture level below 200 ppm). 

Rankine cycle with reheat is a modification of the Rankine cycle in which the steam is expanded in the turbine in two stages and reheated in between. Reheating is a practical solution to the excessive moisture problem in the lower-pressure stages of turbines, and it is used fre-quendy in modern steam power plants. 

ISIAQ (1996) Control of moisture problems effecting biological indoor air quality. ISAQ international society of indoor air quality and climate. Ottawa, p 8... 

The moisture problem can be solved by analytical means when the following conditions are met ... 

McCarthy, L. R., Here are Tips on Solving Common Moisture Problems, PW Directory, pp. 313-317, 1989. 

Nylon-epoxy film adhesives have the tendency of picking up substantial amounts of water before use. They also tend to lose bond strength rapidly after use on exposure to water or moist air. After 18 months of exposure to 95% RH, conventional nitrile-phenolic adhesive loses only a fraction of its initial strength, going from 21 to 18 MPa in tensile shear. On the other hand, one of the best nylon-epoxy adhesives available degraded from about 34 to 6.8 MPa in just two months under the same test conditions. A considerable effort has been made to solve this moisture problem, but nitrile-epoxy or acetal-toughened epoxy film adhesives are still superior in durability. "" ... 

Does not require predrying, inherently free of moisture problems... 

We even have used sugar right from the bag, if everything else was dry, with no noticeable differences in results. However, the moisture problem gets more and more aggravated, of course, as both the scale and the degree of reaction advance. One has reason to be more concerned about preventing invasion of water which would complicate and slow the reaction at D.E.s above 3.5 under the realities of the reaction on a plant scale. 

After the energy crisis in the 1970s the application of thermal insulation materials in buildings increased. As a result, moisture problems in lightweight insulated envelope parts were also experienced and studied in countries with moderate climates. Many of the building researchers in the United States and Western Europe adopted similar conclusions and recommendations as were recommended earlier for cold climates [19-22]. 

While the identification of air leakage as a source of moisture problems is half a century old, the prediction of its effects is more recent. During the past decade the understanding of the moisture performance of building envelopes has increased with the development of powerful computer models. Hens [24] gave an extensive survey of the state-of-the-art of heat, air and... 

A.G. Wilson and G.K. Garden in Proceedings of the RILEM/CIB Symposium on Moisture Problems in Buildings, Helsinki, Finland, 1965, Paper No.2-9. 

Moisture Problems, CMHC Report No.NHA 6010, Canada Mortgage and Housing Corporation, Ottawa, Ontario, Canada, 1987. 

Our company s natural gas dehydration station was located in a picturesque section of the desert just south of El Gringo, Texas. When I arrived there on a Saturday evening to consult on an excessive moisture problem in our gas shipments, I was surprised to find the station deserted, Unlike petroleum refineries, natural gas processing equipment is designed to operate unattended. 

Figure 4-16 shows the theoretical curve for the variation in moisture content with the container pressure. To obtain gas with a low moisture content, the cylinder should be left with approximately 200 psig (1380 kPa) to 300 psig (2070 kPa) residual pressure. The moisture problem can be greatly reduced by special surface treatment of the inside of the container and proper handling. Do not leave the valve open. 

Humidity. During operation, heat is generated, and moisture seldom condenses on the equipment. A moisture problem is most likely to develop during inoperative periods or during storage. If necessary, apply humidity control measures during these periods. 

Reijula, K., 2004. Moisture-problem buildings with molds causing work-related diseases. Adv. AppI Microbiol. 55, 175-189. 

Tsongas G (1992) A field study of indoor moisture problems and damage in new Pacific Northwest homes. In Proceedings, ASHRAE/DOE/ORNL Thermal Performance of Exterior Envelope of Buildings, vol V. Clearwater Beach, FL. 

As with floors, it is important to have acceptable substrates to which to bond the finished wall covering. Many walls are out of plumb and require some type of furring or adjustment in order to be receptive to a plumb finished wall. Other walls may have moisture problems. 

Myhre SH, Labor JD, Aker SC (July 1982) Moisture problems in advanced composite structural repair. 

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