Aging oven-accelerated

There is a striking difference, however, in the action of various alkaline materials. Neutralizing acid paper with sodium carbonate, as is shown later, prolongs its life. Alkalizing paper to pH 10 with sodium carbonate causes paper to darken, to oxidize, and to degrade. The effects are most pronounced in humid-oven accelerated aging, less so in the dry-oven aging. 

While Barrow solved the main problem, there are other modes of degradation which must be considered. As an organic material, cellulose and paper can be easily oxidized. Very small amounts of the transition metals, compounds of iron, copper, and cobalt, under humid conditions can accelerate oxidation and embrittlement of paper. This type of degradation, as is shown later, does not show up in the dry-oven accelerated aging which Barrow used. Thus his alkaline papers, if they contained the oxidation catalysts, may not always have been permanent. 

A. Linear rates of change must be obtained at all temperatures used in the study by a consistent mathematical treatment of the data. This can be verified by measurements at multiple withdrawal times from accelerated-aging ovens. 

Relative Humidity 90°C Humid Oven Accelerated Aging ... 

Oven aging is the test generally used and preferred by application engineers for thermal oxidative aging. Its accelerating effect is achieved by increasing the temperature to a point just below the melt range of the plastic [86]. 

An acceleration factor of 31 means that reproducing the age of an average six-year-old tire in Phoenix would require -10 weeks in the oven at 70°C using air as the inflation media. The time can be shortened to about 8.5 weeks using 65°C and 50/50 N2/O2 inflation or seven weeks using 70°C and 50/50 N2/O2. Other conditions can be estimated from the different shift factors. 

An electrically heated oven supplied with circulating kit, originally used in accelerated ageing tests. 

A hot air chamber used for heating or drying raw rubber, for vulcanising rubber products by the dry heat method, or for carrying out accelerated ageing by the air oven method. On the continent of Europe, the term oven is sometimes used in the sense of autoclave. 

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