Outdoor weather testing

Figure 11.7. Outdoor weather testing, Phoenix, AZ 75-g.m sample thickness, 1% carbon black loading in LLDPE.

However, outdoor weathering tests are not quite reproducible due to the instability of the climate. Moreover, they are invariably slow, longer and longer exposure periods being required for the evaluation of new polymers with improved stability. This gradual increase in exposure time and a tendency towards more standardized methods has led industries to develop more powerful light sources and artificial weathering devices. 

Figure 9.5 Compressive strength of Vs in. thick glass fabric laminated flat RPs exposed to outdoor weathering tested at 23C (73F)...

Other authors have been less content, commenting in one paper [7] that This amount of variability [between machines of the same type] makes the use of specifications that require a certain performance level after a specified exposure time highly questionable . The same authors have also reviewed variations that can occur in superficially identical outdoor weathering tests [8]. 

The installation of a panel onto a sloping roof approximates to standard outdoor weathering test conditions, which are severe. The sheeting may... 

Blekkenhorst et al. (1991) have developed a 10-week cyclic test that has good accord with practice but some anomalies. Goodwin et al. of British Steel (1991) have, however, concentrated on developments in outdoor weathering tests in view of the limitations of cyclic tests. 

Bijl P, HeikJdla A, Syrjalh S, Aarva A, Poikonen A (2011) Modeling of sample surface temperature in an outdoor weathering test. Polym Test 30 485-492... 

This chapter describes the development of an outdoor certilication test program and subsequent efforts to create an accelerated weathering test method that could be used to predict the results of the outdoor protocol with a high degree of accuracy. Outdoor weathering tests were conducted in Florida, Arizona, and the northern temperate locations to obtain baseline data for comparison. This part of the research led to the development and subsequent publication of ASTM D6864. 

Figure 5.77 Outdoor weathering tests aooording to DIN 53386 (Ofringen, Switzerland, 45° southward) with PVC-P compression sheets (with 2 parts each ofBa/Cd and 0.43 parts of ester wax) influence of filler content at constant DOP or of DOP content at given constant filler bad, respectively, on ultimate tensile strength and elongation at break of PVC-P (WO parts each) [683]...

Sites in southern Florida (with high solar radiation coupled with high humidity, i.e. a tropical climate) and the Sonora Desert in Arizona (with high solar radiation coupled with low humidity, i.e. a desert climate) were used as sites for outdoor weathering tests. The present direct natural exposure in Miami (Florida) is regarded as real time exposure, against which the results obtained with various accelerated weathering devices may be compared. 

Table 10.29 ASTM standards for the outdoor weathering testing of polymers and laboratory testing devices...

The standardization of outdoor weathering testing of polymers, plastics and paints can be accomplished by using established standards distributed by the following organizations ... 

Stability is Increased during proccsssing and in the final product where the useful life is greatly extended. Outdoor weathering tests Witco conducted in Arizona show that a Drapex epoxy plasticizer can triple or guadruple the life of a flexible vinyl compound. 

Since one quarter of all polymers end up in outdoor applications, outdoor weathering tests have become very popular (6). 

Searle, N.D. Activation spectra techniques and applications to stabilization and stability testing of materials. In Ketola, W.D., Evans, J.D. (eds.) Durabihty 2000 Acceltaated and Outdoor Weathering Testing, p. 41. ASTM, West Conshohocken, PA (2000)... 

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