3
xuchaowei:
XLPE與XLPVC按ul標準伸長率測試速度是多少?請各位大俠指教。
XLPVC老化前的伸長率為150%(外被和絕緣),老化后殘率值跟溫度等級,用途有關;
XLPE絕緣老化前伸長率為300%,老化后的殘率跟隨溫度等級,用途的不同而不同;
XLPE外被老化前伸長率為150%,老化后的殘率取決于溫度等級跟,用途.
以上觀點是在查了UL1581,UL444,UL62標準下的結論.一般情況下,不同的UL標準對同一種物料的物理性能要求會有差別,特別是老化條件跟老化后的值是不一樣的.
5
goleye:
3樓的可以說下 伸長率測試速度是多少 嗎?在1581里面有的是沒有具體注明的!
如果找統(tǒng)一的 在哪可以找到啊!要不你和我們直接指導下?
8.5mm/s見UL2556.
The elongation and tensile strength tests shall be conducted simultaneously at ROOM TEMPERATURE.
The specimen shall be conditioned at ROOM TEMPERATURE for at least 30 min prior to testing. Video,
laser, or mechanical extensometers or a scale method shall be used to determine elongation. When other
than a mechanical extensometer is used, two gauge marks, 25 mm (1 in) apart and equidistant from the
center of the specimen, shall be placed on the specimen. These gauge marks shall be at right angles to
the direction of pull in the testing machine and as narrow as possible, to facilitate measurement. The
specimen shall be completely at rest while being marked. The specimen shall be clamped in position, with
25 mm (1 in) gauge marks between the grips so that the section between the gauge marks is straight but
not under tension. The distance between a gauge mark and the adjacent grip shall not exceed 13 mm (0.5
in). The grips shall be separated at a uniform rate until the specimen ruptures. The rate of separation shall
be 8.5 mm/s (20 in/min) unless specified otherwise in the product standard. During the separation of the
jaws, the distance between the gauge marks shall be measured continuously so that the distance at the
instant of rupture can be recorded to within 2 mm (0.1 in). The maximum load before break, W, shall be
recorded to the nearest 0.5 N (0.1 lbf). If the specimen breaks outside of the gauge marks or the grips of
the mechanical extensometer at a value below that specified as the acceptable minimum, the test results
shall be disregarded and the test shall be repeated with another specimen.
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8
goleye:
5樓的大哥 可以給我發(fā)個UL2556的電子檔不!不要上傳,窮人啊!gc03@cntition.com
已經發(fā)給你了.不用客氣.
