彩钢板耐干热实验

彩涂板经规定温度和规定时间烘烤老化后，评定其涂层失光、变色、起泡、开裂、T 弯性能的变化和涂层抗脱落性能的变化等。彩涂板或预先进行T弯处理的彩涂板经烘烤老化后，评定其T弯处的涂层抗脱落性能和开裂变化的过程叫耐干热试验。耐干热试验对不同的试验方式有不同的技术要求:

(1)彩涂板平板试样的加热试验。试验前先测定试样的光泽和色度坐标值。然后将试样放人烘烤炉中加热到规定时间，取出并放16h后，按CB/T1766-1995 标准评定其失光和变色等级，取平行试样的最差值为试验结果。
(2)经T弯处理后试样的加热试验。将试样制备成规定T弯值的试验样。像平板试样一样，将试样放入烘烤炉中，试验后取出也按 GB/T1766-1995 标准评定试样 T 弯处的失光和变色等级，取平行试样的最差值为试验结果。

(3)试样经加热老化后的T弯试验。准备不少于3件试样，留下一件作试验后的对照样用。其余的与平板试样一样放炉中试验，试验后取出与对照样一起作T弯试验，然后评定经加热老化的试样T弯值的变化，取平行试样的最差值为试验结果。

After baking and aging at specified temperature and time, the changes of gloss loss, discoloration, blistering, cracking, t-bending performance and anti peeling performance of the coating were evaluated. The process of evaluating the anti peeling performance and cracking change of the coating at the T-bend is called dry heat resistance test. The dry heat resistance test has different technical requirements for different test methods

(1) Heating test of plate sample. Before the test, the coordinate values of luster and chromaticity of the sample were measured. Then put the sample into the baking oven and heat it to the specified time, take it out and put it for 16h, and evaluate the light loss and color change grade according to CB / t1766-1995 standard, and take the maximum difference of parallel sample as the test result.

(2) Heating test of samples after T-bend treatment. The samples are prepared into test samples with specified T-bend value. Like the flat sample, the sample is put into the baking oven and taken out after the test. The grade of loss of light and discoloration at the T-bend of the sample is also evaluated according to the GB / t1766-1995 standard, and the worst value of the parallel sample is taken as the test result.

(3) T-bend test of samples after heating aging. Prepare no less than 3 samples, and leave one for the control sample after the test. The rest of the samples are put into the furnace for test just like the flat sample. After the test, they are taken out and tested together with the control sample for T-bend test. Then the change of T-bend value of the sample after heating aging is evaluated, and the maximum difference of the parallel sample is taken as the test result.