Research On The Barrier Development Of Vacuum Insulation Panels Using Thermoplastic Polyurethane Material With The Features Of Good Wear Resistance And Puncture Resistance

Vacuum Insulation Panel(VIP) is famous of its super thermal insulation ability while the mechanical weakness of its barrier envelope, like the lack of wear resistance and puncture resistance, has limited the extensive application recently. This thesis tried to prepare Thermoplastic Polyurethanes(TPU) coating on the surface of Aluminum Foil(AF) which was one of the present typical barrier envelopes of VIP using dry compound technology in order to develop the wear and puncture resistance of VIP envelopes. A three-factors and three-levels orthogonal experiment on the combination technology of TPU coating was designed according to the three major control conditions, namely roll temperature, roll pressure and TPU coating thickness before the barrier envelopes and VIP samples coated with TPU were made. Results of some relevant performance tests and comparisons proved that the wear resistance and puncture resistance of those barrier envelopes coated with TPU improved significantly compared with the AF. Then the range-method of orthogonal experiment was utilized to analyze how wear resistance, puncture resistance and thermal insulation performance of those corresponding samples changed with technological parameters. Additionally, three kinds of aging tests were carried out on TPU VIP and VIP samples, seeing their macroscopic or microscopic differences, variation trends of mechanical properties and changes of thermal conductivities, from which it turned out that TPU VIP samples had better properties of high and low temperature bearing, anti-cracking at low temperature and rub withstanding than the latter ones. Simultaneously, the aging mechanism of VIP was stated and its life prediction model was established using which the service life of TPU VIP was evaluated to be around 120 years, which is far superior to the present VIP having a service life limit of up to 60 years.Moreover, target optimization by MATLAB neural network revealed that the minimum quality loss of TPU coatings was 897.639μg/cm2 with the corresponding roll temperature being 130℃, roll pressure being 520 k Pa and TPU coating thickness being 84μm; the maximum puncture strength of TPU coating was 12.62 MPa correlated to the roll temperature being 125 ℃, roll pressure being 540 k Pa and TPU coating thickness being 163μm; while the minimum thermal conductivity of TPU VIP was 1.91 m W/(m·K) matching the roll temperature to be 135℃, roll pressure to be 400 k Pa and TPU coating thickness to be 42μm. On this basis, a balance of wear resistance, puncture resistance and thermal insulation performance of those samples was reached with the help of multipurpose optimal method. That is to say when the roll temperature, roll pressure and TPU coating thickness was 130℃, 473 k Pa and 67μm respectively, the integrated performance of samples was the best with the minimum quality loss being 963.259μg/cm2, the maximum puncture strength of TPU coating being 12.05 MPa and the minimum thermal conductivity of TPU VIP being 1.92 m W/(m·K) correspondingly.