流滴棚膜表面结构对薄膜流滴性能的影响

Effect of Surface Structure of the Dripping Agricultural Film on the Performance of the Dripping Film

采用白光干涉轮廓仪对三种棚膜样品,乙烯-醋酸乙烯共聚物(EVA)膜、国产聚烯烃(PO)膜、进口PO膜的表面结构进行对比,并对样品表面形貌、球晶尺寸、热性能、雾度与透过率进行分析。结果表明:国产EVA膜和PO膜主要基于表面改性实现流滴性,薄膜球晶尺寸较小且表面相对平整,因此表面雾度较小,整体雾度较低。同时,由于基材结晶度偏高,最终国产棚膜光透过率低于进口PO膜。而日本进口PO膜具有更密集、突起更明显的表面结构,与荷叶的起伏结构相类似,从而改善流滴性能。相比表面改性,结构的改善能够使薄膜流滴性能更持久。然而,由于表面起伏较大,对光的散射更明显,因此进口PO膜表面雾度更高。但进口PO膜基材的结晶度较低,使薄膜的光透过率更高。

The surface structures of three agricultural film samples, ethylene-vinyl acetate copolymer(EVA) film,domestic polyolefin(PO) film, and imported PO film were compared by using a white light interference profiler. The surface morphology, spherulite size, thermal properties, haze and transmittance of samples were also analyzed. The results show that domestic EVA film and PO film are mainly based on surface modification to achieve dripping properties, the film spherulites are small in size and the surface is relatively flat, so the surface haze is small and the overall haze is low.At the same time, due to the high crystallinity of the substrate, the final light transmittance of the domestic greenhouse film is lower than that of the imported PO film. Moreover, the imported PO film from Japan has a denser surface structure with more obvious protrusions, which is similar to the undulating structure of a lotus leaf, to improve the dripping properties in the structure. Compared with the surface modification, the structural improvement can make the film droplet performance more durable. However, due to the larger surface undulations and the more obvious light scattering, the imported PO film has a higher surface haze, and the overall haze is higher than that of the domestic agriculture film.However, due to the low crystallinity of imported PO film substrate, the light transmittance of imported PO film is higher.