农膜作为温室的主要覆盖材料之一,对建设高产、优质、高效的农业,起着尤为重要的作用。分辨农膜质量好坏时应注意以下几点。1.高透光农膜透明度好,而一般农膜颜色发白、发乌。2.优质农膜耐候性好,在寒冷的冬天,仍然保持很好的柔软性,而一般农膜则会变硬,稍一折就会有白痕。3.耐久性农膜拉力强度高,如剪一小条,拉伸时可伸长6~7倍,仍不 As one of the main cover materials for greenhouse, plastic sheeting plays an especially important role in building high-yielding, high-quality and efficient agriculture. To distinguish the quality of agricultural plastic film should pay attention to the following points. 1. High transmittance of plastic sheeting is good, while the general plastic sheeting color is white, black hair. 2. Good quality plastic sheet weathering is good, in the cold winter, still maintain good softness, while the general plastic sheeting will be harder, a slight discount will have white marks. 3. Durable plastic sheeting high tensile strength, such as cutting a small stretch can be stretched 6 to 7 times, still not