关键词: 黄麻落麻, 粘胶, 水性聚氨酯, 非织造, 包装材料

Abstract: Plastic, with its light weight, high strength and corrosion resistance, is widely used in aerospace, military, agriculture, industry and daily life. At present, most plastic bags commonly used in the market are made of polyethylene, and their wastes are difficult to degrade and pollute the environment, which will affect human health. Therefore, it is an important research direction to explore packaging materials with simple preparation process, low production cost and biodegradability to replace plastic bags.
This study mainly explored the preparation technology and performance test of packaging materials. Biodegradable jute noil fiber and viscose were mixed and carded into a net. After needling, water-based polyurethane powder was evenly spread on the mixed fiber net of needled jute and viscose, and then hot-pressed to prepare jute/viscose/water-based polyurethane packaging materials, and the performance test and process optimization were carried out.
Firstly, the effects of different mixing ratios of raw materials and gram weight on the mechanical properties of packaging materials were explored. The results show that the breaking strength of the material is the highest when the weight is similar and the ratio of jute/viscose/waterborne polyurethane is 30:50:20. Under the same gram weight, the influence of the change of the ratio of viscose to waterborne polyurethane on the tensile properties of the samples with a certain jute fiber content was compared. The results show that the breaking strength of the material is the highest when the ratio of jute/viscose/waterborne polyurethane is 40:35:25. With the increase of the proportion of waterborne polyurethane, the breaking strength of the samples increases gradually. It shows that waterborne polyurethane can improve the tensile properties of materials in a certain range.
Secondly, the influence of hot pressing process parameters on the properties of jute/viscose/waterborne polyurethane packaging materials was studied. The results show that the strength of packaging materials first increases and then decreases with the increase of hot pressing temperature, and the breaking strength of materials is the highest when the hot pressing temperature is 160℃. The breaking strength of the material increases with the increase of hot pressing time, and the breaking strength is the highest when the hot pressing time is 30℃. With the gradual increase of pressure, the breaking strength of the material increases gradually, and the breaking strength is the highest when the pressure of the material is 5 MPa.
Finally, the orthogonal test method was used to explore the optimal process scheme of hot pressing process parameters. The results show that under the conditions of weight of 105 g/m2 and raw material mixing ratio of 40:40:20 of jute, viscose and waterborne polyurethane, the comprehensive optimal hot pressing process parameters of nonwoven packaging materials are as follows: a hot pressing temperature of 160℃, a hot pressing time of 20 s and a pressure of 5 MPa. The mechanical properties of nonwoven packaging materials prepared under the above process parameters are as follows: the longitudinal and transverse breaking strength are 126.0 and 82.6 N, respectively, which can meet the requirements of mechanical properties of packaging bags.
In the future, degradable packaging materials will seek more long-term development in the fields of production technology and technical intelligence. The research results can provide reference for the development and utilization of degradable packaging materials.

Key words: jute noil, viscose, waterborne polyurethane, nonwoven, wrapper