According to the national plan, during the Eleventh Five-Year Plan period, China's grain output will break through a series of high and new technologies, such as increasing grain production, by jointly launching the "High-yielding Science and Technology Project of Grain". From 2007 to 2010, China's comprehensive grain production capacity will reach 540 million tons (currently 500 million tons). According to the relevant data, due to the vast territory, unbalanced agricultural development and different varieties of grain produced in different parts of China, the grain transports frequently, with an average annual national grain circulation of more than 150 million tons, accounting for 1/3 of the total grain output, of which flour accounts for 1/3, or more than 500 million tons. For a long time, the loss of grain due to improper packaging in the process of storage, transportation and sale in China reached 18 million tons, with the loss rate being 12%-14.8% of the total output. The above situation shows that improving grain transport packaging is an important issue facing the current grain production and marketing departments.
    For a long time, traditional open cotton bags have been used in flour packaging in China, which not only need to use a large number of high-quality cotton, which is expensive, but also cause confusion and serious pollution in the use of trademarks because of the exchange between manufacturers in the repeated use of bags. In recent years, the use of plastic bags for flour packaging has been found in the market. Although this plastic woven bag has high strength and can reduce damage, it has many disadvantages, such as leakage, soil entry, insect entry and water entry, which can easily lead to flour worms, mildew, deterioration and short shelf life. At the same time, the harmful gas released by plastics pollutes grain, affects human health, and is not easy to recycle, and easily causes environmental pollution. It can be seen that the current open plastic woven packaging has brought many disadvantages to the measurement, preservation and consumption of flour, so flour packaging must be improved.
    In order to meet the functional characteristics of grain packaging and environmental protection requirements, the industry has targeted the reform of flour packaging on cardboard-based multi-layer paper bags and new reinforced paper bags. At present, the flour circulating in Shanghai and Shenzhen and the flour exported have already been packaged in paper bags. Paper bags have the outstanding advantages of non-toxic, tasteless, non-polluting, and meet the national food hygiene standards. Paper bags have better sealing ability than cloth bags, which can prevent flour leakage and dust invasion. Under the same conditions, the shelf life of grain packaged in paper bags can be extended by 2-3 months. There is no need to worry about the strength of paper bags made of stretchable paper bags or kraft paper. Some people have done experiments. A paper bag filled with 25 kilograms of flour (consisting of four layers of stretching paper) falls 15 times from 1.5 meters high without breakage. This multi-layer paper bag with paste bottom is generally made of four layers of stretching paper. Its structure is scientific and reasonable, and consumers can rest assured that it can be used. In addition, Shanghai Rongshen Paper Co., Ltd. recently put into production a better high strength pulp composite green stiffener paper. Its uniqueness lies in the one-time completion of papermaking and compounding, that is, the upper and lower pulps and mesh cloth are not bonded by glue, which not only does not destroy the pulp's permeability function, but also strengthens the hydrogen bond bonding force of the fibers themselves, enhances the paper's burst resistance index, has moisture-proof characteristics, and ensures the quality of the packaged products. The point is incomparable with traditional wrapping paper. Paper has high strength due to the close bonding of paper substrates. This paper maintains the properties of natural fibers, and its good air permeability makes it suitable for packaging with high air permeability requirements such as flour. The product can be used for recycling and reuse, and belongs to two-way green environmental protection products. Experts believe that, in view of the unique performance advantages of reinforced paper, in the future improvement of powder and even the whole grain packaging, reinforced paper bags will become the first choice of enterprises and the leading role of the market.