Application and promotion measures of green packaging materials (in)

2. Polylactic acid packaging materials

The United States CollegeFarm brand candy uses bio-degradable resin PLA-Nature-Works natural material packaging film. This film has the same appearance and performance as a traditional candy wrap (glassine or biaxially stretched polypropylene film) and has only crystalline transparency, excellent kink retention, printability, and strength, and has a higher barrier property and is better Keep the sweet smell. At present, the company has a set of PLANatureWorks film in the high-speed kink packaging equipment, with a production capacity of 1,300 pieces/min. The Faerch Plastics Company of Denmark invented the use of polylactic acid as a packaging material, and the new product is suitable for packaging low-temperature fresh foods, including various kinds of noodles, pasta and salads. Faerch's current packaging products include various trays and bottles. The original processing resins that can be heat sealed are PS, PP, and PET. Adopting this new product will put the company and its users at the front end of the packaging industry. A German company successfully developed a green food cup with rapid natural decomposition using polylactic acid as a raw material, which has opened up a practical new way to solve the problem of degradation of disposable plastic packaging. The degradable material developed by the company belongs to the polyester polymer. The lactic acid can be extracted from sugar liquid fermented from sugar beet and undergo ring-opening polymerization to form polylactic acid.

Polylactic acid has become a worldwide research and development hotspot. It is a biodegradable polymer material that is polymerized by many lactic acid molecules and can be completely decomposed into water and carbon dioxide without any harm to the environment. In November 2004, the degradable polylactic acid material developed by Shanghai Xinli Industrial Microbial Technology Co., Ltd. and the School of Materials Science and Engineering of Tongji University has been successfully developed and has been listed as a major industrialization project in Shanghai City for Science and Education. The production of polylactic acid is based on lactic acid. Most of the traditional lactic acid fermentation uses starch-based raw materials. At present, the United States, France, Japan and other countries have used corn, sugarcane, sugar beet, potatoes and other agricultural and sideline products as raw materials to produce lactic acid, thereby producing polylactic acid. . The process used by US LLC to make biodegradable plastics from corn is as follows: First, the corn is ground into powder, the starch is separated, and the original glucose is extracted from the starch. Then anaerobic fermentation of Lactobacillus, the fermentation process with liquid caustic soda to generate lactic acid, fermentation broth after purification, using electrodialysis process, made up to 99.5% purity of L-lactic acid. The extracted lactic acid is then made into the final polymer-polylactic acid. The annual global output of 600 million tons of corn makes it the raw material of choice for biodegradable plastics.

3, natural biological packaging materials

Natural bio-packaging materials such as wood, bamboo woven materials, sawdust, hemp cotton, wicker, reeds, and crop stalks, rice straw, wheat straw, etc., are all easily decomposed in the natural environment; they do not pollute the dusty environment, and the resources are renewable and the cost is low. . Bamboo packaging materials can be reduced, such as hollow-shaped bamboo baskets. Reuse and recycle (Reuse), bamboo packaging products can be used twice, waste can be burned and utilized, and compost can be used as fertilizer. Waste can degrade naturally. From bamboo cutting, bamboo processing, and the manufacture and use of bamboo packaging materials, the entire process of recycling or degrading the waste will not cause any harm to the human body and the environment. It conforms to the 3RID principles of green packaging and the requirements of the Life Cycle Analysis (LCA) Law. Bamboo-engraved plywood is an excellent green packaging material because of its characteristics of high strength, low price, light weight, easy recycling of waste, and no environmental pollution. Bamboo plywood is based on bamboo fiber structure perpendicular to each other, according to warp and weft woven into a seat after drying, gluing, forming blanks, hot pressed together, made of bamboo plastic sheet has good physical properties and chemical properties, product format Large, vertical and horizontal directions of small physical and mechanical properties, high strength, good moisture resistance.

4, food waste green packaging

According to the New Scientist magazine, biochemists at the Hawaii Institute of Natural Energy have made food waste a biodegradable polymer that researchers have humorously called "perfect plastic." This type of plastic, which can be degraded in a short time, is widely used not only for making packages such as bottles and bags but also for making capsules for medicines. According to the “New Scientist” quoted biochemist of the Institute of Natural Energy as saying, the raw material of the new biodegradable plastic is a mixture of water and various food wastes. It can produce 22~25kg biodegradable plastic per 100kg mixture, which not only greatly reduces the production cost. .

(to be continued)