PLA has a lot of applications, can be used in extrusion, injection molding, film pulling, spinning and other areas of application, specifically as follows: Extrusion grade resin is the main market application of PLA, mainly used in large supermarkets in the packaging of fresh fruits and vegetables, this type of packaging has become an important member of the European market chain; secondly, used in a number of electronic product packaging to promote safety, energy saving, environmental protection. In these uses PLA high transparency, high gloss, high steel and other advantages embodied in the fullest, has been the leading direction of PLA applications. In addition, extrusion grade resin in horticulture applications are beginning to gain attention, in the slope greening, sandstorm management and other areas have been applied.
However, the extrusion processing of PLA is not an easy task, and is only suitable for processing on some advanced PET extrusion molding machines, and the thickness of the extruded sheet is generally only in the range of 0.2-1.0mm. Processing of water content and processing temperature is particularly sensitive, extrusion processing, the general requirements of its water content to be less than 50PPM, which is the drying system of equipment and temperature control system and put forward new requirements. In the process, if there is no suitable crystallization equipment, the recycling of trimmings is also a major problem, which is precisely the reason why there are a large number of PLA trimmings circulating in the market. In the market application of PLA injection molding, the more widely used is the modified resin. Although pure PLA has a high degree of transparency, high gloss and other advantages, but its hard and brittle, difficult to process and not heat-resistant and other shortcomings affect its application in injection molding. Of course, the chemical and plastics industries have been working to solve these problems. For example, the use of BPM-500 this additive can improve the impact strength of PLA; add a small amount of a vinyl called Biomax Strong **** polymer can improve the toughness of PLA; with another biodegradable resin PHA **** mix can improve some of the properties of PLA; in addition, Japanese scientists have developed a heat-resistant PLA resin with pulp. Through some of the above ways modified PLA products sacrificed transparency, but improved PLA in heat resistance, flexibility, impact resistance and other aspects of the defects, improve its processing ease, so the scope of application has also been expanded. About 70% of Hazen's injection molding grade resin sales are modified PLA.
And overall, the relatively high cost is the biggest reason preventing PLA from being widely used in the injection molding market. While pure resins can be modified by filling to reduce some costs, this measure is of limited use if their performance is guaranteed, and even more costly if PLA's performance deficiencies, such as heat resistance, need to be improved under the premise that it is fully biodegradable. Biaxially oriented film is by far the most successful PLA film, after biaxially oriented and heat-set PLA film heat-resistant temperature can be increased to 90 ℃, just to make up for the PLA is not resistant to high temperatures this defect. Through the adjustment of the bi-directional stretching orientation and molding process, it is also possible to control the heat sealing temperature of BOPLA film in the range of 70 to 160°C. This advantage is not found in ordinary BOPET film. This advantage is common BOPET does not have. In addition, BOPLA film transmittance of 94%, very low haze, surface gloss is also very good, this type of film can be used for flower packaging, envelope transparent window film, candy packaging and so on.
PLA nonwoven fabrics have been used in spunbond nonwoven fabrics, because of the implementation of China's plastic restrictions, this nonwoven fabrics used in the production of shopping bags on the more popular. The blown film, the two areas of the film because of some of the characteristics of the PLA itself defects, the application is still being further explored, some successful applications are modified PLA after use. In order to save petroleum resources while reducing the earth's greenhouse effect, and to further expand the application fields of PLA manufactured from renewable biological resources, many Japanese companies have conducted in-depth research on the application of PLA in the field of electrical and electronic appliances and have achieved excellent results.
NEC Japan notebook computer parts materials
NEC Japan developed a high-performance PLA/KENAF composite materials, which is modified PLA, which improves the impact resistance of PLA, heat resistance, rigidity and flame retardancy. It was applied to "LaVie T" laptop computer parts sold in September 2004, and further promoted in 2005 for use in "LaVie TW, VersaPro" computer parts.
Fujitsu's laptop case materials
Fujitsu adopted a 0.2-quality, pure PLA component for the infrared receiving part of the "FMV-BIBLO NB" series of laptop computers launched in Japan in 2002. In 2005 Fujitsu spring model notebook computer "FMV-BIBLO NB80K" case, all by Japan Fujitsu, Japan Fujitsu Research Institute and Japan's Toray Corporation, three companies **** the same development of PLA / PC alloy, the weight of the case is about 600G, the PLA content of about 50%. The PLA content is around 50%. Compared with the use of petroleum-based resins, the housing alone saves about 1L of usage. In terms of carbon dioxide emissions over the entire product life cycle, thermal recycling of the recycled resin reduces the amount of carbon dioxide emissions by about 15% compared to the existing resin. Fujitsu's latest notebook computer uses PLA resin for almost 93% of the entire casing.
Mobile phone parts and casing materials
NTT DoCoMo and Sony Ericsson Mobile Communications trial-produced a cell phone in April 2005 that uses PLA in the casing. The prototype phone ah 140G of self-measurement of 22G PLA resin. 2005 May, NTT DoCoMo in the market sale of "premini-IIS" cell phone with a button using PLA resin. 2006 Fujitsu, Fujitsu Research Institute and Toray jointly developed a successful impact resistance equivalent to 1.5 times the PLA1.5 times. In 2006, Fujitsu, Fujitsu Research Institute and Toray jointly developed a PLA/PC alloy with impact resistance equivalent to 1.5 times that of PLA, which is used in parts such as cell phone housings.
Japan's Sony DVD player shell materials
Japan's SONY company listed in 2002, "MVP-NS999ES" type DVD player front panel using PLA materials, the company and Mitsubishi Plastics to further develop an inorganic flame retardant PLA materials, which The company and Mitsubishi Plastics further developed an inorganic flame-retardant PLA material with a PLA content of about 60%. This material was used in the front panels of the "DVP-NS955V" and "DVP-NS975V" DVD players that were released in the fall of 2004. The strength of modified PLA is comparable to that of ABS resin. At the same time, by changing the additives and processing conditions, it is possible to use a general injection molding machine, and the molding efficiency is the same as that of ordinary plastics.
Discs
September 2003, Sanyo Mavic Mcdia and Mitsui Chemicals Co. jointly developed a music CD, VCD and CD-ROM discs "MildDisc" using PLA as the base material. The company claims that it is difficult to produce 10 CD disks from one corncob. The company has developed a high-speed and precise transfer CD model technology, and by strictly regulating the mold temperature and improving the ionizing agent, it has produced PLA CD discs with a slow curing speed. The use of biodegradable resins solves the problem of environmental pollution caused by the disposal of existing CD disks. PLA consumes less energy when burned than PC, thereby reducing carbon dioxide emissions. If landfilled, PLA biodegrades rapidly in 2-5 years, while PC remains semi-permanently in the soil.
Fujitsu's LSI Packaging Tape
In February 2005, Fujitsu and Fujitsu Research Institute jointly developed an LS packaging tape for cellular phones using PLA as the raw material. A life cycle evaluation of this product showed an 11% reduction in overall CO2 emissions over the cycle and 18% less energy consumption in the manufacturing process. After improving the strength of PLA and antistatic and dimensional stability improvements, its tear strength and compression strength when the PC preparation of more than twice the material, tensile strength of about 1.5 times, the folding strength of nearly 2 times, impact strength and peel strength also reached the product required performance requirements. Biomedical industry is the earliest application of PLA. Polylactic acid has a high degree of safety to the human body and can be absorbed by the tissue, coupled with its excellent physical and mechanical properties, can also be used in the field of biomedical applications, such as disposable infusion tools, non-removable surgical sutures, drug-relieving packaging agents, artificial bone fracture internal fixation materials, tissue repair materials, artificial skin and so on. High molecular weight polylactic acid has very high mechanical properties, in Europe and the United States and other countries have been used to replace stainless steel, as a new type of orthopedic internal fixation materials, such as bone nails, bone plates and is used in large quantities, its absorption and metabolism by the human body, so that the patient is free from the pain of the second surgery. Its high technical value-added is a promising polymer material for the medical industry.