PA6
PA6 wire rod is a semi crystalline thermoplastic polymer, which is one of the most widely used nylon in the world. The melting point of PA6 is 220 ℃, which can be processed by a variety of traditional processes, and because of its good performance and cost ratio, it is widely used in various fields. In recent years, it has gradually become popular in the field of 3D printing. Compared with standard plastics such as PLA or ABS, PA6 is a more difficult material for 3D printing. Its working temperature range is 250-270 ° C, so it is necessary to ensure a suitable working environment so that it will not shrink.
PA6 is formed by ring opening polymerization, which is one of the synthetic routes of many polymers. This makes it a special case of comparison between condensation (the whole monomer molecule becomes part of the polymer) and addition (the monomer molecule loses part when it becomes part of the polymer). When analyzing the environmental impact of polyamide 6 and developing towards more sustainable materials, two important aspects must be considered. First, the production process used to obtain the material, followed by the raw materials involved in the conversion process; Both will determine the carbon footprint of this polyamide.
PA11 and PA12
In chemistry, PA11 and PA12 are very similar, they only differ by one carbon atom in the main chain. However, this atom makes a huge difference in the way the polymer is organized. PA11 is a semi crystalline bio based polymer, that is, it is produced from renewable raw materials from plant derivatives, mainly castor oil. It is mainly used where good chemical resistance, flexibility, low permeability and dimensional stability are required.
PA12 is a fine synthetic powder, which is generally extracted from petroleum. Its basic characteristics are given by the chemical structure of polyamide itself and the additives or fibers added to the ingredients. Its most important characteristics are high resistance to chemical agents, environmental conditions and impact, low water absorption, high processability, and finally good wear resistance and sliding resistance. In its main applications, this plastic is used in advanced industries, such as automobile or aviation.
In order to realize environmental protection, fisap S3 company developed biological nylon PA11 HP based on biological materials. "Our PA11 HP is produced based on 100% renewable biomass resources. We extract Castor seeds from castor plants and then turn them into oil. Then, the oil is converted into monomer (11 aminoundecanoic acid) and finally polymerized into PA11 HP. It can be used as a substitute for PA11 and PA12." Nuno Neves, design director, said.
At first glance, biological nylon is more environmentally friendly than petroleum based nylon, but Nevis said: "in order to determine whether biological nylon is more beneficial to the environment than traditional nylon, we must consider several factors in the whole life cycle of the two kinds of nylon, including production, greenhouse gas emissions and recycling opportunities. After strict testing, we can draw a conclusion, rather than casually carrying the banner of environmental protection."
Like other synthetic plastics, nylon is not a material that can be degraded by the environment. Therefore, the best way to deal with plastic is to recycle and convert it. However, at present, many cities do not have equipment to deal with bioplastics, such as PA11, which makes it difficult to recycle bioplastics at present. Considering that bioplastics can degrade, most bioplastics are finally landfilled and produce methane. This greenhouse gas is 23 times stronger than carbon dioxide, which will cause greater ozone depletion than traditional plastics.
In the field of 3D printing, SLS 3D printing has a key advantage. There is no need for additional support when printing. The powder around the parts can play a supporting role, and up to 70% of the unsintered powder can be reused for future printing. It saves more materials than FDM process.
It is obvious that all materials used in manufacturing will have some impact on the environment, whether through the emission of gases or the recyclability of components. In the long run, bio based nylon will be more environmentally friendly than petroleum based nylon.