Extrusion machine: hot spots of functional additives for plastics: flame retardant, weather resistant, conductive, reinforcing, wear resistant, anti-bacterial, anti-hydrolysis
They are plastics that are modified in the resins of general purpose plastics (PE, PP, PVC, PS, ABS)PP/PE/PVC plastic extrusion line and engineering plastics (PA, PC, POM, PBT, PPO) through filling, blending and other methods of processing to make them more superior in performance such as flame retardant, impact resistant and easy to process.
Overcome the defects of ordinary plastics such as poor heat resistance, low strength and toughness, and weak wear resistance, and also give new characteristics such as flame retardant, weather resistant, antibacterial, antistatic, chemical resistant, conductive, wear resistant, and thermally conductive. These superior comprehensive properties of modified plastics make them widely used in home appliances, automobiles, communications, medical, electrical and electronic, rail transportation, precision instruments, home building materials, security, aerospace and other fields.
Plastic modification rate
It refers to the total production of modified plastics as a percentage of the total production of plastics (including modified plastics and unmodified resin), is an important symbol of the level of development of the plastics industry in a country or region.
Currently, China’s industrial enterprises above the scale of modified plastics annual output of more than 20 million tons, modified rate of about 22%, although this is related to China’s large production of basic resins, but compared with the global plastic modification rate of nearly 50%, there is still much room for improvement.
In the process of plastic modification, functional additives are the core elements to achieve resin modification, it can often play the role of four, two, a thousand pounds, point into gold! Currently the hottest and most commonly used functional additives for plastics are flame retardants, weathering agents, conductive agents, enhancers, wear agents, antibacterial agents, anti-hydrolysis agents and so on.
It is the second largest amount of plastic additives, in addition to the conventional flame retardant requirements, for the application of different scenarios and resin, but also for other performance requirements, such as ultra-high flame retardant, halogen-free, thin-walled, high CTI, high heat resistance, low temperature resistance, high impact resistance, resistance to precipitation, high transparency, etc. ……
They mainly include antioxidants and light stabilisers. Antioxidants can be divided into primary and secondary antioxidants; light stabilizers can be mechanically divided into: free radical capture agents (mainly hindered amine light stabilizers HALS), ultraviolet absorbers (UVA), light shielding agents. However, they also have precautions in actual use, such as some antioxidants can not withstand high temperatures, hindered amine light stabilizers HALS will cause PC degradation ……
They are important additives to achieve antistatic or conductive plastics, mainly carbon materials, metal fibres, conductive polymers, etc. Currently the most commonly used is the addition of conductive carbon black, graphene, carbon nanotubes and other carbon materials. Usually the surface resistivity of plastics is 10^12-10^16 ohm/sq, while antistatic plastics require in the range of 10^6-10^9, conductive plastics require a surface resistivity of 10^5 or less, which requires a large amount of conductive agents added and very good dispersion technology …..、
However, additives are often encountered in the process of practical application of a variety of problems, one is that no matter how much is added, its properties can not reach the target value, such as PMMA thin-walled transparent flame retardant is the industry has been a problem; second is that although the additives to enhance the characteristics of a certain aspect, but caused a significant decline in other properties, the loss of practical application value, such as conventional conductive carbon black will make the material impact and other properties significantly reduced. In addition, how to achieve auxiliary synergy and cost reduction is also an important topic of concern.