How Much Do You Know About Nylon or PA?
Nylon, also called polyamide or PA, is a kind of crystalline material. As a leading manufacturer of polymer composite plastics, we supply qualified nylon pipes and nylon plates. All of these nylon products can be customized as per your demands. Nylon product's advantages and disadvantages are as follows:
PA Processing Requirements: Generally speaking, it is suitable to take the forming conditions of low mold temperature, low material temperature, long time and high injection pressure.
The primary varieties of nylon are PA6 and PA66, which take the dominant position. In the second place are PA11, PA12, PA610,PA612, and PA1010, PA46, PA7, PA9, PA13, etc.
The new nylon products are PA61, PA9T and special nylon MXD6.
There are many different kinds of modified nylons, such as: reinforced nylon, monomer casting nylon, MC nylon, RIM (reaction injection moulding) nylon, aromatic nylon, transparent nylon, highly impact and super-tough nylon, electrically conductive nylon, flame retardant nylon, nylon and other polymer blends and alloys, etc. These modified nylons are manufactured and developed to meet various special requirements, used as different structural materials to replace metal, wood and other traditional materials.
More About Nylon: Nylon is one of the most important engineering plastics, and its production ranks first in the five kinds of general engineering plastics. Nylon is a kind of resilient angular translucent or milk white crystalline resin. As engineering plastic, its molecular weight is usually 1.5-3 million. Nylon has extremely high mechanical strength, high softening point, heat-resistant, low friction coefficient, wear resistance, self-lubricating, shock absorption, silencing, anti-oil, weak acid and general solvent resistant, good insulation, self extinguishing, non-toxic odorless, good weather-ability, poor dyeability. Nylon has good affinity with glass fiber. The hardness and rigidity of nylon66 are the strongest, while the toughness worst. All kinds of nylon are sorted by toughness: PA66, PA66/6, PA6, PA610, PA11, PA12. The combustion of nylon is UL94v-2, and its oxygen index is 24-28. Nylon’s decomposition temperature is 299 DEG C. And when the temperature ranges from 449 DEG C to 499 DEG C, nylon’s spontaneous combustion occurs. Nylon has good melt flow and its wall thickness can be as small as 1mm.
Nylon has wide application in various mechanical and electrical parts nowadays, such as: bearings, gear, pulley pump impeller, blade, high-pressure seal pad, valve seat bushing, oil pipe, oil reservoir, rope, belt wheel, adhesive, battery box, electric coil, cable joint and so on. What’s more, nylon can also be made into packing belt, food film, thin film for cooked food at high temperature, thin film for cool drinks at low temperature, etc. All these applications have considerably large quantity demands.
Nylon can be made flame retardant by halogen, antimony, red phosphorus or melamine, and other halogen-free flame retardant systems. From the quantity perspective, halogen/antimony collaboration system is still the most widely used nylon flame retardant system. In Europe and Asia, some people are trying to find the replacement for halogen flame retardant. However, generally speaking, these alternative systems all have problems of low thermal stability or moisture absorption. Besides, storage is also a problem for red phosphorus as it is combustible. The following are respective advantages and disadvantages of some main flame retardants.
One of the most important flame retardant systems is brominated styrene polymer, which is widely used abroad and has extremely excellent thermal stability. Moreover, it has good liquidity when processing, because it can be mixed and melted with nylon. In addition, the flame-retardant nylon made with halogen has superior electrical properties and good mechanical properties. The limitation o the flame retardant is poor light stability and partially compatible with nylon. In addition, the cost is higher than the ten PBDEs, which is currently widely used. Nowadays, the most widely used flame retardant in China is decabromodiphenyl ether, which is the most economical flame retardant because of its high bromine content and high flame retardancy efficiency. But as it is a kind of filler type of flame retardant, it has great negative influence on physical and mechanical properties and processing fluidity of products. And its thermal stability and light stability are also kind of poor. In recent years, people use ten brominated two phenoxy ethane as new nylon flame retardant. It has the same bromine content and flame retardant efficiency as polybrominated diphenyl ether. It doesn’t contain DPO. Moreover, it has good thermal stability and light stability. However, it also belongs to filler type flame retardant, and has poor compatibility with polymers, therefore, it has poor and flow mechanical properties. Besides, it has higher cost than that of ten brominated diphenyl ethers.
The halogen free flame retardant system widely used for nylon is red phosphorus and melamine salts. Red phosphorus has high flame-retardant efficiency and it can improve the arcing resistance of products. However, it has limited application in nylon because of its storage and color. Generally speaking, it usually used in PA6. As for melamine salts, they have good flame retardant efficiency but poor thermal stability. And it absorbs moisture easily and has poor electrical stability under moisture environment.