Nylon line is the most traditional fishing line, which is generally made of resin material and processed and drawn. After molding, other processes are added to the surface of the finished product, such as coloring, glazing and other processes.
Analysis of properties and structural characteristics of nylon thread
1. What factors affect the strength of nylon fishing line and why the strength is higher
●The influence of molecular weight. Nylon, also known as nylon, is a general term for polyamide materials. It is obtained by the polymerization of monomeric substances containing an amide group - cONH - by ring-opening{. The macromolecules of this polymer are assembled in chains, and the monomers before polymerization become the chain links of the chain macromolecules. Due to the limitation of the processing technology, the length of the polymer macromolecular chains cannot be equal, so the molecular weights are not equal. Rather, it is distributed within a certain range. Under certain conditions, the strength of nylon yarn will increase with the increase of the molecular weight of the macromolecules, but the increase rate of the strength is not obvious when it increases to a certain level. The molecular weight distribution range of the polymer also affects the strength of the fishing line. The nylon line with a wide distribution range has low average strength, high elongation, poor fatigue resistance, and large uneven strength. Therefore, the molecular weight distribution of the material used to make the fishing line The narrower the better,
● Influence of hydrogen bonding. There are many hydrogen bonds between the macromolecules of nylon materials, so nylon is a kind of synthetic material with higher strength, and nylon itself is divided into many kinds. Different brocade materials have different numbers of hydrogen bonds in their contents, and the strengths are quite different. The materials used to make fishing lines are mostly varieties with more hydrogen bonds between macromolecules.
●Influence of binding molecules in the amorphous region in the supramolecular structure. According to the internal supramolecular structure of the fishing line. It can be divided into crystalline region structure and amorphous region structure. In the crystal structure, due to the strong hydrogen bonds, the crystallinity and crystal size have little effect on the strength of the fishing line, and the breaking of the fishing line mainly occurs in the weakest link inside the fishing line. That is, the breakage of the bound molecules in the amorphous region (ie, the amorphous region). Therefore, the number of binding molecules in the amorphous area directly affects the strength of the fishing line.
●The influence of the degree of orientation on the strength of the fishing line. The degree of orientation refers to the degree of parallelism between the macromolecules of the fishing line and the axis of the fishing line, and is an important parameter reflecting the supramolecular structure of the fishing line. It is one of the important factors that determine the physical and mechanical properties of the fishing line.
Generally speaking, the higher the degree of orientation, the higher the breaking strength of the wire and the lower the elongation; on the contrary, the lower the degree of orientation, the lower the breaking strength of the wire and the higher the elongation. One of the reasons for the three situations of high strength and low elongation, medium strength and medium elongation, and low strength and high elongation.
2. Why is nylon thread easy to age?
●The C—N bond in the macromolecular amide group inside the fishing line and the C—C bond in the macromolecular main chain are easily broken after being heated, which reduces the degree of polymerization of the macromolecular and causes the strength to decrease.
●Amino groups and carboxyl groups at both ends of macromolecules are sensitive to light, heat and oxygen, especially amino groups, whose number decreases during oxidative thermal cracking, resulting in a decrease in strength.
●The amide group on the macromolecular chain is prone to acid hydrolysis, which leads to the scission of the macromolecular chain and the decrease of the degree of polymerization. Therefore, nylon is not resistant to acid, especially inorganic acid.
3. Does nylon fishing line absorb water?
The amino groups and carboxyl groups at both ends of the Oita stem in nylon are relatively hydrophilic, so nylon has high water absorption, and its highest water absorption rate can reach 3.5-4.5%. In order to overcome this shortcoming of nylon fishing line and at the same time increase the wear resistance of the fishing line, a coated line appeared a few years ago. The so-called ceramic wire.
4. Why only high strength and low extension are suitable for fishing line
The elasticity of the line is very useful in fishing, it can help the rod to break down the impact of the fish, so that the line is not easy to break. People often think that the elongation of the fishing line is not good. This is because the high elongation rate is usually accompanied by the low strength of the fishing line, so only the nylon yarn with high strength and low elongation is suitable for the fishing line.
5. Why nylon has good elasticity and wear resistance
The nylon macromolecular chain is composed of alkane chains (-cH-) except for the amide group. The c-c single bond has a small internal rotation resistance, so the macromolecular flexibility is better, which provides local mobility. This slip is restrained by the macromolecular hydrogen bond of the amide group. Therefore, nylon has better resilience. The flexibility of nylon macromolecules is good, so the initial modulus (Note) is low. Good resilience and low initial modulus are necessary conditions for synthetic yarns to be wear-resistant. Therefore, the abrasion resistance of nylon is the best among synthetic yarns. The elasticity of the fishing line has a certain limit, which exceeds the limit. When the hydrogen bonds between molecules are broken, they cannot be recovered or restored. It should be replaced in time.
Note: Initial modulus: It can be understood as the ease of elongation of the fishing line under tension. Nylon has the lowest initial feel and is easily stretched.
6. Advantages and disadvantages
Features: colorless and transparent, strong pulling force, good elasticity, fast water cutting, high fishing sensitivity. Durable, durable, soft, not easy to be hard and brittle in winter, and has better verticality, so nylon thread occupies a dominant position in the market.
Advantages: low price and many specifications, better ductility and elasticity, widely used in traditional fishing methods.
Disadvantages: draft, easy to age.