What are the factors that affect the strength of polypropylene high-strength yarn?
1. The influence of melt index
The melt index of the raw material represents the molecular weight of the raw material to a certain extent. Under the same process conditions, the amount of fiber increases. When the molecular entanglement is large, the strength of the drawn fiber increases with the increase of the molecular weight. When the molecular weight is low, the slippage between the molecular chains is easy to occur, which is manifested in the decrease of the fiber strength. In the spinning process of polypropylene high-strength yarn, several different melt index raw materials are used.
During the trial spinning process, it was found that under the same process conditions, the melt index of the raw material was different, and the strength of the finished yarn was different and showed a certain regularity.
Under the same spinning temperature, the same stretching ratio and the same process parameters, the lower the melt index of polypropylene chips, the higher the strength of polypropylene high-strength yarn.
2. The influence of stretch ratio
The stretching process of the primary fiber is to destroy the original structure of the primary fiber and generate a new ordered structure. Under the action of tensile stress and thermal effect, the mobility of the macromolecular segment increases, and various structural units slide on the fiber. Axial orientation aggregates, rearranges and adds new bonding points, so that more molecular chains of the fiber are in a particularly good stress-bearing state, and the regularity of the three-dimensional structure (that is, crystallization) is generated, and the fiber density increases with the increase of the stretching ratio. .
With the increase of the stretching ratio, the strength of the fiber increases, and the stretching ratio contributes more to the strength of the fiber.
Jiangyin Jinmeng Textile Co., Ltd. is a professional manufacturer of high-strength polypropylene industrial yarns, engineering fibers, high-strength polypropylene yarns, woven geotextiles and polypropylene luminous yarns. Industrial zone, the traffic is very convenient.
polypropylene high-strength yarn has the advantages of environmental protection, non-toxicity, acid resistance, alkali resistance, light specific gravity, low thermal shrinkage, low thermal conductivity, low static electricity accumulation, and almost no moisture absorption. The product has great potential in industrial yarn and can be widely used. It is a novel textile material that partially replaces nylon and polyester in industrial slings, safety belts, conveyor belts, woven geotextiles, filter cloths, canvas, thread making, ropes, cables and other industries.