1.Water
Natural fibers absorb moisture, increasing diameter and length. Natural fiber ropes become hard and heavy ,hard to use. Long time in natural waters, ropes will decay, loss of breaking strength and abrasion resistance ,so they rapidly can’t use. Decayed natural fiber ropes have a typical sourness or mustiness, fibers become brittle.synthetic ropes are not afraid of erosion by water, but PA rope except, if PA rope not heat treatment, no only breaking strength will be reduced, but also a little curly,
2.Light, temperature and the chemicals
Due to long-term exposure to sun, rope will loss breaking strength and finally to complete damage. As far as possible prevent sun direct illuminate during use and storage,.special attention on tropics, sun is very intense ,can be covered with masking ropes or Put them in the shade, or by coloring (in black) or use light spectrum stabilizer when production, choose less sensitive fiber produce rope can also reduce damage.Ropes must be avoid on place where extreme heat or hot surfaces, pe ropes ceiling temperature 40-50 C. Natural fibers are more susceptible by chemicals. they are particularly susceptible when touch acids. it is important to remember that high phenolic can damage PA fibers. All chemicals touch rope must be washed in water.
3.Dirt
Long time immersed in natural water ,rope will be covered by animal and plant organisms.The main biological attachment.
Chlorophyceae,diaomeae,hydroidea,tubularia,actiniaria,serpulidae,cirripedia,balanus,bryozoa,amphipoda,tunicata.
There are about 130 species of plants and animals can cause dirt.The type of dirt depends on the environment. There are more species in tropical waters than subtropical, temperate zone or polar climate water, and species in seawater is different with freshwater. Low nutritional water is different with high biological activity of fertile water and turbid water. Just as ships or submarine structures in water for a long time will suffer dirty,organisms have time grow. The fishing gear such as cages, trap net, setting net, bagging net. Dirty increases the weight of fishing gear, use more difficult and block the meshes, thereby reducing efficiency for get fish. Seapocks are particularly annoying because their lime-colored shells can cause mechanical damage and difficult to eradicate.
All types of ropes be affected by dirty almost the same. Due to remove the organic matter will use a lot of time.so we hope organic matter can’t grow on rope and fishing gear.Decontaminant is an effective way. if they contain copper and zinc compounds,it will be better. Special binders ensure gradual release of toxic components for long time.Decontaminant should be easy to use, cheaper and effects many microorganisms for long time.
4.Kink
Kinking is one of the most reason for rope damage. The main effect of kinking is permanent deformation in the structure, in particular affecting the roving on surface. If a rope with a kink is subjected to load, the deformed rope is subjected to more stress than in normal position and may break. Due to the deformation of the rope, the kinked portion is also less abrasive. In addition, kinking rope are more difficult to coiled and will not pass sheaves or pulleys smoothly. the kink on the rope carefully unwound before loading. However, in most cases there will still be a certain amount of decline in breaking strength.
5.Abrasion
Abrasion is another major reson for rope damage. When inspecting the rope, extreme caution on surface.also attention must be paid to internal abrasion. Regular inspection shows that the rope can not be used, should be scrapped.
6.Ageing
Even if the rope is undamaged after use and is retained under suitable conditions, quality can not be maintained over a long period of time. With most other materials, the fiber material gradual changes, reduction in physical properties. Similar with biological process is called aging.
These changes can be very complex natural phenomena, including changes in the molecular structure of fibrous materials, which are related time and environmental conditions.PA multifilament twine which has a 20% -27% loss in breaking strength after 9 years.
