Product Info

Product Information - Fishing netting, twines and ropes, basic terms

Mesh size knot to knot - the distance between two sequential knots or joints, measured from centre to centre when the yarn between those points is fully extended.

Mesh opening - for knotted netting, the distance between two opposite knots in the same mesh when fully extended in the finished (N)- direction. For knotless netting, the distance between two opposite joints in the same mesh when fully extended along it’s longest possible axis. For measuring the mesh opening a mesh gauge in triangular shape with a certain pressure can be inserted into the mesh.

Types of mesh shape:

A. Diamond mesh shape The mesh bars have a diagonal course to the edges in the netting panel. This is the normal shape of meshes in netting.	B. Square mesh shape The mesh bars have a parallel course to the edges in the netting panel. Netting with square mesh shape would have to be converted from diamond shape netting. This caused higher costs for working time and scraps of material.

Length and depth of netting panels

The length of a netting panel is stated with the number of meshes or the length in metres when the netting is stretched

With the number of meshes and the size of the mesh knot to knot the length in metres can be calculated as follows.

Example: mesh size 40 mm knot to knot, length 1000 meshes

Calculation: mesh size knot to knot x 2 x number of meshes = 40 mm x 2 x 1000 = 80 m stretched length.

Should a gill net by this example be mounted at half the stretched length the float line would be 40 metres long (ratio 2 : 1 or 2 metres of stretched netting mounted to 1 metre of float line)

The depth of a netting panel usually is stated with the number of meshes.

If the fishing height of a gill net shall be calculated so is the height related to the mounting ratio of the float line.

Is the depth of a netting panel for example 100 meshes and the mesh size knot to knot 40 mm the calculation is the same as for the length (40 mm x 2 x 100 = 8 metres stretched height).

If the mounting ratio of the float line is 2 : 1 (2 metres of stretched netting to 1 metre of float line) the meshes open up and the 8 metres stretched height is reduced by approx. 13 % to 6,95 metres of fishing height.

Material information

Characteristics of synthetic materials used for netting, twines and ropes

Characteristics	Nylon / Perlon PA	Polyester PES	Polypropylene PP	Polyethylene PE	Green Power PP+PE
Specific gravity	1,14	1,38	0,91	0,94	0,92
Performance in water	sinks	sinks	floats	floats	floats
UV- resistance	medium	very good	medium*	very good*	medium*
Abrasion resistance	good	very good	medium	good	mediuml
Water absoption	5 - 7%	0,4 - 2%	0%	0%	0%
Breaking load, dry, linear	very high	high	medium	lower	high
Breaking load, wet, linear	85%	100%	100%	100%	100%
Breaking load, wet, with knot	60%	55%	60%	55%	55%
Breaking elasticity	16 - 35%	7 - 30%	15 - 35%	7 - 30%	7 - 30%
Melting point approx.	220°C	250°C	170°C	140°C	140°C

Synthetic raw materials are used for:

Multifilament endless fibres. Single filaments with a fineness of 0,6 g – 2,0 g per 1000 m are combined and twisted or braided to twines or ropes. Twines or ropes made of multifilament endless fibres have a smooth surface.

Staple- fibre or Spun-fibres: Staple- fibres ore short pieces of filaments which are spun to Spun-nylon or spun-polyester twines. This is a similar process as done when producing wool or cotton twines. Spun-nylon or spun-polyester twines have a “woolly” structure and knots made with these twines keep tight. That’s why such twines are used for assembling, mounting or repairing fishing nets.

Monofilaments: These are single endless fibres with diameters of 0,12 – 3,0 mm or even bigger. Nets (mainly gill nets) are made of such single monofilaments.

Multi-monofilaments: Here two or more of the thinner monofilaments are combined with a light twist and used for producing netting (gill nets). This netting is softer and more flexible than gill nets of monofilaments and are claimed to have a better catchability.

Types of ropes

Form A	3-strands
Form B	4-strands
Form E	round braided with braided core, also called double braided
Form H	solid braided
Form K	braided coat with parallel filler yarns as core
Form L	square braided, 8-strands, mainly for bigger diameters of 24 mm and up, can be spliced

Quality: All in the shop stated characteristics and breaking strength refer to materials when new and unused. Influences like UV-exposure, chemicals, gas, abrasion or overloading can reduce the breaking strength and useful life. Nets after having been used should be carefully cleaned and stored in a way that mice, rats or other animals cannot damage the fishing gear. A cover as UV-protection is recommended.

Warning: Because of the wide range of rope use and rope condition, exposure to several factors affecting rope behaviour, and the degree of risk to life and property involved, it is impossible to make blanket recommendations as to work loads. However, to improve guidelines working loads should not exceed 20 % of the breaking strength for ropes in good condition with appropriate splices, in noncritical application, and under normal service conditions. When breaking synthetic ropes and especially nylon (PA) or polyester (PES) ropes can develop an enormous back lash which can cause extremely dangerous injuries or damages. If loads can't be controlled appropriate precautions have to be taken and sufficient safety distance should be kept.