In-depth analysis of fishing braids

By Dédé

Who doesn't use braid today!

... but who really knows what's behind that word "braid"...

This fiber has, little by little, replaced our good old nylon on our reels.

But what is this fiber?

Spectra or dyneema (info web)

This is the trade name for the fiber that makes up our braids.

Dyneema is a synthetic fiber based on ultra-high molecular weight polyethylene (UHMWPE, i.e. "Ultra High Molecular Weight PolyEthylene). So, for the same weight, braid is 15 times stronger than steel, and up to 40% stronger than Kevlar. This fiber is commonly used in bullet-proof vests, bows, ropes, climbing and high-performance equipment, sails, yachting, etc. Dyneema was invented by DSM in 1979 and has been in commercial production since 1990 at a plant in Heerlen, the Netherlands. DSM has a cooperation agreement with Toyobo Co. in Japan. In the United States, DSM granted a license to Honeywell, which had developed a chemically identical product. The Honeywell product is sold under the Spectra brand name. Although the manufacturing details are undoubtedly different, the materials obtained are comparable.

The "gel spin"

process

How can a polymer as a priori banal as polyethylene achieve such high performance? It all comes down to the so-called "gel spin" manufacturing process developed by DSM in 1979. Polyethylene macro-molecules are dissolved in a solvent and spun through a die. During this process, they disentangle and orient themselves parallel to each other and in the longitudinal direction of the fiber. It is this very high level of orientation that gives the fiber its amazing performance.

Density ranges from 0.941 to 0.965 g/cm3, its melting temperature is between 130 and 136°. This fiber also has high resistance to water, mildew, a large number of chemicals, micro-organisms, as well as UV.

Since the invention of high-modulus polyethylene by Albert Penning in 1963, PE fiber has been constantly evolving to improve its characteristics. These fibers are now produced in different modules, obtaining different characteristics. Modules have been evolving since 1990: SK38, SK62, SK75, SK78, SK99.

PE fiber is used in many applications: ropes, nets, textiles, gloves, cycling, sails, bowstrings, paragliding or kite surfing lines, bulletproof vests, helmets....

The braid we use in fishing is only a tiny part of the use of this fiber. The grade used to make the braid is never communicated, which is a pity because this grade influences strength.

Then, this braid receives a core or surface treatment that will improve its presentation and performance, mainly UV resistance, color and glide.

Braid strength: tests and findings

One of the arguments put forward is the near-absence of braid elasticity; indeed, this is generally advertised at around 3%.

However, during my strength tests, I was able to observe a much higher elongation of the samples than the advertised 3%!!!

Braid testing protocol

I'm carrying out a test to measure this elasticity of the braid. To facilitate the test, I put a 100mm length of braid under load.
The pitch of the tensioning screw on my machine is 2.5mm, so when I make one turn of the screw, the carriage moves by 2.5mm and the braid lengthens by 2.5mm.
To measure the hook's displacement, I attached an arrow to it and a ruler to the fixed support.

When I've made one turn of the screw, the braid shouldn't theoretically break, as I'd only be at 2.5% elongation, so still within the elasticity zone of PE fibers. The strain-gauge electronic load cell undergoes little deformation and its own elongation is therefore negligible.

I start turning the screw, one turn, the braid holds.
Two turns, so 5 mm of elongation, the braid still holds and yet I've exceeded the announced elastic limit.
I continue, one more turn, 7.5 mm, still no breakage
Another turn and a little more, I'm at 11 mm of stretch, will break, won't break?

It breaks at over 12 mm stretch!!!! That's an elasticity of 12%

In their advertising, manufacturers flaunt the low elasticity rate of braids (3%) and use it as a selling point. The rate they emphasize is that of the raw material, polyethylene fibers: so it's not the elasticity rate of the finished product, which is totally different.

It is thus the braiding of the fiber that provides this elasticity, and its elasticity is a function of the tension given to the fibers during braiding. This elasticity is welcome as it helps absorb the energy released in use, repeated shocks, fish departures, brake force.... When you're hooked to the bottom and pulling on the braid by hand to try to unhook yourself, you feel this elasticity very well.

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All this to show you that you shouldn't always take for granted what you see in braid ads.

Braids in use are subject to constraints that will cause their characteristics to evolve.

Braiding through time...

The aging of braids modifies their structure, there is an increase in diameter caused by the destructuring of the braiding and the breaking of the polyethylene fibers. This phenomenon occurs very rapidly and is accompanied by a reduction in strength.

Here's a view showing on the right a new braid and on the left the same one after a stay in Madagascar. Whatever the brand, it's the same phenomenon for all braids. The loss of strength was 25%.

After having a few breaks with some beautiful beasts, I wanted to know a little more about the aging of my braid.

For the test, it will be 8 days of jigging in Madagascar.
The reel of my jig rod is loaded with new PowerPro 8 slick 65 lb/0.36mm braid from the US. I measure the resistance of my PowerPro and carry out resistance tests again on my return from the trip.

Result: on the first three meters, I notice a 24.48% loss of resistance!!
At 10 m and 20 m, I also had a loss, but this one was much smaller.

Only 8 days of fishing and still, I had changed leaders and shortened my braid a bit during the stay.

The causes of this degradation:
Fiber breakage caused by repeated passage through the head ring, thus a small-diameter bend that PE fiber doesn't like at all.
Add to this that this was a test in a saline environment: salt crystallizes in the braid during drying. And let's not forget the UV rays and the fighting...

Hence the need to cut a few meters of braid regularly.

Braid marketing:

Braid #1: Braid X

My first example is the "X braid", but I could have used another one - it's not an isolated case. So, the data provided by the manufacturer, for Europe, and taken from the net:

There's an indication of PE; this measurement system is actually based on an ancient Japanese system for measuring the diameter of natural silk. The PE 4 sample I tested is advertised by the manufacturer as having a diameter of 0.28mm and a strength of 26.5kg. However, a PE4 is supposed to correspond to a diameter (theoretical; see table at the end of the article) of 0.33mm. Bad luck, I measure it at 0.405 !!! Fortunately for the resistance, it's not bad, the Silk is all the more resistant...

The same table, for the same braid reference, but the version intended for the American market, so with data in imperial measurements...

If, like me, one has the impudence to convert and compare the values given on the tables (but what a funny idea, really...), it gives:

• on the European side, a 40 lb braid is given at 0.24mm for 18 kg, in PE 3;
• on the American side, braid referenced at 40 lb is given for 0.32mm diameter and 19 kg strength...

Note in passing the non-constant conversion from lb to kg... when one lb corresponds to 0.454 kg...

First guess: two different braids for a 40 lb, one that's 0.24mm and one that's 0.32mm? No..... that's not it!

If we take the 0.28mm diameter, the European table gives a resistance of 26.5kg, when the American table announces 14kg...

This is totally incoherent, and it would be wise for this manufacturer to go back to the drawing board, as it sounds more like "unbridled marketing" than reliable measurements...

Too bad because I think the product is good, but this kind of marketing can (unfortunately) only make the consumer suspicious...

Braid #2: Braid Y

Following on from this first test, and to emphasize that the reference taken as example #1 is just one of many, let's take a second example from another brand: the "Y braid".

As with many braids, there's the version for the European market, and the version for the American and Asian markets. Labeling differs somewhat, too.

Example: 0.28mm / 40 lb (America, Brazil...). The same braid in France is marked 0.28mm / 28kg / 62lb

Let's get to the measurements now... A quick test on the 0.28mm / 40lb / PE4, from Brazil:

• Measured diameter; 0.35mm
• Resistance 24.2 kg or 52.91 lb
• Conclusion: it makes more than the advertised resistance!!
• As a reminder, a PE4 should theoretically correspond to a diameter of 0.33mm

The same test on the advertised 0.28mm / 28kg / PE4 (0.33mm) braid, from Brittany:

• Measured diameter: 0.34mm
• Resistance 26.8 kg or 57.32 lb
• Conclusion: it makes a little less than the advertised resistance, but more than the first one!!

Comparison of tables according to European and American markets:

Conclusion

It's not easy to make sense of it all... What we can say is that braid comes out of looms like these, and very often comes from China... As for the true diameter and strength of braids, this is still an area full of surprises...

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Other articles:

Well-chosen rings for braiding...

Interview with Dédé, the author...

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Table of theoretical diameters by PE

PE#	Diameter (in mm)
PE0.6	0.128
PE0.8	0.148
PE1	0.165
PE1.2	0.185
PE1.5	0.205
PE1.7	0.218
PE2	0.235
PE2.5	0.260
PE3	0.285
PE3.5	0.310
PE4	0.330
PE5	0.370
PE6	0.405
PE7	0.435
PE8	0.470
PE10	0.520
PE12	0.570