About Polyesters

Introduction to Polyesters

PLEASE NOTE : There is often a HUGE confusion about Polyesters. Let me EXPLAIN this clearly.

1st generation polyesters – Came out around the 1980s , other then its durability and control, it is quite bad. ( Has no ability to maintain tension, nor playability, etc )

2nd generation polyesters – Came out around the 1990s, chemical additives now added to the polyesters, now known as co-polyester. The huge flaws in the 1st generation are now somewhat bearable.

3rd generation polyesters – Came out around 2004, higher concentration of chemical additives with new mixtures added to increase the strings, playability , comfort, tension stability etc. Huge success . These strings are also known as Co-Polyesters.

As of today, 1st and 2nd generation polyesters are Rarely sold. ( Luxilon being the only exception )
Most polyester string you find today are mostly all 3rd generation polyesters.

Also –

All polyesters today are 3rd generation but THERE IS a huge range of different 3rd generation Polyesters as there are many different chemical additive and formulas used! Some are much softer then others, some are much livelier, etc but they all boosts the unique properties of polyesters, such as their control, durability and special dynamic elasticity!

Also please note: One cannot really compare Polyester strings to soft strings like natural guts and multi-filaments, they are a very different breed of strings!

Now you could probably see why it is soo confusing, but the trick is to completely disregard 1st/2nd generation polyesters. No one needs them, nor should any pro shops sell them!

Important Note

There are 2 main types of polyestersStiff Polyesters and Soft polyesters.

Stiff ones offers the true high level of control of polyesters.
Soft polyesters can be strung 5-6 pounds higher to offer this same control but, they will lose playability and tension too quickly.

( Most soft polyester do have tension stability and playability issues, so I strongly recommend Signum Pro and Weiss Cannon polyesters, these German Soft polyesters are superior in tension stability and playability compared to almost any other soft polyesters. )

Characteristics and properties of polyesters

In the modern game of tennis more than 90% of the pros has polyester strings in their racket, either a full set-up or a hybrid one.

I will have to define 2 important terms.

1 – Dynamic Elasticity, the normal term of elasticity is actually a subset or a simplified version of dynamic elasticity. Dynamic elasticity refers to the rate at which elasticity is lost when the string is being stretched.
(e.g take a rubber band as an example, say it takes 1 newton to stretch the string the first cm, but it now takes 4 newtons of force to stretch it the next 1 cm. If dynamic elasticity is now much lower, the first cm might still take around 1 newton but the second cm will now take 8 newtons )
2 – Dynamic tension is measure by the force needed to bend the string one cm downwards. This is different from regular tension.

Polyesters have low dynamic elasticity which causes it to have high dynamic tension. That is why all Polyesters should be strung 8-10% lesser then softer string types. This is also the reason why they can be strung at VERY low tensions such as 35-44 pounds.

Polyesters has the best spin potential compared to all other strings.

  • They are strong and durable, allowing for thinner gauges and angular structures that bites the ball a lot better.
  • Polyesters string are low in their dynamic elasticity and have smooth sleek surfaces thus these strings tend to snap back in position when displaced, adding to the topspin of the ball that is being brushed upwards.
  • Topspin strokes causes strings to run more often as the racket brush up across the ball. Polyester strings has the least string running issues( strings often goes back to their orderly positions ).
  • The low dynamic elasticity of polyester helps when one is taking huge cuts at the ball. ( lower the dynamic elasticity = higher the rate of tension rise when it is stretched. The ball doesn’t sink too deep into the string-bed )


Polyesters are a lot more ruggard

These strings are extremely durable. If you are not a hard hitter, it could likely last you for a year or more without bursint. But this is not optimal as they do tend to lose playability and feel dead after a few months  assuming that you play about 3 times a week.. ( you can still use it though, just be aware that they can cause elbow issues and reduce performance in this dead state )

A great thing about this string is that its probably the most water resistant string compared to the other types of strings.
However like all strings, they are not resistant to high temperatures, (eg. do not leave them in your car boots under the sun) they will lose tension.


Polyesters are better at control

One of the main reasons pros prefer polyester strings, is that they offer tremendous control for big powerful shots. The reason for this amazing control is due to the high dynamic tension of polyesters, when the ball is struck hard and bends the string, polyester string will rise greatly in tension, providing a higher level of control.

This string thrives in the modern game where racquet head speed is getting faster and faster.

They are firmer strings with lower trampoline effect.

Co-polyester have low dynamic elasticity, which means they take large impacts much better, with more consistent responses.

They offer more spin, and with more spin, one also gets more control.


Polyester of your choice

The co-polyesters you’d want to be using are the 3rd generation ones, they are more comfortable and have greater playability. But as explained above, these co-polyesters are actually a blend of different elements, but with polyester as the base. 3rd gen poly are also cheaper and easier to manufacture, as such there is a diversified range of 3rd generation co-polyesters.

Due to the large range, there are many different polyesters to choose from, a hard hitter would probably go for a more crisp/ lively one with better tension stability and control. A short swing less hard hitter would probably prefer a poly that offers better feel and more power.

It is not that hard to manufacture a 3rd generation polyester, as such there is a huge proliferation of them. Quality wise they are about the same for the better brands. Each brand will have their own range of different models with different chemical combinations and different characteristic make-up , pick the ones that suits you best.

I would recommend, Signum Pro line of 3rd generation polyesters, they have good variety, reasonable prices for a brand that is endorsed by top ATP pros. Its a premium brand of strings made in Germany and are very well known for their tension stability.

Polyesters are dynamic!

I have written this down in another page. Click here

Disadvantageous and weaknesses of polyesters.

To be continued…