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Episode 22: Springs and Technology

Hello everyone.
I think we are beginning to feel the world’s economies becoming more vigorous. I think they are now gradually beginning to recover.
There are some of the hottest contests yet to come in the world.

Yes, that’s right!
The 19th FIFA World Cup will be held from June 11 to July 11, 2010 in South Africa.
(For some reason, when I write the drafts for Springs and Technology, worldwide sporting events are always occurring.)

Anyway, let me give you a brief introduction to South Africa.
The Republic of South Africa is located at the southern tip of the African continent. To the east are Swaziland and Mozambique, to the north are Zimbabwe, Botswana, to the west is Namibia. Lesotho is completely enclosed on all sides. The capital is Pretoria.

Have you ever had the chance to touch an official soccer ball?

Read the following for reference. It describes the specifications of soccer balls that are used in official matches.
■Soccer ball material quality
・Shape: Round
・Material Quality: Leather or other suitable material
・Circumference: Max. 70 cm; Min. 68 cm
・Weight: When match starts: Max. 450 g; Min. 410 g.
・Air pressure: 0.6 to 1.1 atmospheric pressures at sea-level


Soccer balls have a three-layer structure of a surface skin, reinforced layer and tube. The following is used as the balls material to satisfy the conditions.

・Surface skin: Artificial leather
Cloth composed of nylon or polyester, and elastic polyurethane resin is used as the artificial leather used in the surface skin. These have low moisture absorption characteristics. This is to prevent the ball from becoming heavy and negatively affected if it rains during the match.

・Reinforced layer: Composite material of cloth and rubber
The reinforced layer is the inner side of the surface skin. This supports the ball’s strength. Blended fabrics of polyester and cotton are used as the materials for the skin, and the rubber is made of a natural latex rubber. The types of cloths and the amount of latex vary according to the qualities desired in the ball.

・Tube: Natural rubber or butyl rubber
The tube is the inner portion of the ball and determines the inner ball pressure. It seems that the tube material is changed depending on the pitch. If the pitch is grass, a natural rubber is used. If the pitch is hard ground, butyl rubber is used for the ball.

Conventional soccer balls use 20 regular hexagonal pieces of skin for the surface skin, and 12 equilateral pentagons. The total number of pieces, then, is 32, which are all sewn together. However, newer official balls have been changed to propeller shapes from the hexagonal and pentagons that were affixed to the ball’s surface. This has reduced the number of pieces from 32 to 14. Compared to conventional soccer balls, there are fewer boundary lines.

Also, a new method called “thermal bonding” is used which affixes the pieces of the skin by heating a special adhesive to hold them together. The changes in the official ball have made the shape rounder, and have reduced the unevenness in air resistance which was a hindrance in controlling the ball. These are said to have increased the precision in the direction the ball is kicked and the balls movement.

Also, by using the ball used in the world cup, they say that there is a higher rate of success for the so-called magic shot, where the ball will fall as it sways back and forth. Because the distribution of the ball’s seams on its surface skin is not uniform, the air around the ball creates an irregular vortex which is said to make the ball behave like magic.
It’s so interesting that even changing just one way to join the pieces of the skin can alter the ball’s behavior. (Reference: Educational Institution ・ College of Analytical Chemistry))


In this way, the degree of a soccer ball’s elasticity greatly affects the outcome of the game, doesn’t it?
What if the ball was made of metal or wood…I don’t want to even think about it…

This is as far as I can go this time.
Anyway, I hope you’ll enjoy supporting your favorite team at the soccer world cup.
Let’s all cheer on Okada Japan!!!!

Anyway, I hope you all will be healthy.

Written by Banekko (a child of spring)