HistoryTennis dates back to 1873 when Major Walter Clopton Wingfield of North Wales published the first book of rules. However, tennis was once played with hands and evolved before the Renaissance in Europe. It was played with hands, then gloved and hands wrapped in rope. The first rackets appeared during the 15th century. The first rackets were strung in different patterns since there were no rules of size, material, or shape.
The International Tennis Federation adopted rules on tennis rackets in 1981. Rackets are now about 71cm long and 284-397g heavy. Most of rackets are made of aluminum or a composite of fiberglass, graphite and other materials.
Tennis Racket from 1876
Materials:
There are several alloys from which aluminum rackets are made. One alloy is 2% silicon, with traces of copper, magnesium, and chromium. Another popular alloy is 10% zinc, and traces of copper, magnesium, and chromium. The silicon alloy is much easier to work with, while the zinc one is harder.
Composite rackets usually consist of different materials around a polyurethane foam core, or a hollow core. The materials used in these rackets are graphite, fiberglass, and kevlar or boron.
Other materials used are gut, nylon, synthetic gut, and leather or vinyl. Manufacturing:
Aluminum racket:
–Forming the frame: There are two ways of forming aluminum rackets. The aluminum can be melted and pushed through a die in the shape of the frame. Or the metal is melted first, and then extruded into a tube. Then that tubing is drawn through a die.
–Drilling and sanding: This rough model of the racket is then placed in a drilling machine. In this step, they drill the holes for the yoke. The drilling machine has several spindles, and every one of them is holding a drill in position. The next step is sanding that’s done to smooth out any edges from drilling.
-Tempering: This is what hardens the aluminum for additional strength. They take every racket and place it on a tray in an oven to be heated until white-hot. Next step is to immerse the rackets in water. They can also be anodized. The rackets are then immersed in a mild sulfuric acid solution; following electric current is passed through.
-Stringing: The yoke is fitted into the base of the racket head. Every racket is strung individually. The employee clamps the racket into the stringing machine. Then the worker pushes the strings the through the holes. Composite racket:
-Forming the frame: These rackets are made of different materials, usually fiberglass and graphite. You can find other materials too such as kevlar, boron, or fiberglass with ceramic particles. The first step is to layer all materials as a flat sandwich. Then they cut the sandwich into strips and roll them around a hollow tube. Then this tube is placed into a racket mold. They heat the mold and pump the air into this tube. The heat and pressure are what connects all the layers.
-Drilling and sealing: Defective rackets are removed once the workers release and carry them all for inspection. Then they cut the end of the frame and place the rocket in a drilling machine. Next step is to brush them with a polymer coating and place them in the dryer. Mostly, they repeat this step a few times. The workers then sand the rackets and apply the brand name decal.
-Stringing: This step is quite similar to stringing an aluminum racket. All that’s left is to string the racket and insert a few other garments. Then they clean, inspect, and pack the rackets.