This presentation gives you an overview of Manufacturing processes of Tennis Racket since 1880s. There are different materials used in manufacturing Tennis Racket. Extrusion, Drawing and Molding are used here. At the end of this presentation, you will get an idea of how the rackets are made, the cost involved and the science behind it. Most of the processes involve automation of machines.

2. EVOLUTION OF MATERIAL USED
• 1870s to 1970s - Wood
• 1980s to 1990s - Metal or Alloy (Aluminium)
• Present - Carbon Fibre, Nano Materials
• Future - Piezo Electrics

3. DINNI FAMILY
• Three generation
people played tennis
with different Rackets.

4. WOODEN RACKETS
 Made from solid sections of wood such as ash, maple and
okoume.
 Until 1965, all professional tennis rackets were made of
wood.
 Man Made, Skill Based.

5. WOODEN RACKETS
 1) Cutting - Wood is cut into a basic rectangular shape
taking into consideration of the required dimensions.
 2) Shaping - Then the rectangular Shape is cut into a
near required shape and then shaped into the required
shape(using an abrasive like sand paper).
 3) Drilling - Holes are made in the frame and then
string is inserted and the tennis string is prepared.

6. He lost!

7. WOODEN RACKET - Disadvantages
 1) Strength
 2) Water Absorption (Warping Occurs)
 3) Anisotropic (Properties are different in different directions)
 4) Frame cannot resist changes in tension (Tension in Strings)
 5) Irreversible Damage (Once damaged can’t be fixed)
 6) Constraints on Design part

8. NOW ITS SON’S TURN!

9. Aluminium Racket
 Material Composition –
1) Zinc Based 2) Silicon Based
 Zinc Based is hard and brittle.
 Silicon Based is easier to handle.
 Strings - Nylon is used

10. Aluminium Racket - Manufacturing
 Forming the Frame : Two Methods
1)Die Casting – 1)The aluminum may be melted and forced through a die in the shape of
the racket frame

11. Aluminium Racket - Manufacturing
 Drilling : 1) Yoke (the throat piece that holds the bottom of the strings—on
the sides for the strings, and at the base of the stick)
2) Multiple Spindles
3) Simultaneous Drilling
 Sanding : The frames are then placed in a sander to smooth out sharp edges left from the drilling

12. Aluminium Racket - Manufacturing
 Tempering : 1) Subjected to heat and rapid cooling
2) Hardens the aluminum, giving the racket additional strength
 Anodization : 1) Immersed in a mild sulfuric acid solution, and an electric current is
passed through the bath
2) Changes the surface of the aluminum, and gives the rackets a shiny
finish

13. Aluminium Racket - Manufacturing
 Stringing : 1) A grommet strip is in laid in the groove around the edge of the
head
2) Pre-Drilled i.e. matching with holes made in the frame
3) Yoke is fitted into the base of the racket head
4) Strings are forced through the holes using a powerful threader
mounted on a movable bar above the racket
5) The length wise strings are pulled first and later width wise
strings are drawn
6) Finally tension is adjusted

14. Aluminium Racket - Manufacturing
 Finishing : 1) Cuts the end of the handle and inserts a cap called the butt cap
2) Wrapping of strong double-stick tape around the handle, followed by
vinyl grip tape
3) Inspection
4) Final cleaning stage

15. He too lost !

16. Aluminium Racket – Disadvantages.
 Lower specific stiffness
 Aluminium was bit heavy for him
 Poor Fatigue performance
 Lower damping capacity

17. Nylon Strings – Manufacturing.
 Raw Materials – 1) Polymers containing Amides (Nylon 6 , Nylon 6,6)
2) Polymers containing ketones
 Procedure : 1) Pellets are poured into hopper.
2) The extrusion screw moves the raw materials through various zones
inside the barrel.
3) Melt-Zone
4) Metering-Zone
5) Extrusion.(Multiple)
6) Cooling
7) Drawing
8) Cycle of heating , Stretching , Cooling .

18. Carbon Fibre Rackets
 Raw materials
1) Carbon
2) Kevlar
3) Fibreglass
4) Boron
 These are made into layers which are stacked upon one another with the help of epoxy resins

19. Carbon Fibre Rackets
 These layers are rolled around a steel bar to form a hollow tube.
 Forming: 1) In a steel mold , the rolled carbon tube is now formed into
racket shape.
2) Addition of prepreg pieces at required locations.
3) This gives basic shape to the tennis racket.

20. Carbon Fibre Rackets - Manufacturing
 Forging
1) The preformed racket is put into a preheated mold and its pressed from
the top
2) Pressure is applied internally from the sides
 Heating process
1) It passes through a heating process to cure and harden the carbon fibre
2) Pressurized air is blown through the centre of the frame to maintain the
shape.

21. Carbon Fibre Rackets - Manufacturing
 Sanding
 Hollow core is filled with foam to improve strength and stability
 Drilling operations are carried out

22. And he won!

23. Carbon Fiber Racket - Advantages.
 Fatigue performance.
 Higher Tensions.
 Desired properties can be achieved even with the slightest modification in the
carbon fiber layers.
 Lower Weight.
 Better Damping properties.

24. Future Scope Nano Materials
 While reducing the weight of rackets, Nano rackets also increase flexibility,
durability and hand-feel.
 Nano material greatly improves the performance of tennis rackets, such as
impact resistance, durability, elastic resistance, stability, shock reduction and hand-
feel.
 it is still unknown what influence nanotechnology will have on human health, and
thus Nano rackets have safety concerns.
Piezo-Electric Materials
 Better damping properties.