Investment casting, one of the oldest and traditional method which egyptians used for preparation of jewellery, is used in this modern era for development of quality tyre moulds.

One of the main reasons for the usage of this method is that it makes the development of complicated and intricate tyre designs quite easy and that too with excellent finishing.It has some features of other methods like Die Casting or Gravity Casting or else it would be in a sense right to say that it is mixture of both these methods employed together.

Technically elaborating about Investment Casting it can be said that it is step by step process :

• Initially we begin with the development of Master Die or the Master piece which is given shape according to the predecided design of the tyre.A Master piece is developed on a clay like material which is a mixture of POP(Plaster of Paris) and other type of sand.This requires a bit of expertise to draw or create the tyre design on the POP model basically done by someone who has expertise.It has to specifically noted that the model is 100% as it's design states or else it will be a waste.
  
• After the Master Die or Piece has been designed its time for the development of the other pieces of the tyre mould which are exactly a replica of the Master piece.Now the question is how??. So first we need to modify the Master piece a bit.For this a special solution of silica and other chemicals is used and it is poured into the grooves of the Master Die and allowed to dry for a 2 days.
• Now this Master Die is ready for making the negatives of the respective tyre mould pieces.The negatives of the mould are developed by pouring POP on the Master Piece or Die.All these negatives are dried up in an oven before they are used for casting out the mould piece.
  
• Now its time for the Investment Casting to come into action.After the negative pieces have been dried up they are ready for casting.Casting in this method involves a technique which is mixture of die casting and gravity casting.The above stated steps were similar to die casting process.And the way in which the mould is cast into an aluminium piece is somewhat similar to gravity casting.

This process of Investment Casting can be employed in two ways--either the mould can be developed piece by piece and then assembled into a complete mould or else it can be developed as a whole.Based on this it can be classified as

• Segmented Tyre Mould:This method of tyre mould development is quite cheap and reliable as compared to the Full ring tyre mould though it takes more time.In this method the whole mould is developed piece by piece and then assembled into complete tyre mould using suitable tools and machines.One of the biggest advantages of this method is that it is easier to remove any defective piece if any in the mould.So this method is quite cheap and reliable as compared to the Full ring tyre mould but at the cost of time.

• Full Ring Tyre Mould:This method of tyre mould development is quite expensive as compared to the Segmented tyre mould development and quite risky.If a single defect occurs then the whole tyre mould would be needed to be replaced.One of the advantages of this method is the it does not involve that much time as Segmented tyre mould development.

Both of these methods can be employed for the development of quality tyre mould with a bit of disadvantages on both sides.