WHY MIXING IS IMPORTANT

In all Rubber products, Rubber compound is a


critical component, which plays a vital role in the

performance and failure of the Product.

The composition of major Rubber Products is as

follows:



PRODUCT                        COMPOUND %

TYRE                                        80-85

TUBE                                          98

MOULDED GOODS                100

CONVEYOR BELTS               45-55
 
Compounding :


Involves deciding what ingredients and in what proportions, should be

mixed, with the goal of providing in the mixed and cured compound, the

properties required for the end application.

Mixing :

Involves deciding what equipment to use, and the speeds, pressures,

temperatures, time and procedures required to blend the chosen

ingredients into an adequately mixed compound. The aim of the mixing

process is to produce a product that has the ingredients dispersed and

distributed sufficiently thoroughly to permit it to shape readily, cure

efficiently and give the required properties for the application, all with the

minimum expenditure of machine, time and energy.
 
DEFINITION OF MIXING


MIXING is defined as the way different types of Raw Materials are

combined together to get a Mass that is substantially different from the

characteristics of individual components and is Homogeneous as far as

its physical and chemical properties are concerned and the same is

achieved through dispersive and distributive operation.
 
The principle task of compounding is concerned with securing an


acceptable balance between the demands arising between the three

considerations mainly;

1. Properties

2. Price

3. Processing
 
 
Four basiic steps are involved in the mixing operaations are 


1. Incorporation : is the first stage of mixing during which the previously

separate ingredients form a coherent mass.

2. Dispersion : is the process during which the carbon black agglomerates

are reduced to their ultimate size

3. Distribution : is simple homogenization, during which the various

ingredients are randomly distributed throughout the mass of the mix.

4. Plasticization : during this operation the mix reaches its final viscosity as

plasticizers effectively lubricate the mix.