Frits of colouring concentrate (colouring products) are used for the colouring process. Copper, chrome, nickel, selenium, cobalt and other elements can be used to produce an entire range of colours.
Various combinations of these elements enable a very large palette of colours.
In order to feed these colouring agents, a specially designed feeding unit needs to be installed. This feeding unit consists of several components:
- a small batch hopper is used to store the colouring agents
- a dosing chute feeds the adjustable quantity of agents from the hopper to a weighing pan
- a special weighing socket weighs the exact quantity of colouring agent
- a pneumatic deduster reduces the fine particles from the agent to prevent refractory corrosion
- charging funnels with distributor for single, double or triple charge, feed the agents through the roof of the forehearth onto the glass surface