How is Kiln Formed Glass Made?

How is Kiln Formed Glass Made?

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“Kiln formed glass can be used as a decorative aspect both to an internal of external face of glass”

Kiln formed glass can be used as a decorative aspect both to an internal of external face of glass to give a variety of different patterns and effects on many different specifications of glazing.

As the name suggested these effects and patterns are created using a kiln oven. A huge variety of effects can be created using this glass decorative method. For smaller patterns and for patterns on thinner glass the pattern or design is designed by hand on a fire rated board, indenting, texturing and scouring the malleable board with to achieve a pattern of choice.

For larger patterns and thicker panes of glass the pattern is designed on a mould created using plaster, sand and chemicals bespokely to suit each unit and design.

All pattern designs have to be made on a level block design table to make sure all pattern templates are completely flat ensuring even glass thicknesses over the patterned effect.

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“The kiln is then heated to temperatures upward of 800 degrees C until the glass takes on a molten quality”

For each case once the design has been finished and approved it is fitted into the base of the kiln oven. These ovens can hold huge sizes of glass of over 18m2 in order to meet the design criteria for a wide variety of projects. Once the pattern base is in place the glass is then lifted and laid flat onto the pattern board inside the kiln.

The kiln is then heated to temperatures upward of 800 degrees C until the glass takes on a molten quality. In this state the glass will mold to the pattern shape etched into the board below it and the design is then acquired.

For coated glazing, be that Low-e or solar control, a slightly different kiln is used. As the coatings applied to the glass reflect heat the glass unit has to be heated from two directions, both above and below, to ensure the glass is formed properly. Specialist kilns using electrical heating at the bottom and radiant heating from above are utilised to kiln form coated glass.

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“The cooling must be done at a very steady pace, ensuring the glass is cooled slowly and evenly”

This process can take anywhere from 10-14 hours depending on the glass thickness and then is cooled in what is called the Annealing Process. The cooling must be done at a very steady pace, ensuring the glass is cooled slowly and evenly to ensure no glass breakages occur due to thermal shock.

Once the Kiln formed design is ready the glass can then be tempered, toughened or laminated.

For more involved projects, or higher specification projects where the intricacies of design are important workshops can be held for architects and designers to come to the factory and design the pattern required.

Contact IQ Glass hello@iqglassuk.com 01494 722880

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Rebecca is Head of Marketing at the IQ Group and has worked in glazing specification for many years. She has a broad range of technical knowledge about all our glazing products and offers technical advice and guidance to architects for specification. Her easy to digest technical advice is often quoted in magazines and publications. You might also recognise her as one of the IQ Glass CPD presenters.