The electric fusion is the most commonly used melting process for manufacturing quartz glass. The name is derived from the method of heating up the material, in this case: an electric current is heating a resistive heater, hence the name "Electrical Fusion".
The benefits of Electrical Fusion is the lower OH-content, compared to other fusion methods. Typical values are in the range of <30ppm. As the OH-content is directly influencing the maximum possible working temperature for the fused quartz, Electrical Fused quartz is especially suitable for high temperature applications.
Electrical Fusion can be used in both – continuous fusion or batch/boule fusion and therefore offer a large variety of geometries, shapes and dimensions.
In opposite to the Electrical Fusion, the Flame Fusion is not using an electric current, but is using am H2/O2-Flame to heat up and melt the material. Heraeus chemist Richard Küch was the first person to ever melt quartz over 100 years ago, he used a flame fusion process for his pioneer endeavor.
Heraeus Conamic is the only material manufacturer who can produce fused quartz in a continuous flame fusion process, combining the benefits of a continuous process with the properties of flame fused quartz.
The extreme low bubble content makes Heraeus flame fused quartz the best choice for plasma etch applications.
Heraeus Conamic also offers flame fused material in very large size ingots in the range of 1.5m x 1.2m and larger.
The main difference between so-called natural quartz material and synthetic quartz material, is the used raw material. While natural quartz is produced from quartz sand minded in a quartz mine, synthetic quartz is using chemical gases as raw material. Such chemical gas containing a silicon source will be put into reaction with oxygen forming pure silicon dioxide. The purity achievable by this manufacturing procedure is magnitudes higher compared to natural quartz.
Synthetic fused quartz (sometimes also called fused silica) is the ideal choice for most demanding applications in which purity of the process environment is of the essence.
Our synthetic fused silica materials are available in the same portfolio of shape, geometry and dimensions as our electrical fused material.