Basalt Fibers can withstand continuous temperatures up to approx. 1,040 degrees F and short term peak temperatures of up to 1,300 degrees F.
In the eyes of many people, these values are considered to be conservative. Often, companies post much higher values; but Basalt is Basalt, the chemical composition is normally not altered. Having that said, as Basalt is mined in various locations, you will experience various qualities, plus the quality can change as the mines are explored. The manufacturer of the Basalt Fiber spends a good amount of effort to keep the quality consistent.
The engineer likes to compare data from Basalt with other technical fibers and can become difficult to make the choice which of the values are correct. When comparing to alternatives, a good rule of thumb is that the values are about 250 degrees F higher than in the case of traditional E-Glass. The traditional E-Glass is the material which contains Boron. Boron free Glass Fibers are molten at higher temperatures and therefore also withstand higher temperatures.
When considering temperature resistances, it is important to know a few very important influencing factors:
- Does the temperature come from one side or from both sides of the product?
- reason is that when heat can be dissipated, the product will be able to withstand higher temperatures (e.g. fire barrier/ welding blanket). If the heat comes from front & back or even from all sides, heat cannot be conducted away from the product and it breaks down faster.
- How dense is the Product?
- If the product has a high density, it can absorb more heat and deal with it better than if it has a low density.
- Is airflow available?
- We all know the effect of the difference in the hot summer; if wind is present, it will help to cool down.
We recommend to ask for the ASTM used to test the materials. Then you will have a true comparison!
Heat & Strength
In some applications, it is critical to have a product which holds up when being faced with elevated temperatures. A good example is "Flexible Expansion Joints". Occasionally people utilize the standard E-Glass fabric. At elevated temperatures, the fabric will loose some strength and the product wears out faster. When utilizing a higher temperature resistant material, in most cases, the strength holds up better at elevated temperatures. In these cases, the engineer needs to compare which material provides more longevity. Basalt can be one of those candidates when comparing to the traditional E-Glass. - The same would apply to abrasion resistances.