You need a programmable muffle furnace to incinerate the plastic components. A step-like incineration process is particularly important for long glass fibers. These can break due to the heat stress during incineration. We recommend the following step program.
At Labo there is a comprehensive comparison of muffle furnaces, it should be added that the Nabertherm series are also programmable. ( Muffle furnace market overview )
Take a sample from the ashed sample. You can see a recommendation table below for the weights. Suspend the amount of glass fibers in 500 ml dist. Water and add approx. 3 - 4 drops of glycerine (approx. 1 ml). Glycerine lowers the surface tension of water and the glass fibers separate more easily, which facilitates homogeneous mixing. Stir with a glass rod or something similar. until there are no more lumps of fiber. Now carry out a dilution series with 1: 2 steps until the concentration of glass fibers is low enough for the analysis with FASEP.
The surface of the Petri dish should also be treated with a detergent so that the plastic of the Petri dish is more evenly wetted. To do this, you can simply put a drop of detergent on the edge and pour in the glass fiber suspension, just enough to cover the bottom of the Petri dish.
Recommended weights for short glass fiber granulates are e.g.
|w (GF) in %||m (Granulat/Sample) in g|