1. The pretreatment method
The filler is put into the solids mixer (high-speed solid mixer or V-type solid mixer, etc.), and the silane solution is directly sprayed on the filler and stirred. The higher the rotating speed is, the better the dispersion effect is. Generally, the stirring time is 10-30 minutes (the slower the speed, the longer the time). The filler should be dried at 120℃ for 2 hours.
2. Amino silane coupling agent in aqueous solution
Glass fiber surface treatment agent usually includes film-forming agent, antistatic agent, surfactant, coupling agent and water. The amount of coupling agent is generally 0.3% - 2% of the total amount of surface treatment agent for glass fiber. The PH value of 5 times aqueous solution is adjusted to a certain value with organic acid or salt. Under full stirring, silane is added until it is transparent, and then the other components are added. Isopropanol can be used to help dissolve the insoluble silane. In the process of drawing, the surface treatment agent of glass fiber is sprayed on the glass fiber for drying, and the solvent and water are removed.
3. Bottom method
The substrate surface was treated by coating, brushing and spraying with 5% - 20% of the solution of amino silane coupling agent, and the substrate surface was treated by coating, brushing and spraying. The substrate was taken out and dried for 24 hours at room temperature and baked for 15 minutes at 120℃.
4. Direct addition method
The silane can also be directly added into the filler/resin mixture. When the resin and the filler are mixed, the coupling agent of amino silane can be directly sprayed into the mixture. The amount of coupling agent is generally 0.1% - 2% of that of filler (determined by the diameter of filler). Then the resin/filler added with silane is molded (extrusion, compression molding, coating, etc.).