I believe that everyone knows about the use of ceramic fiber blankets. When using it, it is necessary to use adhesives. How should we prepare the adhesives? Let’s take a look at them:
1. Research on adhesive compounding: Organic adhesive can give good physical strength to ceramic fiber blanket. The reinforcing effect of phenolic resin is better than CMC, CMC is better than PVA, but organic adhesive can’t resist high temperature; inorganic adhesive can resist high temperature, but enhance effect Poor, in which the water glass has the best reinforcing effect; the organic adhesive compounding can play the role of mutual filter aid, thereby enhancing the reinforcing effect.
CMC can be used as a reference reagent, and other reagents can be added to obtain the best ratio of CMC to cationic starch of 1:1, and the optimal ratio of CMC and PVA is 8:2.
The combination of inorganic and inorganic binders can enhance the reinforcing effect, and the ratio of silica sol to water glass is finally determined to be 10:1.
By discussing the ratio of water glass to PVA 10:1, the fabricated ceramic fiber blanket can withstand the high temperature of 400 ° C, and give the paper a higher physical strength at normal temperature;
2. Research on modification of inorganic adhesive: By modifying the water glass with disodium hydrogen phosphate and sodium tetraborate, the high temperature collapsibility of the water glass and the brittleness of the paper are improved.
The experimental determination of the initial determination of the amount of disodium hydrogen phosphate is 4%, the amount of sodium tetraborate is 2.5%; the water glass is modified by sodium dihydrogen phosphate and sodium tetraborate, the tensile strength and resistance of the ceramic fiber blanket The degree of folding has been significantly improved, and the effect of sodium tetraborate modification is better than that of sodium dihydrogen phosphate in improving the strength of the sheet;
3. Preparation of modified organic adhesive: The organic resin phenolic resin is modified with boric acid. The optimum conditions are: reactant molar ratio n (phenol): n (formaldehyde): n (boric acid) = 1.0: 1.5: 0.4, the amount of catalyst ammonia is 10% of the total mass of the reactant; the condensation reaction temperature is in the range of 60 ° C to 70 ° C, the time is 2.0 h to 2.5 h, the esterification reaction temperature is 100 ° C, and the time is about 3 hours;
It has been found through application that the boron-modified phenolic resin not only has a good bonding effect on aluminum silicate fiber paper at normal temperature, but also has a high paper-forming strength and a good bonding effect at high temperatures, and can withstand up to 600. °C high temperature.
The high temperature resistance mechanism of boric acid modified phenolic resin was discussed. The phenolic resin modified by boric acid not only reduced the free phenolic hydroxyl group in the system, but also the bond energy of the introduced boron-oxygen bond was much larger than that of the carbon-carbon bond. Can withstand a certain high temperature;
4. Discussion of solid adhesives The optimum conditions for adding PVA fiber to make aluminum silicate fiber paper are: 20% PVA fiber addition; drying at 140 ° C; dispersion time is 210 s.
Through the research of adhesive compounding, the optimal dosage of compound adhesive is 10% CMC, 50% of PAC, silica sol and water glass. 5. Formulation of different product adhesives: Insulation cup insulation paper adhesive selection The organic phenolic resin is added in an amount of 10%; the humidifier insulating paper adhesive is selected from the combination of water glass and PVA, and the added amount is water glass 20%, PVA 2%;
The high temperature furnace is lined with aluminum silicate fiberboard, the adhesive is made of sodium tetraborate modified water glass, the dosage is set to 20%; after the paper is dried, the adhesive is formed into a film, and the aluminum silicate fiber is used as a skeleton to form a closed gas chamber locally. Here we can regard this gas cylinder as a closed pore. This closed pore reduces the convective heat transfer of the air and improves the thermal insulation performance of the aluminum silicate fiber paper to some extent.
After understanding the special adhesive for how to prepare the ceramic fiber blanket, it will not be troublesome in the process of preparation in the future, which also provides convenience for itself.