It is produced from Urea and formaldehyde.
Industrial Formaldehyde (36%) 960
potassium hydroxide(30%) some
Urea(Nitrogin content 46.6%) 370
Formic Acid(20%) some
Put formadehyde into reactor,mixing,and add potassium hydroxide to make PH to 7.5,
heating to 40℃，adding 3/4 urea of total amount,then heat to 90℃ in 50-60mins and keep
20mins. Then adding remining Urea and reacting for 40mins in 90℃. To add formic acid to
make PH in 5.3-5.6 and in 92℃ keep warming 30mins,then heating slowly to 97℃。
When viscosity reaches to requested one,adding potassium hydroxide to make PH at 7.5-8.
Vacuum dewatering,when it reaches to 65% of formaldehyde water and stop dewartering.
Cooling,and add potassium hydroxide to make PH at 7-8 at same time. When temperature
cool to 50℃ and release the glue to tank.
【Title of this article】：Urea-formaldehyde Glue for Blocks，【Site address】：http://www.invech-machinery.com/industrydynamics/144.html