How to Use UF Powder

Urea formaldehyde (UF) adhesives are available as either liquid resins or powder form. Both will produce similar glue line characteristics: strong, rigid, thermosetting, and excellent heat resistance.
Urea formaldehyde molding powder are preferred where production runs are infrequent, where the ambient temperature is high, and where longer storage life is needed. UF powder have a one-year shelf life. This are pre-formulated should be mixed with required fillers, hardener and catalyst to meet a wide range of process requirements.

Preparation of UF Adhesive Resin

To make urea resin from UF powder, use water necessary to reconstitute the powder resin. Amount of water is about 50-65% dry weight of the dry powder to be mixed.

• Filled the container with 2/3 part of water needed to the mixing vessel.
• Slowly add the powder with stirring motor with slow speed ( < 2,000 rpm) with a mechanical agitator.
• Stirr continuously for about 5 minutes using a spatula to scrape powder from the sides back into the liquid. The mixture should be creamy and virtually lump-free at this point.
• Add the remaining 1/3 water and mix for an additional minute. Mix should be smooth, creamy, and lump-free.

To use this UF paste to the surface of wood or plywood evenly and glued together both wood to make stick each other. Press both of wood and lets it on the press condition and let it dry. Urea formaldehyde is a termosetting resing that mean this resin can cured (hard) need time and temperature. Curing time can be faster if apply in higher temparature, but it can be longer if lets this ply in room temperature.

The required condition is as follows:

• Solid wood glue-ups will require from 150 psi for low-density species up to 250 psi for high-density species.
• Cold pressing panels at 70 °F will require from 4 hours press time on low density species to 6 hours on high density species. At 90 °F this range will be from 2 hours to 4 hours.