urea formaldehyde slide share

1. Urea Formaldehyde
Presented By
Himmat Purohit

2. Index
 Introduction
 Chemical structure
 Manufacturing Process
 Properties
 Advantages & disadvantages
 Application

3. Introduction
 UF resin was first produced in 1884 by Holzer, who was working with Bernhard
Tollens.
 Urea-formaldehyde, also known as urea-methanal, so named for its common
synthesis pathway and overall structure, is a non-transparent thermosetting resin
or plastic.
 It is produced from urea and formaldehyde. These resins are used in adhesives,
finishes, particle board, and moulded objects.
 UF glue resins were the most important type of adhesives in the wood industry last
60 years, especially for the production of wood based panels.

4.  In industrial production, urea resins are made by the condensation of
formaldehyde and urea in an aqueous solution, using ammonia as an
alkaline catalyst .
 The condensation reaction gives a colourless, solution that can be spray-dried
to a powder for later use in coatings or adhesives.
 it can also be mixed with cellulose filler to produce powders for moulding into
solid objects.
 Under the influence of heat and pressure, the resin, at this point made up
largely of low-molecular-weight intermediate polymers or prepolymers, is
cured to its final state,
 which consists of a three-dimensional network of interlinked polymer.

5. Chemical Structure

6. UF Condensation Reaction

7. Manufacturing Process
 Urea and formaldehyde reacted at reflux under acid
conditions to a required viscosity.
 Resin is neutralized and cooled.
 A further amount of urea is added to react with
remaining free formaldehyde.
 Resin is evaporated to obtain the correct viscosity and
solids

8. Diagram

9. Process control
 Formaldehyde and urea are weighed into a reactor
from a weigh vessel.
 Precision on formalin weighing is 0.02%.
 Precision on urea weighing is 0.5%.
 Viscometers and pH meters are calibrated daily.
 Thermocouples are calibrated bi-annually

10. Properties
 It has a very high tensile strength.
 Has the property of flexural modulus.
 Has the property of heat distortion temperature.
 Has the capacity of low water absorption .
 It has the property of mould shrinkage.
 Has a property of high surface hardness.

11. Advantages
 Higher maximum operating temperature.
 Better dielectric constant.
 Tracking resistance.
 Dimensional stability compared with cellulose filled
urea formaldehyde
 Lower cost
 Good electrical insulator

12. Disadvantages
 Lower High Density Temperature(HDT).
 Higher water absorption and mould shrinkage.
 Lower surface hardness.
 can have toxic effects
 breathing difficulties,

13. Application
 Electrical Casings
 Tableware
 Decorative worktop laminates
 Plug & switches Buttons
 Paints
 Surface coating

14. Urea formaldehyde powder glue is used in many wood practices and its shell life is only 1
month but it can be longer in liquid glues.

16. Thank You