COATING STARCH IN PAPER APPLICATION (part 2)
Characteristic of coating starch product needed :
Has good viscosity stability after storage , event was store for 24 hours the viscosity stay stable.
Coating starch product has to in very narrow viscosity specification
No viscosity fluctuation results in highest latex replacement at high dry solid coating
– To be cooked at high dry solids
– To be used in high dry solid coatingsLow Mottling tendency (Molecular weight distribution)
Molecular weight of starch molecules have influence on the migration of the starch through a coating layer.
Small starch molecules migrate more, resulting in higher mottling tendencyHigh dry solid coating
Coating starch product can be cooked at max. 40% dry solid
High dry solid coating will:
- decrease binder consumption
- decrease drying energy
- Improve Pick up Coating Colour (gr/m2)
- Reduced Over all cost of Coating Colour
- As a retainable starch binder
Retainable starches have following advantages
• low BOD/COD values of waste water
• less bacteriological- and pH- control problems
• less problems with enzymatic degradation of wet-end starch