Cationic Starch from Starch Solution

PT. Starch Solution Internasional is the biggest Modified Tapioca Starch producer for paper and textile application in Indonesia. They produced derivative products of tapioca starch by changing the characteristics of tapioca starch according to the customer’s requirement through chemical process/reaction.

The product of tapioca starch modification is used by paper, textile, paper packaging, ceramics, and some other industries.

Some trades marks of our products have launched to the market are NYLGUM, SOLSACAT, SOLSACOAT, SOLSATEX, SOLSABOND, SOLSAMIC, SOLSAPSRAY, IndoTex Starch-OX, IndoTex Starch-SPR etc. We also still produce under license of AVEBE UA brand name (AMYLOFAX, AVETEX) for some overseas customers

Cationic Starch in Wet End Paper Application

A cationic starch has two function to do in the wet end system.

a. First function    : to emulsify ASA or AKD (Alkaline sizing

b. Second function : to improve fiber to fiber bonding

• Better internal bond
• Better tensile
• Improve burst

How does it work?
Fiber in the wet end is anionic (-) or negative charged.
Solsacat is attracted to the fiber and thus can help bond fibers together.

How does it work with ASA and AKD?
Cationic starch mixed with either ASA or AKD size under precise conditions by the sizing supplier.
The Cationic starch then provides a liquid layer around the sizing that “sticks” it to fiber. The cationic (+) charge is the main mechanism.
The starch protects the sizing chemical from other chemicals when wet and flows away when in the dryers

Basic laboratory emulsification test
•Emulsion stability vs time
•Starch concentration variation
•ASA : starch mixing ratio
•Water quality effect (hardness)
• ASA dosage variation

Summary
• ASA emulsion should be directly dosed to the machine without storage
• Starch concentration should be kept @ 4 % solids
• The emulsification ratio of ASA : Starch should be 0.5 – 1.0 : 1.0
• The emulsion particle size should be in the range of 0.5 – 1.5 micron and pH should be between 3.5 – 4.5

COATING STARCH IN PAPER APPLICATION

Theoritical of Advantages and Disadvantages of coating starch

Advantages:

Lower total coating cost ( about 15%)
Improved board stiffness (good for packaging)
Better water holding for coatings
Improved holdout of top coat

Disadvantages:
Higher viscosity of coating and lower coating solids (may affect drying load)
Potential decrease in quality of fold (cracking due to stiffness)
Potential poorer wet pick (must use more crosslinker to offset this)

Some benefit of coating starch are :

• High Binding power and comparable with standard SBR latex
• High dry solid coating
• Good water retention
• Improve paper stiffness compared to all-latex
• Optimal run ability at high speed.
• Printability improvement.
• Less downtime.
• Cost Reduction

Characteristic of coating starch product needed :

1. Has good viscosity stability after storage , event was store for 24 hours the viscosity stay stable.
2. 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 coatings
3. Low 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 tendency
4. High 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

1. 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

reff : (https://steemit.com/coating/@deviasyifak)