Specialist supplier of scientific water analysis, beverage and laboratory test equipment

The Use of Starch in Paper and Adhesive Manufacturing

Written by Janice M on . Posted in Technical Tips

Application Notes:

http://selectech.co.za/wp-content/uploads/2016/06/paper.jpg

1. The Use of Starch

Starch is widely used in paper manufacturing for applications such as bonding, surface coatings and cardboard adhesives.
During production and quality control, the concentration of starch is commonly measured, usually with a refractometer, such as the Pal Refractometer.


 
Hand-held Pal Refractometer


Another factor which paper manufacturers are starting to consider is the viscosity. The viscosity level of starch will differ for different applications.
The new portable VISCO™ Viscosity Meter is ideal for starch viscosity measurements.

The new Visco™

2. Relationship between Starch and Viscosity in Paper Applications

Application

Type of Starch

Property

Purpose of Use

Internal Strengthening Agent

Cationic Starch
Amphoteric Starch

Viscosity: High
Charge: Positive

Add starch paste in pulp suspension to improve paper strength and filler retention, or to expedite the drying process of pulp sheet

Sizing Agent

Oxidized Starch
Acid-modified Starch
Enzyme-modified Starch

Viscosity: Low to Moderate
Fluidity: High

Apply starch paste evenly on the surface of dried paper to improve paper surface strength and to withstand the load of printing

Coating Agent

Oxidized Starch
Acid-modified Starch
Enzyme-modified Starch
Starch Phosphate

Viscosity: Low
Fluidity: High
Easy to mix but do not agglomerate with pigment

Mix starch paste and latex with pigment to increase viscosity of coating material, and apply the mixture evenly on the surface of dried paper to improve paper surface strength

Interlayer Adhesive

Unmodified Starch
Starch Phosphate

Viscosity: High
Gelatinization temperature proper for paperboard production

Spray un-gelatinized starch between pulp sheets to strongly paste the sheets for paperboard. No special equipment is required for producing adhesive

Cardboard Adhesive

Unmodified Starch
Soluble Starch

Viscosity: High
Strong alkaline

Gelatinize starch with alkali and apply on the apexes of corrugated sheet to paste together with flat cardboard sheet. No special heating system is required for producing adhesive

Ref: Agriculture & Livestock Industries Corporation (Japanese only)

 

3. Effect of Starch Solids / Viscosity on the Paper Property Relationship

Property

Low Viscosity
High Solids
(more penetration)

High Viscosity
Low Solids
(stays on surface)

Surface strength

Good

Better

Internal strength

Better

Good

Porosity

Decrease

Decrease

Ink hold out

Good

Better

Opacity

Slight loss

Least loss

Stiffness

Increase

Most increase

Source: Papermaking Surface Starch by Tongaat Huletts

Measuring the Strength of Paper / Cardboard


A Burst Strength Tester is used to measure the strength of paper / cardboard.

This instrument is able to identify failure in the direction of least resistance. It is measured by producing hydraulic pressure through a diaphragm on a circular area of the sample. The force required to burst or complete rupture of the board is measured. The bursting strength is expressed in terms of kg/cm.

You can now compare quality of different materials. The value of the bursting strength will give an indication of how much weight may be carried in a box.

 

A basic, economical Bursting Strength Tester

 

Various models are available from Selectech.
Please Email us for brochures and prices.

Trackback from your site.

Leave a comment

Products

Product lists in

language icon language icon language icon language icon

Newsletter Signup

Stay up-to-date with our monthly newsletter.

Corporate Member
Wildlife Society