GROSIZE-200 - Oxidized Starch for Spray & Sizing of Paper

Why GROSIZE-200 and not Native Maize Starch?

In many paper mills Native Maize Starch is used for web sizing and surface sizing. But Oxidized Starch has many advantages over Native Maize starch in paper making process.

In industrial water-borne coatings applied at high shear rates the molecular weight of native starch has to be reduced in order to achieve sufficient low viscosity of the starch solution. This can commonly be performed by oxidation, which is a degrading process. Native starch has a very high viscosity at high starch concentrations whereas the viscosity of degraded starch is not greatly affected by an increase in concentration. This makes oxidized starch easier to use than native starch at higher concentrations. The oxidation process is mild and is performed under controlled conditions, and this allows the oxidant to attach to the most reactive bond on the starch polymer.

The gelatinization temperature of the starch is reduced in proportion to the degree of oxidation. The granules disintegrate when cooked and this results in a reduction in the peak viscosity. All these properties make oxidized starches suitable as paper coating binders and in addition, the anionic character of oxidized starches prevents agglomeration of pigments in coating formulations.

Oxidized Starch for Paper Industry

GROSIZE-200 (Oxidized Starch) in the surface treatment of paper & board

In papermaking, starch is the third largest component by weight, surpassed only by Cellulose fiber and mineral pigments. This makes the GROSIZE-200 one of the most important raw material for the paper industry.

The main application areas for starch within the papermaking process are-

    Furnish preparation prior to web formation
    – GROSIZE-200 is used as a flocculating agent and retention aid, and to improve internal sheet strength.
    Surface Sizing
    – GORSIZE-200 is used as an adhesive to bond vessel segments and loose Fibers at the sheet surface, to enhance paper strength and stiffness, to give dimensional stability & improve offset printability
    – GROSIZE-200 is used as a binder for pigments.
Oxidized Starch for Paper Industry

Surface treatment - Sizing & Coating

Most grades of paper and board need to be resistant to wetting and penetration by liquids. The properties of the final paper surface can be modified in several different ways, the most important being surface sizing, coating and calendaring by GROSIZE-200.

Surface Sizing

Surface sizing is a process whereby chemical additives are applied to provide the paper with resistance to wetting and penetration of liquids, i.e. make it more water repellent and to bind the particles in the surface and increase the surface strength. Internal sizing is a process where chemicals are added to the paper stock and retained on the fibers in the wet end. Surface sizing is the application of a size to the web surface at the dry end of the process. GROSIZE-200 is used as binder in surface sizing. Besides raising the surface strength, starch addition also lowers water sensitivity, reduces dimensional changes, imparts stiffness, and raises air-leak density of the sheet and it also improves the tensile strength and internal bonding of the paper.

Surface Treatment

A paper surface sized by the application of GROSIZE-200 resists penetration of water over a relatively long period of time despite its hydrophilic character. However, the application of a GROSIZE-200 improves the resistance to water. GROSIZE-200 is resistant to retro gradation and their dispersions can be held at a lower temperature than is required for the products of chemical or thermal/chemical conversion. GROSIZE-200 is used for surface sizing of paper and paperboard at the size press machine for increasing the mechanical strength, including the strength of the surface, and also as a bonding additive in the manufacture of drywall. GROSIZE-200 is commonly used to provide water-resistance (prevent paper from blurring with water or ink) and printability to paper by surface application.


  • Improved paper appearance with respect to brightness, gloss, smoothness of paper.
  • Faster drying of inks and sharpness of print on paper.
  • Can be used when a high degree of sizing is required.
  • Great hand feel.
  • Provides additional starch/ cellulose hydrogen bonds resulting in improved bursting strength.
  • Improves the pick resistance property of paper.

Typical Analysis

Characteristic Property
Color/ Form White to off-white powder
Moisture % 12.00, Max.
Ash % 3.00, Max.
Viscosity of 10 % solution cooked: At 90O C and checked at 50O C in Cps in B.F. Viscometer 25-35
Brightness % (on Elrepho) 85.00, Min.
pH of 10 % solution 5.50 – 6.50

Method of Use

The product at a required concentration is mixed with cold water under agitation to form homogenous slurry. The slurry is cooked by means of jet cooker or steam heated jacketed vessel with agitation at 90O C for about 20 minutes. The cooked paste can be directly added to the size press at a desired dose.


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Frequently Asked Questions

Corrugated paper box is used mainly for shipping / transportation and storage of variety of items for their strength and durability. In the process of making box mainly paper and gum adhesives are major players which determine strength of the box. More moisture in the box will cause lower compression strength of the box. Lower compression causes collapse of stacked boxes and thus damage to the goods packed inside.

So control of moisture in corrugated box means controlling moisture in paper and in gum adhesives used in box making.

1.Controlled moisture in paper.

The major component of paper, cellulose fiber, is hygroscopic in nature and therefore tends to absorb moisture from a damp or humid atmosphere or release moisture in dry atmosphere. When paper gains moisture corrugated box loses its bursting strength (BS) and compression strength (CS) and when it loses moisture corrugated box develops the cracking or board breaking problem.

To avoid this cracking of corrugated sheets use of sprayer to spray water onto base paper, changing of machine speed and adjustment of the flexible paper-lead roller to cut preheat area are required. Avoid exposure of paper reels in open sun heat which will bring down paper moisture substantially to cause cracking of corrugated sheets at the end.

To overcome excess moisture in corrugated board use of correct paper cob, changing machine speed, use of preheaters etc. are some of the solutions.

2. Moisture control through gum adhesives

Gum adhesives play major role in avoiding excess moisture in corrugated box. Type and quality of starch used in adhesives, type of fillers used, modifications to starch and chemicals used in the gum adhesives are major players in causing excess moisture in corrugated board.

a) Gel temperature of gum is important in automated plants and in single face. High pin adhesion at low temperature gives complete dry liners and board. If gum fails to get gelatinized immediately when it reaches heaters at the set speed of machine, it fails to develop stronger bond adhesion and develops the tendency of gaining moisture from atmosphere in later stage even after complete drying.

b) Type of starch used and specific modification to starch to develop moisture resistance are very important factors. Usually hydrolysis of starch with the use of acid and then use of strong alkali to get viscous gum is a common product which is available in the market. These type of adhesives are bound to gain moisture in damp atmosphere and humid climatic conditions. Special modification treatment to high quality starch to develop moisture resistance is required.

c) Different fillers are used in gum adhesive making to bring down cost and make our adhesives cheaper in the market of competition. Very low cost fillers such as different flours, clay, Urea etc. are used which pay no role in gum quality than reducing price substantially. Flour, clay or urea are more of hygroscopic in nature and cause more and more moisture gain whenever gets opportunity.

d) Chemicals used in gum adhesives such as Sodium Hydroxide (caustic soda) is highly hygroscopic and not only absorbs moisture but carbon dioxide, sulfur dioxide in the air. It is also highly deliquescent and absorbs moisture to form an aqueous solution. More moisture means lesser bursting and compression strength which results in collapse of stacked boxes.

Grodex Moisture Resistant Powder adhesives are made of finest quality of different types of starch. A unique modification process with the state of art technology develops complete moisture resistance in adhesives. These products are not only Sodium Hydroxide (caustic soda) free but no other chemical is used in it make it eco and worker friendly. These are proved adhesives for moisture resistance all over the world over past several years for guaranteed moisture resistance and control in corrugated paper board industry. Use of these adhesives will solve not only your moisture problems but will provide you totally new thinking line of grabbing huge hidden profits from your box in a very competitive market.

Powder Adhesives For Corrugated Paper Boards