Starch

What is Starch
Starch is a natural carbohydrate polymer. The molecular formulae of starch is (C6H10O5)n. Mainly starch is used in paper mill to improve dry strength and surface. Its molecular weight is very high. Native starch has a very high viscosity. On the other hand modified starch has lower viscosity. The main sources of starches are regular corn, tapioca, waxy maize, wheat and potato. After cellulose fiber and mineral filler, starch is the third most widespread raw material in paper mill industries.

Molecular weight of starch is a factor for application of starch in paper mill industries. The maximum molecular weight (non-degraded) of starch is suitable for wet-end application. Because the non-degraded starches have huge dimensions, so the binding power is increased. On the other hand, reduced molecular weight (degraded) starches is suitable for surface application. This is the reason that degraded starches have lower viscosity.

Generally the starch is used in paper mill in three different stages for different function. The stages are wet end section for internal sizing, size press for surface sizing, and size press or off-machine application for coating. The most common wet-end starches are cationic starches or amphoteric starches or native starches while the surface starches are oxidized or hydroxyethylated.

Types of starches
Mainly starch is classified into two types. Native starch and modified starch.

Native starch: The most common native starches are corn starch, tapioca starch, waxy maize starch, potato starch, wheat starch and rice starch.

Modified starch: Cationic starch, amphoteric starch, oxidized starch etc.

Function of starches:

  • Starch enhances the stiffness and bonding of paper sheet.
  • Improve formation
  • improve internal bond,
  • Improve surface strength and wax-pick
  • Increase tensile strength
  • Improve fiber fines, filler and chemical retention.
  • Improve drainage.
  • increase dry strength properties
  • better writing and printing surface
  • reduce linting and dusting
  • Reduce cost, because it is allowed to use more filler and more recycled fibers.
  • Increase runnability and productivity. As breaks are lower.
  • Energy consumption lower due to high binding power.
This entry was posted in Dry strength additives and tagged . Bookmark the permalink.

20 Responses to Starch

  1. vivek kaushik says:

    I wants to know how to use Maize Starch In Kraft paper industries , in which ratio we should use it & with the area such as Pulper, Chester etc.

  2. DINESH. E says:

    I want the details of chemicals added to the native starch for starch modification for paper industry, textile industry and food industry to do the controller design for starch modification project.
    Thanking You.

  3. You really make it seem so easy with your presentation but I find this matter to be really something that I think
    I would never understand. It seems too complex
    and extremely broad for me. I am looking forward for your next post, I’ll try to
    get the hang of it!

  4. Aloke Chatterjee says:

    dear sir,
    we are making 3 layer kraft from 100 % recycled occ/ndlkc/kcb etc.on using Native starch @ 70-90 kg/t of paper,the final corrugated board are cracking in CD.But at the same time the Bursting strength of the paper & corrugated boards are increasing substantially (say + 3 bf ),can reduce the costly imported raw material.
    Kindly suggest the best starch & its dose on surface sizing so that BF doesn’t reduce but at the same time the corrugated board avoids Cracking.
    Aloke Chatterjee.

    • SHANKAR GARG says:

      YOU CAN USE LOWER MOLECULAR WEIGHT (HAVING LOW VISCOCITY) STARCHES FOR SURFACE SIZE APPLICATION IN POND TYPE SIZEPRESS, AND MODIFIED STARCH OF LOW GEL TEMP. IN WET END APPLICATION TO AVOID CRACKING PROBLEM IN CORRUGATED BOARD .
      SHANKAR GARG.

    • Naveen Kumar Gurung says:

      Mr.Aloke,

      It is not recommended to use native starch 70-79kg/ton.
      Definitely you face the problem of cracking. As starch having the nature of hydroscopic.
      Recommendation – Use modified high viscosity starch at size press, with lower solid.
      your problem will be solved.

  5. Sibeeswaran says:

    Any one need tapioca starch

  6. sahar says:

    Dear sir
    Please kindly tell me the differences between method of using native starch and oxidized starch to produce fluting paper. When we use native starch we get good results.but we dont get the same result with oxidized starch.
    We add APS (Ammonium per sulfate ) for native starch.

  7. Vikram Kausal says:

    While using Corn Starch at sizing press, initially work well but if power goes off, after that the BF of paper is not achieved. what can be the reason behind that.

  8. Norm of starch at size press should be max kg/ton in Kraft paper without any prob.we want to reduce starch consumption

  9. We are facing a problem of starch consumption at size press for making kraft paper from recycle waste paper I want to know the max KGS/ton of paper should be ,have any norms.

  10. Abdelfatah says:

    Dear sir
    about native starch, we need to know
    the mechanism of reaction of nstive starch
    with fibers when we use the native starch
    in wet end in paper machine, addition in
    machine chest.

    • Naveen Kumar Gurung says:

      As native starch has no charge, hence there is no diverse effect on fiber.
      As far as dosing point is concern while dosing that same on machine chest the retention of starch is very low around 65-70%.

      Kindly let know the objective of using native starch in wet end than only I will suggest you the dosing point.

  11. Meena says:

    Please advice on how to use starch in tissue paper making from waste.
    What quantity to be mixed and what is the procedure at the pulling .

  12. vikash singh says:

    Sir,
    I want to know woud i use starch in machine cheast because we face stifeness problam in 120 gsm paper.we use oxidized starch in size press @20 kg/ton please give me some soulation

Leave a Reply

Your email address will not be published. Required fields are marked *