Applications

Wet-end starches improve strength and print characteristics of ready paper and contribute at the same time to improved retention, dewatering and runability at the paper machine.

The function of wet-end starch in the machine is affected by a number of factors, such as fibre (raw material), pH, conductivity, charge and disturbing substances. A first step in the process of optimizing the wet-end starch is to carry out a wet-end survey and to map which chemicals are being used. The objective of the wet-end survey is to check the function of the existing wet-end starch. A second step in the optimisation process could be a laboratory study to investigate the efficiency of different starches. Depending on your requirements we can select from the following evaluations;

• starch adsorption
• retention and dewatering
• sheet-forming study including strength evaluation

To achieve the optimum performance of your wet-end starch you need to secure a proper cooking and handling of the product, select an optimal product for a specific paper machine and an optimal addition strategy for the product.

Solam has a broad product portfolio of cationic starches and we can offer cook-up starches and cold-water soluble starches. The cationic starches have a degree of substitution from 0.02 to 0.17. The brand name for Solam wet-end starches are Solbond.

The Solam team is ready to assist you in achieving the optimum benefit of your wet-end starch.

Starches in surface application improves printing characteristic of ready paper. Starches can also improve barrier properties such as oxygen and fat barrier of ready paper.

The optimal product for a paper quality depends on several parameters, such as the required film-forming properties and barrier properties, application equipment, temperature at the application, dry content of cooked starch solution and its required storage stability as starch solution.

Solam can investigate the starch behaviour at our application lab, for example storage stability with different dry content and temperatures. Surface application of different starch products can also be done at our application lab.

Solam has a broad product portfolio of starches for surface application. The products need to be viscosity-adjusted to get a good performance and runability at the paper machine. The brand name for Solam surface application starches are Solsize and Solcoat.

The Solam team is ready to assist you in the selection of an optimal starch product for your surface application.

Starch products can be used in coating applications as binders. Starches contribute to excellent binder characteristics and improved water retention. Starch can replace latex up to a certain amount which results in cost savings.

To find an optimal product for a coating formulation is a rather complicated process. Together with the customer we start with lab work. We produce different coating formulations and investigate viscosity, dry content, water retention and storage stability. As a second step we continue with lab coating on paper and evaluate the surface properties.

The next step is a pilot trial or a full-scale trial depending on which resources are available at the customer. Solam has experience of latex replacement in both pre- and top-coating.

Solam has a broad product portfolio for coating applications. The brand names for the products that are suitable for latex replacement are Solsize and Solcoat.

The Solam team is ready to assist you in finding an optimal starch product for your coating application.

Starches in spray application improve strength characteristics, especially Z-strength and Scott bond value, of the ready paper/board.

A starch slurry (uncooked) is sprayed between layers during board manufacture or in the wet section at fluting production. The starch granules swell/gelatinize when the paper/board comes to the drying section. The swollen granules provide a glue effect and increase the contact surfaces between fibres, fine material and filler and result in higher strength properties. The gelatinization temperature is affected by the type of starch and modification. It is important to find a starch with the proper characteristics for your system; a too low gelatinization temperature can result in bad runability and deposits in the wire section, while a too high gelatinization temperature will result in no gelatinization and no strength increase. It is also important that there is sufficient water left when the paper/board reaches the drying section to enable the starch granules to swell.

If the water content is too low, the granules will not swell and the glue effect is not achieved. Dry content after press section and temperature profile in the drying section are important parameters to control in order to achieve maximum benefits of a spray starch.

Our application lab can investigate the gelatinization temperature for different starches and modifications.

Solam has a broad product portfolio of spray starches. The brand name for Solam spray starches are Solspray.

The Solam team is ready to assist you in selecting an optimum starch for your spray application.