Rosin Sizing-The Most Essential Internal Paper Sizing Chemical
Sizing reduces the tendency of paper when dry to absorb the liquid to allow the paints or the inks to remain on the paper's surface. This will help in providing precise printing and writing surface.
In papermaking, there are two types of sizing which help in reducing the liquid absorption tendency, which is as follows:
● Internal sizing
● Surface sizing
Internal Sizing and Internal Sizing Chemicals
The internal sizing is applied to almost all papermaking processes, especially those which are made with machines. With the right type of sizing agents, the papermakers can create a unique quality of papers. The prime role of the internal paper sizing chemicals is to improve the resistance against liquid penetration such as ink and water.
Using internal sizing, the paper becomes ready for printing, writing, graphic, and various other purposes. Therefore, to achieve this, the paper manufacturers can also use the wet-end additives, and in addition to this, the dried paper is coated with the best internal sizing agent.
The correct sizing agent helps provide precise control over the ink spreading process. In addition to this, the sized paper can accumulate less dust and retain the fillers and fibers.
Rosin Sizing-Effective for Acidic Type Paper Sizing
The internal sizing chemicals that are effectively used in the wet end are rosin and alkyd ketone dimer. Above this, the internal sizing agent can greatly influence the retention of the paper sheet's fibers and deteriorating process. Moreover, it also affects the running speed of the paper machine.
Rosin sizing is a resinous material that remains hard when the whole of the turpentine's volatile contents are either boiled away or washed away. It is an acidic type sizing agent highly usable in the paper mill as an internal sizing agent.
Besides that, other rosins' derivatives are still the most widely accepted option obtained from the regenerative raw material. Therefore, these are widely accepted and used as wet-end sizing agents.
Another essential resource of the rosin is the "tail oil," produced during the manufacturing process of kraft pulp from the softwood. One of the important rosin components is abietic acid, an unsaturated compound with three fused six-membered rings and a carboxyl group.
Other Rosin Derivatives which are used as Internal Sizing Agents
Cationic Rosin Sizing Agents
This agent is highly effective for the paper's sizing because it helps decrease the consumption of paper additives like aluminum sulfate, which reduces environmental pollution and improves the quality of the paper. It is further helpful in reducing the discharge of acidic sewage.
Fortified Rosin Size
Another essential internal paper sizing chemical is fortified rosin size, produced by the reaction of the fumaric acid and gum rosin under suitable conditions. It acts as an internal sizing agent because it has Diels-alder adducts containing the extra carboxyl group, which help produce more proficient sizing.
Rosin Soap Size Agent
It's the derivative of a rosin sizing agent, consisting of the resin acids' sodium salts. The resin acids' saponification obtains the rosin size with those sodium bases or the NaOH or the Sodium Carbonate. However, various forms of the rosin soap sizing agent are available as the paste size, extended size, and dry size.
Neutral Size Rosins
The neutral size rosins can also be used as the internal sizing agent. It is highly suitable for the use of calcium carbonate for improving the optical properties.
Functions of the Rosin Sizing Agents
The rosin sizing agent has aluminum resinate, which is the most active compound used to reduce the paper's absorption tendency and improve the quality. This component opposes the penetration of the water into the surface of the paper.