JPS6410633B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for alleviating pitch defects in a paper manufacturing process. Wood, the raw material for the paper industry, consists of five components: cellulose, hemicellulose, lignin, organic matter, and extracted components. Although it varies depending on the tree species, pulping method, type of process, bleaching conditions, temperature conditions, etc., abietic acid, saturated fatty acids, and other components in the extracted components may dissolve or become fine particles in the water. As they flow through the papermaking process, they become cloudy and are subject to chemical or physical changes, and due to the mutual properties of the components, they gradually form into larger particles or clumps. In most cases, they are black or brown in color and are clean, but also sticky and cause various so-called pitch problems. Paper breaks during paper making, and water containing pitch adheres to all machines and tools that come into contact with it, causing staining of paper products, deterioration of quality, and even suspension of operations. When this happens, operations must be stopped and the pits must be removed by cleaning. The reality is that we are suffering from the obstacles caused by these pits, and the damage we suffer from them is considerable. Therefore, in order to prevent problems caused by these pitches, it is necessary to remove the generated pitches and the substances that cause them from the water, or to prevent the adhesion of paper or machinery. Pitch control agents have come into use for these purposes. There are two types of pitch control agents: dispersion type and adsorption type. Dispersed pitch control agents are fairly commonly used. This has the ability to disperse pitch particles that are about to associate, aggregate, or adhere to the water, but does not remove pitch itself from the water. However, recently, factory water has become closed-circuited, and factory water is now being recycled as much as possible. If a dispersed pitch control agent is used in this closed water system, pitch is not removed from the water, and the pitch concentration gradually increases, resulting in pitch injury or wastewater treatment. It has the disadvantage of being a burden and has many problems. Talc is also used as an adsorption type pitch control agent.
When a fine powder such as clay is added and suspended in water, the fine powder adsorbs the pitch and passes into the paper that is being made, and the pitch is removed. but,
There are many disadvantages such as an increase in ash content in the paper and a decrease in paper strength. The colloidal monohydrated aluminum oxide used by the present inventors is positively charged and tends to combine with negatively charged pitch particles to form new particles with zero charge. The particles are non-sticky and flocculent. This flock is used during paper making.
Due to the overaction, it remains in the paper, which has the advantage of removing pitch from the papermaking water and keeping the pitch concentration in the papermaking water low. However, if there is a large amount of pitch, there is a tendency that the pitch cannot be removed sufficiently. The present inventors have discovered that by using the above-mentioned colloidal monohydrated aluminum oxide in combination with aluminum sulfate, it is possible to efficiently remove pitch and reduce pitch injury in a small amount, efficiently, and at low cost. . In other words, the method for reducing pitch damage of the present invention applies colloidal monohydrated aluminum oxide to pulp.
It consists of using together an amount of 20 ppm to 600 ppm and an amount of aluminum sulfate of 400 ppm to 4000 ppm (in terms of aluminum oxide) based on the pulp. Colloidal monohydrated aluminum oxide and aluminum sulfate are applied to Saveall, Nissui Bit, and Huang Pump, but can also be added to Chiest, Peter, and Pulper. Aluminum sulfate is preferably used simultaneously with the aforementioned hydrated aluminum oxide, but it can also be used before or after the addition of the aforementioned hydrated aluminum oxide. These are added directly or diluted with water. When used together, the amounts of both colloidal monohydrate aluminum oxide should be
20ppm~600ppm, aluminum sulfate 400ppm~
Desirably it is 4000ppm (aluminum oxide equivalent). It goes without saying that colloidal monohydrated aluminum oxide in such an amount does not adversely affect the quality of paper. The pit damage reduction method of the present invention uses colloidal monohydrated aluminum oxide and aluminum sulfate in combination to coagulate and remove fine pits that are present in valve fluid and have been difficult to remove in the past. I can do it. In addition, an aggregation effect can be seen in a short period of time. Colloidal monohydrated aluminum oxide can be reduced to 1/5 to 1/3 of the amount when used alone. Example 1 Test method Predetermined amounts of colloidal monohydrated aluminum oxide and aluminum sulfate were added to 100ml of pulp liquid (pulp concentration 2%, pitch concentration 660ppm), stirred for 10 minutes, and passed through a 120 mesh wire. The pitch concentration of the solution was measured to determine the pitch removal rate. 2 Test Results The amounts of colloidal monohydrated aluminum oxide and sulfuric acid band are expressed in terms of pulp, and aluminum sulfate is expressed in terms of aluminum oxide.

【table】

[Table] When used together, it showed excellent pitch removal effect. Reference Example 1 Test method Predetermined amounts of colloidal monohydrated aluminum oxide and aluminum sulfate were added to 100ml of pulp liquid (pulp concentration 2%, pitch concentration 660ppm), and after stirring for 10 minutes, a 120 mesh wire was added. The pitch concentration of the liquid was measured to determine the pitch removal rate. For comparison, rosin was dissolved in a 2% pulp concentration solution (addition amount: 450 ppm) and the rosin removal rate was determined by the same treatment. 2 Test results The test results are as follows.

【table】

Claims (1)

[Claims] 1. In a papermaking process characterized by using colloidal monohydrated aluminum oxide in an amount of 20 ppm to 600 ppm based on the pulp and aluminum sulfate in an amount of 400 ppm to 4000 ppm (in terms of aluminum oxide) based on the pulp. Pituchi disability reduction method.