JP5571333B2 - Method for producing waste paper pulp from old newspaper - Google Patents

Description

  The present invention relates to a method for producing waste paper pulp using old newspaper as a raw material.

  Traditionally, newspapers are important printed materials that can convey social events as news. The number of newspapers issued in Japan was approximately 50 million copies / day in 2007, and the amount used as newspaper paper is 3.7 million tons. Per year, about 70 kg / year is consumed per household.

  In recent years, with the aim of environmentally friendly paper based on the resource environment, each paper manufacturer has been developing technology for recycling and reducing the weight of used newspaper. Moreover, the newsprint collected by the used paper recovery becomes wastepaper pulp, and about 60-80% of newsprint is blended.

On the other hand, newspapers are becoming lighter and now it is 43 g / m ² . Waste paper pulp is a black low-quality waste paper pulp that does not remove printing ink, and is called deinked pulp (deinked pulp: DIP in overseas) as a raw material for paperboard and corrugated board, etc. Therefore, it has become a raw material for paper that requires whiteness, such as printing paper and toilet paper.

  In addition, recycled newspaper paper containing ink oil is still used as a raw material for bathroom / facial tissue, napkins and paper towels. For example, as in Patent Document 1.

Japanese National Patent Publication No. 10-506155

  In this way, recycling saves raw wood resources, while reducing the burden of waste collection and processing and reducing power consumption related to manufacturing. Recycling is preferred as a result.

  Accordingly, an object of the present invention is to provide special electrolyzed water or a surfactant in the deinking process in the manufacturing process of used paper pulp made from newspaper (used paper) that is discarded or collected from households or business establishments. The purpose of this method is to obtain a method for producing waste paper pulp using old newspaper as a raw material, whereby white paper with an excellent recovery rate can be obtained.

  As means for solving the problems of the present invention, alkaline electrolyzed water obtained by electrolyzing water to which a small amount of refined salt is added is used in the process of producing waste paper pulp made from old newspaper, In the deinking (deinking) step, a liquid surfactant is added to obtain used paper pulp made from old newspaper.

According to the present invention, in order to agitate and disaggregate old newspapers that have been shredded, they are treated with alkaline electrolyzed water obtained by electrolysis using salt, so that the generated sodium is converted into sodium hydroxide and used. The remaining chlorine exhibits an effect as a bleaching agent.
In the first place, the residual color of used paper and the use of wood as a raw material are largely attributed to the presence of lignin or denatured lignin that is the cause of browning of fibers due to pulping. Since the treatment is performed using the alkaline electrolyzed water obtained by electrolysis using, the strength of the pulp that has been broken into fibers is prevented from decreasing and the strength is maintained.

  Further, among electrolyzed water, alkaline electrolyzed water and various surfactants were examined. As described above, newspaper paper was particularly treated by coexisting with a liquid surfactant (sodium linear alkylbenzene sulfonate). As a result, the deinking (deinking) of the used paper from the surface of the used paper proceeds efficiently, and the intended white used paper can be obtained.

It is explanatory drawing which shows one Example of this invention. It is process drawing which shows one Example of this invention.

  Hereinafter, a preferred embodiment of the present invention will be described. In the waste paper pulp manufacturing process using old newspaper, the waste paper such as newspaper is fragmented, and a small amount of purified salt is added to the fragmented waste paper. Adding alkaline electrolyzed water obtained by electrolyzing water and stirring / disaggregating; deinking the disaggregating solution; and the liquid used in the stirring / disaggregating step is a liquid surfactant. It is a method for producing waste paper pulp using old newspaper as a raw material, which is used in combination.

  An embodiment of the present invention will be described in detail according to an experiment. A process of cutting old newspaper into pieces by shredding or the like, and a piece of old newspaper (1) into about 20 g [four newspapers] (Corresponding to a length of 54.5 × 81.2 cm) is added, 1 liter of alkaline electrolyzed water (3) is added thereto, and the mixture is stirred at a high speed to make old newspaper into a fiber, and this fiber is formed. The disaggregated solution was transferred to a 5 liter stirring tank (4), 4 ml of a liquid surfactant was added, and then gently stirred, and the ink released on the solution surface was prototyped with gauze (vertical A step of removing the floating ink by attaching a lager (string) of 40 cm in width to the blade type stirring rod (5) and rotating it slowly at a low speed (60 to 70 rotations / minute), and then lager While observing the state of dirt A process of replacing and washing the lager repeatedly about 5 times, a process of obtaining deinked (deinked) and disaggregated fibrous waste paper pulp (6), and a process of dehydrating (filtering) this Then, the collected waste paper pulp is washed with water (5 liters x 3 times), and then dried and deinked (deinked) to obtain waste paper pulp. As a result, 12.2 g (recovered paper) 60.1%).

  In addition, instead of the alkaline electrolyzed water described above, except that acidic electrolyzed water was used, the operation was performed on exactly the same scale, but the waste paper pulp treated with this acidic electrolyzed water cannot efficiently remove lignin, The waste paper was poor in bleaching, and had an adverse effect such as weakening the strength of the pulp due to the influence of acid. As a whole, the paper pulp was slightly darkened and white paper as white as expected was not obtained.

  Furthermore, in order to increase the whiteness of the used paper pulp obtained by using tap water instead of the electrolyzed water (alkaline water and acidic water) described in [0014] and [0015], a surfactant to be used is used. It is necessary to increase the amount to 2 times (8 milliliters), and a large amount of water must be used for water washing to remove the surfactant used at the same time. The outflow of pulp fibers also increased, and the recovery rate (20-40%) as waste paper pulp decreased.

  As described above, the present invention has examined alkaline electrolyzed water and various surfactants among electrolyzed water. In particular, by treating with coexisting liquid surfactant (sodium linear alkylbenzene sulfonate), newspapers can be used. The deinking (deinking) progressed efficiently from the surface of the used paper, and the desired white pulp fiber was obtained.

  Increasing the whiteness can be dealt with by increasing the number of times the ink that has been deinked (deinked) and adhered to the disaggregated pulp fibers is washed with water, but it also caused a decrease in the recovery rate of used paper.

  On the other hand, it is necessary to increase the amount of surfactant used (0.0025%) in order to increase the whiteness of recycled paper pulp using normal water (tap water), and the surfactant used at the same time is removed. A large amount of water was required for washing. Moreover, every time the number of water washings was increased due to the influence of the remaining acid, the outflow of pulp fibers also increased, and the recovery rate (20-40%) as waste paper pulp decreased.

  From the above, the method for producing waste paper pulp made from the old newspaper of the present application is preferably a method using alkaline electrolyzed water obtained by electrolysis of salt, and is used for toilet paper that does not require high whiteness. It has been developed and a processing method that can be recovered as recycled waste paper pulp material has been developed.

  Whether or not the first drainage after the deinking (deinking) treatment can be recycled can be flocculated and separated by adding a cationic polymer flocculant. It can prevent pollution.

  It can be utilized industrially by establishing, implementing and selling a method for producing waste paper pulp using the old newspaper of this invention as a raw material.

DESCRIPTION OF SYMBOLS 1 Shredded old newspaper 2 Mixer 3 Alkaline electrolysis water 4 Stirrer tank 5 Feather-type stir bar 6 Waste paper pulp

Claims (1)

In the manufacturing method to obtain waste paper pulp from waste paper,
Using old newspapers cut into small pieces of waste paper,
Add an appropriate amount of alkaline electrolyzed water to these shredded old newspapers,
A high-speed stirring to make the old newspaper into a fiber,
Adding the disaggregation solution of linear alkylsodium benzene sulfonate, which is an appropriate amount of a liquid surfactant, to the fibrous old newspaper in a stirring vessel;
Gently ink liberated stirring solution surfaces, mounting gauze made of lager (the string) to the vane-type stirrer, is liberated into the solution surface while rotating slowly at low speed (60-70 rev / min) Removing the ink
At that time, while observing the dirt of the lager, it consists of the process of replacing and washing the lager five times ,
The electrolyzed water used in the process of deinking these disaggregation solutions is alkaline electrolyzed water obtained by electrolyzing water to which a small amount of purified salt is added. Production method.

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