CN117802814A - Plasma direct deinking method - Google Patents

Abstract

A plasma direct deinking method relates to the technical field of paper deinking. The invention relates to a plasma direct deinking method, which adopts ionized working gas as a working medium to generate plasma jet flow to directly treat the surface of paper materials by designing and manufacturing a plasma spray gun with a specific electrode structure, and further adopts different carrier gases according to different printing inks. The invention adopts ionized gas to replace chemical deinking agent, adopts a direct surface treatment method, under the bombardment of plasma particles, the binding force between the ink component and paper fiber is lost, and the pigment and other particles which are colored in the component are peeled off from the surface of the paper, so that the ink on the surface of the paper is directly removed. The invention can obtain a plasma direct deinking method.

Description

A plasma direct deinking method

Technical field

The invention relates to the technical field of paper deinking, and in particular to a plasma direct deinking method.

Background technique

Nowadays, recycling is an important way to save resources and control costs, and waste paper recycling technology has been widely used in the printing and papermaking industry. However, the traditional waste paper recycling process requires first beating the waste paper into pulp, then using chemical solvents or enzymes to remove the ink attached to the paper fibers, and then reusing it into paper. However, this process unit has large facilities and complex processes, and will produce a large amount of wastewater and chemical pollutants during the production process.

Paper and other printing materials have always been the main consumables in the printing and packaging industry, and their recycling and reuse technology has always been the focus of research. Although traditional recycling and reuse technology has scale advantages and cost advantages, in the face of various products and renewable resources generated in different usage environments, traditional waste paper recycling technology has obvious limitations. For example, engineers at the University of Cambridge use lasers to directly remove printed and copied text on paper without causing any damage to the paper. However, this technology is more environmentally friendly than traditional chemical methods to recycle waste paper, reducing the use of chemicals and carbon dioxide emissions.

Therefore, developing a more efficient and environmentally friendly paper deinking technology has become a common technical problem that needs to be urgently solved in the industry.

Contents of the invention

The purpose of the present invention is to solve the above technical problems and provide a plasma direct deinking method.

A direct plasma deinking method, proceed as follows:

Step 1. Prepare plasma spray gun:

1) One end of pipeline a1 is used as the gas inlet, and several gas outlets are provided at the other end of pipeline a1;

2) Extend the hollow tungsten needle into the quartz tube b2, and fix the hollow tungsten needle on the center line of the quartz tube b2 through the connector;

3) One end of a quartz tube b2 having the same number of gas outlets as the pipeline a1 is connected with a wire a3, and the gas outlet of the pipeline a1 is sealed and connected to one end of the quartz tube b2, and a section of the wire a3 is sealed in the quartz tube b2; the outlet of the other end of the quartz tube b2 is covered with a copper tube, and the wire b4 is set on the other end of the quartz tube b2, and is electrically connected to the copper tube on the quartz tube b2;

4) Electrically connect both ends of wire a3 and wire b4 to the AC power supply to obtain a plasma spray gun. The hollow tungsten needle serves as the needle electrode, the copper tube serves as the ring electrode, and the end of the quartz tube b2 where the ring electrode is located is the plasma jet outlet;

Step 2. Direct plasma deinking:

Place the plasma jet outlet of the plasma spray gun obtained in step 1 1 to 3 mm away from the paper to be deinked, then inject the working gas through the gas inlet, and turn on the AC power supply at the same time; the working gas generates plasma under the ionization of the needle electrode and ring electrode The plasma is ejected from the plasma jet outlet to deink the ink on the paper to be deinked. After 10 to 25 seconds of deinking, direct plasma deinking is completed.

Principle of the invention:

The plasma direct deinking method of the present invention designs and manufactures a plasma spray gun with a specific electrode structure, uses ionized working gas as the working medium, generates a plasma jet to directly treat the surface of the paper material, and uses different carrier gases according to different inks. The present invention uses ionized gas instead of chemical deinking agent and adopts direct surface treatment method. Under the bombardment of plasma particles, the ink components lose their binding force with paper fibers, and the colored pigments and other particles in the components are peeled off from the paper surface. , the ink on the paper surface is removed directly.

Beneficial effects of the present invention:

The invention discloses a plasma direct deinking method, which studies direct deinking technology of paper printed products based on plasma technology, directly treats the ink on the surface of paper through plasma, and directly removes the ink from the paper; at the same time, since the distance between the tip of the jet and the paper is 1 to 3 mm, and the action position is 1 to 3 μm thick on the surface of the paper, the overall strength and properties of the paper are not affected, and the treated paper can be directly reused, providing a new idea for paper recycling.

The present invention uses plasma to directly treat the paper surface, without complicated paper disintegration and re-making, avoiding the use of chemical reagents, making parameter control and process control simpler, convenient for digital control, the treatment process is easy to adjust, and there is no waste gas. Liquid discharge is more environmentally friendly.

The present invention aims to realize a new waste paper regeneration process, achieve pollution-free reuse of paper, avoid the use of a large amount of water resources and the generation of waste water, avoid secondary papermaking, and greatly simplify the waste paper regeneration process. At the same time, the variables controlled by this technology are gas volume, voltage, frequency and power, etc., which is easy to control.

The invention can obtain a plasma direct deinking method.

Description of drawings

Figure 1 is a schematic diagram of the installation structure of the plasma spray gun in Embodiment 1. 1 represents pipeline a, 2 represents quartz tube b, 3 represents wire a, 4 represents wire b, and 5 represents polytetrafluoroethylene tube; in the figure, polytetrafluoroethylene The tube is a schematic cross-section;

Figure 2 is a comparative rendering of the paper containing offset printing ink before and after deinking in Example 1;

Figure 3 is a comparative view of the paper containing flexible water-based ink before and after deinking in Example 1.

Detailed ways

Specific implementation method 1: This implementation method is a plasma direct deinking method, which is carried out according to the following steps:

Step 1: Prepare plasma spray gun:

1) One end of the pipeline a1 is used as a gas inlet, and a plurality of gas outlets are provided at the other end of the pipeline a1;

2) Extend the hollow tungsten needle into the quartz tube b2, and fix the hollow tungsten needle on the center line of the quartz tube b2 through the connector;

3) One end of the quartz tube b2 with the same number of gas outlets as the pipeline a1 is connected to the wire a3, and the gas outlet of the pipeline a1 is sealingly connected to one end of the quartz tube b2, and a section of the wire a3 is sealed in the quartz tube b2; The outlets of the other end of the quartz tube b2 are covered with copper tubes, and the wires b4 are arranged on the other end of the quartz tube b2, and are electrically connected to the copper tubes on the quartz tube b2;

4) Both ends of the wire a3 and the wire b4 are electrically connected to an AC power source to obtain a plasma spray gun, wherein the hollow tungsten needle is used as a needle electrode, the copper tube is used as a ring electrode, and the end of the quartz tube b2 where the ring electrode is located is a plasma jet outlet;

Step 2. Direct plasma deinking:

Place the plasma jet outlet of the plasma spray gun obtained in step 1 1 to 3 mm away from the paper to be deinked, then inject the working gas through the gas inlet, and turn on the AC power supply at the same time; the working gas generates plasma under the ionization of the needle electrode and ring electrode The plasma is ejected from the plasma jet outlet to deink the ink on the paper to be deinked. After 10 to 25 seconds of deinking, direct plasma deinking is completed.

Beneficial effects of this implementation:

The present embodiment is a plasma direct deinking method, which studies the direct deinking technology of paper prints based on plasma technology. The ink on the surface of the paper is directly treated by plasma to directly remove the ink from the paper. At the same time, since the distance between the tip of the jet and the paper is 1 to 3 mm, the action position is 1 to 3 μm thick on the surface of the paper, which does not affect the overall strength and properties of the paper. The treated paper can be directly reused, providing a new idea for paper recycling.

This embodiment uses plasma to directly treat the surface of paper, without complicated paper shredding and re-papering, avoiding the use of chemical reagents, making parameter control and process control simpler, facilitating digital control, and making the treatment process easy to adjust. It is more environmentally friendly without waste gas and waste liquid emissions.

This implementation mode aims to realize a new waste paper regeneration process, achieve pollution-free reuse of paper, avoid the use of a large amount of water resources and the generation of waste water, avoid secondary papermaking, and greatly simplify the waste paper regeneration process. , at the same time, the variables controlled by this technology are gas volume, voltage, frequency and power, etc., which is easy to control.

Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that the outer diameter of the quartz tube b2 described in step 1 is 3 mm and the inner diameter is 1.5 mm.

The other steps are the same as those in the first specific implementation.

Specific Embodiment 3: The difference between this embodiment and Specific Embodiment 1 or 2 is that the inner diameter of the hollow tungsten needle described in step 1 is 0.8 mm.

Other steps are the same as the first or second embodiment.

Specific Embodiment 4: The difference between this embodiment and one of Specific Embodiments 1 to 3 is that the length of the copper tube described in step 1 is 5mm, the outer diameter is 5mm, and the inner diameter is 3mm.

The other steps are the same as those in Specific Embodiments 1 to 3.

Specific Embodiment 5: The difference between this embodiment and any one of Embodiments 1 to 4 is that the quartz tube b2 described in step 1 is installed in the sealed polytetrafluoroethylene tube 5 .

Other steps are the same as the specific embodiments one to four.

Specific Embodiment 6: The difference between this implementation mode and one of the specific implementation modes 1 to 5 is that in step 2, the frequency of the AC power supply is 300kHz, the voltage is 10kV, and the input power is 30~300W.

The other steps are the same as those in Specific Embodiments 1 to 5.

Specific Embodiment 7: The difference between this embodiment and any one of Specific Embodiments 1 to 6 is that the working gas in step 2 is one or both of oxygen and argon.

Other steps are the same as the specific embodiments one to six.

Specific Embodiment 8: The difference between this implementation mode and any one of Specific Embodiments 1 to 7 is that the flow rate of oxygen is 0 to 5 sccm.

Other steps are the same as the specific embodiments one to seven.

Specific Embodiment 9: The difference between this embodiment and one of Specific Embodiments 1 to 8 is that the flow rate of argon gas is 100 to 250 sccm.

Other steps are the same as the specific embodiments one to eight.

Specific Embodiment 10: The difference between this embodiment and one of Specific Embodiments 1 to 9 is that the ink on the paper to be deinked in step 2 is offset printing ink, flexible water-based ink, laser printing ink, inkjet printing ink or screen printing ink.

Other steps are the same as the specific embodiments one to nine.

The following examples are used to verify the beneficial effects of the present invention:

Example 1: A plasma direct deinking method, proceed as follows:

Step 1. Prepare the plasma spray gun, as shown in Figure 1:

1) One end of the pipeline a1 is used as a gas inlet, and a plurality of gas outlets are provided at the other end of the pipeline a1;

2) Extend the hollow tungsten needle into the quartz tube b2, and fix the hollow tungsten needle on the center line of the quartz tube b2 through the connector;

3) One end of the quartz tube b2 with the same number of gas outlets as the pipeline a1 is connected to the wire a3, and the gas outlet of the pipeline a1 is sealingly connected to one end of the quartz tube b2, and a section of the wire a3 is sealed in the quartz tube b2; The outlets of the other end of the quartz tube b2 are covered with copper tubes, and the wires b4 are arranged on the other end of the quartz tube b2, and are electrically connected to the copper tubes on the quartz tube b2;

4) Electrically connect both ends of wire a3 and wire b4 to the AC power supply to obtain a plasma spray gun. The hollow tungsten needle serves as the needle electrode, the copper tube serves as the ring electrode, and the end of the quartz tube b2 where the ring electrode is located is the plasma jet outlet;

The outer diameter of quartz tube b is 3 mm and the inner diameter is 1.5 mm;

The inner diameter of the hollow tungsten needle is 0.8mm; the length of the copper tube is 5mm, the outer diameter is 5mm, and the inner diameter is 3mm;

The quartz tube b is installed in a sealed polytetrafluoroethylene tube.

Step 2: Plasma direct deinking:

Place the plasma jet outlet of the plasma spray gun obtained in step 1 1 to 3 mm away from the paper to be deinked, then inject the working gas through the gas inlet, and turn on the AC power supply at the same time; the working gas generates plasma under the ionization of the needle electrode and ring electrode The plasma is ejected from the plasma jet outlet to deink the ink on the paper to be deinked. After 10 to 25 seconds of deinking, direct plasma deinking is completed.

The frequency of the high-frequency and high-voltage AC power supply is 300kHz, the voltage is 10kV, and the input power is 30~300W. It can be adjusted appropriately according to the type or thickness of the ink to be processed.

The working gas is oxygen and argon, which are regulated and controlled by an adjustable flow meter and passed into the plasma generator (plasma spray gun) through the gas pipeline. Industrial high-purity argon is used, with a purity of >99.99%, a 40L steel cylinder, and an initial pressure of 13±0.5MPa; industrial high-purity oxygen is used, with a purity of >99.99%, an 8L steel cylinder, and an initial pressure of 9±0.5MPa.

The working gas is ionized by the electrode in the plasma spray gun to form plasma. After the plasma is ejected, it directly acts on the ink part of the paper surface to deink the paper. The ink processing time per unit area is determined by the thickness and composition of the ink layer and the plasma jet of the spray gun. Determined by the diameter, the distance between the jet tip and the paper is about 1 to 3 mm. For a plasma jet with a diameter of 2 to 4 mm, the processing time per unit area is about 20 seconds.

Appropriately increasing the power and air volume can increase the processing speed, but the nozzle temperature needs to be controlled from being too high. The processing time is determined by the actual ink layer thickness of the printed matter.

Features: The air path passes through both the hollow silicon tube and the hollow tungsten electrode. The plasma jet tip is thin, which can achieve the ability to concentrate energy to process ink.

The plasma direct deinking method of this embodiment is used to sequentially conduct deinking tests on papers containing offset printing ink, flexible water-based ink, laser printing ink, inkjet printing ink or screen printing ink. The test data are shown in Table 1:

Table 1 shows different ink processing parameters;

Figure 2 is a comparative rendering of the paper containing offset printing ink before and after deinking in Example 1. Figure 3 is a comparative rendering of the paper containing flexible water-based ink in Example 1 before and after deinking.

As shown in Figure 2-3, the plasma direct deinking method of this embodiment is used to deink the paper. The deinking effect is excellent, and the fiber structure of the paper after deinking is obvious, which proves that this deinking method will not affect the overall quality of the paper. The strength and properties are affected, and the treated paper can be directly reused.

Claims (10)

1. A plasma direct deinking method is characterized in that the direct deinking method is carried out according to the following steps:

step 1, preparing a plasma spray gun:

1) One end of the pipeline a (1) is used as a gas inlet, and a plurality of gas outlets are arranged at the other end of the pipeline a (1);

2) The hollow tungsten needle is inserted into the quartz tube b (2), and is fixed on the central line of the quartz tube b (2) through a connecting piece;

3) One end of a quartz tube b (2) with the same number as the gas outlets of the pipeline a (1) is connected with a lead a (3), the gas outlets of the pipeline a (1) are connected with one end of the quartz tube b (2) in a sealing way, and one section of the lead a (3) is sealed in the quartz tube b (2); the outlet of the other end of the quartz tube b (2) is sleeved with copper tubes, and the lead b (4) is arranged on the other end of the quartz tube b (2) and is electrically connected with the copper tubes on the quartz tube b (2);

4) Both ends of a lead a (3) and a lead b (4) are electrically connected with an alternating current power supply to obtain a plasma spray gun, a hollow tungsten needle is used as a needle electrode, a copper tube is used as a ring electrode, and one end of the quartz tube b (2) where the ring electrode is positioned is a plasma jet outlet;

step 2, directly deinking by plasma:

the plasma jet outlet of the plasma spray gun obtained in the step 1 is 1-3 mm away from the paper to be deinked, and then working gas is injected through a gas inlet, and an alternating current power supply is connected at the same time; the working gas generates plasma under the ionization action of the needle electrode and the ring electrode, the plasma is ejected from a plasma jet outlet, the ink on the paper to be deinked is deinked, and after deinking for 10-25 s, the plasma direct deinking is completed.

2. A method of direct deinking of plasma according to claim 1, characterized in that the quartz tube b (2) in step 1 has an outer diameter of 3mm and an inner diameter of 1.5mm.

3. A method of direct plasma deinking according to claim 1, characterized in that the hollow tungsten needle in step 1 has an inner diameter of 0.8mm.

4. A method of direct deinking plasma according to claim 1, wherein the copper pipe in step 1 has a length of 5mm, an outer diameter of 5mm and an inner diameter of 3mm.

5. A method of direct deinking of plasma according to claim 1, characterized in that the quartz tube b (2) in step 1 is mounted in a sealed polytetrafluoroethylene tube (5).

6. The method for directly deinking plasma according to claim 1, wherein the frequency of the alternating current power supply in the step 2 is 300kHz, the voltage is 10kV, and the input power is 30 to 300W.

7. A direct plasma deinking process according to claim 1, characterized in that the working gas in step 2 is one or both of oxygen and argon.

8. A method of direct plasma deinking according to claim 7, characterized in that the flow of oxygen is 0-5 sccm.

9. The method for directly deinking plasma according to claim 7, wherein the flow rate of the argon gas is 100-250 sccm.

10. The method according to claim 1, wherein the ink on the paper to be deinked in the step 2 is offset ink, flexible aqueous ink, laser printing ink, inkjet printing ink or silk screen printing ink.