A method of plasma direct deinking

Abstract

The application relates to a plasma direct deinking method, belonging to the paper deinking technical field.The plasma direct deinking method is characterized in that: a plasma spray gun with a special electrode structure is designed and manufactured, ionized working gas is used as a working medium, a plasma jet is generated to directly process the surface of paper materials, and different carrier gases are used according to different inks.The application uses ionized gas instead of chemical deinking agents, adopts a direct surface processing method, and under the bombardment of plasma particles, the combination of ink components with paper fibers is lost, and the pigments and other particles in the components are stripped from the surface of the paper, so that the ink on the surface of the paper is directly removed.The application can obtain a plasma direct deinking method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of paper deinking, and particularly relates to a plasma direct deinking method. BACKGROUND

[0002] 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 first beats the waste paper into pulp, and then removes the ink attached to the paper fiber by using chemical solvents or enzymes, and then reprints and utilizes. However, such process has large facilities and complex process, and a large amount of waste water and chemical pollutants are generated in the production process.

[0003] Paper and other printing materials have always been the main consumables in the printing and packaging industry, and the recycling technology has always been the focus of people's research. Although the traditional recycling technology has scale advantage and cost advantage, it has obvious limitations in the face of various different products and renewable resources generated in different use environments. For example, Cambridge University engineers use laser to directly remove printed and copied text on paper without causing any damage to the paper. This technology is more environmentally friendly than traditional chemical methods for recycling waste paper, reducing the use of chemicals and carbon dioxide emissions.

[0004] Therefore, it is urgent to develop a more efficient and environmentally friendly paper deinking technology in the industry. SUMMARY

[0005] The purpose of the present application is to solve the above technical problems, and provide a plasma direct deinking method.

[0006] A plasma direct deinking method is carried out in the following steps:

[0007] Step 1, preparing a plasma spray gun:

[0008] 1) One end of pipeline a1 is used as a gas inlet, and a plurality of gas outlets are arranged at the other end of pipeline a1;

[0009] 2) The hollow tungsten needle is inserted into the quartz tube b2, and the hollow tungsten needle is fixed on the center line of the quartz tube b2 through the connecting piece;

[0010] 3) The end of the quartz tube b2 connected with the same number of gas outlets of the pipeline a1 is connected with the lead a3, and the gas outlet of the pipeline a1 is sealingly connected with the end of the quartz tube b2, and a section of the lead a3 is sealingly arranged in the quartz tube b2; the outlet of the other end of the quartz tube b2 is sleeved with a copper pipe, and the lead b4 is arranged on the other end of the quartz tube b2 and electrically connected with the copper pipe on the quartz tube b2;

[0011] 4) Connect both ends of wires a3 and b4 to an AC power source to obtain a plasma spray gun. The hollow tungsten needle is used as the needle electrode, the copper tube is used as the ring electrode, and the end of the quartz tube b2 where the ring electrode is located is the plasma jet outlet.

[0012] Step 2, Direct Plasma Deinking:

[0013] The plasma jet outlet of the plasma spray gun obtained in step 1 is placed 1-3 mm away from the paper to be deinked. Then, the working gas is injected through the gas inlet, and the AC power is turned on at the same time. The working gas generates plasma under the ionization of the needle electrode and the ring electrode. The plasma is ejected from the plasma jet outlet to deink the ink on the paper to be deinked. After deinking for 10-25 seconds, the direct plasma deinking is completed.

[0014] The principle of this invention:

[0015] This invention relates to a direct plasma deinking method. By designing and fabricating a plasma spray gun with a specific electrode structure, and using an ionized working gas as the working medium, a plasma jet is generated to directly treat the surface of the paper material. Different carrier gases are used depending on the type of ink. This invention uses ionized gas instead of chemical deinking agents and employs a direct surface treatment method. Under the bombardment of plasma particles, the ink components lose their binding force to the paper fibers, and the pigments and other particles in the components peel off from the paper surface, thus directly removing the ink from the paper surface.

[0016] The beneficial effects of this invention are:

[0017] This invention discloses a plasma direct deinking method, which studies the direct deinking technology of paper printed materials based on plasma technology. The method directly removes the ink from the paper surface by directly treating the paper surface with plasma. At the same time, since the distance between the jet tip and the paper is 1-3 mm and the action position is 1-3 μm thick on the paper surface, it 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.

[0018] This invention uses plasma to directly treat the paper surface, eliminating the need for complex paper dismantling and re-making, avoiding the use of chemical reagents, simplifying parameter and process control, facilitating digital control, making the process easy to adjust, and resulting in more environmentally friendly emissions of no waste gas or waste liquid.

[0019] This invention aims to realize a novel waste paper recycling process, enabling the reuse of paper without pollution, avoiding the use of large amounts of water resources and the generation of wastewater, avoiding secondary papermaking, and greatly simplifying the waste paper recycling process. At the same time, the variables controlled by this technology are gas volume, voltage, frequency and power, which are easy to control.

[0020] This invention provides a direct plasma deinking method. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the installation structure of the plasma spray gun in Example 1. 1 represents pipe a, 2 represents quartz tube b, 3 represents wire a, 4 represents wire b, and 5 represents polytetrafluoroethylene tube.

[0022] The polytetrafluoroethylene tube in the figure is a cross-sectional schematic diagram;

[0023] Figure 2 This is a comparison image of the paper containing offset printing ink in Example 1 before and after deinking.

[0024] Figure 3 This is a comparison image showing the effect of deinking paper containing flexible water-based ink in Example 1 before and after deinking. Detailed Implementation

[0025] Specific Implementation Method 1: This implementation method is a direct plasma deinking method, which is carried out according to the following steps:

[0026] Step 1: Prepare the plasma spray gun:

[0027] 1) One end of pipe a1 is used as a gas inlet, and several gas outlets are set at the other end of pipe a1;

[0028] 2) Insert the hollow tungsten needle into the quartz tube b2 and fix the hollow tungsten needle on the center line of the quartz tube b2 using the connector;

[0029] 3) One end of a quartz tube b2, which has the same number of gas outlets as pipeline a1, is connected to a wire a3, and the gas outlets of pipeline a1 are sealed to one end of the quartz tube b2, with one end of the wire a3 sealed inside the quartz tube b2; a copper tube is fitted at the outlet of the other end of the quartz tube b2, and wire b4 is placed on the other end of the quartz tube b2, and is electrically connected to the copper tube on the quartz tube b2.

[0030] 4) Connect both ends of wires a3 and b4 to an AC power source to obtain a plasma spray gun. The hollow tungsten needle is used as the needle electrode, the copper tube is used as the ring electrode, and the end of the quartz tube b2 where the ring electrode is located is the plasma jet outlet.

[0031] Step 2, Direct Plasma Deinking:

[0032] The plasma jet outlet of the plasma spray gun obtained in step 1 is placed 1-3 mm away from the paper to be deinked. Then, the working gas is injected through the gas inlet, and the AC power is turned on at the same time. The working gas generates plasma under the ionization of the needle electrode and the ring electrode. The plasma is ejected from the plasma jet outlet to deink the ink on the paper to be deinked. After deinking for 10-25 seconds, the direct plasma deinking is completed.

[0033] The beneficial effects of this implementation method are:

[0034] This embodiment describes a plasma direct deinking method. Based on plasma technology, it studies the direct deinking technology of paper printed materials. The plasma directly treats the ink on the paper surface and removes the ink directly. At the same time, since the distance between the jet tip and the paper is 1-3 mm and the action position is 1-3 μm thick on the paper surface, it 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.

[0035] This embodiment uses plasma to directly treat the paper surface, eliminating the need for complex paper dismantling and re-making, avoiding the use of chemical reagents, making parameter control and process control simpler, facilitating digital control, making the treatment process easy to adjust, and eliminating waste gas and waste liquid emissions, thus making it more environmentally friendly.

[0036] This embodiment aims to realize a novel waste paper recycling process, enabling the reuse of paper without pollution, avoiding the use of large amounts of water resources and the generation of wastewater, avoiding secondary papermaking, and greatly simplifying the waste paper recycling process. At the same time, the variables controlled by this technology are gas volume, voltage, frequency and power, which are easy to control.

[0037] Specific Implementation Method Two: The difference between this implementation method and Specific Implementation Method One is that the outer diameter of the quartz tube b2 mentioned in step 1 is 3mm and the inner diameter is 1.5mm.

[0038] The other steps are the same as in Specific Implementation Method 1.

[0039] Specific Implementation Method 3: The difference between this implementation method and Specific Implementation Method 1 or 2 is that the inner diameter of the hollow tungsten needle mentioned in step 1 is 0.8 mm.

[0040] The other steps are the same as in Specific Implementation Method 1 or 2.

[0041] Specific Implementation Method Four: The difference between this implementation method and Specific Implementation Methods One to Three is that the copper tube mentioned in step 1 has a length of 5mm, an outer diameter of 5mm, and an inner diameter of 3mm.

[0042] The other steps are the same as those in Specific Implementation Methods One to Three.

[0043] Specific Implementation Method 5: The difference between this implementation method and Specific Implementation Methods 1 to 4 is that the quartz tube b2 mentioned in step 1 is installed inside the sealed polytetrafluoroethylene tube 5.

[0044] The other steps are the same as those in Specific Implementation Methods One through Four.

[0045] Specific Implementation Method Six: The difference between this implementation method and Specific Implementation Methods One to Five is that the frequency of the AC power supply in step 2 is 300kHz, the voltage is 10kV, and the input power is 30~300W.

[0046] The other steps are the same as those in Specific Implementation Methods 1 to 5.

[0047] Specific Implementation Method Seven: The difference between this implementation method and Specific Implementation Methods One to Six is ​​that the working gas in step 2 is one or both of oxygen and argon.

[0048] The other steps are the same as those in Specific Implementation Methods 1 to 6.

[0049] Specific Implementation Method Eight: The difference between this implementation method and Specific Implementation Methods One to Seven is that the oxygen flow rate is 0 to 5 sccm.

[0050] The other steps are the same as those in Specific Implementation Methods 1 to 7.

[0051] Specific Implementation Method Nine: The difference between this implementation method and Specific Implementation Methods One to Eight is that the flow rate of argon gas is 100-250 sccm.

[0052] The other steps are the same as those in Specific Implementation Methods 1 to 8.

[0053] Specific Implementation Method 10: The difference between this implementation method and Specific Implementation Methods 1 to 9 is that the ink on the paper to be de-inked in step 2 is offset printing ink, flexible water-based ink, laser printing ink, inkjet printing ink, or screen printing ink.

[0054] The other steps are the same as those in Specific Implementation Methods 1 to 9.

[0055] The beneficial effects of the present invention are verified using the following embodiments:

[0056] Example 1: A plasma direct deinking method, performed according to the following steps:

[0057] Step 1: Prepare the plasma spray gun, such as... Figure 1 As shown:

[0058] 1) One end of pipe a1 is used as a gas inlet, and several gas outlets are set at the other end of pipe a1;

[0059] 2) Insert the hollow tungsten needle into the quartz tube b2 and fix the hollow tungsten needle on the center line of the quartz tube b2 using the connector;

[0060] 3) One end of a quartz tube b2, which has the same number of gas outlets as pipeline a1, is connected to a wire a3, and the gas outlets of pipeline a1 are sealed to one end of the quartz tube b2, with one end of the wire a3 sealed inside the quartz tube b2; a copper tube is fitted at the outlet of the other end of the quartz tube b2, and wire b4 is placed on the other end of the quartz tube b2, and is electrically connected to the copper tube on the quartz tube b2.

[0061] 4) Connect both ends of wires a3 and b4 to an AC power source to obtain a plasma spray gun. The hollow tungsten needle is used as the needle electrode, the copper tube is used as the ring electrode, and the end of the quartz tube b2 where the ring electrode is located is the plasma jet outlet.

[0062] The outer diameter of quartz tube b is 3mm, and the inner diameter is 1.5mm;

[0063] The hollow tungsten needle has an inner diameter of 0.8 mm; the copper tube has a length of 5 mm, an outer diameter of 5 mm, and an inner diameter of 3 mm.

[0064] Quartz tube b is installed inside a sealed polytetrafluoroethylene tube.

[0065] Step 2, Direct Plasma Deinking:

[0066] The plasma jet outlet of the plasma spray gun obtained in step 1 is placed 1-3 mm away from the paper to be deinked. Then, the working gas is injected through the gas inlet, and the AC power is turned on at the same time. The working gas generates plasma under the ionization of the needle electrode and the ring electrode. The plasma is ejected from the plasma jet outlet to deink the ink on the paper to be deinked. After deinking for 10-25 seconds, the direct plasma deinking is completed.

[0067] The high-frequency high-voltage AC power supply has a frequency of 300kHz, a voltage of 10kV, and an input power of 30-300W, which can be adjusted according to the type or thickness of the ink being processed.

[0068] The working gases are oxygen and argon, which are regulated and controlled by an adjustable flow meter and introduced into the plasma generator (plasma gun) through the gas pipeline. Industrial high-purity argon (purity >99.99%) is used, in a 40L cylinder with an initial pressure of 13±0.5MPa; industrial high-purity oxygen (purity >99.99%) is used, in an 8L cylinder with an initial pressure of 9±0.5MPa.

[0069] The working gas is ionized by the electrodes 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 de-ink the paper. The ink treatment time per unit area is determined by the ink layer thickness, composition and plasma jet diameter of the spray gun. The distance between the jet tip and the paper is about 1 to 3 mm. For a plasma jet diameter of 2 to 4 mm, the treatment time per unit area is about 20 seconds.

[0070] Increasing power and air volume appropriately can improve processing speed, but the nozzle temperature must be controlled to prevent it from becoming too high. The processing time is determined by the actual ink layer thickness of the printed material.

[0071] Features: The gas path passes through both hollow silicon tubes and hollow tungsten electrodes, and the plasma jet tip is fine, enabling concentrated energy processing of ink.

[0072] The plasma direct deinking method of this embodiment was used to conduct deinking tests on paper containing offset printing ink, flexible water-based ink, laser printing ink, inkjet printing ink, or screen printing ink in sequence. The test data are shown in Table 1.

[0073] Table 1 shows the processing parameters for different inks;

[0074]

[0075] Figure 2 These are comparison images of the offset printing ink paper before and after deinking in Example 1. Figure 3 This is a comparison image showing the effect of deinking paper containing flexible water-based ink in Example 1 before and after deinking.

[0076] like Figures 2-3 As shown, the plasma direct deinking method of this embodiment is used to deink paper. The deinking effect is excellent, and the fiber structure of the paper is obvious after deinking. This proves that the deinking method does not affect the overall strength and properties of the paper, and the treated paper can be directly reused.

Claims

1. A plasma direct deinking method, characterized in that... This direct deinking method is performed according to the following steps: Step 1: Prepare the plasma spray gun: 1) One end of pipe a(1) is used as a gas inlet, and several gas outlets are provided at the other end of pipe a(1); 2) Insert the hollow tungsten needle into the quartz tube b(2) and fix the hollow tungsten needle on the center line of the quartz tube b(2) through the connector; 3) One end of a quartz tube b(2) with the same number of gas outlets as pipe a(1) is connected to a wire a(3), and the gas outlets of pipe a(1) are sealed to one end of quartz tube b(2), and a section of wire a(3) is sealed inside quartz tube b(2); copper tubes are fitted at the outlets of the other end of quartz tube b(2), and wires b(4) are set on the other end of quartz tube b(2), and are electrically connected to the copper tubes on quartz tube b(2); 4) Connect both ends of wire a(3) and wire b(4) to an AC power source to obtain a plasma spray gun. The hollow tungsten needle is used as the needle electrode, the copper tube is used as the ring electrode, and the end of the quartz tube b(2) where the ring electrode is located is the plasma jet outlet. The inner diameter of the hollow tungsten needle mentioned in step 1 is 0.8 mm; Step 2, Direct Plasma Deinking: The plasma jet outlet of the plasma spray gun obtained in step 1 is 1-3 mm away from the paper to be de-inked. Then, the working gas is injected through the gas inlet, and the AC power is turned on at the same time. The working gas generates plasma under the ionization of the needle electrode and the ring electrode. The plasma is ejected from the plasma jet outlet to de-ink the ink on the paper to be de-inked. After de-inking for 10-25 seconds, the direct plasma de-inking is completed. In step 2, the frequency of the AC power supply is 300kHz, the voltage is 10kV, and the input power is 30-300W. The working gas in step 2 is one or both of oxygen and argon, with the oxygen flow rate being 0-5 sccm and the argon flow rate being 100-250 sccm. In step 2, the ink on the paper to be de-inked is offset printing ink, flexible water-based ink, laser printing ink, inkjet printing ink, or screen printing ink.

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

3. The plasma direct deinking method according to claim 1, characterized in that... The copper tube mentioned in step 1 has a length of 5mm, an outer diameter of 5mm, and an inner diameter of 3mm.

4. The plasma direct deinking method according to claim 1, characterized in that... The quartz tube b (2) described in step 1 is installed inside a sealed polytetrafluoroethylene tube (5).

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