A paper-plastic mold cleaning system and a cleaning process thereof

Abstract

The present application relates to a kind of paper plastic mold cleaning system and its cleaning process, micro-nano bubble generating device is communicated with mold soaking pool by liquid pipeline, micro-nano bubble generating device is equipped with air inlet, water input by liquid pipeline is mixed with gas inhaled by air inlet, micro-nano bubble water is generated and is transported to mold soaking pool;Mold soaking pool is used to store micro-nano bubble water, and immerse the paper plastic mold to be cleaned;Filter system is used to handle the waste water discharged from mold soaking pool, and the water after processing is recycled for the preparation of micro-nano bubble water;Spraying system is used to flush the paper plastic mold after being soaked in mold soaking pool.The present application does not need complex modification original system, mold does not need to be removed copper net, greatly reduce cost;With the adsorption, desorption, cavitation effect and microjet of micro-nano bubble, residual dirt can be efficiently penetrated pore clearance, solve the problem of low efficiency, residual, easy to damage mold of traditional method;And cleaning technology is strong in universality.

Description

Technical Field

[0001] This invention relates to mold cleaning equipment, and more specifically to a paper-plastic mold cleaning system and its cleaning process. Background Technology

[0002] The environmental pressure posed by traditional plastic packaging is becoming increasingly prominent, leading to the emergence of plant fiber molded environmentally friendly packaging, which uses plant fibers as the main raw material. Among them, pulp molded packaging, with its core advantages such as wide availability of raw materials, recyclability, biodegradability, and excellent cushioning and support properties, has been widely used in the packaging of various high-end industrial products, including electronics, cosmetics, food, and handicrafts, and market demand continues to expand.

[0003] The pulp molding process involves pulp preparation, die casting, high-temperature drying, and cutting and shaping. However, due to the high pressure and high temperature conditions involved, plant fibers in the pulp easily adhere to and clog the surface and internal pores of the mold. This directly leads to an increased defect rate in molded products, severely disrupting normal production. To ensure product quality, production must be paused at most once a week to thoroughly clean the mold. However, the high pressure and temperature significantly enhance the adhesion of these pulp residues, making cleaning extremely difficult. Mold cleaning efficiency and quality have become key factors restricting the improvement of pulp molding production efficiency and yield. If plant fibers on the mold surface and in the pores are not completely removed, subsequent production will result in defects such as product deformation, dirt, and uneven thickness. In severe cases, it may even prevent the finished product from being demolded properly, causing production to stop.

[0004] To address the aforementioned mold cleaning issues, various traditional cleaning methods have been developed in the existing technology. However, all of them have significant shortcomings and cannot meet the demands for efficient, economical, environmentally friendly, and safe production.

[0005] Mechanical cleaning primarily relies on manual removal of dirt from the mold surface. Dirt within pores requires drilling and cleaning each hole individually before rinsing with a spray nozzle. This method not only consumes significant manpower and time (a mature mechanical cleaning process for a single mold requires over 2 hours), but also leaves substantial dirt residue. Furthermore, physical cleaning methods can easily damage the mold surface, leading to defects in subsequent molded products and increasing the likelihood of pulp dirt re-adhesion, further impacting production efficiency and product quality.

[0006] Chemical cleaning methods use chemical solvents such as acids, alkalis, and organic solvents to soak or spray the mold. Through chemical reactions, impurities adhering to the mold surface are dissolved and peeled off. Although this method can quickly remove dirt, chemical solvents are expensive and can easily cause corrosion damage to the mold. In addition, the wastewater generated by chemical cleaning requires additional high costs for treatment, otherwise it will cause environmental pollution problems and does not meet the requirements of environmentally friendly production.

[0007] Dry ice cleaning uses low-temperature dry ice to freeze and embrittle pulp residue, reducing its adhesion to the mold surface for easier cleaning. It has the advantages of being highly efficient and environmentally friendly. However, the low-temperature operation process poses a high safety risk, and the low-temperature environment may cause some damage to the mold, which limits its widespread application.

[0008] Laser scanning vaporization uses laser scanning to vaporize residual fibers. However, this method is costly and involves certain risks, and it has not yet been widely adopted in industrial applications. Summary of the Invention

[0009] In order to solve the problems of low efficiency, high cost, easy damage to molds, poor environmental protection or insufficient safety of existing paper and plastic mold cleaning methods, this invention aims to provide a paper and plastic mold cleaning system and its cleaning process.

[0010] The paper-plastic mold cleaning system according to the present invention includes a micro / nano bubble generator, a liquid pipeline, a mold soaking tank, a filtration system, and a spraying system. The micro / nano bubble generator is connected to the mold soaking tank through the liquid pipeline. The micro / nano bubble generator is provided with an air inlet. Water input through the liquid pipeline mixes with gas drawn in through the air inlet to generate micro / nano bubble water, which is then transported to the mold soaking tank. The mold soaking tank is used to store the micro / nano bubble water and immerse the paper-plastic mold to be cleaned. The filtration system is used to treat the wastewater discharged from the mold soaking tank, and the treated water is recycled for the preparation of micro / nano bubble water. The spraying system is used to rinse the paper-plastic mold after it has been soaked in the mold soaking tank.

[0011] In a preferred embodiment, the micro / nano bubble generator is made based on the principles of rotational shearing, porous membrane, cavitation, pressure change, or electrochemical methods.

[0012] In a preferred embodiment, the mold soaking tank is equipped with a heating and temperature control module to control the temperature of the micro-nano bubble water in the tank at 50-70℃.

[0013] In a preferred embodiment, the water source for the spray system is micro-nano bubble water treated by the filtration system.

[0014] The cleaning process of the paper-plastic mold cleaning system according to the present invention includes the following steps: S1, adding water to the mold soaking tank, and the water level submerging the paper-plastic mold to be cleaned; S2, activating the micro-nano bubble generator, so that the water in the mold soaking tank is filtered by the filtration system and enters the micro-nano bubble generator, while gas is drawn in through the air inlet, and the water and gas are mixed in the micro-nano bubble generator to generate micro-nano bubble water; S3, the micro-nano bubble water is returned to the mold soaking tank and the cycle is repeated to increase the concentration of micro-nano bubbles; S4, immersing the paper-plastic mold to be cleaned in the micro-nano bubble water in the mold soaking tank; S5, activating the spray system to rinse the soaked paper-plastic mold.

[0015] In a preferred embodiment, in step S3, based on the total water volume of the mold soaking tank and the water inflow per unit time of the micro / nano bubble generator, the number of cycles is ensured to be no less than 5, and the micro / nano bubble concentration is 6.2 ± 0.2 × 10⁻⁶. 7 per mL.

[0016] In a preferred embodiment, in step S4, the soaking time is not less than 30 minutes.

[0017] In a preferred embodiment, in step S5, the water source for the spray system is micro-nano bubble water treated by the filtration system.

[0018] In a preferred embodiment, in step S5, the spray water pressure of the spray system is greater than 20 MPa.

[0019] In a preferred embodiment, in step S5, the front and back sides of the paper-plastic mold are rinsed separately, and the rinsing time for each side is not less than 5 minutes.

[0020] This invention utilizes a micro-nano bubble generator to produce micro-nano bubble water that works synergistically with a spray system. Combined with immersion treatment and water recycling, it eliminates the need for complex modifications to existing cleaning systems. Molds can be cleaned directly after removal from the machine without disassembling the copper mesh, significantly reducing labor and energy costs. Furthermore, the adsorption, desorption, cavitation, and micro-jet effects of micro-nano bubbles efficiently penetrate the tiny pores of the mold to thoroughly remove residual dirt, solving the problems of low efficiency, excessive dirt residue, and mold damage associated with traditional cleaning methods. Simultaneously, the cleaning process does not involve the addition of chemical reagents, and wastewater can be treated with simple filtration, balancing environmental protection and economy. Moreover, the cleaning technology is universally applicable to molds and residues, effectively extending mold lifespan and ensuring the production quality and schedule of paper-plastic products. Attached Figure Description

[0021] Figure 1 This is a flowchart of a paper-plastic mold cleaning process according to a preferred embodiment of the present invention.

[0022] Figure 2 This is a flowchart of a paper-plastic mold cleaning process according to another preferred embodiment of the present invention. Detailed Implementation

[0023] The preferred embodiments of the present invention are given below with reference to the accompanying drawings and described in detail.

[0024] This invention utilizes micro- and nano-bubbles to clean molds. The micro- and nano-bubbles include micro-bubbles with a size of 1-100 micrometers and nano-bubbles with a diameter of less than 1 micrometer. Micro-bubbles are easily adsorbed at the solid-liquid interface, and the cavitation effect generated when they float and break can loosen pollutants. Nano-bubbles have unique advantages such as ultra-large specific surface area, ultra-high stability, easy adsorption of pollutants by negative surface charge, ability to generate free radicals to assist desorption, controllable size, and being green and pollution-free.

[0025] like Figure 1 As shown, the paper-plastic mold cleaning system according to the present invention includes a micro-nano bubble generator, a liquid pipeline, a mold soaking tank, a filtration system, and a spraying system.

[0026] The micro / nano bubble generator is connected to a liquid input pipe and a liquid output pipe. It can draw in gas through its built-in air inlet. Water input through the liquid input pipe mixes with the gas drawn in through the air inlet to generate micro / nano bubble water. This micro / nano bubble water is then output to the mold soaking tank through the liquid output pipe. In a preferred embodiment, the micro / nano bubble generator is based on the principle of rotational shearing. This principle involves sending gas into a high-pressure chamber with rotating water flow, utilizing the shearing effect of the water to generate micro / nano bubbles. It should be understood that the micro / nano bubble generator can be based on principles such as porous membrane methods (where gas enters the liquid phase through nanoscale pores under pressure, and at the pore opening, the synergistic effect of interfacial tension, membrane surface wettability, and liquid phase shear force enables restricted growth and rapid desorption of gas nuclei, thereby forming stable and dispersed nanobubbles), cavitation methods, pressure change methods, and electrochemical methods. In a preferred embodiment, the gas includes, but is not limited to, one or more of oxygen, hydrogen, air, carbon dioxide, nitrogen, or ozone. In a preferred embodiment, an air compressor is used as the gas supply device. Compared to natural aspiration, this significantly increases the concentration of micro-nano bubble water. When air is used as the gas source, the concentration of micro-nano bubbles can increase from 3 ± 0.2 × 10⁻⁶ after 30 minutes of operation. 7 The concentration / mL increased to 6.2 ± 0.2 × 10⁻⁶. 7 per mL.

[0027] The mold soaking tank is used to store micro-nano bubble water and immerse the mold to be cleaned. The tank is equipped with a heating and constant temperature module, which can stabilize the liquid temperature in the tank at 50-70℃. This temperature setting can promote the penetration of micro-nano bubbles into the mold pores without significantly reducing the number of micro-nano bubbles (for example, at 50℃, the concentration of nano-bubbles only decreases by about 10% after the device runs for 30 minutes).

[0028] The filtration system includes a mesh filter with a pore size of approximately 3 mm, used to filter the soaking wastewater. The filtered water can be recycled for the preparation of micro-nano bubble water. In a preferred embodiment, it can also be used for spray rinsing to improve water resource utilization.

[0029] The spraying system includes a high-pressure water gun and associated piping. The spraying water source is an external fresh water source, and the generated high-pressure water flow rinses the soaked mold. In a preferred embodiment, the spraying water source is replaced with micro-nano bubble water from the mold soaking tank, which has been treated by a filtration system. This increases water resource utilization and improves cleaning efficiency. In a preferred embodiment, the spraying system can uniformly rinse the mold in both directions, with the single-sided cleaning speed controlled at less than 2.5 square meters per hour, and the spray water pressure greater than 20 MPa, for example, set to 25 MPa, to ensure that carbonized debris in the mold pores is completely rinsed out.

[0030] like Figure 1 As shown, the water flow path of the paper-plastic mold cleaning system according to the present invention includes: external water source is filtered by a filtration system and then input into a micro / nano bubble generator; water mixes with inhaled air in the micro / nano bubble generator to generate micro / nano bubble water; the micro / nano bubble water is transported to a mold soaking tank through a liquid output pipe for soaking the mold to be cleaned; the wastewater after soaking flows back to the filtration system, completing one water cycle and realizing the reuse of water resources. Figure 1 On this basis, Figure 2 The water source for the spray system is micro-nano bubble water from the mold soaking tank after being treated by the filtration system, rather than a new external water source. This enables the recycling of micro-nano bubble water in both the soaking and spraying stages, which not only improves cleaning efficiency but also further saves water resources.

[0031] like Figure 1 As shown, the airflow path of the paper-plastic mold cleaning system according to the present invention includes: air directly enters the device through the air inlet of the micro-nano bubble generator, and is fully mixed with water to generate micro-nano bubbles, without any additional gas delivery branch. Figure 1 The natural air intake method can be replaced with Figure 2 The system provides pressurized gas through a gas cylinder / air compressor. The pressurized gas enters the micro-nano bubble generator through a delivery path, mixes with water to generate micro-nano bubble water, increases the concentration of micro-nano bubbles, and enhances the cleaning effect.

[0032] The cleaning operation of the paper-plastic mold cleaning system according to a preferred embodiment of the present invention includes the following steps:

[0033] S1: Preparation of micro / nano bubble water

[0034] Add enough clean water to the mold soaking tank to ensure that the water can completely submerge the mold to be cleaned;

[0035] The inlet and outlet of the rotary shearing micro-nano bubble generator are both submerged in the water at the bottom of the mold soaking tank, and the filtration system and water pump are connected at the same time.

[0036] Start the air compressor to allow pressurized air to continuously enter the device through the air inlet of the micro-nano bubble generator;

[0037] Start the water pump and micro-nano bubble generator so that the water in the soaking tank is filtered by the filtration system and then enters the micro-nano bubble generator through the liquid input pipe, where it mixes with pressurized air to generate micro-nano bubble water.

[0038] The micro-nano bubble water was repeatedly passed through a micro-nano bubble generator to increase its concentration. Specifically, the micro-nano bubble water was returned to the mold soaking tank through a liquid output pipe, completing one cycle. This cycle was repeated, and the total water volume in the mold soaking tank and the water inflow rate per unit time of the micro-nano bubble generator were used to ensure that all water in the tank circulated through the generator at least 5 times. The particle number and size of the prepared micro-nano bubble water were analyzed using a nanoparticle tracking analysis (NTA) system (ZetaView, ParticleMetrix). The final micro-nano bubble concentration was 6.2 ± 0.2 × 10⁻⁶. 7 Micro-nano bubble water with a particle size of 50-200 nm and a single-peak distribution, per mL.

[0039] S2: Mold Pre-treatment

[0040] Select a pulp molding die to be cleaned (e.g., 30cm x 70cm), and record the surface contamination and the number and location of any blocked pores.

[0041] Surface contamination detection: Visual inspection confirmed the presence of centimeter-sized contaminants formed by carbonized fiber adhesion on the mold surface;

[0042] Pore ​​blockage detection: The degree of pore blockage is determined using a backlight detection method. No light transmission indicates complete blockage, while weak light transmission indicates partial blockage. The pore blockage rate is affected by factors such as pore diameter and pore morphology. In a preferred embodiment, the mold pore diameter is mainly divided into two types: 1mm and 0.08mm. The blockage rate before cleaning is 70%-85% for 1mm pores and 65%-80% for 0.08mm pores. Pore morphology includes straight-through and curved types. Curved pores account for a smaller proportion but have a blockage rate exceeding 95%, while straight-through pores have a blockage rate of approximately 65%-70%.

[0043] After pretreatment, the mold does not need to have the copper mesh removed from its surface and can be used directly in subsequent cleaning steps.

[0044] S3: Mold Immersion Treatment

[0045] The heating and temperature control module in the mold soaking tank is activated to stabilize the temperature of the micro-nano bubble water in the tank at 50°C. The pretreated mold is then completely immersed in the micro-nano bubble water. In a preferred embodiment, the soaking time is no less than 30 minutes, for example, maintaining the soaking state for 30 minutes to 1 hour, allowing the micro-nano bubbles to fully penetrate into the mold surface and internal pores. The negative surface charge of the nanobubbles adsorbs pollutants, generates free radicals to assist desorption, and the cavitation effect generated by the rising and bursting of microbubbles loosens the adhered carbon fiber residue. In particular, when the microbubbles burst on the mold surface or in the pores, the high-speed micro-water jets generated by the cavitation effect, i.e., micro-jet, can impact the carbon fiber residue on the mold surface and in the pores at extremely high speeds. Because the micro-jet diameter is extremely small and the impact force is concentrated, it can accurately penetrate deep into pores (e.g., micropores less than 1 mm) that are difficult to reach by traditional cleaning methods, and can completely flush away the dirt that has been loosened by the cavitation effect from the mold, avoiding residue.

[0046] S4: High-pressure spray rinsing

[0047] After soaking, remove the mold and place it at the spray station;

[0048] Start the spray system and use micro-nano bubble water filtered through a mesh with a pore size of about 3mm as the spray water source. Use a spray water pressure of 25MPa to evenly rinse the front and back of the mold. The rinsing time for each side is not less than 5 minutes, for example, 10 minutes.

[0049] During the rinsing process, ensure that the spray head moves evenly and control the cleaning speed on one side to less than 2.5 square meters per hour to ensure that all areas of the mold are covered by high-pressure water flow and thoroughly rinse out the carbonized debris in the pores.

[0050] S5: Cleaning effect test

[0051] Surface contamination detection: Visual inspection shows that the original centimeter-sized carbonized fiber stains on the mold surface have been completely removed without any residue, meeting the industry's surface contamination cleaning requirements.

[0052] Pore ​​unblocking test: The backlight test method was used again to count the ratio of the number of unblocked pores to the total number of pores (i.e., pore unblocking rate). The test results showed that the pore unblocking rate of the mold increased from less than 30% before cleaning to more than 98%, and the straight and curved pores with diameters of 1mm and 0.08mm were effectively unblocked.

[0053] Through the specific operations described above, this invention achieves efficient cleaning of paper-plastic molds, and its core advantages are as follows:

[0054] Ease of operation: The introduction of micro-nano bubbles is flexible and quick, without the need for complex modifications to the existing cleaning workshop. Except for the micro-nano bubble generator and air compressor, the other components can use the existing tools of traditional mechanical cleaning methods. After the mold is removed from the machine, it can be directly immersed without removing the copper mesh, which greatly reduces the input of manpower and material resources.

[0055] High efficiency: Based on the principle of static pressure difference, the micro-nano bubble water makes the gas reach a supersaturated state in the liquid phase. After being depressurized to atmospheric pressure through the pipeline outlet, it generates micron and nano bubbles. By combining micro-nano bubble water immersion with high-pressure spraying, the local high temperature and micro-jet generated by capillary action and bubble cavitation effectively reduce the interaction force between the pulp and the mold surface. It achieves deep cleaning of tiny pores that are difficult to clean by traditional methods. The total cleaning time for 8 molds of the same specifications is only 2.5 hours, compared with more than 6 hours of traditional mechanical cleaning methods, which increases production efficiency by more than 2.4 times.

[0056] Environmental and economic benefits: No chemical reagents are added during the cleaning process, and the wastewater can be treated to meet the standards after sedimentation and filtration, with no risk of environmental pollution; water resources are recycled through the filtration system, reducing water resource loss, and the operating cost and energy consumption are low.

[0057] Safety and mold protection: During operation, only the mold immersion tank has a mild temperature environment of 50-70℃, and there are no other high temperature or high pressure dangerous conditions; the gas used is air (or other non-toxic, harmful, and chemically stable gases), and no dangerous tools are involved, so the safety factor is high; the cleaning process has no physical impact or chemical corrosion, and will not damage the mold, which can extend the service life of the mold, and the micro-nano bubble cleaning technology is universally applicable to molds and residues.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. That is, all simple and equivalent changes and modifications made based on the claims and description of this invention fall within the protection scope of the claims. All aspects not described in detail in this invention are conventional technical content.

Claims

1. A paper-plastic mold cleaning system, characterized in that, The paper-plastic mold cleaning system includes a micro-nano bubble generator, liquid pipelines, a mold immersion tank, a filtration system, and a spraying system. The micro-nano bubble generator is connected to the mold soaking tank through the liquid pipe. The micro-nano bubble generator is provided with an air inlet. Water input through the liquid pipe is mixed with gas drawn in through the air inlet to generate micro-nano bubble water, which is then transported to the mold soaking tank. The mold soaking tank is used to store micro-nano bubble water and immerse the paper-plastic mold to be cleaned; The filtration system is used to treat the wastewater discharged from the mold soaking tank, and the treated water is recycled for the preparation of micro-nano bubble water. The spray system is used to rinse the paper-plastic mold after it has been soaked in the mold soaking tank.

2. The paper-plastic mold cleaning system according to claim 1, characterized in that, The micro / nano bubble generator is made based on the principles of rotational shearing, porous membrane, cavitation, pressure change, or electrochemical methods.

3. The paper-plastic mold cleaning system according to claim 1, characterized in that, The mold soaking tank is equipped with a heating and constant temperature module to control the temperature of the micro-nano bubble water in the tank at 50-70℃.

4. The paper-plastic mold cleaning system according to claim 1, characterized in that, The water source for the spray system is micro-nano bubble water that has been treated by the filtration system.

5. A cleaning process based on the paper-plastic mold cleaning system according to any one of claims 1-4, characterized in that, The cleaning process includes the following steps: S1, add water to the mold soaking tank, and the water level should be submerged in the paper-plastic mold to be cleaned; S2, start the micro-nano bubble generator, so that the water in the mold soaking tank enters the micro-nano bubble generator after being filtered by the filtration system, and at the same time, gas is drawn in through the air inlet. The water and gas are mixed in the micro-nano bubble generator to generate micro-nano bubble water. S3, the micro-nano bubble water is returned to the mold soaking tank and repeatedly circulated to increase the concentration of micro-nano bubbles; S4, Immerse the paper-plastic mold to be cleaned in the micro-nano bubble water in the mold soaking tank; S5, start the spray system to rinse the soaked paper-plastic mold.

6. The cleaning process according to claim 5, characterized in that, In step S3, based on the total water volume of the mold soaking tank and the water inflow per unit time of the micro-nano bubble generator, the number of cycles is ensured to be no less than 5, and the micro-nano bubble concentration is 6.2 ± 0.2 × 10⁻⁶. 7 per mL.

7. The cleaning process according to claim 5, characterized in that, In step S4, the soaking time shall not be less than 30 minutes.

8. The cleaning process according to claim 5, characterized in that, In step S5, the water source for the spray system is micro-nano bubble water that has been treated by the filtration system.

9. The cleaning process according to claim 5, characterized in that, In step S5, the spray water pressure of the spray system is greater than 20 MPa.

10. The cleaning process according to claim 5, characterized in that, In step S5, the front and back sides of the paper-plastic mold are rinsed separately, and the rinsing time for each side is not less than 5 minutes.

Images