Semi-dry press system and process for disposable pulp molded tableware

Abstract

A semi-dry pressing preparation system and process of disposable paper pulp molded tableware, relates to the field of paper mold processing; Including the multi-surface hub machine forming machine, drying equipment, hot pressing forming machine and edge trimmer connected in turn, the multi-surface hub machine forming machine is used for suction forming, vacuum dewatering, preparing wet blank, the multi-surface hub machine forming machine is provided with airtight ventilation hood, which covers the hub forming part to control the temperature and humidity of the hub forming part; The drying equipment includes a heater, an air supply device and a single or multi-layer chain plate for transferring the wet blank, the waste heat tail wind pipeline of the drying equipment is communicated with the ventilation hood; The hot pressing forming machine is used for hot pressing drying and shaping of semi-dry blank; The edge trimmer is used for edge trimming and shaping of semi-finished product. Semi-dry pressing method is adopted, which improves work efficiency, avoids that fine fiber components are sucked into exhaust holes of the mold to form blockage and coking, reduces labor cost and time cost of cleaning.

Description

Technical Field

[0001] This invention belongs to the field of paper mold processing, specifically relating to a semi-dry pressing preparation system and process for disposable pulp molded tableware. Background Technology

[0002] Existing disposable fast food containers are mainly made of plastic, primarily polypropylene or polystyrene. This organic material cannot degrade naturally in a short period, and burning it produces toxic substances, causing serious environmental pollution. Therefore, there is currently no effective way to deal with the large amount of plastic waste generated. When plastic comes into contact with hot oil and water, it may release chemicals harmful to human health, and in some cases, even carcinogenic.

[0003] With the development of the times, people's health awareness is constantly improving, and health issues are receiving increasing attention and importance. Governments around the world have also introduced various plastic bans, and the use of plastic in the disposable tableware industry will be gradually phased out. Green and environmentally friendly paper-molded tableware will become the best alternative to plastic tableware. Therefore, the catering industry will consume more and more paper-molded tableware. Biodegradable paper-molded tableware will quickly gain acceptance, placing higher demands on the quality and production process of paper tableware. Current production processes generally use wet-process suction molding, followed by hot pressing, calendering, edge trimming, and sterilization to obtain the finished product.

[0004] Traditional manufacturing processes involve a setting machine to transform the product from wet to dry blanks, which takes a long time to dry and set. Furthermore, during the forming and setting of the paper blank, fine fibers from the product are drawn into the vacuum pipes, easily clogging the pores of the heated mold or causing coking. This results in high cleaning and maintenance costs. Additionally, the long drying and setting process from wet to dry blanks leads to low single-machine capacity. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a semi-dry pressing preparation system for disposable pulp molded tableware. The semi-dry pressing method is adopted to improve work efficiency and avoid fine fiber components being sucked into the vent holes of the mold to form blockages and coking, thereby reducing cleaning labor and time costs.

[0006] The second objective of this invention is to provide a semi-dry pressing process for disposable pulp molded tableware, which can significantly reduce the time spent on drying and setting in the setting machine, reduce the clogging of the production mold pores, and increase production capacity.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A semi-dry pressing preparation system for disposable pulp molded tableware includes a multi-faceted rotary drum forming machine, a drying device, a hot pressing and shaping machine, and an edge trimming machine connected in sequence.

[0009] The multi-faceted rotating drum forming machine is used for suction molding, vacuum dehydration, and preparation of wet blanks. The multi-faceted rotating drum forming machine is equipped with a sealed ventilation hood that covers the rotating drum forming part to control the temperature and humidity of the rotating drum forming part.

[0010] The drying equipment includes a heater, an air supply device, and a single or multiple chain plates for transferring wet blanks. The waste heat exhaust duct of the drying equipment is connected to a ventilation hood.

[0011] The hot press shaping machine is used for hot pressing, drying, and shaping of semi-dry blanks;

[0012] The edge trimming machine is used for trimming and shaping semi-finished products.

[0013] Furthermore, the multi-faceted rotating hub forming machine is a coaxial 2 to 12-faceted rotating hub device, with the same number of forming molds installed on each face. The multi-faceted rotating hub machine is equipped with a vacuum suction device and a sealed air chamber inside.

[0014] Furthermore, a fan is installed on the waste heat exhaust duct, and the output end of the fan is connected to the ventilation hood.

[0015] Furthermore, it also includes a hydraulic pulper, a transition pulp tank, a pulp conditioning tank, and a pulp forming tank connected in sequence. The pulp forming tank is connected to a multi-faceted rotary drum forming machine, and a dewatering device is provided after the transition pulp tank.

[0016] Furthermore, the slurry conditioning tank is equipped with a sand separator, which includes a first-stage sand separator and a second-stage sand separator; the tail slurry output end of the first-stage sand separator is connected to the second-stage sand separator.

[0017] A semi-dry pressing process for preparing disposable pulp molded tableware includes the following steps:

[0018] S1, Wet blank forming: The pulp is fed into the multi-faceted rotary drum forming machine, and the pulp is sequentially sucked into shape, vacuum dewatered, and the product is transferred to obtain a wet blank with a moisture content of 65-80%; the multi-faceted rotary drum forming machine is equipped with a sealed ventilation hood, which covers the rotary drum forming part, and the wet blank is heated and dewatered for 10-30 seconds in a hot air environment of 90-130°C inside the ventilation hood;

[0019] S2, Drying: The wet blank is fed into the drying equipment and dried at 120-200℃ for 4-10 minutes to obtain a semi-dry blank with a dryness of 50-90%. The waste heat exhaust air of the drying equipment is sent back to the ventilation hood to preheat and dry the wet blank.

[0020] S3, Hot pressing and shaping: Transfer the semi-dry blank to a hot pressing and shaping machine, and dry it at 180-200℃ to obtain a semi-finished product;

[0021] S4, Trimming: Transfer the semi-finished product to the trimming machine, trim and shape the semi-finished product, stack it, and obtain the finished product.

[0022] Furthermore, it also includes a pulp pretreatment step:

[0023] (1) Put the pulp board and water into the pulper and pulp for 8-12 minutes to obtain pulp liquid;

[0024] (2) Pump the slurry into the transition slurry tank and add clean water to adjust the slurry concentration to 2.5-3.0%, or use a disintegration device to disintegrate the adjusted slurry again to obtain disintegrated slurry;

[0025] (3) Pump the slurry into the slurry preparation tank, add water to adjust the slurry concentration to 0.3-0.8%, add waterproofing agent and oil-proofing agent, stir for 10-15 minutes, and send the slurry into the pulping tank to obtain paper pulp.

[0026] Furthermore, the pulp board is any one of bamboo pulp, bagasse pulp, wood pulp, and reed pulp.

[0027] Furthermore, step (3) also includes a two-stage sand removal process, which specifically involves: sending the slurry into a first-stage sand remover to remove heavy sand particles from the slurry, and the resulting first-stage good slurry entering the slurry forming tank, the tailings entering the second-stage sand remover, the resulting second-stage good slurry returning to the slurry conditioning tank, and the slag slurry being directly discharged.

[0028] Further, the specific process of step S1 is as follows: the pulp is fed into the pulp tank of the multi-faceted rotary drum forming machine, and the rotary drum is controlled to rotate by a servo motor or grooved wheel mechanism to completely immerse the mold in the pulp. Under vacuum, the pulp is adsorbed onto the mold and retained by its filter screen. After 1 to 10 seconds of pulp suction, the rotary drum continues to rotate to make the mold leave the pulp surface. Vacuum dewatering is performed for 10 to 30 seconds, wherein the pressure of the vacuum suction device is controlled at 0.06 MPa to 0.08 MPa, and the pressure of the compressed air in the sealed air chamber is controlled at 0.40 to 0.75 MPa to obtain a wet blank with a moisture content of 65 to 80%. The rotary drum continues to rotate to produce the wet blank for the next mold.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] By employing multi-faceted rotary drum forming and hot air preheating vacuum dehydration technology, products can achieve higher dryness and temperature during forming, resulting in better bonding strength. This reduces shrinkage and deformation during the drying process and prevents fine fiber components from being sucked into the mold's vents, causing blockages and coking, thus reducing cleaning labor and time costs. Furthermore, through continuous suction forming and preheating dehydration processes, a significant breakthrough in production volume can be achieved, greatly increasing single-machine capacity. Currently, single-machine capacity is approximately 300-600 kg / day, while with this invention, single-machine capacity can reach several tons per day.

[0031] Compared with existing batch drying methods, this invention adopts a continuous exhaust gas waste heat preheating system and combines it with single-layer or multi-layer drying equipment to carry out centralized large-scale drying of wet blanks, which improves drying speed and efficiency, reduces the pressurization time in the hot press setting machine, and reduces production energy consumption.

[0032] Compared to existing wet pressing processes, this invention employs a semi-dry pressing method. By increasing the dryness of the product before hot pressing to 50-90%, the fiber bonding strength of the product is already relatively high when hot pressing is performed at this dryness level. Even if vacuum drying is performed again, the impact on the hot pressing mold is minimal, preventing problems such as fine fiber components of the product being sucked into the mold's vent holes and causing blockages or coking. This extends the production cycle of the hot pressing mold, reduces production downtime caused by blockages and coking, and also lowers the labor costs for equipment maintenance. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the semi-dry pressing preparation system for disposable pulp molded tableware of the present invention.

[0034] Figure 2 This is a flowchart of the semi-dry pressing process for preparing disposable pulp molded tableware according to the present invention.

[0035] In the diagram: 1. Pulper; 2. Transition slurry tank; 3. Dewatering equipment; 4. Sand remover; 5. Slurry conditioning tank; 6. Slurry forming tank; 7. Multi-faceted rotary drum forming machine; 8. Drying equipment; 9. Finished product. Detailed Implementation

[0036] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0037] A semi-dry pressing preparation system for disposable pulp molded tableware includes a hydraulic pulper, a transition pulp tank, a pulp conditioning tank, a pulp forming tank, a multi-faceted rotary drum forming machine, a drying equipment, a hot pressing and shaping machine, and an edge trimming machine connected in sequence.

[0038] The multi-faceted rotating hub forming machine is a coaxial 2-12 faceted rotating hub device, with the same number of forming molds installed on each face. The multi-faceted rotating hub machine is equipped with a vacuum suction device and a sealed air chamber. The multi-faceted rotating hub forming machine is used for slurry suction forming, vacuum dehydration, and preparation of wet blanks. The multi-faceted rotating hub forming machine is equipped with a sealed ventilation hood that covers the rotating hub forming section to control the temperature and humidity of the rotating hub forming section.

[0039] The drying equipment includes a heater, an air supply device, and a single or multiple chain plates for transferring wet blanks. A fan is installed on the waste heat exhaust duct, and the output end of the fan is connected to a ventilation hood. The hot pressing and shaping machine is used for hot pressing, drying, and shaping of semi-dry blanks; the edge trimming machine is used for trimming and shaping of semi-finished products.

[0040] The transition slurry tank is equipped with a descaling device to further descale the slurry. The descaled slurry is then pumped to the conditioning tank. The conditioning tank is equipped with a desander, which includes a primary desander and a secondary desander. The tail slurry output end of the primary desander is connected to the secondary desander.

[0041] The paper mold tableware is formed using a multi-faceted rotary drum machine, which can include various types of rotary drum forming machines with 2 to 12 faces. Existing paper mold tableware forming methods mainly use reciprocating slurry injection or turning (flipping) wet forming methods, generally with one face, at most two faces. However, this invention uses a multi-faceted (including 2 to 12 faces) rotary drum type slurry suction wet forming method, which is quite different from the previous method.

[0042] By employing multi-faceted rotary drum forming and hot air preheating vacuum dehydration technology, products can achieve higher dryness and temperature during forming, resulting in higher bonding strength. This reduces shrinkage and deformation during the drying process and prevents fine fiber components from being sucked into the mold's vents, causing blockages and coking, thus reducing cleaning labor and time costs. Furthermore, through continuous suction forming and preheating dehydration processes, a significant breakthrough in production volume can be achieved, greatly increasing single-machine capacity. Currently, single-machine capacity is approximately 300-600 kg / day, while with this invention, single-machine capacity can reach several tons per day.

[0043] Compared with existing batch drying methods, this invention adopts a continuous exhaust gas waste heat preheating system and combines it with single-layer or multi-layer drying equipment to carry out centralized large-scale drying of wet blanks, which improves drying speed and efficiency, reduces the pressurization time in the hot press setting machine, and reduces production energy consumption.

[0044] The semi-dry pressing process for preparing disposable pulp molded tableware includes the following steps:

[0045] Pulp pretreatment steps:

[0046] (1) Put the pulp board and water into the pulper and pulp for 8-12 minutes to obtain pulp liquid; the pulp board is any one of bamboo pulp, bagasse pulp, wood pulp and reed pulp; renewable and biodegradable environmentally friendly plant fiber is used as raw material, which is not only easy to obtain, but also easy to biodegrade.

[0047] (2) Pump the slurry into the transition slurry tank and add clean water to adjust the slurry concentration to 2.5-3.0%, or use a disintegration device to disintegrate the adjusted slurry again to obtain disintegrated slurry;

[0048] (3) Pump the descaling pulp into the pulp conditioning tank, add clean water to adjust the pulp concentration to 0.3-0.8%, add waterproofing agent and oil-proofing agent, stir for 10-15 minutes, and send the pulp into the pulping tank to obtain paper pulp. It also includes a two-stage sand removal process, which is as follows: send the pulp into a first-stage sand remover to remove heavy sand particles from the pulp, and the resulting first-stage good pulp enters the pulping tank. The tail pulp enters the second-stage sand remover, and the resulting second-stage good pulp returns to the pulp conditioning tank. The slag pulp is directly discharged.

[0049] S1, Wet blank forming: Pulp is fed into the pulp tank of the multi-faceted rotary drum forming machine. The rotary drum is controlled to rotate by a servo motor or grooved wheel mechanism, and the mold is completely immersed in the pulp. Under vacuum, the pulp is adsorbed onto the mold and trapped by its filter screen. After 1-10 seconds of pulp suction, the rotary drum continues to rotate, causing the mold to leave the pulp surface. Vacuum dewatering is performed for 10-30 seconds. The pressure of the vacuum suction device is controlled at 0.06MPa-0.08MPa, and the pressure of the compressed air in the sealed air chamber is controlled at 0.40-0.75MPa, resulting in a wet blank with a moisture content of 65-80%. The rotary drum continues to rotate to produce the wet blank for the next mold. The multi-faceted rotary drum forming machine is equipped with a sealed ventilation hood that covers the rotary drum forming part. The wet blank is heated and dewatered for 10-30 seconds in a hot air environment of 90-130°C inside the ventilation hood.

[0050] S2, Drying: The wet blank is fed into the drying equipment and dried at 120-200℃ for 4-10 minutes to obtain a semi-dry blank with a dryness of 50-90%. The waste heat exhaust air of the drying equipment is sent back to the ventilation hood to preheat and dry the wet blank.

[0051] S3, Hot pressing and shaping: Transfer the semi-dry blank to a hot pressing and shaping machine, and dry it at 180-200℃ to obtain a semi-finished product;

[0052] S4, Trimming: Transfer the semi-finished product to the trimming machine, trim and shape the semi-finished product, stack it, and obtain the finished product.

[0053] This process is relatively simple and reasonable, easy to operate and control, and highly safe and reliable. Furthermore, the production process significantly extends the mold maintenance cycle and reduces labor intensity. The product is an environmentally friendly and recyclable product with oil and water resistance. The waste generated after use can quickly and naturally degrade, is harmless to humans, and causes no pollution to the environment.

[0054] Existing hot-pressing processes involve directly hot-pressing and drying wet paper blanks with a dryness of approximately 25-28%. This invention employs a method where, after forming, the paper blank is preheated with hot air, and then, under vacuum suction, the moisture content is reduced to 65-70%, and the dryness increases to 30-35%. Simultaneously, the temperature of the wet paper blank is raised to 60-90°C. It then enters a single-layer or multi-layer box-type drying line for further drying, increasing the product's dryness to 50-90%. Finally, it undergoes hot-pressing and setting at 180-200°C to achieve a final product with a dryness of over 95%.

[0055] Compared to existing wet pressing processes, this invention employs a semi-dry pressing method. By increasing the dryness of the product before hot pressing to 50-90%, the fiber bonding strength of the product is already relatively high when hot pressing is performed at this dryness level. Even if vacuum drying is performed again, the impact on the hot pressing mold is minimal, preventing problems such as fine fiber components of the product being sucked into the mold's vent holes and causing blockages or coking. This extends the production cycle of the hot pressing mold, reduces production downtime caused by blockages and coking, and also lowers the labor costs for equipment maintenance.

[0056] Example 1,

[0057] See Figure 1 A semi-dry pressing preparation system for disposable pulp molded tableware includes a pulper 1, a transition pulp tank 2, a pulp conditioning tank 5, a pulp forming tank 6, a multi-faceted rotary drum forming machine 7, a drying equipment 8, a hot pressing and shaping machine, and an edge trimming machine connected in sequence.

[0058] The multi-faceted rotating hub machine 7 is a coaxial 12-faceted rotating hub device, with the same number of forming molds installed on each face. The multi-faceted rotating hub machine 7 is equipped with a vacuum suction device and a sealed air chamber. The multi-faceted rotating hub machine 7 is used for suction molding, vacuum dehydration, and preparation of wet blanks. The multi-faceted rotating hub machine 7 is equipped with a sealed ventilation hood that covers the rotating hub forming section to control the temperature and humidity of the rotating hub forming section.

[0059] The drying equipment 8 includes a heater, an air supply device, and a single or multiple chain plates for transferring wet blanks. A fan is installed on the waste heat exhaust duct, and the output end of the fan is connected to a ventilation hood. The hot pressing and shaping machine is used for hot pressing, drying, and shaping of semi-dry blanks; the edge trimming machine is used for trimming and shaping of semi-finished products.

[0060] The transition slurry tank 2 is equipped with a slurry clearing device 3 and a sand remover 4 to further clear the slurry. The cleared slurry is then pumped to the slurry conditioning tank 5.

[0061] This embodiment uses a 12-sided rotary drum machine to form paper mold tableware. Existing paper mold tableware forming methods mainly use reciprocating slurry injection or turning (flipping) wet forming, which generally has one side, or at most two sides. However, this invention uses a 12-sided rotary drum suction wet forming method, which is quite different from the previous method.

[0062] The semi-dry pressing process for preparing disposable pulp molded tableware includes the following steps:

[0063] Pulp pretreatment steps:

[0064] (1) Put the pulp board and water into the pulper and pulp for 12 minutes to obtain pulp liquid; the pulp board is wood pulp.

[0065] (2) Pump the slurry into the transition slurry tank, add clean water to adjust the slurry concentration to 3.0%, and use a disintegration device to disintegrate the adjusted slurry again to obtain disintegrated slurry;

[0066] (3) Pump the descaling pulp into the pulp conditioning tank, add clean water to adjust the pulp concentration to 0.8%, add waterproofing agent and oil-proofing agent, stir for 15 minutes, and send the pulp into the pulping tank to obtain paper pulp;

[0067] S1, Wet blank forming: Pulp is fed into the pulp tank of the multi-faceted rotary drum forming machine. The rotary drum is controlled to rotate by a servo motor or grooved wheel mechanism, and the mold is completely immersed in the pulp. Under vacuum, the pulp is adsorbed onto the mold and trapped by its filter screen. After 3 seconds of pulp suction, the rotary drum continues to rotate, causing the mold to leave the pulp surface. Vacuum dewatering is performed for 10-30 seconds, during which the pressure of the vacuum suction device is controlled at 0.08 MPa, and the pressure of the compressed air in the sealed air chamber is controlled at 0.75 MPa, resulting in a wet blank with a moisture content of 65%. The rotary drum continues to rotate to produce the wet blank for the next mold. The multi-faceted rotary drum forming machine is equipped with a sealed ventilation hood, which covers the rotary drum forming part. The wet blank is heated and dewatered for 30 seconds in a 90°C hot air environment inside the ventilation hood.

[0068] S2, Drying: The wet blank is fed into the drying equipment and dried at 200°C for 10 minutes to obtain a semi-dry blank with a dryness of 90%. The waste heat exhaust air of the drying equipment is sent back to the ventilation hood to preheat and dry the wet blank.

[0069] S3, Hot Press Shaping: The semi-dry blank is transferred to a hot press shaping machine and dried and shaped at 200℃ to obtain a semi-finished product. Specifically, the semi-dry blank coming out of the drying chain plate automatically falls to a conveyor belt with mechanical positioning. Through a robot or other transfer mechanism, the semi-dry blank is transferred by a suction cup mechanism and placed into the mold of the shaping machine with a heating temperature of 200℃ for hot press shaping. Depending on the product, the shaping time is 5 to 10 seconds, and a semi-finished product with a dryness of more than 95% can be obtained.

[0070] S4, Trimming: The semi-finished product is transferred to the trimming machine for trimming, shaping, and stacking to obtain the finished product. A robot uses a suction cup mechanism to transfer the product onto the trimming mold of the trimming machine to cut off excess trimming material. A robot or other transfer mechanism uses a suction cup mechanism or mold to transfer the product from the trimming machine to a stacking platform. The product is then inspected, disinfected, and packaged to produce the finished paper-mold tableware.

[0071] Compared to existing wet pressing processes, this invention employs a semi-dry pressing method. By increasing the dryness of the product to 90% before hot pressing, the fiber bonding strength of the product is already relatively high. Even if vacuum drying is performed again, the impact on the hot pressing mold is minimal. This prevents the fine fiber components of the product from being sucked into the mold's vent holes, causing blockages or coking. It can extend the production cycle of the hot pressing mold, reduce production downtime caused by blockages and coking, and also reduce the labor costs of equipment maintenance.

[0072] Example 2,

[0073] A semi-dry pressing preparation system for disposable pulp molded tableware includes a hydraulic pulper, a transition pulp tank, a pulp conditioning tank, a pulp forming tank, a multi-faceted rotary drum forming machine, a drying equipment, a hot pressing and shaping machine, and an edge trimming machine connected in sequence.

[0074] The multi-faceted rotating hub forming machine is a coaxial three-sided rotating hub device, with the same number of forming molds installed on each face. The multi-faceted rotating hub machine is equipped with a vacuum suction device and a sealed air chamber. The multi-faceted rotating hub forming machine is used for suction molding, vacuum dehydration, and preparation of wet blanks. The multi-faceted rotating hub forming machine is equipped with a sealed ventilation hood that covers the rotating hub forming section to control the temperature and humidity of the rotating hub forming section.

[0075] The drying equipment includes a heater, an air supply device, and a single or multiple chain plates for transferring wet blanks. A fan is installed on the waste heat exhaust duct, and the output end of the fan is connected to a ventilation hood. The hot pressing and shaping machine is used for hot pressing, drying, and shaping of semi-dry blanks; the edge trimming machine is used for trimming and shaping of semi-finished products.

[0076] The transition slurry tank is equipped with a descaling device to further descale the slurry. The descaled slurry is then pumped to the conditioning tank. The conditioning tank is equipped with a desander, which includes a primary desander and a secondary desander. The tail slurry output end of the primary desander is connected to the secondary desander.

[0077] The paper mold tableware is formed using a multi-sided rotary drum forming machine, which can include various types of rotary drum forming machines such as 3-sided machines. Existing paper mold tableware forming methods mainly use reciprocating injection or turning (flipping) wet forming methods, generally with one side, or at most two sides. However, this invention uses a 3-sided rotary drum suction wet forming method, which is quite different from the previous method.

[0078] Reference Figure 2 The semi-dry pressing process for preparing disposable pulp molded tableware includes the following steps:

[0079] Pulp pretreatment steps:

[0080] (1) Put the pulp board, chemical additives and white water into a hydraulic pulper and pulp for 8 minutes to obtain pulp liquid; the pulp board is bamboo pulp; the raw material is a renewable and biodegradable environmentally friendly plant fiber, which is not only easy to obtain, but also easy to biodegrade.

[0081] (2) Pump the pulp liquid to the transition slurry tank, add clean water to adjust the slurry concentration to 2.5%, use the disintegration equipment to disintegrate the adjusted slurry again, add disintegration aid to obtain disintegrated slurry;

[0082] (3) The pulp is pumped into the pulp conditioning tank, clean water is added to adjust the pulp concentration to 0.3%, and waterproofing agent and oil-proofing agent are added. The mixture is stirred for 10 minutes, and the pulp is pumped into the pulping tank to obtain paper pulp. The process also includes a two-stage desanding process, which is as follows: the pulp is pumped into a first-stage desander through a first-stage desanding pump to remove heavy sand particles from the pulp. The resulting first-stage good pulp enters the pulping tank, and the tail pulp enters the second-stage desanding tank and is pumped into a second-stage desander through a second-stage desanding pump. The resulting second-stage good pulp returns to the pulp conditioning tank, and the slag pulp is directly discharged.

[0083] S1, Wet Fabric Forming: A pulp supply pump pumps the pulp from the pulping tank to the pulp tank of the multi-faceted rotary drum forming machine. A servo motor or grooved wheel mechanism controls the rotation of the drum, ensuring the mold is fully immersed in the pulp. Under vacuum, the pulp is adsorbed onto the mold and trapped by its filter screen. After 5 seconds of suction, the drum continues to rotate, causing the mold to leave the pulp surface. Vacuum dewatering is performed for 10 seconds, with the vacuum suction device pressure controlled at 0.06 MPa and the compressed air pressure in the sealed chamber controlled at 0.60 MPa, resulting in a wet fabric with a moisture content of 80%. The drum continues to rotate to produce the next wet fabric for the next mold. The multi-faceted rotary drum forming machine is equipped with a sealed ventilation hood that covers the drum forming section. The wet fabric undergoes 30 seconds of heating and dewatering in a 130°C hot air environment within the ventilation hood. Pulp overflowing from the multi-faceted rotary drum forming machine is collected in a return pulp tank and returned to the pulping tank via a return pulp pump.

[0084] S2, Drying: The wet blank is fed into the drying equipment, which is a single-layer box-type drying line or a multi-layer box-type drying line. It is dried at 120°C for 10 minutes to obtain a semi-dry blank with a dryness of 60%. The waste heat exhaust air of the drying equipment is returned to the ventilation hood by a fan to preheat and dry the wet blank.

[0085] S3, Hot Pressing and Shaping: The semi-dry blank is transferred to the hot pressing and shaping machine via the robot transfer platform 1. It is then hot-pressed and dried at 180°C to obtain a semi-finished product. Specifically, the semi-dry blank coming out of the drying chain plate automatically falls to a conveyor belt with mechanical positioning. Through a robot or other transfer mechanism, the semi-dry blank is transferred by a suction cup mechanism and placed into the mold of the shaping machine with a heating temperature of 200°C for hot pressing and shaping. Depending on the product, the shaping time is 5 to 10 seconds, and a semi-finished product with a dryness of over 95% can be obtained.

[0086] S4, Edge trimming: The semi-finished products are transferred to the automatic edge trimming machine via the robot transfer platform 2 to trim and shape the semi-finished products. The finished products are then transferred to the product stacking platform via the robot or other motion mechanism transfer platform 3 for stacking. The products are inspected, disinfected, packaged, and stored in the warehouse.

[0087] The vacuum suction device of the multi-faceted rotary drum forming machine is a vacuum tube with a valve. The other end of the vacuum tube is connected to a steam-water separator, a buffer tank, and a vacuum pump, respectively. The vacuum tube is connected to a vacuum branch pipe, which is connected to a hot press forming machine. The water vapor extracted by the vacuum pump is discharged through a silencer.

[0088] This preparation process also includes a water recirculation system. The pulp produced by the dehumidification of the multi-faceted rotary drum forming machine and the hot press setting machine and separated by the steam-water separator is transported to the white water tank by a negative pump, diluted with clean water, and then returned to the hydraulic pulper by a white water pump, realizing the recycling of water and pulp resources, saving resources and protecting the environment.

[0089] This process is relatively simple and reasonable, easy to operate and control, and highly safe and reliable. Furthermore, the production process significantly extends the mold maintenance cycle and reduces labor intensity. The product is an environmentally friendly and recyclable product with oil and water resistance. The waste generated after use can quickly and naturally degrade, is harmless to humans, and causes no pollution to the environment.

[0090] Compared to existing wet pressing processes, this invention employs a semi-dry pressing method. By increasing the dryness of the product to 50% before hot pressing, the fiber bonding strength of the product is already relatively high. Even if vacuum drying is performed again, the impact on the hot pressing mold is minimal. This prevents fine fiber components from being sucked into the mold's vent holes, causing blockages or coking. It can extend the production cycle of the hot pressing mold, reduce production downtime caused by blockages and coking, and also lower the labor costs for equipment maintenance.

[0091] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A semi-dry pressing process for disposable pulp molded tableware, executed by a semi-dry pressing system for disposable pulp molded tableware, characterized in that, Includes the following steps: S1, Wet blank forming: The pulp is fed into the pulp tank of the multi-faceted rotary drum forming machine, and is sequentially subjected to pulp suction forming, vacuum dewatering and product transfer to obtain a wet blank with a moisture content of 65-80%; the multi-faceted rotary drum forming machine is equipped with a sealed ventilation hood, which covers the rotary drum forming part, and the wet blank is heated and dewatered for 10-30 seconds in a hot air environment of 90-130°C inside the ventilation hood; S2, Drying: The wet blank is fed into the drying equipment and dried at 120-200℃ for 4-10 minutes to obtain a semi-dry blank with a dryness of 50-60%. The waste heat exhaust air of the drying equipment is sent back to the ventilation hood to preheat and dry the wet blank. S3, Hot pressing and shaping: Transfer the semi-dry blank to a hot pressing and shaping machine, and dry it at 180-200℃ to obtain a semi-finished product; S4, Trimming: Transfer the semi-finished product to the trimming machine, trim and shape the semi-finished product, stack it, and obtain the finished product; It also includes a pulp pretreatment step: (1) Put the pulp board and water into the pulper and pulp for 8-12 minutes to obtain pulp liquid; (2) Pump the slurry into the transition slurry tank and add clean water to adjust the slurry concentration to 2.5-3.0%. Use a disintegration device to disintegrate the adjusted slurry again to obtain disintegrated slurry. (3) Pump the descaling pulp into the pulp conditioning tank, add clean water to adjust the pulp concentration to 0.3-0.8%, add waterproofing agent and oil-proofing agent, stir for 10-15 minutes, and send the pulp into the pulping tank to obtain paper pulp; The specific process of step S1 is as follows: The pulp is fed into the pulp tank of the multi-faceted rotary drum forming machine. The rotary drum is controlled to rotate by a servo motor or a grooved wheel mechanism, and the mold is completely immersed in the pulp. Under vacuum, the pulp is adsorbed onto the mold and retained by its filter screen. After 1 to 10 seconds of pulp suction, the rotary drum continues to rotate, causing the mold to leave the pulp surface. Vacuum dewatering is performed for 10 to 30 seconds, during which the pressure of the vacuum suction device is controlled at 0.06 MPa to 0.08 MPa, and the pressure of the compressed air in the sealed air chamber is controlled at 0.40 to 0.75 MPa, resulting in a wet blank with a moisture content of 65% to 80%. The rotary drum continues to rotate to produce the wet blank for the next mold. The semi-dry pressing preparation system for the disposable pulp molded tableware includes a multi-faceted rotary drum forming machine, a drying device, a hot pressing and shaping machine, and an edge trimming machine connected in sequence. The multi-faceted rotating drum forming machine is used for suction molding, vacuum dehydration, and preparation of wet blanks. The multi-faceted rotating drum forming machine is equipped with a sealed ventilation hood that covers the rotating drum forming part to control the temperature and humidity of the rotating drum forming part. The drying equipment includes a heater, an air supply device, and a single or multiple chain plates for transferring wet blanks. A fan is installed on the waste heat exhaust duct of the drying equipment, and the output end of the fan is connected to a ventilation hood. The hot press shaping machine is used for hot pressing, drying, and shaping of semi-dry blanks; The edge trimming machine is used for trimming and shaping semi-finished products; It also includes a pulper, a transition pulp tank, a pulp conditioning tank and a pulp forming tank connected in sequence. The pulp forming tank is connected to a multi-faceted rotary drum forming machine. The transition pulp tank is equipped with a dewatering device. The slurry conditioning tank is equipped with a sand remover, which includes a first-stage sand remover and a second-stage sand remover; the tail slurry output end of the first-stage sand remover is connected to the second-stage sand remover.

2. The semi-dry pressing process for preparing disposable pulp molded tableware as described in claim 1, characterized in that: The multi-faceted rotating hub forming machine is a coaxial 2 to 12-faceted rotating hub device, with the same number of forming molds installed on each face. The multi-faceted rotating hub machine is equipped with a vacuum suction device and a sealed air chamber inside.

3. The semi-dry pressing process for preparing disposable pulp molded tableware as described in claim 1, characterized in that: The pulp board is any one of bamboo pulp, bagasse pulp, wood pulp, and reed pulp.

4. The semi-dry pressing process for disposable pulp molded tableware as described in claim 1, characterized in that, Step (3) also includes a two-stage sand removal process. Specifically, the two-stage sand removal process is as follows: the slurry is sent into a first-stage sand remover to remove the heavy sand particles in the slurry. The resulting first-stage good slurry enters the slurry forming tank, the tail slurry enters the second-stage sand remover, the resulting second-stage good slurry returns to the slurry conditioning tank, and the slag slurry is directly discharged.

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