WO2022120554A1

WO2022120554A1 - Energy-saving production process method for rapid drying and dewatering of paper-plastic products

Info

Publication number: WO2022120554A1
Application number: PCT/CN2020/134431
Authority: WO
Inventors: 黄茂荣
Original assignee: 常州市诚鑫环保科技有限公司
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2022-06-16
Also published as: US20240035236A1

Abstract

An energy-saving production process method for rapid drying and dewatering of paper-plastic products, which is applied to production of paper-plastic products, and mainly comprises a cold extrusion press station (2) which is independent and is arranged between a pulp suction forming station (1) and a hot-press shaping station (3); the cold extrusion press station (2) is provided with a top mold and a lower mold (21, 22) which can form a mold closing gap according to the shape and size of a product, the mold closing gap is used to first press a primary product to discharge water of about 30% to 50%, and then send same to the hot-press shaping station for continuous dewatering to below 3% to form a paper-plastic product. The paper-plastic product produced by using the present production process can shorten the production time and reduce the consumption of heat energy for drying.

Description

Production technology of paper-plastic products with energy saving and rapid drying and dehydration

technical field

The invention relates to a production process of a paper-plastic product, in particular to a production process method of the paper-plastic product with energy saving and rapid drying and dehydration.

Background technique

With the deepening and demand for the concept of environmental protection, the technological advancement of the production process of degradable and recyclable products is becoming more and more important, especially the non-toxic, degradable, The characteristics of recyclability and remanufacturing have become the leading soldiers in environmental protection products, and the production process of paper and plastic products is nothing more than: continuous production processes such as suction molding, hot pressing and trimming, among which how to reduce thermal energy loss and Reducing the time for hot pressing and setting is a technical field that the technicians in the paper-plastic product manufacturing industry have long been eager to break through; the general pulp suction process uses the pulp to form the initial embryo of the paper-plastic product by vacuum suction technology. At this time, the initial embryo The moisture content of the product is about 70%-80%, and various heating and dehydration techniques are used to dry the first embryo product. However, in the process of directly reducing the moisture content of the first embryo product to below 3% by using thermal power, the heat loss It is quite huge, and it takes a lot of time to complete, and the heat energy and time consumed in this process are obviously contrary to the concept of environmental protection. At the same time, the production cost is greatly increased, and the paper-plastic products completed by this production process are greatly reduced. profit.

It is known that another improved paper-plastic production process is: suction forming, cold-pressing dehydration, hot-pressing and trimming. The mold is closed, so that the preliminary embryo in the suction mold is pressed and the extruded water is discharged, which can reduce the moisture content of the preliminary embryo from 70%-80% to 50%-60%. The embryo product is then moved to the hot-pressing setting station and dehydrated to a moisture content of less than 3% to form a semi-finished product. The pulp mold 91 is provided with a ventilating mesh 93 for pulp suction, filtration and molding. The ventilating mesh 93 is a sheet-like ventilating mesh 93 formed by a combination of a plurality of criss-crossing mesh wires, as shown in FIG. 6 , and the ventilating mesh 93 A plurality of meshes 930 are formed, and when the extrusion die 92 is pressed, the surface of the semi-dry and wet embryo M and the suction die 91 in contact with the mesh 930 of the air-permeable mesh 93 is engulfed in the mesh 930 to produce a meshing phenomenon, as shown in the figure. As shown in 5, in the currently known production process of cold-pressed paper-plastic products, only the semi-dry and wet embryo M with a large mold pull-out slope can be demolded. If the pull-out slope is small or close to The surface of the semi-dry and wet embryo M of the vertical plane will be scratched by the breathable mesh 93 when demoulding, which will not be able to be demolded smoothly or cause the pulp fiber to break, resulting in the phenomenon of plugging holes. There are many restrictions on the shape or angle.

Furthermore, if only using the extrusion die 92 to directly press the first embryonic product in the suction mold 91, only considering the pressing and dehydration without calculating the clamping gap after extrusion (that is, the thickness of the first embryonic product after being squeezed), it is easy to cause If the thickness of the semi-dry and wet embryo M is too thick or too thin, if the thickness is not appropriate, the defective rate of the first embryo will be higher after the finished product; If the thickness of the semi-dry and wet embryo product M is too thin, the bursting resistance, folding endurance and strength of the paper-plastic product will be too low, and the surface of the finished product will have obvious uneven lines. The defects of technology as the production method of paper-plastic products also prevent the production efficiency from being improved and increase the production cost.

technical problem

The main purpose of the present invention is to provide an energy-saving and fast drying and dehydrating paper-plastic product production process method.

technical solutions

It is a cold extrusion press station that is combined with an upper mold and a lower mold to extrude a first embryo, and the cold extrusion press station is set at a suction forming station and a hot pressing setting station. During the process, the overall process flow is suction forming-cold pressing-hot pressing. The aforementioned upper and lower molds of the cold extrusion press station can form a clamping gap when the molds are closed, and the upper and lower molds of the cold extrusion press station can be used to form a clamping gap. The pressing force after the lower die is closed to press the first embryo; based on the thickness of a finished product, that is, the clamping gap of the aforementioned hot-pressing setting station is also maintained at the distance of the thickness of the finished product, according to the setting of the distance of the finished product thickness. The thickness of the semi-finished product after drying in the hot-pressing setting station is also maintained at the distance of the thickness of the finished product, and the distance between the clamping gap of the aforementioned cold extrusion station is 1~1.3 times the thickness of the finished product, that is, the cold extrusion press The distance between the clamping gap of the station is between 1 and 1.3 times the thickness of the finished product, and the thickness of the semi-dry and wet embryo extruded by the cold extrusion station is also maintained at 1 to 1.3 times the thickness of the finished product. The distance of the clamping gap of the suction forming station is 2~2.3 times the thickness of the finished product, that is, the thickness of the initial embryo formed by the suction forming station is also maintained at 2~2.3 times the thickness of the finished product.

Preferably, a vacuum cavity is formed at the bottom of the lower die of the cold extrusion station, and the other side of the lower die is provided with an accommodating space for placing the preliminary embryos. The molding die surface, which is shaped for the positioning and shaping of the preliminary embryo, is provided with a plurality of air holes between the vacuum chamber and the accommodating space, and these air holes pass through between the vacuum chamber and the accommodating space for the aforesaid accommodating space. The vacuum negative pressure of the suction forming station, the cold extrusion pressing station and the hot pressing setting station extracts the water.

Preferably, a ventilating net is provided on the mold surface of the lower mold whose demolding angle is greater than 5 degrees, and the ventilating net is not provided on the die surface whose demolding angle of the lower die is less than 5 degrees.

Preferably, after the suction forming station enters the slurry tank to absorb and form the preliminary embryo, the preliminary embryo is transferred to the accommodating space of the lower mold of the cold extrusion station, and the above-mentioned upper 2. When the lower mold is closed and extruded, the aforementioned preliminary embryo is completely attached to the molding die surface of the lower mold and the aforementioned breathable mesh by the compression of the extrusion force of the upper mold and the adsorption force of the vacuum negative pressure, and the aforementioned preliminary The thickness of the embryo is formed from the thickness formed by the initial suction forming station to the thickness formed by the cold extrusion press station, and the pressed initial embryo strain is squeezed out of water and On the discharge surface, the discharged water is then adsorbed to the vacuum cavity by the vacuum negative pressure through the aforesaid air holes and then discharged out of the aforesaid lower mold, and the aforesaid preliminary embryo product is also reduced from the original moisture content of 68%-75% to the moisture content. 55%-60%, thereby obtaining a semi-dry and wet embryo product with a lower moisture content; then transfer the semi-dry and wet embryo product to the aforementioned hot pressing and setting station, and the aforementioned semi-dry and wet embryo can be made by the pressurization and heating drying of the heating system. The free water on the surface of the dry and wet embryos and the bound water in the interior are completely vaporized and evaporated, so that the aforementioned semi-dry and wet embryos have a moisture content of 55%-60% and a moisture content of less than 3% to obtain a semi-finished product.

Preferably, the preliminary embryos that have undergone the aforementioned cold extrusion process are then moved to the aforementioned hot-pressing setting station for heating and drying time, and the preliminary embryos that have not been subjected to the aforementioned cold-extrusion pressing process are directly moved to the aforementioned hot-pressing setting station for heating and drying. The drying time ratio used by the two is 1:2, and the consumption ratio of heat energy is 2:3.

beneficial effect

After adopting the above-mentioned technical scheme, the present invention makes the three processes of vacuum suction dehydration, cold extrusion dehydration and hot pressing drying and dehydration play to the maximum limit of dehydration and drying. The distance of the clamping gap of the forming station is 2~2.3 times of the thickness of the finished product. Use vacuum suction and dehydration to reduce the moisture content of the initial embryo A to the limit of 68%-75%, and then set up a cold extrusion press. The distance of the clamping gap is 1~1.3 times of the thickness of the finished product. Use cold extrusion to dehydrate the semi-dry and wet embryo B with the most appropriate moisture content of 50%-60%, and then set up a hot-pressing setting station. The clamping gap is kept at the distance of the thickness of the finished product, and the semi-dry and wet embryo product B is dried to the semi-finished product C with a moisture content of less than 3% by hot pressing drying and dehydration. The means used in the whole process are the maximum application of this station. , without wasting time and energy consumption to do unnecessary consumption.

Description of drawings

Fig. 1 is a flow chart of the present invention and a diagram showing the change of moisture content and thickness of the initial embryo.

Figure 2 is a schematic diagram of the cold extrusion press die clamping of the present invention.

FIG. 3 is a schematic structural diagram of the lower die of the cold extrusion press station of the present invention.

FIG. 4 is a schematic diagram of a conventional cold pressing extrusion die and a slurry suction die for pressing.

FIG. 5 is a schematic diagram of a conventional cold-pressed wet green product and an air-permeable mesh for generating an occlusal adhesive mesh.

Figure 6 is a schematic diagram of a breathable mesh.

Symbol description: 1... Suction forming station.

2...Cold extrusion press station.

21...upper extrusion die.

22...lower extrusion die.

221...Accommodating space.

222...Forming die face.

223...Vacuum chamber.

224...Stomata.

225...Clamping clearance.

3...Hot press setting station.

4...Breathable mesh.

91...Suction mold.

92...Extrusion die.

93...Breathable mesh.

A...Primary embryo.

B...semi-dry and wet embryos.

C...Semi-finished products.

X...finished thickness.

M...semi-dry and wet embryos.

Embodiments of the present invention

Please refer to FIG. 1 to FIG. 3 , the present invention provides a production process method for energy-saving and fast drying and dehydrating paper-plastic products, which mainly has an upper mold 21 and a lower mold 22 combined to form an initial embryo for extrusion An independent cold extrusion press station 2 of product A, the cold extrusion press station 2 is set between a suction forming station 1 and a hot pressing setting station 3, so that the overall process flow is suction forming- Cold extrusion press-hot press setting, the aforementioned upper and lower dies 21 and 22 of the cold extrusion press station 2 can form a clamping gap 225 when the mold is closed, and the upper and lower dies 21 and 22 can be used to close the mold. The squeezing force behind the die is used to squeeze the aforementioned preliminary embryo product A; with a finished product thickness X as the benchmark, that is, the mold clamping gap of the aforementioned hot-pressing setting station 3 is also maintained at the distance of the finished product thickness X, according to the finished product thickness X. The setting of the distance, the thickness of the semi-finished product C after drying in the hot pressing and setting station 3 is also maintained at the distance of the thickness X of the finished product, and the distance of the clamping gap of the aforementioned cold extrusion station 2 is 1~1.3 of the thickness X of the finished product times, that is, the distance between the clamping gap of the cold extrusion press station 2 is between 1 and 1.3 times the thickness X of the finished product, and the thickness of the semi-dry and wet embryo product B extruded from the cold extrusion press station 2 is also maintained. 1~1.3 times of the thickness X of the finished product, and the distance of the clamping gap of the aforementioned suction forming station 1 is 2~2.3 times of the thickness X of the finished product, that is, the initial embryo formed by the suction forming station 1 The thickness of A is also maintained at 2 to 2.3 times the thickness X of the finished product; a vacuum cavity 223 is formed at the bottom of the lower die 22 of the cold extrusion station 2, and a vacuum cavity 223 is formed on the other side of the lower die 22 for the first embryo product A to be placed. There is an accommodating space 221 in the accommodating space 221, and there is a molding die surface 222 in the accommodating space 221 that matches the same shape as the aforementioned preliminary embryo A for positioning and shaping the preliminary embryo A, and is provided between the aforementioned vacuum chamber 223 and the aforementioned accommodating space 221. There are a plurality of air holes 224, and these air holes 224 penetrate between the aforementioned vacuum chamber 223 and the aforementioned accommodating space 221 for the vacuum of the aforementioned suction forming station 1, cold extrusion pressing station 2, and hot pressing setting station 3 Negative pressure extracts water; the aforementioned molding die surface 222 is a die surface with different angles to match the shape of the paper-plastic product, and a ventilating mesh 4 is provided on the die surface where the demolding angle of the aforementioned lower die 22 is greater than 5 degrees, and the lower die The mold surface with the demolding angle of 22 less than 5 degrees is not provided with the aforementioned ventilating mesh 4, but the molding die surface 222 without the aforementioned ventilating mesh 4 still has air holes 224 penetrating between the aforementioned die surface and the aforementioned vacuum cavity 223.

Technical personnel familiar with the paper and plastic product industry know that if the cost of dehydration is 1 based on vacuum suction dehydration, the cost ratio of vacuum suction dehydration, cold extrusion dehydration and hot pressing drying dehydration is 1:70 : 330, that is, under the same amount of dehydration, the reduction cost of this cold extrusion dehydration is 70 times that of the vacuum suction dehydration, and the reduction cost of the aforementioned hot pressing drying and dehydration is about 5 times that of the aforementioned cold extrusion dehydration; The dehydration characteristics of different drying methods are as follows: the aforementioned vacuum suction dehydration can only absorb the free water on the surface of the aforementioned primary embryo product A, so its dehydration effect is very limited, and only about 10% of the aforementioned primary embryo product A can be discharged. -15% free water; the above-mentioned cold extrusion dehydration is to use the extrusion force to squeeze the thickness of the aforesaid first embryo product A to thin, so that the water in the aforementioned first embryo product A is squeezed and discharged, according to different The proportion of water discharged from the thickness and shape of the paper-plastic product is different. The water that can be discharged is about 30%-50% of the water content of the aforementioned first embryo product A, but the aforementioned cold extrusion dehydration can only be discharged freely. Water, the bound water cannot be discharged from the interior of the aforementioned preliminary embryo product A; the aforementioned hot-press drying and dehydration is to use thermal energy to vaporize the free water on the surface of the aforementioned preliminary embryo product A and the internal bound water, which can dry the moisture content of the paper-plastic product to 3% or less, and depending on the size, shape and thickness of the paper-plastic product, the time of the aforementioned hot-pressing drying and dehydration has a big gap, but the lower the moisture content of the aforementioned preliminary embryo product A, the aforementioned hot-pressing drying and dehydration time is The shorter, the relative thermal energy consumption is also reduced.

The specific implementation method of the present invention is as follows: between the aforementioned suction forming station 1 and the aforementioned hot pressing setting station 3, a cold extrusion pressing station 2 of the present invention is arranged, and when the aforementioned suction forming station 1 enters the pulp tank to suck After the pulp is formed into the aforementioned preliminary embryo product A, the preliminary embryo product A is transferred to the accommodating space 221 of the lower die 22 of the aforementioned cold extrusion press station 2, and the aforementioned upper and lower dies 21 and 22 are closed and extruded. During pressing, the aforementioned preliminary embryo product A is completely attached to the molding die surface 222 of the lower mold 22 and the aforementioned breathable mesh 4 by the pressing force of the upper die 21 and the suction force of the vacuum negative pressure, so that the aforementioned preliminary embryo is formed. The thickness of the product A is formed from the thickness of 2X-2.3X formed by the initial suction forming station 1 to the thickness 1X-1.3X squeezed by the aforementioned cold extrusion press station 2. The first embryo product A is squeezed out of water and discharged from the surface, and the discharged water is then adsorbed to the aforesaid vacuum cavity 223 by the vacuum negative pressure through the aforementioned air holes 224 and then discharged out of the aforementioned lower mold 22, and the aforementioned first embryo product A is also reduced from the original moisture content of 68%-75% to 50%-60%, thereby obtaining a semi-dry and wet embryo product B with a lower moisture content; then transfer the semi-dry and wet embryo product B to the aforementioned heat Pressing and setting station 3, using the pressurization and heating drying of the heating system, the free water on the surface of the semi-dry and wet embryo B and the bound water in the interior can be completely vaporized and evaporated, so that the moisture content of the semi-dry and wet embryo B is 50%. The semi-finished product C is obtained by reducing the moisture content of -60% to less than 3%; in addition, the extrusion force and vacuum suction force have been disclosed in other conventional patent documents, so they will not be repeated here.

The above-mentioned implementation method is through the following actual testing process: the first embryo product A with a moisture content of 72.8%, if not directly through the aforementioned cold extrusion press station 2 and directly to the aforementioned hot pressing and setting station 3 to be dried to a semi-finished product C with a moisture content of 1.4% , the drying time is 29 seconds; if the initial embryo with the same moisture content of 72.8% is first extruded for 10 seconds through the cold extrusion press station 2 of the present invention, a semi-dry and wet embryo with 33.3% moisture removed can be obtained. Product B, the aforementioned semi-dry and wet embryo product B after pressing is moved to the aforementioned hot-pressing setting station 3 and hot-pressed and dried for 15 seconds to obtain a semi-finished product C with a moisture content of 1.4%; from the above-mentioned experimental data, through two different The drying and dehydration process dries the preliminary embryo product A with a moisture content of 72.8% to a semi-finished product of 1.4%, and the preliminary embryo product A without the aforementioned cold extrusion process needs to use 29 seconds of drying time; The first embryo product A of the process can be completed with only 15 seconds of drying time, and the ratio of drying time used by the two is 2:1; the 33.3% water removed by the above-mentioned cold extrusion station 2 can save The thermal energy consumed by the hot-pressing setting station 3 saves 33.3% of the thermal energy consumption, and the ratio of thermal energy consumption between the two is 3:2; however, under different mold design, product shape, size and thickness and other factors, drying The proportion of time will be different, but in any case, the time for drying the first embryo product A, which is first pressed with water in the cold extrusion press station 2 of the present invention, to the semi-finished product C is definitely shorter, and the required heat energy is also less.

According to the test results, it can be known that the moisture content of the semi-dry and wet embryo product B passing through the cold pressing station 2 and the moisture content of the unpressed first embryo product A differs by 33.3%, and it is dried to the moisture content. The time of 1.4% is 15 seconds and 29 seconds respectively, and the difference between the test results of the two is 14 seconds. That is to say, adding the aforementioned cold extrusion press station 2 and the water squeezed can save 14 seconds of energy consumption and drying time; this The difference of 20 seconds is due to the large amount of water contained in the first embryo product A, so that when the above-mentioned hot-pressing and setting station 3 is hot-pressed and dried, the above-mentioned lower mold 22 is cooled by water and evaporated. Therefore, the hot-pressing setting die that has not undergone the aforementioned cold-extrusion pressing process must be replenished to the default heating temperature, and in addition, the required drying and evaporation of water is more, so it needs to use more time; The semi-dry and wet embryo product B of the extrusion pressing process has a lower moisture content and has a smaller cooling effect on the hot-pressing setting die, so the hot-pressing setting die is warmed up and evaporated faster.

To sum up, the present invention is to use the three processes of vacuum suction dehydration, cold extrusion dehydration, and hot pressing drying and dehydration to the maximum limit of dehydration and drying, that is, to use vacuum suction dehydration to first make the first embryo product A. The moisture content is reduced to the limit of 68%-75%, and then cold-pressed and dehydrated to the semi-dry and wet embryo B with the most appropriate moisture content of 50%-60%, and then the semi-dry and wet embryo B with a moisture content of 50%-60% is used for hot pressing drying and dehydration. For the semi-finished product C, which is dried to a moisture content of less than 3%, the whole process uses the means to maximize the application of the station, without wasting time and energy consumption for unnecessary consumption.

Claims

A production process method for energy-saving and fast-drying and dehydrating paper-plastic products, which is a cold extrusion press station for extruding a primary embryo product formed by combining an upper mold and a lower mold, the cold extrusion press It is located between a suction forming station and a hot-pressing setting station, so that the overall process flow is suction forming-cold extrusion pressing-hot pressing setting. It is characterized in that: the aforementioned cold extrusion pressing station When the upper and lower dies are closed, a clamping gap can be formed, and the pressing force of the upper and lower dies after clamping can be used to press the aforementioned preliminary product; based on the thickness of a finished product, the aforementioned hot-pressing setting station The clamping gap is also maintained at the distance of the thickness of the finished product. According to the setting of the distance of the thickness of the finished product, the thickness of the semi-finished product after drying in the hot pressing and setting station is also maintained at the distance of the thickness of the finished product. The aforementioned cold extrusion station The distance of the clamping gap is 1 to 1.3 times the thickness of the finished product, that is, the distance of the clamping gap of the cold extrusion press station is 1 to 1.3 times the thickness of the finished product. The thickness of the semi-dry and wet embryo is also maintained at 1~1.3 times the thickness of the finished product, and the distance of the clamping gap of the aforementioned suction forming station is 2~2.3 times the thickness of the finished product, that is, the suction forming station. The thickness of the formed preform is also maintained at 2 to 2.3 times the thickness of the finished product.
The method for producing energy-saving and fast-drying and dewatering paper-plastic products as claimed in claim 1, wherein a vacuum cavity is formed at the bottom of the lower die of the cold extrusion station, and a vacuum cavity is formed on the other side of the lower die. An accommodating space for placing the first embryonic product, in the accommodating space, there is a molding die surface matching the same shape as the aforementioned preliminary embryonic product for the positioning and shaping of the aforementioned preliminary embryonic product, and between the aforesaid vacuum chamber and the aforementioned accommodating space is provided with A plurality of air holes, the air holes run through the space between the vacuum chamber and the accommodating space for the vacuum negative pressure extraction of the suction forming station, the cold pressing station, and the hot pressing station to extract water.
The method for producing energy-saving and fast-drying and dewatering paper-plastic products as claimed in claim 2, characterized in that: the mold surface where the demolding angle of the lower mold is greater than 5 degrees is provided with a ventilating net, and the release angle of the lower mold is provided with a ventilation net. If the mold angle is less than 5 degrees, the ventilation net is not provided.
The method for producing energy-saving and fast-drying and dewatering paper-plastic products according to claim 3, characterized in that: after the suction forming station enters the pulp tank to absorb and form the preliminary embryo product, the preliminary embryo product is formed. It is transferred to the accommodating space of the lower die of the cold extrusion press station. When the upper and lower dies are closed and extruded, the first embryo is pressed by the pressing force of the upper die and adsorbed by the vacuum negative pressure. Force to fully fit the molding die surface of the lower mold and the aforementioned breathable mesh, so that the thickness of the aforementioned preliminary embryo is formed from the thickness of the initial suction molding station to the thickness of the aforementioned cold extrusion press station. The thickness formed by extrusion, the pressed first embryo strain is squeezed out of water and discharged from the surface, and the discharged water is then adsorbed to the vacuum cavity by the vacuum negative pressure through the air hole and then discharged from the lower mold In addition, the aforesaid preliminary embryos also decreased from the original moisture content of 68%-75% to 55%-60%, so as to obtain semi-dry and wet embryos with lower moisture content; then transfer the semi-dry and wet embryos. Loaded to the aforementioned hot-pressing setting station, and the pressurization and heating drying of the heating system can completely vaporize and evaporate the free water on the surface of the semi-dry and wet embryos and the bound water in the interior, so that the aforementioned semi-dry and wet embryos have a moisture content of 55. %-60% to the moisture content below 3% to obtain semi-finished products.
A production process method for energy-saving and fast-drying and dewatering paper-plastic products as claimed in claim 1, characterized in that: the preliminary embryo product through the cold-extrusion pressing process is moved to the hot-pressing setting station for heating and drying time The ratio of drying time used by the two is 1:2, and the ratio of heat energy consumption is 2:3.