A method for preparing a water pressure bag in a conveyor belt joint vulcanizer

Abstract

The application provides a preparation method of a water pressure bag in a conveyor belt joint vulcanizing machine, 1) two raw rubber sheets are stacked together and then subjected to vulcanization treatment, and inflation expansion only vulcanizes and bonds the peripheral edge portions together; 2) a reinforcing cloth is pasted on the rubber inner tube through an adhesive; 3) then a heating and pressing plate is used to press the whole length and width outer surface of the intermediate product hollow bag, inflation expansion is performed, and then vulcanization treatment is performed, the remaining part of the two raw rubber sheets is subjected to vulcanization treatment, and the rubber inner tube and the reinforcing cloth are integrated by vulcanization, thereby obtaining the water pressure bag; the peripheral edge portions of the two raw rubber sheets are integrated by cross-linking reaction; the remaining part, the adhesive and the reinforcing cloth are integrated by vulcanization reaction, and the rubber inner tube is subjected to vulcanization reaction, thereby improving the connection strength between the rubber inner tube and the reinforcing cloth; and the sealing property, pressure uniformity, pressure resistance and service life of the water pressure bag are improved.

Description

Technical Field

[0001] This invention belongs to the technical field of processing and preparation of water pressure bags for vulcanizing machines, specifically relating to a method for preparing a water pressure bag for a conveyor belt joint vulcanizing machine. Background Technology

[0002] The vulcanization of rubber results in the formation of a three-dimensional structure within the raw rubber, which possesses high elasticity, heat resistance, tensile strength, and insolubility in organic solvents. Based on the vulcanization conditions, it can be divided into three categories: cold vulcanization, room temperature vulcanization, and hot vulcanization.

[0003] Rubber-to-rubber bonding can be divided into three types: bonding of unvulcanized rubber to unvulcanized rubber, bonding of unvulcanized rubber to vulcanized rubber, and bonding of vulcanized rubber to vulcanized rubber. Conveyor belt joints typically use a heat-vulcanization bonding method. Specifically, unvulcanized rubber sheets and adhesive are filled at the interface between vulcanized rubbers, followed by heated and pressurized vulcanization.

[0004] The conveyor belt vulcanizing machine, also known as an electrically heated conveyor belt vulcanizing machine, is made of lightweight aluminum alloy. It features small size, light weight, easy assembly and disassembly, and is suitable for manual handling. It also boasts rapid heating, uniform temperature, and high thermal efficiency, making it an ideal bonding device for conveyor belt joints. Currently, water-filled pressure bags are used in conveyor belt vulcanizing machines. These bags uniformly transmit pressure upwards and downwards, utilizing the incompressible nature of liquids or gases and their ability to uniformly transmit pressure to apply pressure evenly to the joint from all directions. When the liquid or gas medium is injected into the water-filled pressure bag through a pressure pump, according to fluid mechanics principles, its pressure remains constant and is uniformly transmitted in all directions, ensuring that the pressure is distributed as evenly as possible at the conveyor belt joint, which is beneficial for vulcanization.

[0005] However, the current dedicated pressure vessels available on the market are hydraulic pressure plates. A hydraulic pressure plate consists of a lower metal plate, an upper rubber layer, a pre-installed air inlet in the middle, and is tightly connected by bolts around the perimeter. This type of hydraulic pressure plate currently suffers from uneven pressure distribution, and the pressure can only be transmitted through the expansion of the upper rubber layer. During repeated pressurization and depressurization, water leakage and pressure loss are prone to occur at the fastening bolts around the perimeter, and it is also relatively heavy.

[0006] Therefore, how to improve the sealing performance, pressure uniformity, and service life of the water pressure bag in the conveyor belt joint vulcanizing machine is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing a water pressure bag in a conveyor belt joint vulcanizing machine.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A method for preparing a hydraulic pressure bag for a conveyor belt joint vulcanizing machine includes the following steps performed sequentially:

[0010] 1) Preparation of rubber inner tube: Raw rubber and vulcanizing agent are mixed by a mixing machine to obtain raw rubber sheets. Then, two raw rubber sheets are stacked together and placed on a vulcanizing machine. Then, a water nozzle is inserted between the two raw rubber sheets. Then, the heating and pressurizing frame of the vulcanizing machine is used to press the four edges of the two raw rubber sheets. Then, air is injected into the cavity between the two raw rubber sheets through the water nozzle. The inflation and expansion make a gap exist between the two raw rubber sheets except for the four edges.

[0011] Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the four edges of the two raw rubber sheets are bonded together to form a hollow bag. After completion, a rubber inner tube with a water nozzle is obtained.

[0012] 2) Apply adhesive to the outer surface of the rubber inner tube, then attach reinforcing fabric to the outer surface of the rubber inner tube, and cover the outer surface of the rubber inner tube with at least one layer of reinforcing fabric. After completion, an intermediate hollow bag is obtained.

[0013] 3) Place the intermediate hollow bag obtained in step 2) on the vulcanizing machine, then use the heating and pressure plate of the vulcanizing machine to press down the entire length and width of the outer surface of the intermediate hollow bag, and then inflate the cavity of the intermediate hollow bag with air through the water nozzle to make the intermediate hollow bag expand.

[0014] Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the remaining parts of the two raw rubber sheets, except for the four edges, are vulcanized, and the rubber inner tube and the reinforcing fabric are vulcanized and bonded together. After the vulcanization is completed, the finished water pressure bag is obtained.

[0015] Preferably, in step 1), the vulcanization temperature is 145℃-150℃, the vulcanization time is 15min-120min, the vulcanization pressure is 0.8MPa-3.5MPa, and the pressure of the gas used for filling is 0.6MPa-2.5MPa.

[0016] Preferably, in step 3), the vulcanization temperature is 145℃-150℃, the vulcanization time is 20-160min, the vulcanization pressure is 1.0MPa-4.0MPa, and the pressure of the gas used for filling is 0.8MPa-2.8MPa.

[0017] Preferably, the vulcanizing machine is a flat vulcanizing machine.

[0018] This application provides a method for preparing a hydraulic bag in a conveyor belt joint vulcanizing machine, comprising the following steps performed sequentially:

[0019] 1) First, prepare the rubber inner tube: first, mix raw rubber and vulcanizing agent to obtain raw rubber sheets through a mixing mechanism, then stack two raw rubber sheets together and perform vulcanization treatment under heat and pressure. During the vulcanization process, air is injected into the sandwich cavity through a water nozzle. The expansion of air makes the two raw rubber sheets have gaps except for the four edges. During the vulcanization process, only the four edges are vulcanized and bonded together to form a hollow bag shape. After completion, the rubber inner tube is obtained.

[0020] 2) Apply adhesive to the outer surface of the rubber inner tube, and then attach reinforcing fabric to the outer surface of the rubber inner tube, covering it with at least one layer of reinforcing fabric;

[0021] 3) Then, the heating and pressure plate of the vulcanizing machine presses down on the entire length and width of the intermediate hollow bag. Then, air is injected into the intermediate hollow bag through the water nozzle. The inflation and expansion make the intermediate hollow bag have gaps and do not contact each other except for the four perimeters. Then, vulcanization is carried out. During the vulcanization process, the remaining parts of the two raw rubber sheets except for the four perimeters are vulcanized, and the rubber inner tube and the reinforcing cloth are vulcanized into one piece. After completion, the water pressure bag is obtained.

[0022] This application first utilizes vulcanization to bond the overlapping peripheries of two raw rubber sheets together, forming a hollow rubber inner tube. This involves bonding unvulcanized rubber to unvulcanized rubber. The raw rubber sheets contain vulcanizing agents. Due to the use of heated and pressurized vulcanization bonding, the peripheries of the two raw rubber sheets undergo a cross-linking reaction to form a single unit, thus avoiding the multi-layered, separate bonding structures of traditional methods, such as splicing seams and adhesive seams. Obviously, the connection strength and other properties of the integrated structure obtained by the vulcanization cross-linking reaction are far greater than those of the original multi-layered, separate bonding structures. This improves the sealing performance, pressure uniformity, pressure resistance, and service life of the rubber inner tube, making it less likely for water to burst and leak from the periphery of the inner tube during water filling. This integrated rubber inner tube, with its periphery fused together, serves as the core of the water pressure bag, further improving the sealing performance, pressure uniformity, pressure resistance, and service life of the water pressure bag.

[0023] Then, reinforcing fabric is glued to the outer surface of the rubber inner tube with adhesive, followed by a second vulcanization. During the second vulcanization, the remaining parts of the two raw rubber sheets (excluding the periphery) and the adhesive undergo a vulcanization reaction, causing the remaining parts of the two raw rubber sheets (excluding the periphery), the adhesive, and the reinforcing fabric to cross-link and fuse together. The reason why only the periphery of the two raw rubber sheets is vulcanized in the first vulcanization, while the remaining parts are vulcanized in the second vulcanization, is to retain the remaining parts as unvulcanized rubber. Unvulcanized rubber still retains the opportunity to undergo a vulcanization reaction, thus allowing the unvulcanized rubber to... The rubber, adhesive, and reinforcing fabric are vulcanized into one piece. During the high temperature and high pressure process, the reinforcing fabric is immersed in the softened rubber, mainly to greatly improve the connection strength between the rubber inner tube and the reinforcing fabric. This allows the reinforcing fabric to more effectively wrap, protect, and support the rubber inner tube. The two work together strongly, and this secondary vulcanization treatment ensures that the rubber inner tube undergoes a complete vulcanization reaction, thereby greatly improving the sealing performance, pressure uniformity, pressure resistance, and service life of the rubber inner tube. The reinforcing fabric, which is vulcanized into one piece, along with the rubber inner tube and the fully vulcanized rubber inner tube, further improves the sealing performance, pressure uniformity, pressure resistance, and service life of the water pressure bag.

[0024] In summary, the two vulcanization treatments complemented and promoted each other, significantly improving the sealing performance, pressure uniformity, pressure resistance, and service life of the water pressure bag. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, and not all of them. Therefore, all other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] This application provides a method for preparing a hydraulic bag in a conveyor belt joint vulcanizing machine, comprising the following steps performed sequentially:

[0027] 1) Preparation of rubber inner tube: Raw rubber and vulcanizing agent are mixed by a mixing machine to obtain raw rubber sheets. Then, two raw rubber sheets are stacked together and placed on a vulcanizing machine. Then, a water nozzle is inserted between the two raw rubber sheets. Then, the heating and pressurizing frame of the vulcanizing machine is used to press the four edges of the two raw rubber sheets. Then, air is injected into the cavity between the two raw rubber sheets through the water nozzle. The inflation and expansion make a gap exist between the two raw rubber sheets except for the four edges.

[0028] Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the four edges of the two raw rubber sheets are bonded together to form a hollow bag. After completion, a rubber inner tube with a water nozzle is obtained.

[0029] 2) Apply adhesive to the outer surface of the rubber inner tube, then attach reinforcing fabric to the outer surface of the rubber inner tube, and cover the outer surface of the rubber inner tube with at least one layer of reinforcing fabric. After completion, an intermediate hollow bag is obtained.

[0030] 3) Place the intermediate hollow bag obtained in step 2) on the vulcanizing machine, then use the heating and pressure plate of the vulcanizing machine to press down the entire length and width of the outer surface of the intermediate hollow bag, and then inflate the cavity of the intermediate hollow bag with air through the water nozzle to make the intermediate hollow bag expand.

[0031] Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the remaining parts of the two raw rubber sheets, except for the four edges, are vulcanized, and the rubber inner tube and the reinforcing fabric are vulcanized together to form an integral structure. After the vulcanization is completed, the finished water pressure bag is obtained.

[0032] In one embodiment of this application, in step 1), the vulcanization temperature is 145℃-150℃, the vulcanization time is 15min-120min, the vulcanization pressure is 0.8MPa-3.5MPa, and the pressure of the gas used for filling is 0.6MPa-2.5MPa.

[0033] In one embodiment of this application, in step 3), the vulcanization temperature is 145℃-150℃, the vulcanization time is 20-160min, the vulcanization pressure is 1.0MPa-4.0MPa, and the pressure of the gas used for filling is 0.8MPa-2.8MPa.

[0034] In one embodiment of this application, the vulcanizing machine is a flat vulcanizing machine.

[0035] In this application, the number of reinforcing fabric layers is increased sequentially in proportion to the pressure required for the finished rubber hydraulic bag.

[0036] In this application, the adhesive (mortar) is preferably a rubber adhesive. Rubber adhesives are a class of adhesives formulated primarily with synthetic rubbers such as chloroprene, nitrile rubber, butyl silicone rubber, and polysulfide, or natural rubber. They possess excellent elasticity and are suitable for bonding soft materials or materials with significantly different coefficients of thermal expansion, such as rubber to rubber, rubber to metal, plastic, leather, and wood. Rubber adhesives are further divided into non-vulcanized and vulcanized types. Vulcanized rubber adhesives are prepared by adding vulcanizing agents, vulcanization accelerators, reinforcing agents, tackifiers, antioxidants, and other compounding agents to plasticized raw rubber, and then dissolving them in an organic solvent after mixing. This type of adhesive has better performance and therefore a wider range of applications. In this application, the adhesive (mortar) is preferably a vulcanized rubber adhesive. In this application, the adhesive (mortar) is preferably a chloroprene rubber adhesive or a nitrile rubber adhesive.

[0037] In this application, the preferred reinforcing fabric is EP canvas.

[0038] Raw materials, compounds, methods, and apparatus not described in detail in this invention are all prior art and will not be elaborated further.

[0039] To better understand the present invention, the following embodiments are provided for further detailed description of the present invention, but they should not be construed as limiting the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above-described invention are also considered to fall within the protection scope of the present invention.

[0040] Example 1

[0041] A method for preparing a hydraulic pressure bag for a conveyor belt joint vulcanizing machine includes the following steps performed sequentially:

[0042] 1) Preparation of rubber inner tube: Raw rubber and vulcanizing agent are mixed by a mixing machine to obtain raw rubber sheets. Then, two raw rubber sheets are stacked together and placed on a vulcanizing machine. A water nozzle is inserted between the two raw rubber sheets. The heating and pressurizing frame of the vulcanizing machine is used to press the four edges of the two raw rubber sheets. Then, air is injected into the cavity between the two raw rubber sheets through the water nozzle. The inflation and expansion make the two raw rubber sheets have gaps and do not contact each other except for the four edges.

[0043] Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the four edges of the two raw rubber sheets are bonded together to form a hollow bag. After completion, a rubber inner tube with a water nozzle is obtained.

[0044] In step 1), the vulcanization temperature is 145℃, the vulcanization time is 60min, the vulcanization pressure is 2.0MPa, and the pressure of the gas used for filling is 2.0MPa.

[0045] 2) Apply adhesive to the outer surface of the rubber inner tube, then attach reinforcing fabric to the outer surface of the rubber inner tube, and wrap three layers of reinforcing fabric on the outer surface of the rubber inner tube. After completion, an intermediate hollow bag is obtained.

[0046] In step 2), the adhesive is a vulcanized rubber adhesive, and the reinforcing fabric is EP canvas;

[0047] 3) Place the intermediate hollow bag obtained in step 2) on the vulcanizing machine, and then use the heating and pressure plate of the vulcanizing machine to press down the entire length and width of the outer surface of the intermediate hollow bag. Then, inflate the cavity in the intermediate hollow bag with air through the water nozzle. The inflation and expansion will make the parts of the intermediate hollow bag except for the four perimeters have gaps and do not contact each other.

[0048] Then the vulcanizing machine starts the vulcanization process. During the vulcanization process, the remaining parts of the two raw rubber sheets, except for the four edges, are vulcanized and bonded together with the rubber inner tube and the reinforcing fabric. After the vulcanization is completed, the finished water pressure bag is obtained.

[0049] In step 3), the vulcanization temperature is 150℃, the vulcanization time is 90min, the vulcanization pressure is 2.5MPa, and the pressure of the gas used for filling is 2.5MPa.

[0050] The vulcanizing machine is a flat vulcanizing machine.

[0051] Example 2

[0052] A method for preparing a hydraulic pressure bag for a conveyor belt joint vulcanizing machine includes the following steps performed sequentially:

[0053] 1) Preparation of rubber inner tube: Raw rubber and vulcanizing agent are mixed by a mixing machine to obtain raw rubber sheets. Then, two raw rubber sheets are stacked together and placed on a vulcanizing machine. A water nozzle is inserted between the two raw rubber sheets. The heating and pressurizing frame of the vulcanizing machine is used to press the four edges of the two raw rubber sheets. Then, air is injected into the cavity between the two raw rubber sheets through the water nozzle. The inflation and expansion make the two raw rubber sheets have gaps and do not contact each other except for the four edges.

[0054] Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the four edges of the two raw rubber sheets are bonded together to form a hollow bag. After completion, a rubber inner tube with a water nozzle is obtained.

[0055] In step 1), the vulcanization temperature is 147℃, the vulcanization time is 80min, the vulcanization pressure is 1.8MPa, and the pressure of the gas used for filling is 1.8MPa.

[0056] 2) Apply adhesive to the outer surface of the rubber inner tube, then attach reinforcing fabric to the outer surface of the rubber inner tube, and wrap three layers of reinforcing fabric on the outer surface of the rubber inner tube. After completion, an intermediate hollow bag is obtained.

[0057] In step 2), the adhesive is a vulcanized rubber adhesive, and the reinforcing fabric is EP canvas;

[0058] 3) Place the intermediate hollow bag obtained in step 2) on the vulcanizing machine, and then use the heating and pressure plate of the vulcanizing machine to press down the entire length and width of the outer surface of the intermediate hollow bag. Then, inflate the cavity in the intermediate hollow bag with air through the water nozzle. The inflation and expansion will make the parts of the intermediate hollow bag except for the four perimeters have gaps and do not contact each other.

[0059] Then the vulcanizing machine starts the vulcanization process. During the vulcanization process, the remaining parts of the two raw rubber sheets, except for the four edges, are vulcanized and bonded together with the rubber inner tube and the reinforcing fabric. After the vulcanization is completed, the finished water pressure bag is obtained.

[0060] In step 3), the vulcanization temperature is 150℃, the vulcanization time is 120min, the vulcanization pressure is 2.2MPa, and the pressure of the gas used for filling is 2.2MPa.

[0061] The vulcanizing machine is a flat vulcanizing machine.

[0062] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a water pressure bag in a conveyor belt joint vulcanizing machine, characterized in that, The following steps are performed sequentially: 1) Preparation of rubber inner tube: Raw rubber and vulcanizing agent are mixed by a mixing machine to obtain raw rubber sheets. Then, two raw rubber sheets are stacked together and placed on a vulcanizing machine. Then, a water nozzle is inserted between the two raw rubber sheets. Then, the heating and pressurizing frame of the vulcanizing machine is used to press the four edges of the two raw rubber sheets. Then, air is injected into the cavity between the two raw rubber sheets through the water nozzle. The inflation and expansion make a gap exist between the two raw rubber sheets except for the four edges. Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the four edges of the two raw rubber sheets are bonded together to form a hollow bag. After completion, a rubber inner tube with a water nozzle is obtained. 2) Apply adhesive to the outer surface of the rubber inner tube, then attach reinforcing fabric to the outer surface of the rubber inner tube, and cover the outer surface of the rubber inner tube with at least one layer of reinforcing fabric. After completion, an intermediate hollow bag is obtained. 3) Place the intermediate hollow bag obtained in step 2) on the vulcanizing machine, then use the heating and pressure plate of the vulcanizing machine to press down the entire length and width of the outer surface of the intermediate hollow bag, and then inflate the cavity of the intermediate hollow bag with air through the water nozzle to make the intermediate hollow bag expand. Then the vulcanizing machine begins the vulcanization process. During the vulcanization process, the remaining parts of the two raw rubber sheets, except for the four edges, are vulcanized, and the rubber inner tube and the reinforcing fabric are vulcanized and bonded together. After the vulcanization is completed, the finished water pressure bag is obtained.

2. The method for preparing a water pressure bag in a conveyor belt joint vulcanizing machine according to claim 1, characterized in that, In step 1), the vulcanization temperature is 145℃-150℃, the vulcanization time is 15min-120min, the vulcanization pressure is 0.8MPa-3.5MPa, and the pressure of the gas used for filling is 0.6MPa-2.5MPa.

3. The method for preparing a water pressure bag in a conveyor belt joint vulcanizing machine according to claim 1, characterized in that, In step 3), the vulcanization temperature is 145℃-150℃, the vulcanization time is 20-160min, the vulcanization pressure is 1.0MPa-4.0MPa, and the pressure of the gas used for filling is 0.8MPa-2.8MPa.

4. The method for preparing a water pressure bag in a conveyor belt joint vulcanizing machine according to claim 1, characterized in that, The vulcanizing machine is a flat vulcanizing machine.