Inflatable continuous foaming device

Abstract

The utility model discloses an inflatable continuous foaming device which comprises a machine barrel, a screw rod screwed in the machine barrel, a foaming box connected with the machine barrel, an air injection mechanism and a heating mechanism, the screw rod comprises a rod body and threads spirally distributed on the rod body, one end of the machine barrel is provided with a feeding port, and the other end of the machine barrel is provided with a foaming outlet. The machine barrel is divided into a softening section, a melting and mixing section, a first foaming section and a second foaming section from a feeding port to a foaming outlet, a material pushing space formed between threads of the screw and the machine barrel is gradually enlarged from the feeding port to the foaming outlet according to sections, and injection ports are formed in the positions, corresponding to the melting and mixing section, the first foaming section C and the second foaming section, of the machine barrel. The injection port is connected with the gas injection mechanism, high-pressure gas permeates into the foaming material and diffuses into the foaming box, the foaming box is divided into a pressure relief expansion section and a forming section, an inlet of the pressure relief expansion section is communicated with the foaming outlet, the diameter of the pressure relief expansion section is larger than that of the foaming outlet, and the diameter of the forming section is larger than that of the pressure relief expansion section.

Description

TECHNICAL FIELD

[0001] The utility model relates to foaming technical field, concretely is a kind of inflatable continuous foaming device. BACKGROUND

[0002] At present, with the diversification and customization needs of plastic products, for example, EVA, TPU, PE, PP, PS, PVC, POE, EPDM, EAA, EMB, EMA, EPOPE, PA, PA12 elastomer, POM, POK, PEEK and other materials have been widely used in various plastic products, thermoplastic product manufacturing fields, such as: shoemaking, blow molding, automobile industry, electrical appliances and other products.

[0003] The method of making the product lightweight mainly has physical foaming method and chemical foaming method, and the physical foaming agent can obtain larger foaming effect compared with the chemical foaming agent, but the requirement of processing process setting is higher, and the mechanical device technology is more complex, the range involved in the process is extensive, so more resources need to be paid for the processing of the product, first, the raw materials and vulcanizing agent, plasticizer, crosslinking agent and other auxiliary materials are mixed and foamed, the traditional foaming method adopts chemical foaming, and other substances are added as foaming agent in the particle interior, but harmful gas is usually generated in the foaming process, which is not conducive to environmental protection, and the microporous foaming of the foaming raw material is a new process compared with the traditional chemical foaming, which does not contain other added materials and does not pollute the environment, how to control the microporous foaming inside the foaming material is a key technical problem to be solved.

[0004] The existing method is to melt and mix the foaming raw material through the extruder lamp, then put it into the reaction kettle, and fill high-pressure carbon dioxide or nitrogen or mixed gas into the reaction kettle, gradually increase the pressure and temperature in the reaction kettle, make the high-pressure gas fill into the foaming material, and then quickly release the pressure, the foaming material coming out of the reaction kettle is placed in the oven or other processing unit for heating and pressure forming, the reaction kettle is a special equipment, the production cost is higher, which is not conducive to large-scale production, and the foaming process is discontinuous between multiple equipments, the foaming material will be caused by the change of temperature and pressure during the switching process, resulting in uneven foaming, local difference in foam density, small bubbles formed in the foaming process may be broken due to mechanical vibration or pressure change, resulting in increased density or uneven structure of the final product, the switching between equipments causes the foaming material to be contaminated, such as dust, impurities or other chemical substances, which affects the foaming effect and product quality, the continuity between equipments is poor, which may cause low production efficiency and difficult to ensure the consistency of product quality, therefore, it is necessary to find a new solution on the basis of the existing physical foaming, so that the method of making the product lightweight by physical foaming can meet the needs of modern production. UTILITY MODEL CONTENT

[0005] The utility model discloses a kind of inflatable continuous foaming devices, to solve the problems presented in the above background technology.

[0006] To achieve the above object, the utility model provides the following technical scheme: a kind of inflatable continuous foaming device, including barrel, screw rod that is screwed in barrel, foaming box that is connected with barrel, gas injection mechanism and heating mechanism, the screw rod includes stem and thread that is arranged in spiral on stem, one end of the barrel is equipped with feed inlet, and the other end is foaming outlet, the barrel is divided into softening section, melt mixing section, foaming section one and foaming section two from feed inlet to foaming outlet, the thread of the screw rod and the push material space between barrel gradually increase according to segmentation from feed inlet to foaming outlet, the feed inlet is connected with gas injection mechanism, high-pressure gas penetrates into the inside of foaming material, and diffuses to foaming box, the foaming box is divided into pressure relief expansion section and forming section, the inlet of the pressure relief expansion section is connected with foaming outlet, the diameter of the pressure relief expansion section is greater than the diameter of foaming outlet, the diameter of the forming section is greater than the diameter of the pressure relief expansion section.

[0007] Further, the feed inlet is multi-point arranged, and is uniformly arranged on the barrel.

[0008] Further, the screw rod is single screw rod structure, the diameter of the stem gradually decreases from feed inlet to foaming outlet, the top diameter of the thread is constant, and the pitch of the thread gradually widens according to segmentation from feed inlet to foaming outlet, the depth of the thread gradually deepens from feed inlet to foaming outlet.

[0009] Further, the stem is equipped with air channel, one end of the air channel is blowout port, the surface of the stem is uniformly provided with air outlet hole, the blowout port is connected with gas injection mechanism.

[0010] Further, the air channel includes 3, and is respectively arranged according to the length of melt mixing section, foaming section one and foaming section two.

[0011] Further, each air channel is provided with air-permeable hole in its corresponding melt mixing section, foaming section one or foaming section two.

[0012] Further, conveying assembly for driving foaming material is arranged in the foaming box.

[0013] Compared with the prior art, the utility model discloses the beneficial effect is: the utility model discloses the screw is mixed and foams, and the foaming raw material is pushed forward when the screw rotates, forms the strong shearing force and mixing effect, and effectively mixes the raw material evenly, thereby improving the foaming effect, and the high-pressure gas is injected through the injection port, and the high-pressure gas penetrates to the inside of the foaming material, and foams, ensure the uniformity of bubble distribution and the continuity of foaming body structure, simultaneously, the push material space that the thread of screw and the machine cylinder between constitute gradually increases according to segmentation from the feeding port to the foaming outlet, provides the deformation space of expansion for the foaming material in the foaming process, and the machine cylinder is connected with the foaming box, and the pre-foaming body transported out of the screw directly enters the foaming box and foams, forms the continuous foaming flow from the raw material to the finished product, reduces the conversion demand between equipment, improves the continuity of system, improves production efficiency, makes the production process of foaming material more stable, and the raw material utilization rate is higher, and the gas in the machine cylinder will diffuse to the foaming box, does not need to additionally pressurize the foaming box, and the energy consumption is lower, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 It is the structural diagram of the inflatable continuous foaming device of the utility model,

[0015] Fig. 2 It is the structural diagram of the screw structure in the inflatable continuous foaming device of the utility model,

[0016] Fig. 3 It is the structural diagram of the gas passage in the inflatable continuous foaming device of the utility model,

[0017] In the drawing, 1-machine cylinder, 11-feeding port, 12-foaming outlet, 13-injection port, A-softening section, B-melting mixing section, C-foaming section 1, D-foaming section 2, 2-screw, 21-rod body, 211-gas passage, 212-blowing port, 213-gas hole, 22-thread, 3-foaming box, E-pressure relief expansion section, F-molding section, 41-motor, 42-reduction box, 43-shaft coupling. DETAILED DESCRIPTION

[0018] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the range of protection of the utility model.

[0019] As Figs. 1-3As shown, the embodiment provides an inflatable continuous foaming device, which comprises a barrel 1, a screw rod 2 driven by a driving mechanism, a foaming box 3 connected with the barrel 1, a gas injection mechanism and a heating mechanism; the driving mechanism comprises a motor 41, a speed reducer 42 and a shaft coupling 43, the motor 41 is connected with the input shaft of the speed reducer 42, and the output shaft of the speed reducer 42 is connected with the screw rod 2 through the shaft coupling 43; the gas injection mechanism comprises a gas storage tank and a high-pressure pump, and the gas storage tank is provided with a valve; the heating mechanism heats the barrel 1 and the foaming box 3 to heat the foaming material, and the heating mechanism is a prior art, which can use heating sheets, heating blocks and the like for heating, and will not be described here.

[0020] One end of the barrel 1 is provided with a feeding port 11, and the other end is a foaming outlet 12; for example, a hopper can be arranged on the barrel 1, the hopper is communicated with the feeding port 11, and the foaming raw material is fed through the hopper; the barrel 1 is divided into a softening section A, a melting mixing section B, a foaming section C and a foaming section D from the feeding port 11 to the foaming outlet 12; the barrel 1 is provided with injection ports 13 corresponding to the melting mixing section B, the foaming section C and the foaming section D; the injection ports are arranged in multiple points and uniformly distributed on the barrel 1, and are connected with the gas injection mechanism; high-pressure gas penetrates into the inside of the foaming material and diffuses to the foaming box 2.

[0021] The screw rod 2 is a single screw structure, which comprises a rod body 21 and a thread 22 arranged in a spiral shape on the rod body 21; the diameter of the rod body 21 gradually decreases from the feeding port 11 to the foaming outlet 12, and the rod body 21 is in a conical shape; the rear end of the rod body 21 corresponding to the foaming section D is not provided with the thread; the rod body 21 is provided with air channels 211; one end of the air channel 211 is a blowing port 212; the air channel 211 comprises three air channels corresponding to the lengths of the melting mixing section B, the foaming section C and the foaming section D; each air channel 211 is provided with a gas permeation hole in the corresponding melting mixing section B, foaming section C or foaming section D; the surface of the rod body 21 is uniformly provided with gas outlets 213; the high-pressure pump is connected with a rotating joint through a pipeline; the rotating joint is provided with a gas output channel; the rotating joint is connected with the output shaft of the speed reducer 32 through a pipeline; the output shaft of the speed reducer 32 is provided with a connecting channel which is communicated with the gas output channel and the air channel 211; high-pressure gas can also be injected into the barrel 1 through the blowing port 212; the top diameter of the thread 22 is constant, and the thread 22 always maintains a certain distance from the barrel 1; the pitch of the thread 22 gradually widens from the feeding port 11 to the foaming outlet 12; the depth of the thread 22 gradually deepens from the feeding port 11 to the foaming outlet 12; the thread 22 adapts to the gradually increasing volume of the foaming material in the foaming process, and provides a deformation space for the expansion of the foaming material.

[0022] The foaming box 3 is divided into a pressure relief expansion section E and a forming section F. The inlet of the pressure relief expansion section E is communicated with the foaming outlet 12. The inlet of the pressure relief expansion section E is in a horn shape, facilitating the foaming material to enter the pressure relief expansion section from the foaming outlet 12. The diameter of the pressure relief expansion section E is greater than the diameter of the foaming outlet 12, being 2-4 times the diameter of the foaming outlet 12. The diameter of the forming section F is greater than the diameter of the pressure relief expansion section E, being 1.5-2 times the diameter of the pressure relief expansion section E. A conveying assembly for driving the foaming material is arranged in the foaming box 3. The conveying assembly can adopt a mesh belt conveying.

[0023] When foaming, the foaming raw material is put into from the feeding port, the heating mechanism heats the cylinder, the foaming raw material is forwarded with the rotation of the screw, is softened in the softening section to form a foaming melt, high-pressure gas is injected through the injection port, the high-pressure gas penetrates into the inside of the foaming melt to form a bubble nucleus in the melting mixing section, the bubble nucleus in the melt gradually expands and grows in the foaming first section and the foaming second section to form a pre-foaming body. The pushing space composed of the screw thread of the screw and the cylinder gradually increases from the feeding port to the foaming outlet according to the segmentation, providing a deformation space for the expansion of foaming;

[0024] The heating mechanism heats the foaming box. With the gradual diffusion of the gas to the foaming box, the pre-foaming body is relieved and expanded in the pressure relief expansion section, and is foamed and formed in the forming section.

[0025] Specifically, the foaming raw material, which can be one or more of EVA, TPR, TPU, PE, PP, PET, PTG, PPS, or a mixture of one or more of EVA, TPR, TPU, PE, PP, PET, PTG, PPS and vulcanizing agent, plasticizer, crosslinking agent and other auxiliary materials, is fed into the cylinder 1 through the feed port 11 from the hopper, and the heating mechanism heats the cylinder 1, the temperature of the softening section is 150-180℃, the temperature of the melting mixing section is 250-280℃, the temperature of the foaming section 1 and the foaming section 2 is 150-250℃, the foaming raw material is rotated forward with the screw 2, the foaming raw material is softened in the softening section A to form a foaming melt, the foaming raw material is gradually heated and expanded, the push space composed of the screw thread and the cylinder gradually widens, which can adapt to the expanded foaming material and extrude the foaming material forward, open the valve, the gas in the gas tank is fed into the high-pressure pump, set the gas pressure of the high-pressure pump, control the pressure of the injected gas through the high-pressure pump to obtain high-pressure gas, the high-pressure gas includes any one of nitrogen, carbon dioxide, methane, ethane, propane, butane and inert gas, the high-pressure gas is injected into the blowing port 212 through the gas injection port 13 into the melting mixing section B, the foaming section 1 and the foaming section 2 of the cylinder 1, wherein the pressure of the softening section A is 1-5Pa, the pressure of the melting mixing section B is 5-40Pa, and the pressure of the foaming section 1 and the foaming section 2 is 5-100Pa, the high-pressure gas injected from the blowing port 212 fills the entire screw 2 through the gas outlet hole 213, the high-pressure gas injected from the injection port 13 penetrates into the interior of the foaming material in the melting mixing section B to form bubble nuclei, since the high-pressure gas injected from the blowing port 212 fills the entire screw 2 through the gas outlet hole 213, when the high-pressure gas is injected from the injection port 13, a pressure gradient is formed in the cylinder 1, which promotes the high-pressure gas to better penetrate into the interior of the foaming material, improves the penetration efficiency, improves the distribution of gas flow, avoids the accumulation of high-pressure gas in the middle section, causes uneven flow, enables the high-pressure gas to penetrate more uniformly, improves the uniformity of foaming, enhances the foaming effect, the foaming material expands and expands, the push space composed of the screw thread and the cylinder gradually increases, which can adapt to the expanded foaming material and extrude the foaming material forward, foaming in the foaming section 1 and the foaming section 2, the bubble nuclei in the melt gradually expand and grow to form a pre-foamed body, the heating mechanism heats the foaming box 3, the temperature of the pressure relief expansion section E is 50-150℃, the temperature of the forming section F is 20-150℃, as the gas gradually diffuses to the foaming box 3, the pressure of the pressure relief expansion section E is 1-10Pa, the pressure of the forming section F is 0-5Pa, the pre-foamed body enters the pressure relief expansion section E through the trumpet-shaped inlet, slowly expands in the pressure relief expansion section E, and is foamed and formed in the forming section F, the conveying assembly conveys the foaming material to the next process.

[0026] The utility model discloses a screw is carried out mixed foaming, and the screw pushes forward foaming raw materials when rotating, forms strong shearing force and mixing effect, and effectively mixes raw materials evenly, thereby improving foaming effect, injects high pressure gas through injection port, and high pressure gas penetrates to the inside of foaming material, and carries out foaming, ensures the uniformity of bubble distribution and the continuity of foaming body structure, simultaneously, the pushing material space that the thread of screw and the machine cylinder between constitute gradually increases according to segmentation from feeding port to foaming outlet, provides the deformation space of expansion for foaming material in the foaming process, connects machine cylinder and foaming box, and the pre-foaming body conveying out of screw directly enters foaming box and carries out foaming, forms the continuous foaming flow from raw material to finished product, reduces the conversion demand between equipment, improves the continuity of system, improves production efficiency, makes the production process of foaming material more stable, and raw material utilization is higher, and the gas in machine cylinder will diffuse to foaming box, does not need to pressurize foaming box additionally, and energy consumption is lower, reduces production cost.

[0027] Although the utility model has been explained in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacement to part of the technical features, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An inflating continuous foaming device characterized by: The utility model relates to a foaming box and injection mechanism for a single screw extruder, and belongs to the field of plastic processing equipment.

2. The inflating continuous foaming device according to claim 1, wherein: The injection ports are arranged in multiple points and uniformly arranged on the cylinder.

3. The inflatable continuous foaming device of claim 1, wherein: The screw rod is a single screw structure, the diameter of the rod body gradually decreases from the feeding port to the foaming outlet, the top diameter of the thread is constant, the pitch of the thread gradually widens according to the segmentation from the feeding port to the foaming outlet, and the depth of the thread gradually deepens from the feeding port to the foaming outlet.

4. The inflatable continuous foaming device of claim 1, wherein: The rod body is provided with an air channel, one end of the air channel is a blowing port, the surface of the rod body is uniformly provided with air outlet holes, and the blowing port is connected with the injection mechanism.

5. An inflating continuous foaming apparatus according to claim 4, wherein: The air channel includes three air channels corresponding to the lengths of the melting mixing section, the foaming first section and the foaming second section.

6. The inflatable sequential foaming device of claim 5, wherein: Each air channel is provided with a gas permeable hole in the corresponding melting mixing section, foaming first section or foaming second section.

7. The inflatable sequential foaming device of claim 1, wherein: The foaming box is provided with a conveying assembly for driving the foaming material.

Images