CN111703006A

CN111703006A - Foaming system of strip-shaped high polymer material

Info

Publication number: CN111703006A
Application number: CN202010439792.8A
Authority: CN
Inventors: 杨庆锋; 张镤
Original assignee: Zhejiang Runyang New Materials Technology Co ltd
Current assignee: Zhejiang Runyang New Materials Technology Co ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2020-09-25

Abstract

The invention belongs to the technical field of foaming material production equipment, and particularly discloses a foaming system for a strip-shaped high polymer material, which comprises an unreeling feeding device, a foaming preheating device, a vertical foaming device and a cooling device; the conveying belt of the foaming preheating device is made of flexible high polymer materials, comprises a laying area and a power area which is matched with the roller to drive the laying area to advance, and adopts a screw as a tensioning mechanism to replace the structures of iron mesh conveying, chain transmission and cylinder tensioning in the prior art; the top and the bottom of the vertical foaming device are respectively provided with an air port, the inner wall of the vertical foaming device is provided with a second heating element, and two-section foaming is realized through an air draft effect. The system can run stably for a long time, is not easy to break down, and has low energy consumption and high production efficiency; the foamed sheet prepared by the system through the steps of preheating, foaming, unfolding, cooling and shaping has fine and uniform foam holes, small size deviation and good quality.

Description

Foaming system of strip-shaped high polymer material

Technical Field

The invention belongs to the technical field of foaming material production equipment, and particularly relates to a foaming system for a strip-shaped high polymer material.

Background

The foaming of the sheet is a process in which a molded tape-shaped polymer material is heated in a foaming furnace, and a foaming agent is decomposed at a high temperature to generate gas, and the gas is filled in the polymer material to generate a foamed material having closed pores. Whole sheet foaming system generally includes material feeding unit, horizontal preheating device, the vertical foaming device that sets gradually, expandes device, cooling device and coiling mechanism, and traditional foaming system has following problem: firstly, a horizontal preheating device generally consists of a conveying mechanism and a heating box body, wherein the conveying mechanism usually takes an iron net or a steel net as a conveying belt, and a gear chain is matched for transmission, so that the structure is characterized in that oil stains are easily accumulated on the iron/steel net, the preheating device is easy to stop due to unstable chain transmission, frequent cleaning and maintenance are needed, the whole production line cannot operate for a long time, and the production efficiency is seriously influenced; the heat conduction efficiency of iron is high, so that the sheet is easily heated unevenly, and subsequent foaming is uneven and even broken; secondly, the vertical foaming device generally adopts a direct radiation heating mode, the temperature in the furnace is unstable, the temperature difference of each area is extremely large, the thickness of the foaming product is uneven, the width of the foaming product is unequal, unqualified products are produced, and the capacity and the yield are low. Therefore, the traditional foaming system has short operation period, low production efficiency and difficult guarantee of product quality.

For example, chinese patent publication No. CN102672872B discloses an electron radiation crosslinked polyethylene foaming apparatus, wherein a conveying mechanism of a horizontal preheating device comprises a straight-axis mesh belt, a steel mesh, and a transmission mechanism composed of a parallel guide rail, a driving sprocket and a driven sprocket, wherein the steel mesh is attached to the outer surface of the straight-axis mesh belt, so that the steel mesh only bears the weight of a sheet material to prolong the service life of the steel mesh, but the aforementioned problem affecting the operation and preheating effect of the production line is not solved; the foaming device comprises a transition area, a pre-foaming area and a foaming area, and the circulating fans and the electric heating pipes are arranged in the three sections to reduce the temperature difference of the areas.

Disclosure of Invention

One of the purposes of the invention is to provide a foaming system of a strip-shaped high polymer material, which can be stably operated for a long time, is not easy to break down, and has low energy consumption and high production efficiency; the prepared foaming sheet has fine and uniform foam holes, small size deviation and good quality.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

a foaming system for a strip-shaped high polymer material comprises an unreeling feeding device, a foaming preheating device and a vertical device

A foaming device and a cooling device; the foaming preheating device comprises a heating box body and a conveying mechanism for conveying the belt-shaped high polymer material to the heating box body; a first heating element is arranged on the inner wall of the heating box body; the conveying mechanism comprises a circular conveying closed-loop conveying belt arranged in the heating box body, one end of the circular conveying belt extends to the outside of the inlet end of the heating box body, and a first roller and a second roller, wherein the two ends of the conveying belt are wound, the first roller is arranged outside the heating box body, and at least one of the first roller and the second roller is a driving roller driven to rotate by power equipment; the conveying belt is made of flexible high polymer materials and comprises a laying area for placing the strip-shaped high polymer materials and power areas which are arranged on two sides of the laying area and drive the laying area to advance; the vertical foaming device is arranged at the discharge end of the foaming preheating device, and the top and the bottom of the vertical foaming device are respectively provided with a first air port and a second air port; the vertical foaming device comprises a first foaming area, a second foaming area and an expansion area from top to bottom; a second heating element is arranged on the inner wall of the second foaming area; the unfolding area is provided with an unfolding device; the cooling device is arranged at the discharge end of the bottom of the vertical foaming device and comprises a water cooling roller set; the unreeling and feeding device is used for conveying the belt-shaped high polymer materials to the placement area.

Preferably, the laydown area is of a grid-like structure.

Preferably, the flexible polymer material is polytetrafluoroethylene.

Preferably, the positions of the first roller close to the two end parts are respectively provided with a clamping groove, and the lower surface of the power area is provided with a driving strip attached to the clamping grooves.

Preferably, both ends of the first roller are provided with screws for tensioning the power area.

Preferably, the heating box body comprises three preheating zones, and a heat insulation plate is arranged between every two adjacent preheating zones; the first heating elements are arranged on the top wall of the preheating zone, and the temperature control systems of the first heating elements in different preheating zones are mutually independent.

Preferably, the foaming preheating device is horizontally and obliquely arranged, so that the foaming preheating device and the vertical heating device are arranged at an acute angle.

Preferably, the density of the second heating elements increases in the transport direction of the polymer material in a belt shape.

Preferably, the vertical foaming device further comprises a transition area communicated with the discharge end of the foaming preheating device, the transition area is located at the feed end of the first foaming area, and a partition plate is arranged between the transition area and the first foaming area.

Preferably, the unwinding device comprises rotatable unwinding rollers respectively arranged on two side surfaces of the belt-shaped polymer material to clamp the belt-shaped polymer material.

Preferably, the unreeling feeding device comprises an unreeling frame and an unreeling traction machine.

Preferably, the device further comprises a traction winding device, wherein the traction winding device comprises a traction roller, a deviation correcting machine, a splitting machine, a winding traction machine and a winding frame.

Another object of the present invention is to provide a method for preparing a foamed sheet using the above foaming system of a belt-shaped polymer material, comprising the steps of:

s1, preheating: the method comprises the following steps that a strip-shaped high polymer material to be foamed is conveyed to the surface of a placement area of a foaming preheating device through an unreeling feeding device, the temperature of a first heating element is controlled in a segmented mode to enable a heating box body to be heated up section by section, a power area is matched with a roller to drive the placement area to enter the heating box body, the strip-shaped high polymer material is preheated in the heating box body, and then the strip-shaped high polymer material enters a vertical foaming device;

s2, foaming: under the action of a second heating element, the second foaming zone reaches a second-stage foaming temperature, the first foaming zone reaches a first-stage foaming temperature through the air draft effect of the first air opening and the second air opening, the strip-shaped high polymer material is subjected to first-stage foaming and second-stage foaming in sequence and then enters the expansion zone;

s3, unfolding: flattening the expanded strip-shaped high polymer material by using an unfolding device to obtain a foamed sheet preliminarily, and then conveying the foamed sheet out of a second air port vertical to the bottom of the foaming device to enter a cooling device;

s4, cooling and shaping: and cooling the expanded foamed sheet to normal temperature by a water cooling roller set.

The invention has the following beneficial effects:

1. the conveying belt of the foaming preheating device is made of flexible high polymer materials and is divided into a holding area and a power area; the flexible polymer material has the characteristics of smooth surface, high temperature resistance (at least 120 ℃ of temperature resistance) and difficulty in oil stain accumulation, so that the flexible polymer material does not need to be cleaned frequently, has long service life, can ensure that the sheet is heated uniformly and is not easy to deform, and improves the preheating effect; the power area and the roller are matched to replace a chain transmission mode in the prior art, so that the arrangement of a gear and a chain is omitted, the problems of tooth clamping and tooth breakage caused by chain transmission are avoided, the transmission is more stable, the fault is not easy to occur, the stable period of the flow line production is obviously improved, and the production efficiency is further improved.

2. On the basis of the above, the conveying mechanism of the foaming preheating device is further improved from the following aspects: firstly, the laying area is in a grid structure, so that the adhesion between the laying area and the sheet is avoided, the sheet is more breathable, the preheating of the sheet is accelerated, the internal and external temperature difference is reduced, and the preheating effect is improved; secondly, the driving strip is arranged in the power area, and the clamping groove matched with the driving strip is arranged on the roller, so that the deviation correction positioning of the conveying belt is realized, the deviation and the steering of the conveying belt are avoided, the friction force between the conveying belt and the roller is increased due to the arrangement of the driving strip, and the slipping of the conveying belt is avoided; the screw is used as a tensioning mechanism of the power area to replace a cylinder commonly adopted in the prior art, so that the precision and the stability of tensioning adjustment are improved, and the stability of transmission is further improved; the material selection of the conveying belt is combined with the design of the transmission structure, so that the conveying mechanism does not need to be cleaned and maintained frequently, and an air cylinder which is poor in adjustment precision and easy to rebound does not need to be detached conveniently.

3. The heating box body of the foaming preheating device comprises three preheating zones for gradually increasing temperature control, and a heat insulation plate is arranged between every two adjacent preheating zones to reduce the temperature influence between every two adjacent preheating zones, so that the temperature distribution of each preheating zone is more uniform, and the preheating effect is further improved.

4. The foaming section of the vertical foaming device comprises two foaming areas, the first foaming area reaches a section of foaming temperature under the air draft effect of an air port through a heating element arranged in the second foaming area, and the conventional foaming second foaming area cannot be influenced, the temperature gradient distribution is more uniform due to the design, the temperature difference of each area is effectively reduced, the foaming is more uniform and sufficient, the size deviation is small, meanwhile, the sheet can be quickly foamed after being preheated, and the foaming quality and the foaming speed are effectively improved; compared with the prior art that heating elements and fans are arranged in each area, the equipment cost is lower, the additional heating elements are not needed, and the energy is saved and the consumption is reduced.

5. The length of an actual foaming area is increased by the two-stage foaming, so that the heating time is increased, and in order to obtain the same foaming completion degree as before, the rolling speed of the sheet can be increased, and the capacity of equipment is further improved. The horizontal conveying device has the advantages of fast preheating and stable transmission, can effectively solve the problems, realizes the improvement of the winding speed on the premise of not influencing the preheating, accelerates the foaming process and further improves the production efficiency.

6. The foaming preheating device is arranged from the inlet end to the outlet end in a horizontal and upward inclined mode, so that the foaming preheating device and the vertical foaming device are arranged at an acute angle, waste gas in the two devices is discharged from an air port at the top of the vertical foaming device through flowing from bottom to top, the waste gas can be prevented from leaking to a work area from the inlet end of the foaming preheating device, and the environmental pollution and the potential safety hazard are avoided.

Drawings

FIG. 1: the invention has a structure schematic diagram.

FIG. 2: fig. 1 is a schematic perspective view of a foaming preheater a.

FIG. 3: FIG. 1 is a schematic view of the stent.

In the figure: 1-unwinding frame, 2-unwinding traction machine, 3-foaming preheating device, 4-vertical foaming device, 5-cooling device, 6-traction roller, 7-deviation correcting machine, 8-splitting machine, 9-winding traction machine and 10-winding frame; 31-a heating box body, 32-a conveying belt, 33-a first roller, 34-a second roller, 35-a screw, 36-a controller, 41-a transition zone, 42-a first foaming zone, 43-a second foaming zone, 44-a spreading zone, 45-a second heating element, 46-a spreading device, 47-a first air port, 48-a second air port and 51-a water-cooling roller group; 311-a heat insulation plate, 312-a first preheating zone, 313-a second preheating zone, 314-a third preheating zone, 315-a first heating element, 317-a connecting part, 321-a resting zone, 322-a power zone, 331-a card slot, 332-a shaft sleeve, 351-a nut, 461-an unwinding roller; 462-fixed part, 463 drive part; 3171-mounting rack.

Detailed Description

The invention is further described below with reference to the accompanying drawings and specific embodiments.

Example 1

A foaming system for a strip-shaped high polymer material is shown in figure 1 and comprises an unreeling feeding device, a foaming preheating device 3, a vertical foaming device 4, a cooling device 5 and a traction reeling device.

The unreeling and feeding device comprises an unreeling frame 1 and an unreeling tractor 2.

The foaming preheating device 3 comprises a heating box 31 and a conveying mechanism for conveying the high polymer material to be strip-shaped to the heating box 31, as shown in fig. 2, a first heating element 315 is arranged on the inner wall of the box 31; the conveying mechanism comprises a circular conveying closed-loop conveying belt 32 which is arranged in the heating box body 31 and one end of which extends to the outside of the inlet end of the heating box body 31, and a first roller 33 and a second roller 34 which are used for winding two ends of the conveying belt 32, wherein the first roller 33 is arranged outside the inlet end of the heating box body 31, and at least one of the first roller 33 and the second roller 34 is an active roller driven by power equipment (in the embodiment, the second roller 4 is an active roller and is driven by a motor to rotate); the conveying belt 32 is made of a flexible polymer material, and includes a holding area 321 of a grid structure for placing a strip-shaped polymer material, and power areas 322 which are arranged on two sides of the holding area 321 and drive the holding area 321 to move; the flexible high polymer material is polytetrafluoroethylene; the positions of the first roller 33 near the two ends are respectively provided with a clamping groove 331, and the lower surface of the power area 322 is provided with a driving strip attached to the clamping grooves 331.

Two ends of the first roller 33 are provided with a screw 35 used for tensioning the power area 322; the two ends of the central shaft of the first roller 33 are sleeved with shaft sleeves 332, and the first roller 33 is fixedly arranged on the vertically arranged connecting parts 317 extending from the two sides of the inlet of the heating box body 31 through the shaft sleeves 332; one end of the screw 35 abuts against the shaft sleeve 332, and the other end of the screw is fixed to the connecting part 317 of the heating box 31 through a mounting bracket 3171; the screw 35 passes through the mounting block 3171 and is locked to the mounting block 3171 by two nuts 351.

The heating box 31 comprises a first preheating zone 312, a second preheating zone 313 and a third preheating zone 314, wherein a first heating element 315 is arranged on the top wall of each preheating zone, and the temperature control systems of the first heating elements 315 in different preheating zones are independent from each other (in this embodiment, the first heating elements 315 are a plurality of electric heating tubes arranged in parallel); a heat insulation plate 311 is arranged between the adjacent preheating zones, a controller 36 is further arranged on the outer surface of the heating box body 31, and a switch is arranged on the controller 36 and used for controlling the first heating element 315 and the conveying mechanism.

The vertical foaming device 4 is arranged at the discharge end of the foaming preheating device 3, and the top and the bottom of the vertical foaming device are respectively provided with a first air port 47 and a second air port 48; the vertical foaming device 4 comprises a transition area 41, a first foaming area 42, a second foaming area 43 and a development area 44 from top to bottom; the transition area 41 is communicated with the discharge end of the foaming preheating device 3; a partition plate is arranged between the transition area 41 and the first foaming area 42, and the transition area 41 separates the foaming preheating device 3 from the foaming area of the vertical foaming device 4, so that the mutual influence of the two is reduced; the inner wall of the second foaming zone 43 is provided with a second heating element 45, and the density of the second heating element 45 increases along the conveying direction of the strip-shaped polymer material so that the first foaming zone 42 can control the temperature within a desired range (in this embodiment, the second heating element 45 is an electric heating tube); the unfolding area 44 is provided with a unfolding device 46, the unfolding device 46 includes a rotatable unfolding roller 461 and a driving portion 463 for driving the unfolding roller 461, the rotatable unfolding roller 461 and the driving portion 463 are respectively disposed on two sides of the strip-shaped polymer material to clamp the strip-shaped polymer material, the unfolding roller 461 is rotatably connected with the fixing portion 462 and is mounted on the side wall of the vertical foaming device 4 through the fixing portion 462, and the fixing portion 462 also provides a stable supporting point for the unfolding roller 461, so that the unfolding roller can rotate at a high speed and is not easy to shake.

The foaming preheating device 3 is horizontally and obliquely arranged, so that the foaming preheating device 3 and the vertical heating device 4 are arranged at an acute angle.

The cooling device 5 is arranged at the discharge end of the vertical foaming device 4, a partition plate is arranged between the cooling device 5 and the expansion area 44, and the cooling device 5 comprises water cooling roller sets 51 which are respectively arranged at two sides of the foaming sheet and are internally provided with cooling water cavities.

The traction winding device comprises a traction roller 6, a deviation corrector 7, a splitting machine 8, a winding tractor 9 and a winding frame 10.

Example 2

IXPE foamed sheets were prepared using the foaming system of example 1, with the following specific steps:

s1, preheating: loading an IXPE master slice into an unreeling frame 1, conveying the IXPE master slice to the surface of a holding area 321 of a foaming preheating device 3 through an unreeling tractor 2, enabling a power area 322 and a roller to cooperate to drive the holding area 321 to enter a heating box body 31 for gradually heating (the temperature of a first preheating area 312 is controlled to be 60-70 ℃, the temperature of a second preheating area 313 is controlled to be 75-85 ℃, the temperature of a third preheating area 314 is controlled to be 90-110 ℃), preheating the master slice to be 90-110 ℃ in the heating box body 31, and conveying the master slice to a vertical foaming device 4 through a conveying belt 32 at the conveying speed of 12-30 m/min;

s2, foaming: under the action of the second heating element 45, the second foaming zone reaches a second-stage foaming temperature of 230-270 ℃, the first foaming zone 44 reaches a first-stage foaming temperature of 270-290 ℃ through the air draft effect of the first air opening 47 and the second air opening 48, and the sheet enters the expansion zone 44 after being subjected to first-stage foaming and second-stage foaming in sequence;

s3, unfolding: flattening the expanded foamed sheet by high-speed rotation of an unfolding roller 461 in the unfolding device 46, wherein the rotating speed of the unfolding roller 461 is 84-180 r/min, and then conveying the sheet out of a second air port 48 at the bottom of the vertical foaming device 4 to enter a cooling device 5;

s4, cooling and shaping: cooling the developed sheet to normal temperature by the cooling roller group 51;

s5, rolling: the sheet is transported out of the cooling device 5 through the traction roller 6, and then sequentially passes through the deviation corrector 7, the splitting machine 8, the winding tractor 9 and the winding frame 10 to finish the procedures of deviation correction, edge cutting, shaping and winding, so that an IXPE foamed sheet finished product is obtained.

This detailed description is to be construed as illustrative only and is not to be taken as limiting the invention, as any changes that may be made by a person skilled in the art after reading the present specification will be protected by the patent laws within the scope of the appended claims.

Claims

1. The utility model provides a banding macromolecular material's foaming system, includes unreels material feeding unit, foaming preheating device (3), vertical foaming device (4), cooling device (5), its characterized in that:

the foaming preheating device (3) comprises a heating box body (31) and a conveying mechanism for conveying the belt-shaped high polymer material to the heating box body (31); a first heating element (315) is arranged on the inner wall of the heating box body (31); the conveying mechanism comprises a circular conveying closed-loop conveying belt (32) which is arranged in the heating box body (31) and one end of which extends to the outside of the inlet end of the heating box body (31), and a first roller (33) and a second roller (34) which are used for winding two ends of the conveying belt (32), wherein the first roller (33) is arranged outside the heating box body (31), and at least one of the first roller (33) and the second roller (34) is an active roller driven to rotate by power equipment; the conveying belt (32) is made of flexible high polymer materials and comprises a laying-aside area (321) for placing the strip-shaped high polymer materials and power areas (322) which are arranged on two sides of the laying-aside area (321) and drive the laying-aside area (321) to move;

the vertical foaming device (4) is arranged at the discharge end of the foaming preheating device (3), and the top and the bottom of the vertical foaming device (4) are respectively provided with a first air port (47) and a second air port (48); the vertical foaming device (4) comprises a first foaming area (42), a second foaming area (43) and a development area (44) from top to bottom; a second heating element (45) is arranged on the inner wall of the second foaming area (43); the unfolding area (44) is provided with an unfolding device (46);

the cooling device (5) is arranged at the discharge end of the bottom of the vertical foaming device (4) and comprises a water cooling roller set (51);

the unreeling and feeding device is used for conveying the strip-shaped high polymer materials to the laying area (321).

2. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the resting area (321) is of a grid-like structure.

3. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the flexible high polymer material is polytetrafluoroethylene.

4. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the positions, close to the two end parts, of the first roller (33) are respectively provided with a clamping groove (331), and the lower surface of the power area (322) is provided with a driving strip attached to the clamping grooves (331).

5. The foaming system of a tape-shaped polymer material according to claim 1, wherein: and both ends of the first roller (33) are provided with screw rods (35) used for tensioning the power area (322).

6. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the heating box body (31) comprises three preheating zones, and a heat insulation plate (311) is arranged between every two adjacent preheating zones; the first heating element (315) is arranged on the top wall of the preheating zone, and the temperature control systems of the first heating elements (315) in different preheating zones are mutually independent.

7. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the foaming preheating device (3) is horizontally and obliquely arranged, so that the foaming preheating device (3) and the vertical heating device (4) are arranged at an acute angle.

8. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the second heating element (45) is arranged at a density which increases along the conveying direction of the strip-shaped polymer material.

9. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the vertical foaming device (4) further comprises a transition area (41) communicated with the discharge end of the foaming preheating device (3), the transition area (41) is located at the feed end of the first foaming area (42), and a partition plate is arranged between the transition area (41) and the first foaming area (42).

10. The foaming system of polymer material in tape form according to claim 1, wherein: the unfolding device (46) comprises rotatable unfolding rollers (461) which are respectively arranged on two side surfaces of the strip-shaped high polymer material to clamp the strip-shaped high polymer material.

11. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the unreeling and feeding device comprises an unreeling frame (1) and an unreeling tractor (2).

12. The foaming system of a tape-shaped polymer material according to claim 1, wherein: the winding machine is characterized by further comprising a traction winding device, wherein the traction winding device comprises a traction roller (6), a deviation correcting machine (7), a splitting machine (8), a winding traction machine (9) and a winding frame (10).

13. A method for producing a foamed sheet using the foaming system of a belt-like polymer material according to claim 1, comprising the steps of:

s1, preheating: the method comprises the steps that a strip-shaped high polymer material to be foamed is conveyed to the surface of a placement area (321) of a foaming preheating device (3) through an unreeling and feeding device, the temperature of a first heating element (315) is controlled in a segmented mode to enable a heating box body (31) to be heated up section by section, a power area (322) is matched with a roller to drive the placement area (321) to enter the heating box body (31), the strip-shaped high polymer material is preheated in the heating box body (31), and then enters a vertical foaming device (4);

s2, foaming: under the action of a second heating element (45), the second foaming zone (43) reaches a second-stage foaming temperature, the first foaming zone (42) reaches the first-stage foaming temperature through the air draft effect of the first air opening (47) and the second air opening (48), and the strip-shaped high polymer material is sequentially subjected to first-stage foaming and second-stage foaming and then enters the expansion zone (44);

s3, unfolding: flattening the expanded sheet after foaming by an unfolding device (46), and then conveying the sheet out of a second air port (48) at the bottom of the vertical foaming device (4) to enter a cooling device (5);

s4, cooling and shaping: the expanded foamed sheet is cooled to normal temperature by a water-cooling roller set (51).