CN115157520A

CN115157520A - Suspension material sheet extruder

Info

Publication number: CN115157520A
Application number: CN202210886847.9A
Authority: CN
Inventors: 杨文光; 靳予; 王帅; 杨烨; 陈朝曦; 孙克原; 林丰; 王孝刚
Original assignee: Nanjing Comptech Composites Corp
Current assignee: Nanjing Comptech Composites Corp
Priority date: 2022-07-26
Filing date: 2022-07-26
Publication date: 2022-10-11

Abstract

The patent provides a suspension material sheet metal extruder, it can extrude the sheet metal that thickness 5mm, width 300mm are about even, mechanical properties is good, and production efficiency is high, low in production cost. The device comprises a rack, a lower template fixed on the rack, an upper template connected with the lower template through a guide pillar, a sliding template arranged on the guide pillar in a sliding manner, a piston rod of an oil cylinder arranged on the upper template is connected with the sliding template, an outer mold is fixed on the lower template, the lower end of the outer mold is connected with a shaping mold, and the periphery of the lower part of the outer mold is provided with a heating device; the outer mold and the shaping mold are internally provided with mold cavities; the lower part of the sliding template is connected with mold cores which have the same number with the mold cavities and can extend into the mold cavities; a material tray base is fixed at the upper end of the outer die, a material tray which rotates relative to the material tray base is arranged on the material tray base, and the material tray is connected with a material tray driving mechanism which drives the material tray to rotate relative to the material tray base; and the tray bottom and the tray base are both provided with a charging chute communicated with the die cavity inlet at the upper end of the die cavity.

Description

Suspension material sheet extruder

Technical Field

The patent relates to a sheet extruder, in particular to a PTFE suspension material sheet extruder.

Background

The existing extruder can only be used for extruding round pipes generally, and cannot extrude thin plates generally due to difficult feeding and large frictional resistance. Even if it can be extruded with difficulty, it often shows defects such as uneven thickness and poor mechanical properties.

Disclosure of Invention

The utility model aims at providing a suspension material sheet metal extruder, it can extrude the sheet metal that thickness 5mm, width 300mm are about even, mechanical properties is good, and production efficiency is high, low in production cost.

In order to achieve the purpose, the suspended material sheet extruder comprises a rack, a lower template, an upper template, a sliding template and an oil cylinder, wherein the lower template is fixed on the rack; at least one cuboid-shaped die cavity which is communicated up and down is arranged in the outer die and the shaping die, and the width of the die cavity in the left-right direction is larger than the thickness of the die cavity in the front-back direction; the lower part of the sliding template is connected with mold cores which have the same number with the mold cavities and can extend into the mold cavities; a material tray base is fixed at the upper end of the outer die, a material tray which rotates relative to the material tray base is arranged on the material tray base, the material tray comprises a tray bottom and a tray edge which extends upwards at the periphery of the tray bottom, and the material tray is connected with a material tray driving mechanism which drives the material tray driving mechanism to rotate relative to the material tray base; and the tray bottom and the tray base are both provided with a charging chute communicated with the die cavity inlet at the upper end of the die cavity.

In the suspension material sheet extruder, the material tray driving mechanism comprises a motor fixed on the upper template or the lower template, a driving gear connected with an output shaft of the motor and meshing teeth which are meshed with the driving gear and arranged on the periphery of the material tray. Preferably, the motor is fixed on the upper template, the output shaft is connected with a driving gear shaft which penetrates through the sliding template and is rotatably supported on the lower template at the lower end, and the driving gear is fixed on the driving gear shaft.

The sheet extruder for suspended material has 2 die cavities arranged in the thickness direction and parallel to each other.

The suspension material sheet extruder also comprises a scraping device mainly comprising a scraping plate and a cylinder, wherein the bottom edge of the scraping plate is close to the upper surface of the plate bottom, the scraping plate is connected with a cylinder piston rod which crosses the plate edge at the upper part of the plate edge, and a cylinder body of the cylinder is fixed on a lower template; the cylinder moves to drive the scraper plate to move back and forth, and the material placed at the bottom of the plate is pushed into the die cavity through the charging chute.

In the suspended material sheet extruder, the scraper is parallel to the width direction of the die cavity; the left side and the right side of the scraping plate are connected with side plates close to the inner sides of the disc edges.

In the suspended material sheet extruder, the two scraping devices are symmetrically arranged on the central plane of the two die cavities in the thickness direction.

In the above-mentioned suspended material sheet extruder, the lower end of the shaping die is provided with a heat-insulating sleeve extending in the vertical direction of the die cavity.

The suspension material sheet extruder adopts PTFE powder as the material, and the extruded PTFE sheet has the thickness of 4.5-5.5 mm, the width of 300-320 mm, the tensile strength of not less than 22MPa and the elongation at break of 280-300 percent.

The suspension material sheet extruder also comprises an automatic feeding device, and a blanking port of the automatic feeding device is arranged above the bottom of the plate.

When the material tray rotates, the suspended material sheet extruder repeats the following actions: rotate forward for 3 weeks and then rotate backward for 1 week.

The beneficial effect of this patent:

the method adopts vertical extrusion molding continuous forming, and after a suspension material (such as PTFE powder) is compressed into a pre-formed product, the suspension material is heated and melted through a mold cavity, and then is cooled and formed, and a thin plate with uniform thickness and meeting the mechanical property is obtained through heat preservation. The specific process is as follows:

filling: the material is placed on the tray bottom, or falls on the tray bottom through an automatic feeding device, and the tray is driven by a tray driving mechanism to rotate, so that the material uniformly falls into a mold cavity.

In order to enable the materials to fall into the die cavity more uniformly, the charging tray rotates reversely for 1 week after rotating positively for 3 weeks, and thus the materials in the die cavity are more uniform.

In order to ensure that the material can reliably fall into the die cavity, the material on the bottom of the plate is pushed into the die cavity through the blanking groove by moving a scraper in the scraping device back and forth.

When the device is used for the first time, in order to prevent the materials in the die cavity from directly leaking out of the lower end of the die cavity through the die cavity, a plug (such as a multilayer braided belt) with certain friction resistance with the inner wall of the die cavity is filled in advance at the lower part close to the inlet of the die cavity.

Pressing: after the die cavity above the plug is filled with the materials, the material tray and the air cylinder stop moving, the scraper returns to the original initial position, the oil cylinder moves to drive the sliding template to move downwards along the guide pillar, the die core moves downwards to stretch into the die cavity to extrude the materials in the die cavity, the materials are pre-pressed, and meanwhile, the plug can move downwards for a certain distance in the die cavity.

Then the oil cylinder drives the mold core to move upwards. And then repeating the processes of filling and pressing, wherein the compacted material in the die cavity gradually reaches the lower part of an outer die with a heating device, the heating device heats the material compressed in the die cavity, and the material is gradually melted due to the friction force between the material and the die cavity.

And (3) pressing the material under a mold core driven by the oil cylinder, gradually cooling and molding the molten material in the shaping mold, enabling the plate to enter the heat-insulating sleeve from the lower end of the shaping mold, gradually reducing the temperature along with the downward movement of the plate in the heat-insulating sleeve, further releasing the internal stress, and finally obtaining the continuously extruded sheet.

When the number of the die cavities is 2, two sheets can be extruded at one time, and the efficiency is higher.

The width direction of scraper blade and die cavity parallels, and the structure of curb plate is connected to the left and right sides of scraper blade simultaneously, more is applicable to the situation that has two or more die cavities, and it can be fast in the material propelling movement die cavity.

When the scraping devices are two, the two scraping devices stagger in a reciprocating mode to scrape materials (the piston rod of one cylinder extends out, the piston rod of the other cylinder contracts), and due to the rotation of the material disc, the materials can uniformly enter the die cavity, so that the obtained thin plate is more uniform in texture.

The PTFE sheet extruded by the extruder has the thickness of 4.5mm-5.5mm, the width of 300mm-320mm, the tensile strength of not less than 22MPa, the elongation at break of 280-300 percent and better quality.

Drawings

FIG. 1 is a perspective view of a suspended material sheet extruder;

FIG. 2 is a perspective view of the upper die plate, the lower die plate, the material tray driving mechanism, etc.;

FIG. 3 is a schematic view of the packing state (left cylinder piston rod retracted, right cylinder piston rod extended);

FIG. 4 is a schematic view of the packing state (left cylinder piston rod extended, right cylinder piston rod retracted);

FIG. 5 is a schematic view of a depressed state (both the left cylinder piston and the right cylinder piston rod retracted);

FIG. 6 is a schematic view of an outer mold, a sizing mold, etc.;

FIG. 7 is a schematic view of a sizing die, an insulating jacket, etc.;

fig. 8 is a plan view of the blade, the cylinder, and the like.

Tray 13, tray bottom 131, tray edge 132,

The tray driving mechanism 14, the motor 141, the driving gear shaft 142, the driving gear 143, the engaging teeth 144, the engaging teeth,

A charging chute 15,

Scraper 16, scraper 161, rubber substrate 162, cylinder 163, side plate 164,

The heat preservation sleeve 20, the automatic feeding device 21, the blanking port 211, the plug 22, the material 23 and the solid plug 231.

Detailed Description

Referring to fig. 1 and 2, the suspension material sheet extruder includes a frame 1, a lower template 2 fixed on the frame, an upper template 4 connected to the lower template through a guide post 3, a sliding template 5 slidably disposed on the guide post 3, and an oil cylinder 6 disposed on the upper template, wherein a piston rod of the oil cylinder is connected to the sliding template 5.

Referring to fig. 7, an external mold 7 is fixed on the lower template 2 through an external mold fixing flange 8, the lower end of the external mold 7 is connected with a shaping mold 9, the lower end of the shaping mold is provided with a heat insulation sleeve 20 which is connected with the rack and extends in the vertical direction of the mold cavity, and the heat insulation cotton is filled in the heat insulation sleeve. The periphery of the lower part of the outer mold 7 is provided with a heating device 10; the outer mold and the shaping mold are provided with 2 rectangular mold cavities 71 which are vertically penetrated, the width of the mold cavity in the left-right direction is 310mm, and the thickness in the front-back direction is about 5mm. The 2 die cavities are arranged in the thickness direction of the die cavity and are mutually parallel.

The lower part of the sliding template 5 is connected with 2 mold cores 11 which can extend into the mold cavity.

A tray base 12 is fixed at the upper end of the outer die 7, a tray 13 which rotates relative to the tray base is arranged on the tray base 12, the tray comprises a tray bottom 131 and a tray edge 132 which extends upwards at the periphery of the tray bottom, and the tray is connected with a tray driving mechanism 14 which drives the tray driving mechanism to rotate relative to the tray base; the tray driving mechanism 14 includes a motor 141 fixed to the upper mold plate, an output shaft of the motor is connected to a driving gear shaft 142 passing through the slide mold plate and rotatably supported at a lower end thereof to the lower mold plate, a driving gear 143 is fixed to the driving gear shaft, and engaging teeth 144 engaged with the driving gear are provided on an outer circle of the tray bottom 131.

The tray bottom 131 and the tray base 12 are both provided with a charging chute 15 communicated with a cavity inlet 711 at the upper end of the cavity 71.

The two scraping devices are symmetrically arranged on the central plane of the two die cavities in the thickness direction. Each scraper 16 mainly includes a scraper 161, a side plate 164, a rubber substrate 162, and a cylinder 163. The blade 161 is parallel to the width direction of the cavity (perpendicular to the thickness direction of the cavity); the left and right sides of the squeegee 161 are connected to side plates 164 near the inner side of the disc edge 132. The bottom edges of the scrapers 161 and the side plates 164 are connected to a rubber substrate 162, and the rubber substrate 162 is in contact with the upper surface of the tray bottom. The scraper 161 is connected to a piston rod of a cylinder 163 which crosses over the disc edge 132 at the upper part of the disc edge, and the cylinder 163 is fixed on the lower template.

The automatic feeding device 21 belonging to the prior art is fixed on one side of the upper die plate, and the blanking port 211 of the automatic feeding device is arranged above the disc bottom 131. The automatic feeding device 21 is filled with a material 23, namely PTFE powder. The automatic feeding device 21 is operated, and the PTFE powder falls onto the tray bottom 131 of the tray 13 through the blanking port 211.

Then, filling: the two cylinders are staggered (the piston rod of one cylinder extends out, the piston rod of the other cylinder retracts, see fig. 3 and 4), and the scraper and the rubber substrate are driven to move back and forth. While the cylinder moves, the material tray repeats the following actions: the rotation is performed for 3 weeks and then for 1 week.

When the squeegee and the rubber substrate are moved forward toward the cavity, the PTFE powder falling on the bottom plate is pushed into the cavity 71 through the chute 15 and the cavity entrance 711.

In order to prevent the material in the cavity 71 from directly leaking out of the lower end of the cavity through the cavity, a plurality of layers of woven tapes having a certain frictional resistance with the inner wall of the cavity are pre-filled as plugs 22 at the lower portion near the entrance 711 of the cavity.

Pressing: after the die cavity above the plug is filled with the material 23, the material tray and the cylinders stop moving, the scraper returns to the initial position (the piston rods of the two cylinders are retracted, see fig. 5), the oil cylinder moves to drive the sliding template 5 to move downwards along the guide pillar 3, the die core 11 moves downwards, the sliding template extends into the die cavity 71 to extrude the material 23 in the die cavity, the material is pre-pressed, and meanwhile, the plug moves downwards for a certain distance in the die cavity.

Then the oil cylinder 6 drives the mould core 11 to move upwards through the sliding mould plate 5. Then, the above-mentioned processes of filling and pressing are repeated, the material 23 compressed in the cavity 71 gradually reaches the lower part of the outer mold 7 having the heating device 10, and the heating device 10 heats the material compressed in the cavity 71 and the material is gradually melted due to the friction force between the material and the cavity.

The materials are pressed down under the mould core driven by the oil cylinder, the molten materials reach the shaping mould 9 and are gradually cooled and shaped, the plate materials come out from the lower end of the shaping mould 9 and enter the heat insulation sleeve 20, the temperature is gradually reduced along with the downward movement of the plate materials in the heat insulation sleeve, the internal stress is further released, and finally two continuously extruded thin plates are obtained.

The outer die 7 is fixed with the lower die plate 2 and the rack 1 through an outer die fixing flange 8, and the die core 11 is connected with the piston rod of the oil cylinder 6 through the sliding die plate 5, so that the die core is accurate in positioning, stable and reliable in movement, uniform in die cavity clearance with the outer die, free of clamping stagnation and free of mutual movement. The heating device 10 adopts a far infrared chain type ceramic heating ring 101, a heat preservation device is added on the outer heat dissipation surface of the heating ring, and a ceramic far infrared heating element is arranged inside the heating ring, so that the outer die can be effectively heated quickly and uniformly, and the work is stable.

The feeding adopts an automatic feeding device. The tray 13 is rotated counterclockwise by the driving gear 143 driven by the servo motor 141 to continuously receive the material, and after the tray is rotated counterclockwise 3 turns, it is rotated clockwise 1 turn (from top to bottom). The pair of cylinders drive the scrapers to scrape materials in a reciprocating staggered manner (see figures 3 and 4), the materials fall under the thrust and the self weight, and after the die cavity and the blanking groove are filled, both the cylinders return to stop positions (see figure 5). The mould core is gradually pushed downwards under the drive of the oil cylinder, the dispersed materials 23 are gradually compacted into a solid plug 231 under the extrusion of the material stress and the four walls. The bottom of the outer die is clamped in a die cavity of the outer die by a plurality of layers of 5mm wide woven belts to provide certain support for materials. The repeated movement of the mold core presses new material at the inlet of the chute and mold cavity into the top of the last section of solid plug 231, causing the material to compact.

The solid plug 231 is pushed to a sintering area with a heating device at the periphery of the outer die, and is subjected to frictional heat with the four walls of the outer die and heat of a heating ring outside the outer die to start melting, and the part which is firstly contacted with the outer wall of the outer die is gradually melted from outside to inside, so that the solid plug is in a full-melting state. At this time, the mold core needs to apply proper pressure holding of the top solid plug to ensure that the clearance in the molten mass is eliminated and higher melting strength is obtained. Referring to fig. 6, the mold sintering zone is installed with a heating device, i.e. 5 sets of heating rings 101,5 heating rings with heating temperatures of 317 ℃, 378 ℃ and 320 ℃. Each section is monitored by an independent thermocouple 102 to ensure accurate temperature and thorough material burning.

The thin plate passing through the sintering area reaches the shaping die and starts to enter a cooling stage, the shaping die is additionally arranged at the lowest end of the outer die, the time of the thin plate in the shaping die can be prolonged, the thin plate is prevented from being exposed in the air too early, the thin plate is well supported when releasing internal stress during cooling, and the product is prevented from deforming. And the thin plate continuously stays in the heat-insulating sleeve after coming out of the shaping die, and the internal stress is continuously released.

The thickness of the suspension extrusion PTFE sheet is 5.0mm, the width is 310mm, the sampling tensile strength can reach 23.5MPa, and the elongation at break is stabilized at about 290%.

Claims

1. The suspended material sheet extruder comprises a rack, a lower template fixed on the rack, an upper template connected with the lower template through a guide pillar, a sliding template arranged on the guide pillar in a sliding manner, an oil cylinder arranged on the upper template, a piston rod of the oil cylinder connected with the sliding template, an outer mold fixed on the lower template, a shaping mold connected with the lower end of the outer mold, and a heating device arranged on the periphery of the lower part of the outer mold; the method is characterized in that: at least one cuboid-shaped die cavity which is communicated up and down is arranged in the outer die and the shaping die, and the width of the die cavity in the left-right direction is larger than the thickness of the die cavity in the front-back direction; the lower part of the sliding template is connected with mold cores which have the same number with the mold cavities and can extend into the mold cavities; a material tray base is fixed at the upper end of the outer die, a material tray which rotates relative to the material tray base is arranged on the material tray base, the material tray comprises a tray bottom and a tray edge which extends upwards at the periphery of the tray bottom, and the material tray is connected with a material tray driving mechanism which drives the material tray driving mechanism to rotate relative to the material tray base; and the tray bottom and the tray base are both provided with a charging chute communicated with the die cavity inlet at the upper end of the die cavity.

2. The suspended material sheet extruder of claim 1, wherein: the material tray driving mechanism comprises a motor fixed on the upper template or the lower template, a driving gear connected with an output shaft of the motor, and meshing teeth which are meshed with the driving gear and arranged on the periphery of the material tray.

3. The suspended material sheet extruder of claim 2, wherein: the motor is fixed on the upper template, the output shaft is connected with a driving gear shaft which penetrates through the sliding template and the lower end of which is rotatably supported on the lower template, and the driving gear is fixed on the driving gear shaft.

4. The suspended material sheet extruder of claim 1, wherein: the number of the die cavities is 2, the die cavities are arranged in the thickness direction of the die cavity and are parallel to each other.

5. The suspended material sheet extruder of claim 1, wherein: the scraping device mainly comprises a scraping plate and a cylinder, wherein the bottom edge of the scraping plate is close to the upper surface of the plate bottom, the scraping plate is connected with a cylinder piston rod which crosses over the plate edge at the upper part of the plate edge, and a cylinder body of the cylinder is fixed on the lower template; the cylinder moves to drive the scraper plate to move back and forth, and the material placed at the bottom of the plate is pushed into the die cavity through the charging chute.

6. The suspended material sheet extruder as set forth in claim 5, characterized in that: the scraper is parallel to the width direction of the die cavity; the left side and the right side of the scraping plate are connected with side plates close to the inner sides of the disc edges.

7. The suspended material sheet extruder of claim 5, wherein: the scraping devices are two and are symmetrically arranged on the central plane of the two die cavities in the thickness direction.

8. The suspended material sheet extruder of claim 1, wherein: the lower end of the shaping mold is provided with a heat insulation sleeve extending in the vertical direction of the mold cavity.

9. The suspended material sheet extruder of claim 1, wherein: the material is PTFE powder; the thickness of the extruded PTFE sheet is 4.5mm-5.5mm, the width is 300mm-320mm, the tensile strength is not lower than 22MPa, and the elongation at break is 280-300%.

10. The suspended material sheet extruder as set forth in claim 1, characterized in that: when the material tray rotates, the following actions are repeated: rotate forward for 3 weeks and then rotate backward for 1 week.