CN216610031U

CN216610031U - Magnetic suspension film biaxial stretching device

Info

Publication number: CN216610031U
Application number: CN202123357297.1U
Authority: CN
Inventors: 杨卫民; 杜长彪; 廖波; 丁玉梅
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2022-05-27
Anticipated expiration: 2031-12-29

Abstract

The invention discloses a magnetic suspension film biaxial stretching device which comprises a film blowing system, a primary cooling system, a slow pull roll, a heating system, a transverse stretching system, a fast pull roll, a secondary cooling system and a winding system, wherein all the parts are sequentially and horizontally arranged. The transverse stretching system mainly comprises an electromagnet monomer, a magnetic ball, a baffle, a driving gear, a change gear and a driven gear. The film enters a heating system after passing through a slow drawing roller, the magnetic suspension array is changed from an initial parallel position to an open position with a certain angle, and the magnetic balls suspended in the film are driven by the film external magnetic suspension array to jointly and transversely expand by utilizing the electromagnetic principle, so that the aim of transversely stretching the film can be fulfilled. The longitudinal stretching is realized by adjusting the speed difference between the slow pull roll and the fast pull roll. The utility model has the advantages of when guaranteeing that film biaxial stretching improves service performance, simplified the complicated structure of traditional biaxial stretching device to avoid the surface damage of tensile department film, reduce the production of waste material.

Description

Magnetic suspension film biaxial stretching device

Technical Field

The invention relates to a plastic stretching forming device, in particular to a magnetic suspension film biaxial stretching device.

Background

The plastic film has been developed into one of the plastic products with the largest output and the largest variety in China, and is widely applied to the fields of packaging, electronic and electric products, agriculture, architectural decoration, daily necessities and the like, and the output of the plastic film accounts for about 20 percent of the total output of plastics. There are many methods for molding plastic films, such as calendering, blowing, stretching, and the like. Among them, biaxial stretching has been one of the methods which have attracted much attention in recent years, and a plastic film produced by the biaxial stretching technique has remarkably improved mechanical properties as compared with unstretched and uniaxially stretched films, and has a tensile strength after stretching 3 to 5 times that of the unstretched film, and improved barrier properties, optical properties, heat resistance and the like.

The film is stretched in two directions in a proper temperature range of the glass transition temperature and the melting point, the film is stretched in a certain multiple along the longitudinal direction and the transverse direction under the action of the external force of a stretcher, so that molecular chains or crystal planes are oriented and orderly arranged in the direction parallel to the plane of the film, then the film is subjected to heat setting in a tensioning state, the oriented macromolecular structure is fixed, and finally the film can be prepared through cooling and subsequent treatment. The traditional film bidirectional synchronous stretching device is characterized in that the two annular rails and the two transmission chain clamps are fixed, and the distance between the transmission chain clamps is gradually increased, so that the distance between two side edges of the film driven by the transmission chain clamps is gradually increased, and the film is transversely stretched. In the longitudinal stretching process, each annular track comprises an inner side rail and an outer side rail arranged outside the inner side rail, the distance between the inner side rail and the outer side rail is gradually reduced from front to back, and when the transmission chain clamp runs on the stretching section, the included angle between adjacent chain plates of the transmission chain clamp is correspondingly increased, so that the distance between the clamps connected with the adjacent chain plates is increased, and the longitudinal stretching of the film is realized. However, in the traditional chain-clamping type film biaxial stretching process, the structure of the film biaxial synchronous stretching device is complex, the surface quality of the film is difficult to ensure at the clamp, and unnecessary cost loss is caused.

Therefore, how to improve the service performance of the film by biaxial stretching, and simultaneously avoid the surface damage of the film at the stretching part and reduce the generation of waste materials is a key problem to be solved in the current biaxial film stretching forming method.

Disclosure of Invention

The invention provides a magnetic suspension film biaxial stretching device for synchronously stretching a film transversely and longitudinally, aiming at the problems that the strength of the existing polymer film in uniaxial stretching is not uniform and a film clamp is easy to damage in biaxial stretching. The film is stretched in cooperation with the magnetic balls in the film through the electromagnetic generator outside the film, and the film is longitudinally stretched through the speed difference between the traction rollers, so that the service performance of the biaxially oriented film is ensured, the surface damage of the film at the stretching part of the clamp is avoided, and the generation of waste materials is reduced.

The technical scheme includes that the magnetic suspension film biaxial stretching device comprises a film blowing system, a primary cooling system, a slow drawing roller, a heating system, a transverse stretching system, a fast drawing roller, a secondary cooling system and a winding system, wherein the film blowing system, the primary cooling system, the slow drawing roller, the heating system, the transverse stretching system, the fast drawing roller, the secondary cooling system and the winding system are horizontally and sequentially arranged in sequence. The film blowing system mainly comprises an extruder, an air hole, a die head and a film guiding roller. The transverse stretching system mainly comprises an electromagnet monomer, a magnetic ball, a baffle, a driving gear, a change gear and a driven gear. In the film blowing system, a film blowing driving motor provides power to drive an extruder screw to rotate, a material to be processed is heated in a machine barrel to be molten and is extruded at a die head, an air hole is formed in the center of the die head, air flow is blown out from the air hole, and the film is stretched for the first time under the inflating action of an air pump and the traction action of a film guiding roller to generate an initial film with a certain blow-up ratio. Through traction, the film passes through a primary cooling system which comprises three vertically arranged cooling rollers, the film is fully cooled to room temperature under the action of the primary cooling system, then the film passes through a slow-drawing roller which is kept in a low-speed state and only plays a role of traction, the film enters a heating system after passing through the slow-drawing roller, the heating system comprises a preheating zone, a stretching zone and a shaping zone, wherein the stretching zone is higher in temperature, and then the preheating zone and the shaping zone are arranged, a transverse stretching system is arranged in the stretching zone in the heating system and comprises a magnetic suspension array, a plurality of magnetic balls, a magnetic suspension array driving motor, a driving gear, a direction-changing gear and a driven gear, wherein the magnetic suspension array consists of a plurality of electromagnet monomers, each electromagnet monomer is horizontally arranged at an interval of 4-5cm, and the end part of each electromagnet monomer is provided with a circular groove, the diameter of the groove is larger than that of the magnetic ball, and the aluminum foil adhesive tape is attached to the surface of the groove, so that the surface smoothness of the groove can be improved, and the friction between the groove and a longitudinally passing film is reduced. The quantity of the magnetic balls is the same as that of the electromagnet monomers, and considering that the magnetic balls are not easy to control when the diameter of the magnetic balls is small, and the magnetic balls are easy to fall off under the influence of gravity when the diameter of the magnetic balls is too large, the magnetic balls with the diameter of 3-4cm are selected. The baffle plate is horizontally arranged on the magnetic suspension array, the length of the baffle plate is the same as that of the magnetic suspension array, the baffle plate is provided with a limiting groove, and when the magnetic balls suspended in the thin film drop due to the reduction of the magnetic force of the electromagnet monomer, the baffle plate can catch the dropped magnetic balls and enable the dropped magnetic balls to roll into the limiting groove. The baffle bottom is equipped with driven gear respectively, arranges under the initiating terminal magnetic force ball, and vertical direction is coaxial with initiating terminal magnetic force ball, and when driven gear rotates in both sides, both sides initiating terminal magnetic force ball position does not change. The film is manually drawn to pass through the preheating zone and then enters the stretching zone, magnetic suspension arrays on two sides of the film in the transverse stretching system are in parallel positions at the moment, when the film passes through the starting end of the magnetic suspension arrays, the magnetic suspension arrays enter a debugging state, magnetic balls are manually and sequentially placed in the film, the inner magnetic balls are sequentially attracted with electromagnets outside the film under the action of magnetic force, when the magnetic balls are completely placed in the film, a temperature control switch of the stretching zone is turned on, the film is heated to a high-elastic state in the stretching zone, a magnetic suspension array driving motor is turned on, the motor shaft is adjusted to rotate through a control circuit, a driving gear rotates by a corresponding angle along with the motor shaft, a driven gear on one side is directly meshed with the driving gear in the magnetic suspension arrays, a driven gear on the other side is meshed with the driving gear through a turning gear, the driven gears on two sides are reversely turned, and the magnetic suspension arrays on two sides are transversely unfolded under the driving of the driven gear, the magnetic suspension arrays are changed from the initial parallel position to the opening position with a certain angle, after the specified stretching ratio is reached, the magnetic suspension driving motor is closed, and the magnetic suspension arrays on the two sides are arranged in a splayed shape, so that the aim of transversely stretching the film is fulfilled. The film longitudinal stretching is realized by means of a slow-drawing roller and a fast-drawing roller and by adjusting the speed difference between the slow-drawing roller and the fast-drawing roller. And the film after the biaxial stretching enters a secondary cooling system, the structure of the film is the same as that of the primary cooling system, and the film is collected into a coil through a winding system after being cooled to room temperature.

According to the magnetic suspension film biaxial stretching device, transverse stretching utilizes an electromagnetic principle, and the magnetic balls suspended in the film are driven by the film external magnetic suspension array to jointly and transversely expand, so that the aim of transversely stretching the film can be fulfilled. Meanwhile, the longitudinal stretching is realized by adjusting the speed difference between the slow drawing roller and the fast drawing roller. The utility model has the advantages of when guaranteeing the biaxial stretching of film and improving performance, simplified the complicated structure of traditional biaxial stretching device to avoid the surface damage of tensile department film, reduce the production of waste material.

Drawings

FIG. 1 is a front view of a magnetic suspension film biaxial stretching device of the present invention.

FIG. 2 is a top view of a magnetic suspension film biaxial stretching device of the present invention.

FIG. 3 is a schematic diagram of a film blowing system of a magnetic suspension film biaxial stretching device of the present invention.

FIG. 4 is a schematic diagram of a transverse stretching system of a magnetic suspension film biaxial stretching device of the present invention.

Fig. 5 is a side view of a magnetic suspension array of a magnetic suspension film biaxial stretching device of the invention.

In the figure: 1-film blowing system; 1-extruder; 1-2-air holes; 1-3-die head; 1-4-a pulling roll; 2-primary cooling system; 3, slow drawing roller; 4-a heating system; 5, a transverse stretching system; 5-1-electromagnet monomer; 5-2-a magnetic ball; 5-3-baffle; 6, quickly pulling a roller; 7-secondary cooling system; 8, a winding system; 9-a driving gear; 10-a change gear; 11-driven gear.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

The invention relates to a magnetic suspension film biaxial stretching device which is shown in figures 1 and 2 and mainly comprises a film blowing system 1, a primary cooling system 2, a slow drawing roller 3, a heating system 4, a transverse stretching system 5, a fast drawing roller 6, a secondary cooling system 7 and a rolling system 8, wherein the film blowing system 1 mainly comprises an extruder 1-1, an air hole 1-2, a die head 1-3 and a traction roller 1-4, and is shown in figure 3, the transverse stretching system 5 mainly comprises an electromagnet monomer 5-1, a magnetic ball 5-2, a baffle 5-3, a driving gear 9, a change gear 10 and a driven gear 11, and is shown in figures 4 and 5. The film blowing system, the primary cooling system 2, the slow pull roll 3, the heating system 4, the transverse stretching system 5, the fast pull roll 6, the secondary cooling system 7 and the winding system 8 are horizontally and sequentially arranged in sequence. In the film blowing system 1, a film blowing driving motor provides power to drive an extruder screw to rotate, a material to be processed is heated in a machine barrel to be molten and is extruded at a die head 1-3, an air hole 1-2 is formed in the center of the die head 1-3, air flow is blown out from the air hole 1-2, and a film is stretched for the first time under the inflating action of an air pump and the traction action of a traction roller 1-4, so that an initial film with a certain blow-up ratio is generated. By pulling, the film passes through a primary cooling system 2, which primary cooling system 2 consists of three vertically arranged cooling rolls, the film being sufficiently cooled to room temperature by the primary cooling system. Then the film passes through a slow drawing roller 3, the slow drawing roller 3 is kept in a low rotating speed state at the moment and only plays a role of traction, the film passes through the slow drawing roller 3 and enters a heating system 4, the heating system 4 comprises a preheating area, a stretching area and a shaping area, the temperature of the stretching area is higher, the preheating area and the shaping area are arranged next, a transverse stretching system 5 is arranged in the stretching area of the heating system 4, the transverse stretching system 5 comprises a plurality of magnetic suspension arrays, a plurality of magnetic balls 5-2, a magnetic suspension array driving motor, a driving gear 9, a turning gear 10 and a driven gear 11, wherein the magnetic suspension arrays are composed of a plurality of electromagnet monomers 5-1, each electromagnet monomer 5-1 is horizontally arranged at intervals of 4-5cm, a circular groove is arranged at the end part of each electromagnet monomer 5-1, the diameter of the groove is larger than the diameter of each magnetic ball 5-2, and an aluminum foil adhesive tape is attached to the surface, the surface smoothness of the grooves can be increased, and the friction between the grooves and the longitudinally passing film is reduced. The number of the magnetic balls 5-2 is the same as that of the electromagnet monomers 5-1, and considering that the magnetic balls 5-2 are not easy to operate when the diameter is small, and the magnetic balls 5-2 are easy to fall off under the influence of gravity when the diameter is too large, the diameter of the magnetic balls 5-2 is 3-4 cm. The magnetic suspension array is provided with a baffle 5-3 which is horizontally arranged, the length of the baffle 5-3 is the same as that of the magnetic suspension array, the baffle 5-3 is provided with a limit groove, and when the magnetic balls 5-2 suspended in the film fall down due to the reduction of the magnetic force of the electromagnet monomer 5-2, the baffle 5-3 can receive the falling magnetic balls 5-2 and roll the falling magnetic balls into the limit groove, as shown in figure 5. The bottom ends of the baffles 5-3 are respectively provided with a driven gear 11, the driven gear 11 is arranged right below the initial end magnetic ball and is coaxial with the initial end magnetic ball in the vertical direction, when the driven gears 11 on the two sides rotate, the positions of the initial end magnetic balls on the two sides are not changed, and the transverse displacement is not generated, which is shown in figures 1 and 4. When the film is manually drawn to pass through the preheating zone and then enters the stretching zone, the magnetic suspension array in the transverse stretching system 5 is at a parallel position at the moment, when the film passes through the beginning end of the magnetic suspension array, the magnetic suspension array enters a debugging state, the magnetic balls 5-2 are manually and sequentially placed in the film, the inner magnetic balls 5-2 are sequentially attracted with the electromagnet 5-1 outside the film under the action of magnetic force, when the magnetic balls are completely placed in the film, a temperature control switch of the stretching zone is started, the film is heated to a high-elastic state in the stretching zone, a magnetic suspension array driving motor is started, a motor shaft is regulated to rotate through a control circuit, the driving gear 9 rotates at a corresponding angle along with the motor shaft, in the magnetic suspension array, the driven gear 11 at one side is directly meshed with the driving gear 9, the driven gear 11 at the other side is meshed with the driving gear 9 through the turning gear 10, the driven gears 11 on the two sides are opposite in rotation direction, the magnetic suspension arrays on the two sides are transversely unfolded under the driving of the driven gears 11, the magnetic suspension arrays are changed from the initial parallel position to the opening position at a certain angle, after the specified stretching ratio is reached, the magnetic suspension driving motors are turned off, and the magnetic suspension arrays on the two sides are arranged in a splayed shape, so that the purpose of transversely stretching the film is achieved, and the film is shown in figures 2 and 3. The film longitudinal stretching is realized by means of a slow-drawing roller 3 and a fast-drawing roller 6 and by adjusting the speed difference between the slow-drawing roller 3 and the fast-drawing roller 6. And the film after the biaxial stretching enters a secondary cooling system 7, the secondary cooling system 7 has the same structure as the primary cooling system 2, and the film is collected into a coil through a winding system 8 after being cooled to room temperature.

Claims

1. A magnetic suspension film biaxial stretching device is characterized in that: the device comprises a film blowing system, a primary cooling system, a slow drawing roller, a heating system, a transverse stretching system, a fast drawing roller, a secondary cooling system and a winding system, wherein all the components are horizontally and sequentially arranged according to the sequence of the film blowing system, the primary cooling system, the slow drawing roller, the heating system, the transverse stretching system, the fast drawing roller, the secondary cooling system and the winding system, the film blowing system mainly comprises an extruder, an air hole, a die head and a film drawing roller, and the transverse stretching system mainly comprises an electromagnet monomer, a magnetic ball, a baffle plate, a driving gear, a turning gear and a driven gear; in the film blowing system, a film blowing driving motor provides power to drive an extruder screw to rotate, a material to be processed is heated in a machine barrel to be molten and is extruded at a die head, an air hole is formed in the center of the die head, air flow is blown out of the air hole, and the film is stretched for the first time under the inflation action of an air pump and the traction action of a film guiding roller to generate an initial film with a certain blow-up ratio; the method comprises the following steps that an initial film passes through a primary cooling system, the primary cooling system comprises three vertically arranged cooling rollers, the film is fully cooled to room temperature under the action of the primary cooling system, then the film passes through a slow drawing roller, and enters a heating system after passing through the slow drawing roller, the heating system comprises a preheating area, a stretching area and a shaping area, wherein the temperature of the stretching area is higher, and then the preheating area and the shaping area are arranged, a transverse stretching system is arranged in the stretching area in the heating system and comprises a magnetic suspension array, a plurality of magnetic balls, a magnetic suspension array driving motor, a driving gear, a turning gear and a driven gear, wherein the magnetic suspension array consists of a plurality of uniformly distributed electromagnet monomers, the end parts of the electromagnet monomers are provided with circular grooves, and the diameter of the grooves is larger than that of the magnetic balls; the number of the magnetic balls is the same as that of the electromagnet monomers, the magnetic suspension array is provided with baffle plates which are horizontally arranged, the length of the baffle plates is the same as that of the magnetic suspension array, limit grooves are formed in the baffle plates, the bottom ends of the baffle plates are respectively provided with driven gears which are arranged under the magnetic balls at the starting end and are coaxial with the magnetic balls at the starting end in the vertical direction, the driving gears rotate corresponding angles along with a motor shaft, in the magnetic suspension array, the driven gears on one side are directly meshed with the driving gears, the driven gears on the other side are meshed with the driving gears through a turning gear path, the directions of the driven gears on two sides are opposite, the film is longitudinally stretched by virtue of a slow pull roller and a fast pull roller, and enters a secondary cooling system after the film is stretched in a two-way, the structure of the secondary cooling system is the same as that of the primary cooling system, and the film is collected into coils through a rolling system after being cooled to the room temperature.

2. A magnetic levitation film biaxial stretching apparatus as recited in claim 1, wherein: the electromagnet monomers are horizontally arranged at intervals of 4-5 cm.

3. A magnetic levitation film biaxial stretching apparatus as recited in claim 1, wherein: an aluminum foil adhesive tape is attached to the surface of a circular groove formed in the end of the electromagnet unit.

4. A magnetic levitation film biaxial stretching apparatus as recited in claim 1, wherein: the diameter of the magnetic ball is 3-4 cm.