Hot melting sealing clamping structure and sealing device and method based on shape memory effect
A two-stage clamping mechanism using shape memory material-based seals addresses the stress issue in space plastic bags, enhancing seal quality by initial relaxation followed by shape memory-induced deformation.
Patent Information
- Application Number
- CN202510761702.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-09
- Publication Date
- 2025-07-15
AI Technical Summary
In the prior art, the plastic bag sealing device in space is prone to stress when clamping the bag mouth, which affects the sealing quality, especially for plastic bags with larger thickness and higher strength.
The sealing strip made of shape memory material realizes two-stage step clamping through the shape memory effect. The initial clamping force is small to release stress, and the subsequent clamping force is large to ensure the sealing quality. The hot melt seal is completed by combining the elastic reset mechanism and the heating structure.
It effectively avoids bag stress, improves sealing quality, and ensures sealing and integrity of the sealing.
Smart Images
Figure CN120308440A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of sealing, and in particular, to a hot melt sealing and clamping structure, a sealing device and method based on the shape memory effect. Background Art
[0002] With the booming development of the space industry, deep space exploration has become a hot topic pursued by space agencies of various countries. In the task of bringing samples back to Earth from space, the application of using plastic bags to package samples has also made remarkable progress. Using plastic bags to package samples not only requires selecting appropriate plastic bag materials and specifications, but also requires reliable sealing to ensure its airtightness and integrity during the round trip between space and Earth.
[0003] Among the existing devices for sealing plastic bags in space, some use a pull pin made of shape memory material. By triggering the deformation of the shape memory material, the pull pin is unlocked, and then the spring is reset to drive the sealing strip to clamp the bag mouth of the plastic bag, and then the sealing strip is heated to achieve hot melt sealing. In such sealing devices, most rely on external forces (such as spring reset force) to push the sealing strip to move and clamp the bag mouth, completing the clamping action at one time. However, the plastic bags used for sample packaging in space need to have high tear resistance, puncture resistance and aging resistance to withstand the extreme space environment. Therefore, the thickness of these plastic bags is usually thicker than that of ordinary plastic bags, and the strength and toughness are also greater. Moreover, in order to hold space samples, the bag mouth of the plastic bag is generally opened to the maximum state. So, clamping in place at one time may cause stress on the bag mouth, affecting the sealing quality. Summary of the Invention
[0004] The problem solved by the present invention is how to avoid generating stress when clamping the bag mouth of the plastic bag and improve the hot melt sealing quality of the plastic bag in space.
[0005] To solve the above problems, the present invention provides a hot melt sealing and clamping structure, a sealing device and method based on the shape memory effect.
[0006] In a first aspect, the present invention provides a hot melt sealing and clamping structure, including a sealing strip, the sealing strip is used to clamp and heat the bag mouth sealing area of the bag to achieve hot melt sealing of the bag; the sealing strip is made of shape memory material, and the sealing strip is also used to deform based on the shape memory effect, so that the clamping surface of the bag mouth sealing area moves and changes along the clamping direction.
[0007] Optionally, the sealing strip deforms based on the shape memory effect when the temperature is higher than or equal to a preset deformation temperature, so that the clamping surface of the bag mouth sealing area moves and changes along the clamping direction, and the preset deformation temperature is lower than the hot melt temperature of the bag.
[0008] Optionally, the hot-melt sealing clamping structure further includes a clamping strip body for supporting and arranging the sealing strip.
[0009] Optionally, the clamping strip body is provided with a groove, the cavity of the groove is used for arranging the sealing strip, and the notch of the groove is configured to face the bag mouth sealing area of the bag.
[0010] In a second aspect, the present invention provides a sealing device based on the shape memory effect, which includes two of the above-mentioned hot-melt sealing clamping structures, and further includes a driving mechanism and a heating structure; the driving mechanism is used to move the sealing strip so that the two sealing strips clamp the bag mouth sealing area; the heating structure is used to heat the sealing strip.
[0011] Optionally, the driving mechanism includes an elastic reset mechanism, on which the hot-melt sealing clamping structure and a pin extractor are arranged; the pin extractor is used to trigger the elastic reset mechanism to perform a reset action, thereby moving the sealing strip so that the two sealing strips clamp the bag mouth sealing area.
[0012] Optionally, the elastic reset mechanism includes a mounting plate and elastic reset components symmetrically arranged on the mounting plate. The elastic reset components include sliding shaft rods, sliders, first elastic elements and connecting rods; the sliding shaft rods are arranged on the mounting plate; the sliders are slidably arranged on the sliding shaft rods; the main body of the slider extends to one side of the mounting plate, and two connecting rods are arranged at the extending end, and each connecting rod is used to connect with one of the hot-melt sealing clamping structures; the first elastic element is used to apply an elastic force to the slider to prevent the slider from sliding on the sliding shaft rod.
[0013] Optionally, the sealing device based on the shape memory effect further includes a bag basket for placing the bag. The mouth of the bag basket is arranged opposite to and spaced from the mounting plate, and is connected by a plurality of support rods.
[0014] Optionally, the pin extractor drives the insertion and extraction of the pin head through the shape memory effect.
[0015] In a third aspect, the present invention provides a sealing method based on the shape memory effect, which uses the above-mentioned hot-melt sealing clamping structure and includes the following steps: Move the sealing strip to clamp the bag mouth sealing area of the bag; Heat the sealing strip to melt the bag mouth sealing area. Before the bag mouth sealing area melts, the sealing strip deforms due to temperature rise and shape memory effect, so that the clamping force on the bag mouth sealing area increases.
[0016] The beneficial effects of the hot-melt sealing and clamping structure of the present invention are as follows: During use, first move the sealing strip to initially clamp the bag mouth sealing area, and then drive the sealing strip to deform based on the shape memory effect to further squeeze and clamp the bag mouth sealing area, thereby forming a two-stage stepped clamping. During the initial clamping, the clamping force on the bag mouth sealing area is small, and the stress generated by the passive mutual fitting of the bag mouth part can be released; when the sealing strip deforms and clamps again, the clamping force on the bag mouth sealing area reaches the preset value to ensure the sealing pressure. Finally, when the bag mouth sealing area is subjected to the clamping force, the stress is small, improving the sealing quality. Brief Description of the Drawings
[0017] Figure 1 It is a schematic diagram of the hot-melt sealing and clamping structure of the present invention.
[0018] Figure 2 It is a schematic diagram of the initial state of the sealing device based on the shape memory effect of the present invention.
[0019] Figure 3 It is a schematic diagram of the state of clamping the bag by the sealing device based on the shape memory effect of the present invention.
[0020] Figure 4 It is a schematic diagram of the initial state of the pin puller of the sealing device based on the shape memory effect of the present invention.
[0021] Figure 5 It is a schematic diagram of the state of the pin puller of the sealing device based on the shape memory effect of the present invention after the pin puller operates.
[0022] Figure 6 It is a disassembled schematic diagram of the pin puller of the sealing device based on the shape memory effect of the present invention.
[0023] Figure 7 It is a schematic diagram of the use process of the hot-melt sealing and clamping structure of the present invention.
[0024] Description of the Reference Numerals: 1. Sealing strip; 11. Heating film; 2. Bag; 3. Clamping strip body; 31. Groove; 411. Mounting plate; 4111. Through hole; 4112. Anti-rebound sheet; 412. Sliding shaft rod; 413. Slide block; 414. First elastic element; 415. Link; 42. Pin puller; 421. Pin head; 422. First seat plate; 423. Second seat plate; 424. Connecting plate; 425. Second elastic element; 426. Guide shaft; 427. Guide sleeve; 6. Bag basket; 61. Support rod. Detailed Description of the Invention
[0025] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.
[0026] As used herein, the term "comprising" and its variants are open-ended, i.e., "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules, or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules, or units.
[0027] It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".
[0028] Before introducing the embodiments of the present invention, two technical knowledges, namely shape memory effect and heat-sealing, will be introduced first.
[0029] Shape memory effect: For a solid material with a certain shape, after undergoing plastic deformation at a certain low temperature state and then being heated to above a certain critical temperature inherent to this material, the material returns to its initial shape. This phenomenon is called the shape memory effect. The material with the shape memory effect is called the shape memory material.
[0030] The heat-sealing technology uses heat energy to melt and bond two or more layers of plastic films. During the sealing process, the plastic films are heated by a heating element to make them reach the molten state, and then quickly cooled and solidified under pressure, thereby achieving a firm bond between the films. This sealing method can ensure the tightness and integrity of the packaging and effectively prevent the product from being externally contaminated.
[0031] Such as Figure 1As shown, a hot-melt sealing and clamping structure provided by an embodiment of the present invention includes a sealing strip 1. The sealing strip 1 is used to clamp and heat the bag mouth sealing area of the bag 2 to achieve hot-melt sealing of the bag 2. The sealing strip 1 is made of a shape memory material, and the sealing strip 1 is also used to deform based on the shape memory effect, so that the clamping surface of the bag mouth sealing area moves and changes along the clamping direction.
[0032] Two sealing strips 1 are spaced opposite to each other. The relative position of the sealing strip 1 and the bag mouth sealing area is initially as Figure 7 shown in (A). When in use, first move the sealing strip 1 to initially clamp the bag mouth sealing area, and then drive the sealing strip 1 to deform based on the shape memory effect, so that the clamping surface of the sealing strip 1 on the bag mouth sealing area moves and changes along the clamping direction, that is, further squeeze and clamp the bag mouth sealing area, thereby forming a two-stage stepped clamping. When initially clamping, as Figure 7 shown in (B), the clamping force received by the bag mouth sealing area is small. This small clamping force can be specifically designed according to the actual situation, and it can make the bag mouth sealing area fit but not tightly. After initial clamping, the bag 2 can move misaligned with each other due to its own strength and toughness to release the stress generated by the passive mutual fitting of the bag mouth part. Then drive the sealing strip 1 to deform based on the shape memory effect. On the basis of initial clamping, further clamp the bag mouth sealing area, that is, clamp again, as Figure 7 shown in (C). At this time, the clamping force received by the bag mouth sealing area reaches a preset value, which can be specifically obtained by controlling the size of the sealing strip 1 after shape memory deformation; finally, through two-stage stepped clamping, the stress of the bag mouth sealing area is small when receiving the clamping force, ensuring the sealing pressure and improving the sealing quality.
[0033] It should be noted that: the clamping direction refers to the direction of the pressure applied by the sealing strip 1 to the bag mouth sealing area during hot-melt sealing, which points from the sealing strip 1 to the bag mouth sealing area; the clamping surface is the surface that directly contacts the bag mouth sealing area of the bag 2 during hot-melt sealing. Usually, there are two sealing strips 1 arranged opposite to each other, and the two sealing strips 1 move towards each other to achieve clamping of the bag mouth sealing area. At this time, it can be considered that the moving direction of the sealing strip 1 is the clamping direction of the sealing strip 1.
[0034] Optionally, the sealing strip 1 deforms based on the shape memory effect when the temperature is higher than or equal to a preset deformation temperature, such that the clamping surface of the bag mouth sealing area moves and changes along the clamping direction, and the preset deformation temperature is lower than the hot melting temperature of the bag 2. That is, the temperature for triggering the shape memory effect by heating the sealing strip 1 is lower than the hot melting temperature of the bag 2. In this way, when the sealing strip 1 clamps and heats the bag mouth sealing area, the sealing strip 1 first deforms due to temperature rise and the shape memory effect, and then the sealing strip 1 continues to heat up, and only then will it melt the bag mouth sealing area. That is, the sealing strip 1 completes the deformation based on the shape memory effect before the hot melting of the bag mouth sealing area, increases the clamping force before the hot melting occurs, and completes the re-clamping, effectively ensuring the sealing pressure. Moreover, using the same heat source can both realize the driving of the shape memory effect of the sealing strip 1 and heat the bag mouth sealing area to achieve melting. The design is ingenious and the structure is simple.
[0035] Optionally, the hot melting sealing and clamping structure further includes a clamping strip body 3, and the clamping strip body 3 is used to support and arrange the sealing strip 1. By supporting and arranging through the clamping strip body 3, it is convenient to install and arrange in the entire sealing device.
[0036] In addition, since the sealing strip 1 needs to be able to withstand and conduct heat, it is preferably made of a shape memory alloy. The present invention selects a one-way shape memory alloy, and the austenite phase transformation temperature is selected in the range of 100~120°C, and the martensite phase transformation temperature is selected in the range of -200°C~-180°C. Correspondingly, the bag 2 is a thermoplastic polymer, and the hot melting temperature range is 250°C~300°C.
[0037] Shape memory alloy is a type of metal alloy with special phase change behavior, which can restore to a preset shape under specific thermal excitation or external conditions; the principle behind it involves the crystal structure transformation of the material at different temperatures, especially the transformation process from the low-temperature martensite phase to the high-temperature austenite phase. The shape memory effect of the shape memory alloy stems from its phase change characteristics. At a lower temperature, the lattice structure of the shape memory alloy is a low-symmetry martensitic structure with a large deformation ability. At this time, the shape memory alloy can be deformed by external force or temperature change; when the temperature rises, the lattice structure of the shape memory alloy transforms into a higher-symmetry austenitic structure, and at this time the shape of the material is fixed and shows a higher stiffness. The reversibility of this process is an important physical property of the shape memory alloy, enabling them to return to their original state multiple times under repeated temperature changes and being widely used in the aerospace field. Different types of shape memory alloys are selected according to different requirements of the use environment, including nickel-titanium alloys, copper-based alloys, and iron-based alloys.
[0038] Optionally, a groove 31 is provided on the clamping strip body 3. The cavity of the groove 31 is used to arrange the sealing strip 1, and the notch of the groove 31 is configured to face the bag mouth sealing area of the bag 2. The sealing strip 1 is embedded in the groove 31 structure, with a simple structure and reliable positioning. It should be noted that the part of the sealing strip 1 facing the notch of the groove 31 protrudes from the notch of the groove 31 or is flush with the notch of the groove 31, and the surface forms a clamping surface for directly contacting the bag 2. After the sealing strip 1 deforms based on the shape memory effect, this clamping surface moves in the clamping direction, that is, moves in the direction of protruding from the notch, so as to clamp the bag mouth sealing area of the bag 2.
[0039] As Figure 1 shown, a feasible structure of the clamping strip body 3 and the sealing strip 1 is schematically shown. Specifically, both the clamping strip body 3 and the sealing strip 1 are in the shape of a cuboid block. A rectangular groove penetrating through both ends, namely the groove 31, is opened on one side surface of the clamping strip body 3; the sealing strip 1 is adaptively embedded in the rectangular groove 31, and the side surface exposed from the notch is the above-mentioned clamping surface. In addition, the sealing strip 1 can be fixed to the clamping strip body 3 by means of bonding, welding, bolt connection, etc., and is designed according to the actual situation, and attention should be paid to minimizing the influence on the deformation of the sealing strip 1.
[0040] As Figures 2 - 6 shown, a sealing device based on the shape memory effect provided by an embodiment of the present invention includes two above-mentioned hot melt sealing and clamping structures, and further includes a driving mechanism and a heating structure; the driving mechanism is used to move the sealing strip 1 to clamp the bag mouth sealing area by the two sealing strips 1; the heating structure is used to heat the sealing strip 1.
[0041] For this sealing device based on the shape memory effect, the driving mechanism is used to move the sealing strip 1 to initially clamp the bag mouth sealing area, and then the heating structure drives the sealing strip 1 to deform based on the shape memory effect, so that the clamping surface of the sealing strip 1 on the bag mouth sealing area moves and changes in the clamping direction, that is, to achieve re-clamping, further squeezing and clamping the bag mouth sealing area, thereby forming a two-stage stepped clamping, so that the stress generated by the clamping of the bag mouth sealing area is small, and the sealing pressure can be effectively guaranteed, improving the sealing quality.
[0042] Optionally, the driving mechanism includes an elastic reset mechanism. The elastic reset mechanism is provided with a hot melt sealing and clamping structure and a pull pin 42; the pull pin 42 is used to trigger the elastic reset mechanism to perform a reset action, and then move the sealing strip 1 to clamp the bag mouth sealing area by the two sealing strips 1.
[0043] The elastic reset mechanism is a common structure, usually composed of components such as elastic elements, support members, and reset members. When an external force acts, the elastic element will deform and store energy; when the external force disappears, the spring will release the stored energy and push the reset member back to its original position, thereby realizing the reset function. Specifically, the elastic reset mechanism of the present invention is used to move the sealing strip 1 to clamp the bag mouth sealing area, that is, the sealing strip 1 is the reset member; the external force is applied by the pin extractor 42 and realized by inserting and pulling out the pin head 421.
[0044] Optionally, the elastic reset mechanism includes a mounting plate 411 and elastic reset components symmetrically arranged on the mounting plate 411. The elastic reset components include a sliding shaft rod 412, a slider 413, a first elastic element 414, and a connecting rod 415; the sliding shaft rod 412 is arranged on the mounting plate 411; the slider 413 is slidably arranged on the sliding shaft rod 412; the main body of the slider 413 extends towards one side of the mounting plate 411, and two connecting rods 415 are arranged at the extending end, and each connecting rod 415 is used to connect with a hot melt sealing and clamping structure; the first elastic element 414 is used to apply an elastic force to the slider 413 to prevent the slider 413 from sliding on the sliding shaft rod 412.
[0045] The elastic reset mechanism is specifically as Figure 2 and Figure 3 shown. The two sealing strips 1 are designed to be arranged parallel and facing each other; the mounting plate 411 is arranged on the top of the two hot melt sealing and clamping structures, and the plate surface is perpendicular to the symmetry plane of the two sealing strips 1. The sliding shaft rod 412 is arranged on the mounting plate 411, and its axis is located on the symmetry plane of the two sealing strips 1 and parallel to the plate surface of the mounting plate 411. The first elastic element 414 is a spring, sleeved on the sliding shaft rod 412, one end is in contact with and abuts against the slider 413, and the other end is in contact with and abuts against the end limiting structure of the sliding shaft rod 412. The slider 413 can slide on the sliding shaft rod 412. Note that a limiting structure is also arranged at the other end of the sliding shaft rod 412 to prevent the slider 413 from slipping off the sliding shaft rod 412; and, the slider 413 always compresses the first elastic element 414 at any position on the sliding shaft rod 412, so that the first elastic element 414 always exerts a thrust on the slider 413.
[0046] In order to enable the slider 413 to drive the sealing strip 1 to move, the main body of the slider 413 extends towards one side of the mounting plate 411, specifically towards the side where the sealing strip 1 is provided, and two connecting rods 415 are arranged at the extending end. One end of each connecting rod 415 is rotatably connected to the end of a sealing strip 1 through a rotating shaft, and the other end is rotatably connected to the slider 413 through a rotating shaft. And the rotating shafts at both ends of the connecting rod 415 are perpendicular to the plate surface of the mounting plate 411. Finally, the two sealing strips 1, or rather the two hot melt sealing and clamping structures, are pulled by the two sliders 413 through the four connecting rods 415 and can move reciprocally towards or away from each other to clamp or release the bag mouth sealing area of the bag 2.
[0047] Optionally, the slider 413 is in a T shape, and the end of the vertical structure of the T-shaped structure is slidably arranged on the sliding shaft rod 412, and a connecting rod 415 is arranged at each end of the horizontal structure.
[0048] Optionally, the sealing device based on the shape memory effect further includes a bag basket 6 for placing the bag 2. The mouth of the bag basket 6 is arranged opposite and spaced from the mounting plate 411, and is connected by a plurality of support rods 61. Integrating the mounting plate 411 and the hot melt sealing and clamping structure on the bag basket 6 makes the entire sealing process simple and fast, and can quickly complete the sealing after putting items into the bag 2, which is suitable for packaging samples in space.
[0049] Specifically, the main body of the bag basket 6 is in a cylindrical shape, which is adapted to the main body of the bag 2 to provide support and protection for the bag 2; the mouth of the basket extends outward to form a flat plate, and the flat plate is arranged parallel and opposite to the mounting plate 411, and the two plates are supported and connected by four support rods 61. The hot melt sealing and clamping structure is arranged between the mouth of the basket and the mounting plate 411. The main body of the bag 2 is placed in the bag basket 6, and the bag mouth extends out of the mouth of the basket and extends above the two hot melt sealing and clamping structures, so that the bag mouth sealing area is located between the two sealing strips 1. A through hole 4111 is opened on the mounting plate 411, and the through hole 4111 is used to provide a channel for placing samples; in space, in order to prevent the samples placed in the bag 2 from escaping, a non-return piece 4112 is arranged on the through hole 4111. The non-return piece 4112 has elasticity, and the main body extends obliquely from the inner wall of the through hole 4111 to the center of the through hole 4111, and four are evenly arranged at intervals along the circumference of the through hole 4111. In addition, two sliding shaft rods 412 are arranged on both sides of the through hole 4111.
[0050] In addition, the bag basket 6 can be made of composite materials. The matrix phase can be polymers such as epoxy and cyanate ester, and the reinforcing phase can be continuous fibers, short cut fibers or particles. Commonly used continuous fibers with good mechanical properties are selected, such as carbon fiber, glass fiber, aramid fiber, polyethylene fiber, etc.
[0051] Optionally, the pull pin device 42 drives the insertion and extraction of the pin head 421 through the shape memory effect. Due to the complex and changeable space environment, the equipment is required to have high reliability. The shape memory material drives the pull pin device 42 to have excellent mechanical properties and stability, as well as a lighter mass, which can meet the requirements of space missions for equipment reliability.
[0052] Optionally, the pin head 421 is inserted and pulled out on the hot melt sealing and clamping structure. As shown in FIGS. Figure 2 and Figure 3 shown, there are two pull pin devices 42 in total, and each pull pin device 42 acts on a clamping strip body 3, and a pin hole adapted to the pin head 421 can be opened on the clamping strip body 3.
[0053] Optionally, as Figures 4 - 6 shown, the pin extractor 42 includes a first base plate 422, a second base plate 423 and a connecting plate 424; the plate surfaces of the first base plate 422 and the second base plate 423 are arranged parallel and facing each other; the first base plate 422 and the second base plate 423 are connected by the connecting plate 424; the first base plate 422 is fixed on the mounting plate 411, and a pin head 421 is arranged on the plate surface of the second base plate 423 away from the first base plate 422; the connecting plate 424 is made of a shape memory material, and based on the shape memory effect, the deformation can make the plate body bend, so that the second base plate 423 and the first base plate 422 approach each other, realizing the extraction of the pin head 421. As Figure 4 shown, the pin extractor 42 is in the initial state; as Figure 5 shown, the pin extractor 42 is in the state after action, and the connecting plate 424 deforms based on the shape memory effect to make the plate body bend.
[0054] Optionally, a second elastic element 425 is further arranged between the first base plate 422 and the second base plate 423. The second elastic element 425 applies an elastic tension to the first base plate 422 and the second base plate 423, so that the first base plate 422 and the second base plate 423 tend to approach each other.
[0055] Optionally, a guide shaft 426 is arranged on the plate surface of the first base plate 422 facing the second base plate 423; the second elastic element 425 is a spring, sleeved on the guide shaft 426, and one end is fixed on the first base plate 422 and the other end is fixed on the second base plate 423. In addition, a guide sleeve 427 adapted to the guide shaft 426 is arranged on the second base plate 423. The guide sleeve 427 is sleeved on the end of the guide shaft 426, and the two can move relative to each other along the axial direction after being nested with each other. When the pin extractor 42 extracts the pin, that is, when the second base plate 423 moves closer to the first base plate 422, the moving path is accurate and the offset is small.
[0056] Optionally, the connecting plate 424 can be prepared by using a shape memory polymer composite material. The shape memory polymer composite material is an intelligent material that can return from a temporary state to an original state under the action of external stimuli such as light, heat, electricity, magnetism, etc. It has advantages such as a large stiffness / weight ratio, light weight, and a large deployment / storage ratio. In the present invention, it is applied to the shape memory pin extractor 42, and can be released by electrothermal drive.
[0057] In addition, the shape memory polymer composite material includes a matrix phase and a reinforcement phase. The matrix phase refers to the polymer material. Different resins are selected according to different use environment requirements. Generally, epoxy or cyanate shape memory polymers are selected. The glass transition temperature of epoxy shape memory polymers is selected in the range of 80-180°C, and the glass transition temperature of cyanate shape memory polymers is selected in the range of 180-200°C. The reinforcement phase can be continuous fibers, chopped fibers or particles. Commonly used continuous fibers with good mechanical properties are selected, such as carbon fibers, glass fibers, aramid fibers, polyethylene fibers, etc., so that the shape memory pin puller 42 has good locking force and stability, and has good aerospace application value.
[0058] Optionally, the heating structure includes a heating film 11 disposed on the sealing strip 1 for heating. Figure 1 As shown, the heating film 11 can be attached to the upper and lower surfaces of the sealing strip 1 . The heating film 11 also has the flexibility to move and is less affected by the deformation of the sealing strip 1 .
[0059] When using, Figure 2 The figure shows the initial state of the sealing device: the two sealing strips 1 or the two hot melt sealing sandwich structures are spaced apart from each other, waiting to clamp the bag opening sealing area. In the initial state, the bag 2 is placed in the bag basket 6, and the bag opening is open; the pin head 421 of the pin puller 42 is inserted into the pin hole of the sandwich strip body 3, the sandwich strip body 3, the connecting rod 415, and the slider 413 are connected in a transmission manner, and the first elastic element 414 is a spring, which is sleeved on the sliding shaft 412, and the first elastic element 414 is maintained in a compressed state by the pin puller 42, thereby keeping the two sealing strips 1 open. When the sampler enters the bag 2 and is detected to be in place, the sampler is restrained by the anti-return spring sheet 4112 to prevent it from falling out of the main body of the bag 2, and a command is issued to the sealing device to drive the connecting plate 424 to deform based on the shape memory effect, so that the pin head 421 is pulled out of the pin hole of the clamping strip body 3, and the compressed first elastic element 414 releases elastic potential energy to push the slider 413, which moves to the end of the sliding shaft 412 and is limited and held, and drives the hot melt sealing clamping structure through the connecting rod 415 to achieve preliminary clamping of the bag mouth sealing area of the bag 2. Figure 3 As shown; the sealing strip 1 is then heated. During the temperature increase of the sealing strip 1, the sealing strip 1 is deformed due to the shape memory effect. The deformation causes the sealing strip 1 to further squeeze and clamp the bag sealing area, thereby increasing the clamping force on the bag sealing area to meet the hot melt pressure requirement. Thereafter, the temperature of the sealing strip 1 is further increased to melt the bag sealing area, and then it is cooled to achieve complete sealing.
[0060] like Figure 7 As shown, a sealing method based on shape memory effect provided by an embodiment of the present invention includes the following steps S10-S30.
[0061] Step S10: Drive the sealing strip 1 to clamp the bag mouth sealing area of the bag 2.
[0062] Step S20: Heat the sealing strip 1 to melt the bag mouth sealing area. Before the bag mouth sealing area melts, the sealing strip 1 deforms due to the temperature rise and shape memory effect, increasing the clamping force on the bag mouth sealing area.
[0063] During the process of the temperature rise of the sealing strip 1, first: the sealing strip 1 deforms due to the shape memory effect, and the deformation causes the sealing strip 1 to further squeeze and clamp the bag mouth sealing area, increasing the clamping force on the bag mouth sealing area. Then the temperature of the sealing strip 1 continues to rise, melting the bag mouth sealing area.
[0064] Optionally, the sealing method based on the shape memory effect further includes step S30: Stop heating the sealing strip 1 to cool and solidify the bag mouth sealing area, completing the sealing.
[0065] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the protection scope of the present invention.
Claims
1. A hot melt sealing and clamping structure, characterized in that, It includes a sealing strip (1), and the sealing strip (1) is used to clamp and heat the mouth sealing area of the bag (2) to achieve the hot melt sealing of the bag (2). The sealing strip (1) is made of a shape memory material, and the sealing strip (1) is also used to deform based on the shape memory effect, so that the clamping surface of the mouth sealing area moves and changes along the clamping direction.
2. The hot melt sealing and clamping structure according to claim 1, wherein The sealing strip (1) deforms based on the shape memory effect when the temperature is higher than or equal to a preset deformation temperature, so that the clamping surface of the mouth sealing area moves and changes along the clamping direction, and the preset deformation temperature is lower than the hot melt temperature of the bag (2).
3. The hot melt sealing and clamping structure according to claim 1, wherein, It further includes a clamping strip body (3), and the clamping strip body (3) is used to support and arrange the sealing strip (1).
4. The hot melt sealing and clamping structure according to claim 3, characterized in that, A groove (31) is provided on the clamping strip body (3), and the cavity of the groove (31) is used to arrange the sealing strip (1), and the notch of the groove (31) is configured to face the mouth sealing area of the bag (2).
5. A sealing device based on the shape memory effect, characterized in that, It includes two hot melt sealing and clamping structures according to any one of claims 1-4, and also includes a driving mechanism and a heating structure; the driving mechanism is used to move the sealing strip (1) so that the two sealing strips (1) clamp the mouth sealing area; the heating structure is used to heat the sealing strip (1).
6. The sealing device based on the shape memory effect according to claim 5, characterized in that, The driving mechanism includes an elastic reset mechanism, and the hot melt sealing and clamping structure and a pin puller (42) are arranged on the elastic reset mechanism; the pin puller (42) is used to trigger the elastic reset mechanism to perform a reset action, and then move the sealing strip (1) so that the two sealing strips (1) clamp the mouth sealing area.
7. The sealing device based on shape memory effect according to claim 6, wherein The elastic reset mechanism includes a mounting plate (411) and elastic reset components symmetrically arranged on the mounting plate (411), and the elastic reset components include a sliding shaft rod (412), a slider (413), a first elastic element (414) and a connecting rod (415). The sliding shaft rod (412) is arranged on the mounting plate (411). The slider (413) is slidably arranged on the sliding shaft rod (412); the main body of the slider (413) extends to one side of the mounting plate (411), and two connecting rods (415) are arranged at the extended end, and each connecting rod (415) is used to connect to one hot melt sealing and clamping structure. The first elastic element (414) is used to apply an elastic force to the slider (413) to prevent the slider (413) from sliding on the sliding shaft rod (412).
8. The sealing device based on the shape memory effect according to claim 7, wherein It further includes a bag basket (6) for placing the bag (2), and the mouth of the bag basket (6) is arranged opposite and spaced from the mounting plate (411) and is connected by a plurality of support rods (61).
9. The sealing device based on the shape memory effect according to claim 6, characterized in that, The pin puller (42) drives the insertion and extraction of the pin head (421) through the shape memory effect.
10. A sealing method based on the shape memory effect, characterized in that, Using the hot melt sealing and clamping structure according to any one of claims 1-4 includes the following steps: Move the sealing strip (1) to clamp the mouth sealing area of the bag (2). Heat the sealing strip (1) to melt the bag mouth sealing area. Before the bag mouth sealing area melts, the sealing strip (1) deforms due to temperature rise and shape memory effect, increasing the clamping force on the bag mouth sealing area.