A method and system for filling and sealing liquid-filled hard capsules

Abstract

The application belongs to the technical field of capsule packaging, and particularly discloses a liquid-filled hard capsule filling and sealing method and system, which comprises the following steps: separating a capsule body from a capsule cap, filling a material into the capsule body, and filling inert gas into the capsule cap, wherein the material at least contains liquid; sleeving the capsule cap and the capsule body obtained in step S1 to obtain a liquid-filled capsule; injecting glue into a sleeving gap, applying pressure to the liquid-filled capsule, using negative pressure to fill the glue into the sleeving gap, and then heating the sleeving gap to realize sealing. The application can realize efficient cleaning and packaging of a large number of hard capsules and make the packaged capsules have better sealing performance.

Description

Technical Field

[0001] This invention belongs to the field of capsule packaging technology, and more specifically, relates to a method and system for filling and sealing liquid-filled hard capsules. Background Technology

[0002] Liquid-filled hard capsules offer advantages such as easy absorption, convenient administration, and no dust generation during preparation. However, their encapsulation technology is demanding and difficult to control, resulting in higher encapsulation costs. The filling formulation of liquid-filled capsules typically contains one or more of the following: liquid, granules, microcapsules, and capsules-in-capsule. Specifically, a filling machine is used to fill the hard capsule shell, forming the desired liquid capsule. To prevent leakage of the liquid drug after filling, the interfaces between the upper and lower shells of the hard capsule need to be sealed to ensure the internal drug is not contaminated or leaks out. Conventional sealing methods include external sealing (tape sealing) and internal sealing (spraying in sealing liquid). For example, Chinese patent document CN107157949B discloses a method for sealing the inside of hard capsules and its application. The method involves filling the inside of the capsule body with material; using inert gas to carry the sealing liquid and spraying the sealing liquid onto the inner surface of the capsule cap to form a liquid film; combining the capsule body filled with material and the capsule cap with the liquid film, and then heating until the capsule is properly sealed, thereby achieving the protection of the material inside the capsule by the inert gas. However, the aforementioned internal sealing method has several problems: (1) Due to the poor solubility of inert gas, the inert gas content in the sealing liquid is not high, and some inert gas will also be lost during the spraying process, resulting in even less inert gas content inside the capsule, which cannot play a good role in anti-oxidation of the material inside the capsule; (2) Due to the limitations of equipment technology and space, it is extremely difficult to achieve continuous and efficient production by spraying the sealing liquid containing inert gas in the form of a spray in actual production; (3) During the process of pre-spraying the sealing liquid inside the capsule cap and then sealing the capsule, it is easy to cause cross-contamination of the material inside the capsule; (4) The sealing reliability of the adhesive sealing method is poor, and the material is easy to be exposed. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method and system for filling and sealing liquid-filled hard capsules, so as to solve the problems of easy oxidation and contamination of materials and unreliable sealing when using internal sealing methods in existing liquid-filled hard capsules.

[0004] To achieve the above objectives, the present invention provides a method for filling and sealing a liquid-filled hard capsule, wherein the hard capsule comprises a capsule body and a capsule cap whose edges can overlap and fit together, and the method includes the following steps:

[0005] S1 Separate the capsule body and the capsule cap, fill the capsule body with material, and fill the capsule cap with inert gas, wherein the material contains at least liquid;

[0006] S2 combines the capsule cap and capsule body obtained in step S1 to obtain a liquid-filled capsule;

[0007] S3 injects adhesive into the fitting gap and applies pressure to the liquid-filled capsule. The negative pressure is used to fill the fitting gap with adhesive, and then the fitting gap is heated to achieve a seal.

[0008] Furthermore, the temperature of the inert gas introduced is in the range of 30℃-60℃.

[0009] Furthermore, the inflation rate in step S1 is in the range of 0.6 ml / s to 1.2 ml / s.

[0010] Furthermore, the capsule body and the capsule cap have different water contents, and between steps S2 and S3, the following steps are performed: the liquid-filled capsule is heated as a whole to cause the surfaces of both the capsule body and the capsule cap to lose water; the liquid-filled capsule after water loss is then cooled to generate an internal and external pressure difference; and then step S3 is performed.

[0011] Furthermore, the method for heating the liquid-filled capsule is as follows: the liquid-filled capsule is heated as a whole, so that the temperature inside and outside the liquid-filled capsule rises, and the gas inside is squeezed out from the fitting gap under the action of internal pressure.

[0012] Furthermore, the temperature for heating the liquid-filled capsule is 45°C to 80°C.

[0013] Furthermore, the temperature for cooling the liquid-filled capsule is 10°C to 30°C.

[0014] Furthermore, the moisture content difference between the capsule body and the capsule cap is 1% to 2%.

[0015] Furthermore, in step S1, the method for separating the capsule body and the capsule cap is as follows: the empty hard capsule is set vertically, with the capsule cap located above the capsule body, and then the capsule body and the capsule cap are separated vertically and arranged in a staggered manner.

[0016] According to another aspect of the invention, a liquid-filled hard capsule filling and sealing system for implementing the method described in any of the preceding claims is also disclosed, the system comprising: sequentially arranged in a ring-shaped configuration:

[0017] Separation module for separating the capsule body and capsule cap;

[0018] A filling module is used to fill the capsule with materials;

[0019] An inflation module is used to fill the capsule cap with inert gas;

[0020] The capsule assembly module is used to fit the filled capsule body and the capsule cap filled with inert gas to obtain a liquid-filled capsule.

[0021] The glue injection module is used to inject glue into the fitting gap of the liquid-filled capsule and apply pressure to the liquid-filled capsule at the same time, so as to fill the fitting gap with glue by using negative pressure.

[0022] A local heating module is used to heat the adhesive in the gaps of the filling capsule to achieve a seal; preferably, an overall heating module and a cooling module are arranged in sequence between the adhesive injection module and the local heating module. The overall heating module is used to heat the filling capsule as a whole so that the surfaces of the capsule body and the capsule cap lose water, and the cooling module is used to cool the filling capsule after water loss so that a pressure difference is generated between the capsule cap and the capsule body.

[0023] Compared with the prior art, the above technical solutions conceived by this invention have the following main advantages:

[0024] This invention ensures sufficient inert gas to protect the filling material within the capsule after sealing by filling the capsule cap with inert gas to purge the air inside before sealing it with the capsule body filled with material. Furthermore, filling the capsule cap with inert gas before sealing ensures that no other impurities are introduced into the sealed liquid-filled capsule, thus preventing contamination of the material. Then, a negative pressure injection method is used to inject adhesive only into the seam between the capsule cap and capsule body, preventing adhesive from entering the liquid-filled capsule and contaminating the material. Simultaneously, targeted heating of the adhesive-filled seam area achieves a tight connection and seal in the sealing area.

[0025] In this invention, the temperature of the inert gas is adjustable within the range of 30℃-60℃. Within this temperature range, the inert gas exhibits advantages such as high average kinetic energy of gas molecules, low intermolecular interaction forces, and a relatively fast nitrogen diffusion rate. Exceeding this temperature range can lead to excessive thermal deformation and damage to the capsule cap, as well as high energy consumption. Below this temperature range, the nitrogen diffusion rate decreases, and the available thermal energy is insufficient, preventing the generation of negative pressure due to temperature reduction and volume shrinkage during subsequent cooling processes.

[0026] In this invention, the inert gas inflation rate is between 0.6 ml / s and 1.2 ml / s to accommodate the volume of capsule caps of different specifications (00#, 0#, 1#, 2#, 3#, 4#). If the rate is too fast, there will be problems such as nitrogen gas flow pushing up the capsule shell and nitrogen overflow. If the rate is too slow, the capsule cap volume cannot be effectively filled, and it will not match the production rhythm of the whole machine.

[0027] The present invention also provides capsule bodies and capsule caps with different water contents. When the two are combined to obtain a liquid-filled capsule, the liquid-filled capsule is heated as a whole to raise both its internal and external temperatures. When its internal temperature rises, the pressure increases, which allows the gas inside the capsule to be squeezed out from the gap between the two, so that only the filling material remains inside the liquid-filled capsule, thus ensuring the purity of the filling material.

[0028] In this invention, when the liquid-filled capsule is heated and loses water as a whole, the capsule body and capsule cap with different water contents have different shrinkage rates during the heating process. Therefore, after heating and cooling, the capsule cap fits more tightly with the capsule body.

[0029] The encapsulation method of this invention is simple, quick, and highly feasible. It can achieve efficient encapsulation of large batches of hard capsules, and the encapsulation process will not introduce other contamination into the internal materials of the hard capsules, making it more suitable for large-scale industrial production. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a liquid-filled hard capsule filling and sealing method provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the process flow of a liquid-filled hard capsule filling and sealing method provided in an embodiment of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] This invention provides a method for filling and sealing a liquid-filled hard capsule. The hard capsule includes a capsule body and a capsule cap whose edges can overlap and fit together. The method includes the following steps:

[0034] S1 separates the capsule body and capsule cap vertically, fills the capsule body with material, and fills the capsule cap with inert gas, wherein the material contains at least liquid; specifically, multiple hard capsules are batch-loaded to the separation station, and the capsule body and capsule cap are separated by applying external forces in opposite directions, and the openings of the separated capsule body and capsule cap are misaligned and opposite, and then filled with inert gas or material respectively.

[0035] S2 combines the capsule cap and capsule body obtained in step S1 to obtain a liquid-filled capsule, specifically by mechanically combining the capsule cap and capsule body into one unit;

[0036] S3 injects adhesive into the fitting gap and applies pressure to the filling capsule at the same time. The negative pressure is used to fill the fitting gap with adhesive, and then the fitting gap is heated to achieve a seal.

[0037] In this embodiment, in step S1, the method for separating the capsule body and the capsule cap is as follows: the empty hard capsule is set vertically with the capsule cap above the capsule body, and then the capsule body and the capsule cap are separated vertically and staggered. This allows inert gas to be filled into the capsule cap from bottom to top, and the inert gas can better expel the air from the capsule cap.

[0038] In this embodiment, the temperature of the inert gas is within the range of 30℃-60℃, such as 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, 41℃, 42℃, 43℃, 44℃, 45℃, 46℃, 47℃, 48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, and 60℃. At these temperatures, the inert gas has the advantages of high average kinetic energy of gas molecules and low intermolecular interaction forces, and the diffusion rate of nitrogen is also relatively fast. If the temperature exceeds this range, there are disadvantages such as excessive thermal deformation and thermal damage to the capsule shell and high energy consumption. ； If the temperature is below this level, the nitrogen diffusion rate decreases and the thermal energy is insufficient, resulting in the inability to generate a negative pressure effect due to the decrease in temperature and volume during subsequent cooling processes.

[0039] In this embodiment, the inflation rate in step S1 is within the range of 0.6 ml / s to 1.2 ml / s, such as 0.6 ml / s, 0.7 ml / s, 0.8 ml / s, 0.9 ml / s, 1.0 ml / s, 1.1 ml / s, 1.2 ml / s, etc. If the inflation rate is too fast, there is a risk of the capsule shell being pushed up, causing nitrogen to overflow. If the rate is too slow, the capsule cap volume cannot be effectively filled, the filling amount is insufficient, and it does not match the production cycle of the whole machine.

[0040] In this embodiment, preferably, the volume of inert gas filled into the capsule cap is 1.2 times the volume of the capsule cap, so that the air inside the capsule cap can be completely expelled by the filled inert gas, and the amount of inert gas used can be saved.

[0041] Specifically, nitrogen is preferred as the inert gas, but other inert gases such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), or radon (Rn) can also be used.

[0042] In a preferred embodiment, the capsule body and capsule cap have different water contents, and the following steps are performed between steps S2 and S3: the liquid-filled capsule is heated as a whole to cause the surfaces of both the capsule body and capsule cap to lose water to generate a pressure difference; the liquid-filled capsule after water loss is cooled, and then step S3 is performed.

[0043] Specifically, the preparation method of the capsule body and capsule cap adopts conventional methods. It is only necessary to ensure that the moisture content of the capsule body and capsule cap meets the requirements of this embodiment. For example, the moisture content of the capsule body is 14%, and the moisture content of the capsule cap is 15% or 16%, or any moisture content value between 15% and 16%.

[0044] A further preferred method for heating the liquid-filled capsule as a whole is to heat the entire liquid-filled capsule, raising the temperature both inside and outside the capsule, and causing the internal gas to be squeezed out from the sealing gap under internal pressure, thereby ensuring the purity of the material inside the liquid-filled capsule and avoiding contamination.

[0045] Specifically, the liquid-filled capsule is placed in a high-temperature environment, raising the temperature of both the inside and outside of the capsule. Under pressure, the inert gas inside is released from the gaps in the capsule, leaving only the filling material inside, unaffected by any other substances.

[0046] More preferably, the aforementioned heating temperature for the liquid-filled capsule is between 45°C and 80°C. That is, the high-temperature environment provided by the overall heating module can be any one of the following temperatures: 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, and 80°C, or the high-temperature environment can be between any two of the above temperatures, thereby achieving stable water loss and shrinkage of the liquid-filled capsule.

[0047] Further preferably, the cooling temperature of the liquid-filled capsule is between 10°C and 30°C, such as any one of the following temperatures: 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, or between any two of the aforementioned temperatures, so that a pressure difference is generated inside and outside the liquid-filled capsule, resulting in a tighter fit.

[0048] Furthermore, the moisture content difference between the capsule body and the capsule cap should be 1% to 2%, such as the moisture content of the capsule body being 1%, 1.5%, or 2% less than that of the capsule cap. Specifically, this difference in moisture content can be achieved by controlling the thickness of the capsule shell. For example, if the adhesive coating thickness of the capsule cap is 0.01mm-0.02mm greater than that of the capsule body, after the same drying process, the moisture content of the capsule cap will be 1%-2% higher than that of the capsule body. If the moisture difference between the capsule body and the capsule cap is too large, the tolerance fitting gap of the cap will be very unstable, which will cause poor pre-locking of the capsule body and the capsule cap (because the hollow capsule shell is transported together after the capsule cap and the capsule body are pre-fitted, which can avoid deformation when the capsule cap and the capsule body are transported separately). During the later drying process, a large moisture content will lead to excessive shrinkage and deformation, causing permanent deformation or even cracks between the capsule body with excessive shrinkage and the capsule cap with normal shrinkage due to excessive locking force, which is actually detrimental to capsule sealing.

[0049] Specifically, when the capsule cap is placed on the outside of the capsule body, the moisture content of the capsule body is 1% to 2% lower than that of the capsule cap. This allows the capsule cap to shrink more than the capsule body, thus securing it tightly to the capsule body. If the capsule cap is placed on the inside of the capsule body, the moisture content of the capsule body is 1% to 2% higher than that of the capsule cap. This also allows the capsule body to shrink more than the capsule cap, resulting in a tighter fit between the two.

[0050] According to another aspect of the invention, a liquid-filled hard capsule filling and sealing system for implementing any of the preceding methods is also disclosed, the system comprising: sequentially arranged in a ring-shaped configuration:

[0051] Separation module for separating the capsule body and capsule cap;

[0052] A filling module is used to fill the capsule with materials;

[0053] An inflation module is used to fill the capsule cap with inert gas;

[0054] The capsule assembly module is used to fit the filled capsule body and the capsule cap filled with inert gas to obtain a liquid-filled capsule.

[0055] The glue injection module is used to inject glue into the fitting gap of the liquid-filled capsule and apply pressure to the liquid-filled capsule at the same time, using negative pressure to make the glue fill the fitting gap.

[0056] A local heating module is used to heat the adhesive liquid in the gaps of the filling capsule to achieve a seal.

[0057] Specifically, in the above system, the separation module, filling module, inflation module, capsule sealing module, and glue injection module are all located on a rotating base. As the rotating base rotates, a carrier assembly for loading hard capsules can sequentially pass through the separation module, filling module, inflation module, capsule sealing module, and glue injection module to complete the multi-station filling and sealing operation of the hard capsules.

[0058] In this embodiment, an overall heating module and a cooling module are sequentially arranged between the glue injection module and the local heating module. The overall heating module is used to heat the liquid-filled capsules as a whole, so that the surfaces of the capsule body and the capsule cap lose water. The cooling module is used to cool the liquid-filled capsules after water loss, so that a pressure difference is generated between the capsule cap and the capsule body. Specifically, the overall heating module is a temperature-adjustable drying tunnel. A row of hard capsules that have undergone glue injection are sent into the drying tunnel at a specific temperature to heat and shrink after water loss. The cold zone module is another temperature-adjustable cooling channel that is lower than the drying tunnel. After cooling, the hard capsules will fit together more tightly due to the internal and external pressure difference.

[0059] To better illustrate the implementation details of the present invention, the following embodiments are provided to further illustrate the present invention. It should be understood that the following embodiments are only preferred implementation methods and are not intended to limit the scope of protection of the present invention in any way.

[0060] Example 1

[0061] In this embodiment, capsule bodies and capsule caps with the same water content are used, and both the capsule body and capsule cap are made of gelatin. Figure 2 As shown, the filling and sealing steps include:

[0062] (1) Capsule loading: The rows of empty hard capsules are transported to the separation station;

[0063] (2) Separation: Separate the capsule cap and capsule body vertically and arrange them in a staggered manner;

[0064] (3) Inspection: Check for any empty capsules that have not been completely separated and remove any capsules that have not been completely separated;

[0065] (4) Fill with liquid, and then fill the capsule with a composite formulation consisting of oil and microcapsules; in other embodiments, the liquid, microcapsules, microsheets or microcapsules at station 4-5 in the figure can be filled in any combination.

[0066] (5) Nitrogen filling: continuously fill the capsule cap with nitrogen gas at 40°C at a filling rate of 0.8 ml / s until it is full;

[0067] (6) Capsule assembly: The capsule cap filled with nitrogen and the capsule body filled with the compound preparation are assembled to obtain a liquid-filled capsule. The assembly method is mechanical assembly, that is, after aligning the opening ends of the capsule cap and the capsule body, the capsule cap and the capsule body are controlled to move closer together vertically to achieve assembly.

[0068] (7) Remove the capsules and send the filled capsules to the distribution station for arrangement.

[0069] (8) Then inject adhesive into the gaps between the capsule caps and capsule bodies, and apply pressure to the filled capsules. Use negative pressure to fill the gaps with adhesive, and then heat the adhesive to achieve a seal. Specifically, when the row of capsules passes through the adhesive injection module, there are several rows of rollers at the bottom of the module. The edges of the rollers are provided with absorbent and soft material. The rollers can rotate in the adhesive below them. The adhesive used in this embodiment can be in various forms, including but not limited to liquid paraffin, ethanol solution, etc. When the side of the roller that has absorbed the sealing adhesive rotates to the top, it can contact the gaps of the capsules that can be transported to it. Apply pressure to the top of the capsule cap and control the adhesive in the edge of the roller to be discharged. At the same time, use capillary and negative pressure to make the adhesive fully enter all the gaps between the capsule body and the capsule cap.

[0070] (9) The heat-conducting sheet is then used to conduct local heat to the joint between the capsule cap and the capsule body, so that the sealing liquid reacts with the gelatin material used in the capsule body and capsule cap, and the gelatin sticks together to achieve a tight bond. Finally, the tightly bonded rows of capsules are dried by natural air blowing to form a sealed capsule product.

[0071] To verify the sealing performance of the capsule products, a sealing test can be performed at the inspection station. The specific testing method is as follows: during the transport of the sealed capsule products, safety agent powder is sprinkled onto them, and then an appropriate amount of wind and vibration is applied to the sealed capsules. If there is oil leakage inside the capsule, the oil will adhere to the safety agent powder, and the safety agent powder will not fall off completely during vibration. Then, the sealing performance of each capsule is judged by a visual camera, and capsules that are not properly sealed are removed using a mechanical structure.

[0072] Example 2

[0073] In this embodiment, capsule bodies and capsule caps with moisture contents of 14% and 16%, respectively, are used. Figure 2 Compared to Example 1, this example has more features. Figure 2 The overall heating, dehydration, and cooling steps are shown. Specific encapsulation steps include:

[0074] First, the capsules are loaded, and the multi-empty hard capsules are transported to the separation station. The capsule caps and capsule bodies are separated and staggered. Then, the capsule bodies are filled with a composite formulation consisting of oil and microparticles, while nitrogen gas at 60°C is filled into the capsule caps at an inflation rate of 1.2 ml / s. Finally, the capsule caps and capsule bodies are aligned and fitted together.

[0075] The multiple rows of liquid-filled capsules are then sent into a heating tunnel at a temperature of 45°C for overall heating, so that the capsule body and capsule cap surfaces lose water to varying degrees. The dehydrated liquid-filled capsules are then sent into a cooling channel at a temperature of 10°C for cooling, so that the temperature inside the capsule decreases and the pressure decreases, making the capsule cap more tightly clamp the capsule body, and creating a pressure difference between the inside and outside of the liquid-filled capsule, thus achieving a tight fit.

[0076] Next, the glue is injected into the joint, and pressure is applied to the liquid-filled capsule. The negative pressure is used to fill the joint with glue. Then, the joint is locally heated to achieve a seal. The sealed capsule is then air-dried naturally.

[0077] One thousand samples were taken from fish oil capsules packaged using conventional methods, and then another thousand capsules were taken from fish oil capsules obtained by filling the capsule cap with nitrogen as provided in this invention. As shown in Table 2, 99.9% of the fish oil capsules packaged using the nitrogen filling method did not show obvious oxidation discoloration, while all the fish oil capsules prepared by the conventional method showed oxidation discoloration and did not meet the packaging requirements.

[0078] Table 1 Comparison of capsule product yields obtained by conventional packaging methods and the packaging method of this invention.

[0079]

[0080] Four samples were randomly selected from capsule products obtained using conventional methods, each containing 10,000 capsules. Four more samples were selected from capsule products obtained using the method of this invention, which involves different moisture contents in the capsule body and cap, and nitrogen gas purging. Each sample also contained 10,000 capsules, and each sample contained capsules of different sizes and specifications (0#, 1#, 2#, and 3#). As shown in Table 2, a significant difference in the sealing yield was observed between capsule products sealed using conventional methods and those sealed using methods that differentiated the moisture content of the capsule body. For every 10,000 capsules, the yield of capsules sealed using the method of this invention exceeded 99.8%, while the yield of capsules sealed using conventional methods was below 99.6%.

[0081] Table 2 Comparison of capsule product yields obtained by conventional packaging methods and the packaging method of this invention.

[0082]

[0083] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0085] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of filling and sealing a liquid-filled hard capsule comprising a capsule body and a capsule cap whose edges can be mutually overlapped to fit together, characterized in that, The method comprises the following steps: S1: separating the capsule body and the capsule cap, filling the capsule body with material, and filling the capsule cap with inert gas, wherein the material comprises at least liquid; S2: fitting the capsule cap and the capsule body obtained in step S1 to obtain a liquid-filled capsule, wherein the water content of the capsule body and the capsule cap is different; heating the liquid-filled capsule as a whole to make the surfaces of the capsule body and the capsule cap lose water; and cooling the liquid-filled capsule after losing water to generate an internal and external pressure difference; S3: injecting glue into the fitting gap while applying pressure to the liquid-filled capsule, using negative pressure to make the glue fill the fitting gap, and then heating the glue to achieve sealing.

2. A method of filling and sealing a liquid filled hard capsule as claimed in claim 1, wherein, The temperature of the inert gas filled in is in the range of 30-60°C.

3. A method of filling and sealing a liquid filled hard capsule as claimed in claim 1, wherein, The filling rate in step S1 is in the range of 0.6-1.2 ml / s; and the volume of the inert gas filled in the capsule cap is 1.2 times the volume of the capsule cap.

4. A method of filling and sealing a liquid filled hard capsule as claimed in claim 1, wherein, The method for heating the liquid-filled capsule as a whole is to heat the liquid-filled capsule as a whole to make the internal and external temperature of the liquid-filled capsule rise, and make the internal gas of the liquid-filled capsule extrude from the fitting gap under the action of internal pressure.

5. A liquid filled hard capsule filling and sealing process according to claim 4, wherein, The heating temperature of the liquid-filled capsule is 45-80°C.

6. A method of filling and sealing a liquid filled hard capsule as claimed in claim 1, wherein, The cooling temperature of the liquid-filled capsule is 10-30°C.

7. A method of filling and sealing a liquid filled hard capsule as claimed in claim 1, wherein, The difference of the water content of the capsule body and the capsule cap is 1-2%.

8. A method of filling and sealing a liquid filled hard capsule as claimed in claim 1, wherein, In step S1, the method for separating the capsule body and the capsule cap is to vertically arrange the empty hard capsule, and the capsule cap is above the capsule body, then the capsule body and the capsule cap are separated and arranged in a staggered manner.

9. A liquid-filled hard capsule filling and sealing system for implementing the method according to any one of claims 1-8, which comprises the following modules arranged in sequence in a ring shape: a separation module for separating the capsule body and the capsule cap; a filling module for filling the capsule body with material; a gas filling module for filling the capsule cap with inert gas; a capsule fitting module for fitting the capsule body filled with material and the capsule cap filled with inert gas to obtain a liquid-filled capsule; a glue injection module for injecting glue into the fitting gap of the liquid-filled capsule while applying pressure to the liquid-filled capsule, using negative pressure to make the glue fill the fitting gap; a local heating module for heating the glue in the fitting gap of the liquid-filled capsule to achieve sealing; and a whole heating module and a cooling module arranged in sequence between the glue injection module and the local heating module, the whole heating module is used to heat the liquid-filled capsule as a whole to make the surfaces of the capsule body and the capsule cap lose water, and the cooling module is used to cool the liquid-filled capsule after losing water to generate a pressure difference between the capsule cap and the capsule body.

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