Thermos cup sealing process: the key to protecting every drop of temperature
In today's fast-paced life, thermos cups have become one of people's daily necessities. Whether it is office workers, students, or outdoor enthusiasts, they cannot do without the company of thermos cups. The sealing process of thermos cups, as a key link in its production process, is directly related to the insulation performance, service life and overall quality of the thermos cup. This article will explore the sealing process of thermos cups in depth, leading readers to understand this seemingly simple but profound technical field.
1. The importance of sealing process
The sealing process of thermos cups is the core step to achieve its insulation function. Thermos cups are usually composed of two layers, inner and outer, with a vacuum interlayer in the middle to achieve the effect of blocking heat transfer. The quality of the sealing process directly determines the airtightness and stability of the vacuum interlayer. If the seal is not tight, air will gradually penetrate into the vacuum interlayer, destroying the insulation effect and shortening the service life of the thermos cup. At the same time, the sealing process also affects the overall structural strength and appearance quality of the thermos cup, and is one of the important criteria for measuring the quality of the thermos cup.
2. Common sealing process methods
Welding sealing
Laser welding sealing: Laser welding uses a high-energy-density laser beam as a heat source to melt the sealing material of the thermos cup to achieve a sealed connection. This method has the advantages of fast welding speed, small heat-affected area, and high welding quality. In the production of thermos cups, laser welding sealing can accurately weld the cup mouth and the cup lid or the cup body and the cup bottom to ensure the sealing and firmness of the seal. For example, some high-end brands of stainless steel thermos cups usually use laser welding sealing technology at the connection between the cup lid and the cup mouth, so that the thermos cup can still maintain good sealing performance under frequent opening and closing, effectively preventing liquid leakage.
Electron beam welding sealing: Electron beam welding is a technology that uses the kinetic energy of an electron beam to convert into heat energy for welding in a vacuum environment. Compared with laser welding, electron beam welding can provide higher energy density and can penetrate the material more deeply, so it performs well in the sealing welding of some thick-walled thermos cups. Its welding quality is stable, deformation is small, and it can achieve welding of dissimilar metal materials. However, due to the high cost of electron beam welding equipment and the need to operate under vacuum conditions, it is relatively rare in actual applications. However, in special scenarios where the quality requirements of thermos cups are extremely high, such as thermos cups used in aerospace, military and other fields, electron beam welding sealing technology has become the first choice.
Brazing seal
Brazing seal: Brazing usually uses brazing filler metals with a melting point higher than 450°C, such as silver-based, copper-based and other alloys. When sealing the thermos cup, the brazing filler metal is placed in the sealing part, heated to melt the brazing filler metal, and filled into the gap of the seal to form a firm welded joint. Brazing seals have strong load-bearing capacity and good heat resistance, and are suitable for some occasions with high requirements for the strength and heat resistance of thermos cups. For example, some large-capacity outdoor thermos kettles may use brazing technology for their sealing parts to ensure that they can withstand certain pressure and temperature changes in complex outdoor environments without loosening or leaking seals.
Soldering seal: The melting point of the solder used in soldering is lower than 450℃, and the common ones are tin-lead alloy, tin-silver alloy, etc. Soldering seal is relatively simple and low-cost, but its strength and heat resistance are not as good as hard soldering. Soldering seal may be used in some small thermos cups or sealing parts that do not require particularly high strength, such as the connection between the sealing ring inside the cup lid and the cup lid. However, when using soldering seal, it is necessary to pay attention to controlling the soldering temperature and time to avoid excessive heating that causes the solder to be lost or damage other parts of the thermos cup.
Ultrasonic welding seal
Ultrasonic welding uses high-frequency vibration ultrasonic energy to make the plastic or metal materials at the sealing part of the thermos cup rub against each other to generate heat, thereby achieving fusion or welding. This welding method has the advantages of fast speed, low energy consumption, no open flame, and environmental protection. Ultrasonic welding seals are widely used in the sealing of plastic parts of thermos cups, such as the assembly process of some thermos cups with plastic shells or plastic accessories. It can quickly seal and weld the plastic shell with the cup body or other plastic parts to ensure the integrity and sealing of the product. At the same time, ultrasonic welding seals can effectively reduce the deformation and warping of plastic materials during welding and improve the appearance quality of the product.
Mechanical seals
Pressing seals: Pressing seals are to press the sealing parts of the thermos cup tightly together through mechanical pressure to form a sealed connection. For example, in the connection between the cup cover and the cup body of the thermos cup, some use thread pressing seals. By rotating the cup cover, the threads on the cup cover and the cup body are engaged with each other. Under the action of mechanical pressure, the sealing ring on the cup cover is compressed to achieve sealing. The advantages of pressing seals are simple structure, easy operation, low cost, and users can disassemble and install them as needed. However, its sealing performance depends to a certain extent on the quality of the sealing ring and the correctness of installation. If the sealing ring is aged or damaged, the sealing effect of the thermos cup may decrease.
Riveting seals: Riveting seals are to fix the sealing parts of the thermos cup together using connectors such as rivets. The riveting sealing process may be used at the bottom of some thermos cups or the connection between the cup body and the cup lid. The riveting seal is firm and reliable and can withstand large tension and pressure, but it may have a certain impact on the appearance of the riveted parts, such as leaving traces of rivets. Therefore, in some thermos cup designs that have high requirements for product appearance, the riveting seal may be combined with other sealing processes to achieve the effect of both ensuring sealing performance and taking into account aesthetics.
3. Key elements of the sealing process
Material selection
The material selection of the sealing part of the thermos cup is crucial. For welding seals, it is necessary to select suitable solder or brazing material according to the characteristics of the cup body material and the requirements of the welding process. For example, in the laser welding seal of a stainless steel thermos cup, a welding wire that matches the stainless steel material is usually selected to ensure the strength and corrosion resistance of the joint after welding. At the same time, the quality of the solder or brazing material must also meet the relevant standards to avoid containing harmful substances to ensure the safety of the product. For mechanical seals, the material selection of seals such as sealing rings is also critical. The sealing ring is generally made of food-grade silicone rubber, rubber and other elastic materials. These materials need to have good heat resistance, cold resistance, aging resistance and elasticity to meet the use requirements of the thermos cup in different environments and maintain good sealing performance for a long time.
Welding parameter control
In the process of welding and sealing, accurate welding parameter control is the key to ensuring the quality of sealing. Taking laser welding as an example, parameters such as welding power, welding speed, spot diameter, and shielding gas flow rate will affect the welding effect. Too high laser power may cause the material to overheat and burn through, while too low power will cause incomplete welding and the phenomenon of cold welding. The speed of welding will also affect the size and cooling speed of the welding pool, and then affect the performance of the welded joint. Therefore, when welding and sealing, it is necessary to accurately adjust the welding parameters according to the specific material, size and structure of the thermos cup through experiments and experience accumulation to achieve the best welding sealing quality.
Environmental control
The sealing process has certain requirements for environmental conditions. During the welding process, it is necessary to keep the working environment clean to prevent dust, oil and other impurities from entering the welding pool or the sealing part to avoid affecting the welding quality and sealing performance. For some welding and sealing processes carried out in a vacuum environment, such as electron beam welding, the vacuum degree needs to be strictly controlled to ensure the stability of the welding process and the welding quality. In addition, factors such as temperature and humidity will also affect some sealing processes. For example, ultrasonic welding is sensitive to ambient temperature and humidity. Too high or too low temperature and humidity may cause welding equipment failure or welding quality degradation. Therefore, corresponding environmental control measures need to be taken to create a suitable sealing process environment.
Quality Inspection
Strict sealing quality inspection is the last line of defense to ensure that the thermos cup products are qualified and shipped out of the factory. Common sealing quality inspection methods include visual inspection, air tightness inspection, water pressure inspection, etc. Visual inspection can intuitively observe whether there are surface defects such as cracks, pores, welding slag, etc. in the sealing part, and whether the seal is complete and flat. The air tightness test is to judge the sealing performance of the sealing part by placing the thermos cup in a sealed detection device, applying a certain pressure, and observing the pressure changes. The water pressure test is to apply water pressure to the inside of the thermos cup to check whether there is water leakage in the sealing part. By conducting strict quality inspections on the thermos cup after each sealing process and promptly discovering and handling sealing quality problems, the product's qualification rate and quality stability can be effectively improved, providing consumers with reliable thermos cup products.
4. Development trend of sealing process
Intelligence and automation
With the continuous advancement of science and technology, the sealing process of thermos cups is developing in the direction of intelligence and automation. In automated production lines, the application of technologies such as robot welding and automated assembly is becoming more and more extensive. These technologies can not only improve production efficiency and reduce errors and unstable factors caused by manual operation, but also realize precise control and real-time monitoring of sealing process parameters. For example, in the production workshops of some large thermos cup manufacturers, robots are used for laser welding and sealing. By programming and controlling the robot's movements and welding parameters, 24-hour uninterrupted production can be achieved, and the welding quality is stable and consistent. At the same time, intelligent testing equipment can also automatically perform quality inspection on the sealed thermos cup, and feed back the test results to the production system to achieve closed-loop control of the production process, further improving product quality and production efficiency.
Environmental protection and energy saving
Today, with the increasing awareness of environmental protection, the sealing process of thermos cups is also constantly exploring ways to protect the environment and save energy. On the one hand, the research and development of sealing materials pays more attention to environmental protection performance, reduces or eliminates solders and fluxes containing heavy metals and harmful substances, and promotes the use of environmentally friendly sealing materials such as lead-free and cadmium-free. On the other hand, in the sealing process, energy consumption can be reduced by optimizing the process flow, adopting energy-saving equipment and heating methods. For example, in vacuum welding sealing, efficient vacuum pumps and heating systems are used to reduce vacuuming time and heating energy consumption; in ultrasonic welding sealing, new ultrasonic welding equipment is developed to improve energy conversion efficiency and reduce equipment operating power. These measures not only meet the requirements of sustainable development, but also help reduce production costs and improve the market competitiveness of enterprises.
Multifunctional sealing and integration
The future thermos cup sealing process may be combined with other functional designs of the product to achieve multifunctional sealing and integration. For example, smart sensors or electronic components are integrated in the sealing part of the thermos cup to enable it to have functions such as temperature monitoring, leakage alarm, and Bluetooth connection. By reserving corresponding interfaces and spaces in the sealing part, these smart components are integrated with the cup body, which can not only provide consumers with a more convenient and personalized use experience, but also expand the product functions and application areas of the thermos cup. At the same time, the design of multifunctional sealing also needs to consider how to achieve collaborative work and reliable connection between various functional components under the premise of ensuring sealing performance, which puts higher requirements and challenges on the sealing process technology.
Integration of new materials and new processes
With the continuous emergence of new materials and the research and development and innovation of new processes, the sealing process of thermos cups will be deeply integrated with these new materials and new processes to provide support for the improvement of product performance and product upgrading. For example, the application of some new composite materials, nanomaterials, etc. in the manufacture of thermos cups may give rise to new sealing process methods that are adapted to them. These new materials have unique physical and chemical properties, such as high strength, high thermal conductivity, good corrosion resistance, etc. It is necessary to develop a sealing process that can give full play to their performance advantages, so as to achieve a comprehensive upgrade of the thermos cup in terms of thermal insulation performance, service life, safety, etc. At the same time, the application of new processes may also affect the material selection and structural design of the sealing part, thereby promoting the technological innovation and development of thermos cup products.
5. Comparison of sealing processes for thermos cups
| Process methods | Advantages | Disadvantages | Scope of application |
| --- | --- | --- | --- |
| Laser welding sealing | Fast speed, small heat impact, high quality | High equipment cost, high requirements for operation precision | Sealing of lid and mouth of stainless steel thermos cups, etc. |
| Electron beam welding sealing | High energy density, good welding quality | Need to operate in a vacuum environment, high equipment cost | Sealing of thick-walled thermos cups and thermos cups in special fields |
| Brazing sealing | High strength and good heat resistance | High brazing temperature and high cost | Sealing of thermos cups with high requirements for strength and heat resistance |
| Soft soldering sealing | Easy operation and low cost | Poor strength and heat resistance | Simple sealing parts of small thermos cups |
| Ultrasonic welding sealing | Fast speed, low energy consumption, environmental protection | Limited applicability to welding of certain materials | Plastic parts sealing of thermos cup |
| Press-fit sealing | Simple structure, easy operation, low cost | Sealing performance depends on the quality of the sealing ring | The lid of the thermos cup is connected to the cup body |
| Riveted sealing | Strong and reliable connection | May affect the appearance | The bottom or body of the thermos cup is connected to the lid |
6, how to choose a suitable sealing process
Clear product positioning and demand
First, it is necessary to clarify the product positioning and target market demand of the thermos cup. If it is some high-end business thermos cups, usually the quality, appearance and performance of the product are high, and advanced process methods such as laser welding sealing or electron beam welding sealing may be preferred to ensure the high-end quality and good sealing performance of the product. If it is some low-cost, disposable thermos cups, relatively simple processes such as soldering sealing or press-fit sealing may be used to reduce costs.
Consider material properties and structural characteristics
Choose the sealing process according to the material properties and structural characteristics of the thermos cup. For example, for thermos cups made of stainless steel, laser welding and brazing are common choices, because stainless steel has good weldability and strength, which can meet the requirements of these welding processes. For thermos cups made of plastic, ultrasonic welding or hot melt sealing is more suitable. At the same time, the structural design of the thermos cup will also affect the choice of sealing process, such as the connection method between the cup lid and the cup body, the shape and size of the sealing part, etc., all need to be comprehensively considered to match the sealing process.
Evaluate process cost and production efficiency
Process cost and production efficiency are factors that cannot be ignored when choosing a sealing process. Different sealing processes differ in equipment investment, material cost, labor cost, etc. For example, laser welding sealing equipment has a high cost, but fast welding speed and high production efficiency, which is suitable for large-scale production; while soft soldering sealing equipment is relatively simple and low cost, but has low production efficiency, which is suitable for small batch production. Therefore, when choosing a sealing process, it is necessary to evaluate and compare the cost and efficiency of different processes according to the production scale and cost budget of the enterprise, and choose the sealing process that best suits the enterprise itself.
Pay attention to the reliability and stability of the process
The reliability and stability of the sealing process are directly related to the consistency and stability of product quality. When choosing a sealing process, you need to fully understand the technical maturity and stability of the process. Some mature sealing processes have been verified by long-term practice and have high reliability and stability, such as laser welding sealing and press-fit sealing, which can ensure the stability of product quality under normal production conditions. For some emerging sealing processes or technologies, although they may have potential advantages, they need to be carefully considered when choosing whether their reliability and stability can meet the production requirements of the enterprise to avoid product quality problems and increased production costs due to unstable processes.
7. Application cases of thermos cup sealing process in actual production
Sealing process application of well-known thermos cup brand A
In the sealing process of its high-end series of products, the well-known thermos cup brand A adopts a combination of advanced laser welding sealing technology and electron beam welding sealing technology. At the sealing part of the cup lid and the cup mouth, the laser welding sealing process is used to ensure the tight combination of the cup lid and the cup mouth, effectively prevent liquid leakage, and at the same time ensure the smoothness and flatness of the cup mouth, improving the appearance quality of the product. At the sealing part of the cup body and the bottom of the cup, the electron beam welding sealing process is used to ensure the firm connection and sealing performance between the cup body and the bottom of the cup under high temperature vacuum environment. Through the application of these two advanced sealing processes, the thermos cup of brand A has excellent performance in terms of thermal insulation performance, service life and product quality, and has won wide acclaim from consumers and high recognition from the market.
Sealing process innovation practice of thermos cup manufacturer B
In order to improve production efficiency and reduce production costs, thermos cup manufacturer B has carried out a series of innovative practices in sealing technology. They introduced automated ultrasonic welding sealing equipment for the sealing assembly of the plastic shell and the cup body of the thermos cup. By optimizing ultrasonic welding parameters and designing reasonable welding molds, the rapid and efficient welding and sealing of plastic parts are achieved, the welding speed is increased by more than 30%, and the sealing defect rate of the product is reduced by 20%. In addition, manufacturer B has also improved the traditional press-fit sealing process. In the press-fit sealing of the cup lid and the cup body, a new sealing ring material and structural design are used. Combined with automated assembly equipment, the sealing performance of the cup lid is more reliable and the service life is extended by 1.5 times. Through the innovative practice of these sealing processes, manufacturer B stands out in the fierce market competition, not only reducing production costs and improving production efficiency, but also enhancing the market competitiveness of products and achieving sustainable development of the enterprise.
8. Common problems and solutions for the sealing process of thermos cups
Welding quality problems
Poor welding and leaking welding: may be caused by improper welding parameter settings, insufficient solder or brazing material, and unclean surface of welding parts. Solutions include accurately adjusting welding parameters, such as laser power, welding speed, current size, etc.; ensuring sufficient supply of solder or brazing material, and evenly applying or placing it on the welding part; strengthening cleaning work before welding, and strictly removing oil, rust and dirt from the welding parts to ensure the cleanliness and finish of the welding surface.
Welding deformation problem: During the welding and sealing process, excessive welding temperature or uneven heating may cause the cup body or sealing parts of the thermos cup to deform, affecting the appearance and sealing performance of the product. To solve this problem, measures such as optimizing the welding sequence, controlling the welding heat input, and using appropriate welding fixtures and tooling can be adopted to reduce welding deformation. For example, when welding a stainless steel thermos cup, a welding sequence such as segmented welding and back-welding method is adopted to control the heat input of each layer of welding, and a special welding fixture is used to fix the cup body to limit the occurrence of welding deformation.
Poor sealing performance problem
Aging and damage of the sealing ring: During long-term use, the sealing ring is affected by factors such as temperature, humidity, and ultraviolet rays, and is prone to aging, cracking, deformation, and other problems, resulting in a decrease in sealing performance. The solution is to use high-quality, aging-resistant, high and low temperature resistant food-grade silicone rubber or EPDM materials in the selection of sealing ring materials, and reasonably increase the compression of the sealing ring and the structural design of the sealing lip in the product design to improve the sealing effect and service life of the sealing ring. At the same time, it is recommended that users replace the sealing ring regularly to ensure the sealing performance of the thermos cup.
Unreasonable design of the sealing part: If there are defects in the structural design of the sealing part, such as too large sealing gap and irregular sealing shape, it will also lead to poor sealing performance. In the product design stage, the sealing performance of the sealing part should be fully considered, and the sealing path and sealing area of the sealing should be increased by optimizing the sealing structure design, such as adopting multi-channel sealing, labyrinth sealing and other structural forms, to improve the sealing reliability of the sealing. At the same time, the sealing structure is simulated and analyzed and optimized by using technical means such as computer-aided design (CAD) and finite element analysis (FEA) to ensure the rationality of the design of the sealing part.
Environmental adaptability issues
Temperature changes affect the sealing quality: When the thermos cup is used in different temperature environments, due to the thermal expansion and contraction characteristics of the material, the sealing part may become loose and cracked, affecting the sealing performance of the seal. In order to improve the environmental adaptability of the sealing part of the thermos cup, a combination of materials with similar thermal expansion coefficients can be used in material selection to reduce the relative displacement and stress concentration of materials caused by temperature changes. At the same time, in the sealing process, appropriate compensation measures are adopted, such as reserving a certain amount of shrinkage in the welding seal, adding elastic elements in the mechanical seal, etc., to adapt to the impact of temperature changes on the sealing part.
Humidity and corrosive environment affect the durability of the seal: In a high humidity or corrosive environment, the sealing part of the thermos cup is easily eroded by moisture and corrosive media, resulting in corrosion and rust of the sealing material, reducing the strength and sealing performance of the seal. To address this problem, special anti-corrosion treatment can be performed on the sealing part, such as coating, coating with anti-corrosion coating, using corrosion-resistant materials such as stainless steel or titanium alloy, etc., to improve the corrosion resistance of the sealing part. At the same time, in product design, try to avoid gaps and grooves in the sealing part, which are easy to accumulate water and corrosive media, to reduce the risk of corrosion.
9. Future Prospects of Thermos Cup Sealing Technology
With the continuous advancement of science and technology and the growing demand of consumers, the sealing technology of thermos cups will usher in a broader development space and more innovation opportunities. The future sealing technology of thermos cups will not only be limited to existing technical means, but will integrate more cutting-edge technologies and new materials to achieve more efficient, reliable, environmentally friendly and intelligent sealing solutions.
On the one hand, emerging technologies such as nanotechnology and micro-electromechanical systems (MEMS) technology will be applied in the sealing technology of thermos cups. For example, by using the special properties of nanomaterials, sealing materials with self-repairing and self-sealing functions are developed. When tiny cracks or damage appear in the sealing part, they can automatically repair and restore the sealing performance of the sealing, thereby extending the service life of the thermos cup. At the same time, MEMS technology can be used to manufacture micro sensors and micro actuators, which can be integrated into the sealing part of the thermos cup to realize real-time monitoring and intelligent control of the sealing state, providing consumers with a safer and more convenient use experience.
On the other hand, as people's attention to environmental protection and sustainable development continues to increase, green and environmentally friendly sealing processes and materials will become the mainstream of future development. The development and application of degradable and recyclable sealing materials, as well as the use of sealing equipment and processes driven by clean energy, will help reduce environmental pollution and resource waste in the production process of thermos cups, and promote the development of the thermos cup industry in a green, low-carbon and environmentally friendly direction.
In short, as a key link in the production and manufacturing of thermos cups, the development and innovation of thermos cup sealing technology will directly affect the quality, performance and market competitiveness of thermos cup products. Through in-depth research and continuous exploration of the sealing process, we have reason to believe that the future thermos cup sealing process will bring consumers more high-quality, reliable and intelligent thermos cup products, meet people's use needs in different scenarios, and continue to play an important role in our daily lives, guarding every drop of temperature and delivering warmth and care.