Pre-vacuum cleaning machine: The cutting-edge technology for precise cleaning

I. Introduction

In modern industrial production and scientific research fields, the requirements for the cleanliness of components and materials are becoming increasingly strict. Whether it is semiconductor manufacturing, precision optical device processing, or the production of aerospace components, residual contaminants can have a significant impact on product performance and quality. As an advanced cleaning device, the pre-vacuum Cleaning machine significantly enhances the cleaning effect by creating a vacuum environment before cleaning, and has become an indispensable key equipment in many high-end manufacturing and scientific research scenarios. This article will provide a comprehensive and in-depth elaboration on the definition, working principle, structural composition, core technologies, application fields, advantages, challenges and future development trends of the pre-vacuum cleaning machine.

Ii. Definitions and Basic Concepts

A pre-vacuum cleaning machine refers to a cleaning device that first evacuates the cleaning chamber to a certain vacuum degree before conducting the cleaning operation. The core lies in using a vacuum environment to reduce the partial pressure of the gas and minimize the interference of the gas on the cleaning process, thereby enhancing the cleaning effect. Compared with traditional atmospheric pressure cleaning equipment, pre-vacuum cleaning machines can more effectively remove contaminants from tiny crevices, blind holes and complex-structured surfaces, meeting the requirements of high-precision cleaning.

Iii. Working Principle

(1) The promoting effect of vacuum environment on cleaning

In a vacuum environment, the density of gas molecules is significantly reduced, and the amount of gas dissolved in the cleaning solution decreases. This makes the cleaning solution more likely to produce cavitation effects under the action of ultrasonic waves. Cavitation effect refers to the fact that when ultrasonic waves propagate in a liquid, liquid molecules form tiny bubbles under high-frequency vibration. These bubbles grow rapidly and suddenly close, generating intense shock waves and micro-jets, which then impact and peel off dirt from the surface of the object. Under vacuum conditions, the formation and rupture of cavitation bubbles are more intense, enabling more efficient removal of stubborn dirt.

In addition, a vacuum environment helps to remove gases from the surface and internal pores of the object being cleaned. Under normal pressure, these gases may prevent the cleaning solution from making full contact with the dirt. However, under vacuum conditions, the gases are extracted, allowing the cleaning solution to penetrate more deeply into tiny crevices and holes, achieving all-round cleaning.

(2) Work in coordination with other cleaning technologies

Pre-vacuum cleaning machines are usually combined with technologies such as ultrasonic cleaning, spray cleaning, and vapor phase cleaning. For instance, after the pre-vacuum environment is established, the ultrasonic cleaning system is activated. The high-frequency vibration of ultrasonic waves, in combination with the enhanced cavitation effect in the vacuum environment, forcefully impacts the dirt. Or, spray cleaning can be carried out under vacuum conditions, allowing the cleaning liquid to cover the surface of the object more evenly and avoiding the problem of uneven spraying caused by the presence of gas. Gas phase cleaning utilizes the evaporation and condensation characteristics of solvents in a vacuum environment to achieve fine cleaning of the surface of objects.

Iv. Structural Composition

(1) Vacuum system

Vacuum pump: It is one of the core components of the pre-vacuum cleaning machine. Commonly used types of vacuum pumps include rotary vane vacuum pumps, scroll vacuum pumps, molecular pumps, etc. The rotary vane vacuum pump features a simple structure, relatively low price and moderate pumping speed. It is suitable for pre-vacuum cleaning with lower vacuum requirements. The scroll vacuum pump has low noise, small vibration and high working efficiency. Molecular pumps can achieve extremely high vacuum degrees and are often used in high-end application scenarios with strict vacuum requirements.

Vacuum pipes and valves: Vacuum pipes are used to connect the vacuum pump with the cleaning chamber. They are required to have good sealing and pressure resistance to prevent gas leakage. Valves include vacuum stop valves, vacuum butterfly valves, etc., which are used to control the flow of gas and the working state of vacuum systems. For instance, valves can be opened during the vacuuming process and closed during the cleaning process to maintain a vacuum environment.

Vacuum measurement devices: Common vacuum measurement instruments include heat conduction vacuum gauges, capacitive thin-film vacuum gauges, etc. The thermal conductivity vacuum gauge determines the vacuum degree by measuring the thermal conductivity of the gas and is suitable for measurement in the low vacuum range. Capacitive thin-film vacuum gauges measure vacuum degree by utilizing the deformation of the film under different pressures, which causes changes in capacitance. They have the advantages of high measurement accuracy and fast response speed, and can be used for medium and high vacuum degree measurement.

(2) Clean the chamber

Material and structure: The cleaning chamber is usually made of corrosion-resistant and high-strength materials such as stainless steel to ensure long-term stable operation in vacuum and cleaning liquid environments. Its structural design should take into account the convenience of placing and taking out the objects to be cleaned, and at the same time ensure good sealing. The interior of the cavity may be equipped with components such as cleaning baskets and brackets to fix and support the objects to be cleaned.

Observation window and interface: The observation window is generally made of transparent pressure-resistant glass or quartz glass, which is convenient for the operator to observe the situation inside the chamber during the cleaning process. The chamber is also equipped with various interfaces, such as the inlet and outlet for the cleaning solution, the inlet and outlet for the gas, as well as electrical interfaces for connecting to external equipment, etc., which are used to achieve functions such as the circulation of the cleaning solution, the introduction of gas, and equipment control.

(3) Cleaning system

Ultrasonic cleaning system: It is composed of an ultrasonic generator, a transducer and a cleaning tank. The ultrasonic generator generates high-frequency electrical signals. The transducer converts the electrical signals into mechanical vibrations, thereby generating ultrasonic waves in the cleaning solution. Transducers are usually installed at the bottom or side of the cleaning tank. Their quantity and power are configured according to the size of the cleaning chamber and the cleaning requirements.

Spray cleaning system: It includes spray pumps, nozzles and cleaning liquid circulation pipelines. The spray pump draws the cleaning solution from the storage tank and sprays it onto the object to be cleaned at a certain pressure and Angle through the nozzle, achieving the rinsing of the object's surface. The cleaning liquid circulation pipeline is used to collect the cleaning liquid after spraying and send it back to the storage tank. After filtration and treatment, it is reused.

Gas phase cleaning system: It is mainly composed of solvent evaporation device, condensation device and recovery device. The solvent is heated and evaporated in the evaporation device to form a gaseous solvent. The gaseous solvent fills the cleaning chamber in a vacuum environment, comes into contact with the dirt on the surface of the object and dissolves it. When the gas-phase solvent comes into contact with the surface of a low-temperature object or a condensation device, it condenses into a liquid. The liquid is collected through a recovery device and sent back to the solvent storage container, achieving the recycling of the solvent.

(4) Control System

Electrical control system: It includes various electrical components, such as relays, contactors, sensors, etc., and is used to control the operation of various components in vacuum systems, cleaning systems, etc. Through control cores such as PLC (Programmable Logic Controller) or industrial control computer, the automatic control of the equipment is achieved, such as automatically completing operations like vacuuming, cleaning, liquid discharge and drying according to the set program.

Human-machine interface: Operators interact with the equipment through the human-machine interface and can set cleaning parameters such as vacuum degree, cleaning time, ultrasonic power, and spray pressure. Meanwhile, the human-machine interface can display the operating status of the equipment in real time, such as vacuum degree values, temperature, cleaning liquid levels and other information, and promptly alarm when the equipment malfunctions to prompt the operator to handle it.

V. Core Technologies

(1) Vacuum sealing technology

Ensuring the high vacuum sealing performance of the cleaning chamber is one of the key technologies of the pre-vacuum cleaning machine. The sealing methods include static sealing and dynamic sealing. Static sealing usually employs rubber sealing rings, metal sealing rings, etc., which are installed at flange connections in the chamber, edges of observation Windows, and other locations to prevent gas leakage. Dynamic sealing is used for moving parts, such as the opening and closing mechanisms of chamber doors and the rotating joints of mechanical arms. Common forms of dynamic sealing include labyrinth sealing and mechanical sealing, to ensure that a good vacuum environment can still be maintained during the movement of the parts.

(2) High-efficiency vacuuming technology

In order to quickly achieve the required vacuum degree, efficient vacuuming technology needs to be adopted. This involves the selection and combination of vacuum pumps, the optimal design of vacuum pipelines, and the formulation of pumping strategies. For instance, for cleaning processes that require a higher vacuum degree, a combination of multiple vacuum pumps can be adopted. First, a coarse vacuum pump is used to quickly reduce the pressure, and then a high vacuum pump is employed to further enhance the vacuum degree. Optimize the diameter and length of the vacuum pipeline to reduce the resistance of gas flow and improve the pumping efficiency; Formulate a reasonable vacuuming strategy, such as staged vacuuming, and adopt different vacuuming rates at different stages to shorten the vacuuming time.

(3) Intelligent control technology

With the development of automation and intelligent technologies, pre-vacuum cleaning machines are increasingly adopting intelligent control technologies. The various parameters during the cleaning process, such as vacuum degree, temperature, and cleaning solution concentration, are monitored in real time through sensors, and the data is fed back to the control system. The control system utilizes advanced control algorithms, such as fuzzy control and PID control, to automatically adjust the cleaning parameters to adapt to different cleaning requirements and changes in working conditions. In addition, intelligent control technology can also achieve fault diagnosis and predictive maintenance of equipment. By analyzing the operation data of the equipment, potential faults can be detected in advance, and timely maintenance and repair can be carried out to improve the reliability and service life of the equipment.

Vi. Application Fields

(1) Semiconductor manufacturing

During the manufacturing process of semiconductor chips, even tiny particulate contaminants and organic residues can lead to a decline in chip performance or even failure. The pre-vacuum cleaning machine can be used for wafer cleaning. In a vacuum environment, it can more effectively remove contaminants such as photoresist, metal impurities, and oxides from the wafer surface, ensuring the ultra-high cleanliness of the wafer surface and meeting the high-precision requirements of semiconductor manufacturing. Meanwhile, the pre-vacuum cleaning machine can also be used for cleaning components such as chips and lead frames during the semiconductor packaging process.

(2) Precision optical device processing

Precision optical components such as lenses, lenses, prisms, etc. have extremely high requirements for surface cleanliness. Any residual dust, oil stains or fingerprints will affect the optical performance. The pre-vacuum cleaning machine, combined with ultrasonic cleaning and gas phase cleaning technologies, can thoroughly remove contaminants from the optical surface without damaging it, ensuring the stability of optical parameters such as light transmittance and refractive index of optical devices. It is widely used in the manufacturing of optical instruments such as digital cameras, microscopes, and telescopes.

(3) Production of aerospace components

Aerospace components usually have complex structures and high-precision requirements. During the manufacturing process, various processing debris, oil stains and protective coatings, etc. may remain. The pre-vacuum cleaning machine can penetrate into the tiny crevices and blind holes of components to remove these contaminants, ensuring the performance and reliability of the components. For instance, aero engine blades, aircraft landing gear parts, etc. all need to undergo strict pre-vacuum cleaning treatment before assembly.

(4) Medical equipment manufacturing

Medical equipment comes into direct contact with the human body, and thus has extremely strict requirements for cleanliness and hygiene. The pre-vacuum cleaning machine can be used for the cleaning of medical devices, such as surgical instruments, medical catheters, implantable medical devices, etc. It can effectively remove biological dirt, blood, protein and other contaminants on the surface of the devices, and prevent secondary pollution during the cleaning process, ensuring the safety and effectiveness of medical equipment.

(V) Scientific research field

In scientific research fields such as materials science, chemistry, and biology, pre-vacuum cleaning machines are often used to prepare high-purity experimental samples. For instance, in the process of preparing nanomaterials, the cleanliness requirements for raw materials and preparation equipment are extremely high. Pre-vacuum cleaning machines can be used to clean reaction vessels, molds, etc., to prevent impurities from interfering with the experimental results. In biological experiments, it is used to clean experimental equipment such as petri dishes and slides to ensure the cleanliness of the experimental environment.

Vii. Advantages

(1) Excellent cleaning effect

Due to the enhanced cavitation effect of the vacuum environment, the pre-vacuum cleaning machine can more thoroughly remove dirt from tiny crevices, blind holes and complex-structured surfaces. Its cleaning effect is significantly better than that of traditional atmospheric pressure cleaning equipment, and it can meet the cleaning requirements of high precision and high cleanliness.

(2) Reduce secondary pollution

In a vacuum environment, there are fewer pollutants such as dust and particles in the air, reducing the risk of secondary pollution during the cleaning process and ensuring the cleanliness quality of the objects being cleaned.

(3) Enhance production efficiency

Pre-vacuum cleaning machines usually adopt automatic control and can quickly complete the cleaning process according to the preset program, reducing manual operation time. Meanwhile, the highly efficient cleaning effect reduces the rework caused by incomplete cleaning, thereby enhancing the overall production efficiency.

(4) Wide range of application

It can be combined with various cleaning technologies and is suitable for cleaning objects of different materials, shapes and sizes. It has broad application prospects in multiple industries and fields.

(V) Energy conservation and environmental protection

Some pre-vacuum cleaning machines adopt solvent recovery and recycling technology, which reduces the consumption of cleaning solvents, lowers production costs, and also meets the requirements of energy conservation and environmental protection.

Viii. Challenges Faced

(1) The equipment cost is relatively high

The pre-vacuum cleaning machine involves multiple complex components such as vacuum systems, precision cleaning systems, and intelligent control systems. Its research and development, manufacturing, and maintenance costs are relatively high, resulting in relatively expensive equipment prices and increasing the procurement costs and investment risks for enterprises.

(2) Strict technical requirements

The operation and maintenance of the equipment require professional technicians. The operators need to be familiar with the working principles and operation methods of the vacuum system, cleaning system and control system, and be able to correctly set cleaning parameters and handle equipment malfunctions. At the same time, the maintenance and upkeep of the equipment also require professional knowledge and skills to ensure its normal operation and stable performance.

(III) Safety Risks

Some cleaning solvents have characteristics such as flammability, explosiveness and toxicity. In a vacuum environment, the evaporation rate of the solvents increases, raising the safety risk. In addition, if the vacuum system is not operated properly, it may cause abnormal chamber pressure and lead to safety accidents. Therefore, it is necessary to take comprehensive safety protection measures, such as installing gas leakage monitoring devices and equipping fire-fighting equipment, etc.

(4) High requirements for the process

The requirements for the pre-vacuum cleaning process vary among different industries and cleaning objects, and process optimization and parameter adjustment need to be carried out based on specific circumstances. For instance, the requirements for cleaning processes in semiconductor manufacturing and aerospace component cleaning vary significantly. This demands that enterprises invest a considerable amount of time and effort in process research and development as well as experimentation to ensure that the cleaning effect meets production needs.

Ix. Future Development Trends

(1) The degree of intelligence and automation has been enhanced

With the continuous development of technologies such as artificial intelligence and the Internet of Things, pre-vacuum cleaning machines will achieve a higher degree of intelligence and automation. Future devices will have more powerful autonomous decision-making capabilities, being able to automatically adjust cleaning parameters based on the type of objects being cleaned, the degree of dirt, etc., to achieve personalized cleaning. Meanwhile, through Internet of Things (iot) technology, the equipment can be connected to the factory's production management system to achieve remote monitoring, fault diagnosis and data analysis, thereby enhancing the efficiency and level of production management.

(II) Technological innovation in energy conservation and environmental protection

In response to the global call for energy conservation and environmental protection, the pre-vacuum cleaning machine will continuously research and apply new energy conservation and environmental protection technologies. For instance, further optimize solvent recovery and recycling technologies to enhance the recovery rate and utilization rate of solvents; Adopt more efficient vacuum pumps and heating systems to reduce the energy consumption of the equipment; Develop new environmentally friendly cleaning solvents to reduce pollution to the environment.

(3) Deep integration with other technologies

The pre-vacuum cleaning machine will be deeply integrated with more advanced technologies, such as nanotechnology and plasma technology. For example, develop new types of nano-cleaning materials in combination with nanotechnology to improve cleaning efficiency and quality; The surface of objects is modified by using plasma technology to enhance the cleaning effect, and at the same time achieve functions such as surface activation and disinfection.

(4) Develop towards miniaturization and portability

In some specific application scenarios, such as on-site maintenance and rapid laboratory cleaning, there is a demand for the miniaturization and portability of pre-vacuum cleaning machines. In the future, pre-vacuum cleaning machines will develop towards miniaturization and lightweight. By optimizing design and adopting new materials, the volume and weight of the equipment will be reduced, and its flexibility and applicability will be enhanced.

X. Conclusion

The pre-vacuum cleaning machine, with its unique working principle and outstanding cleaning effect, plays a significant role in modern industrial production and scientific research fields. Despite the current challenges such as high equipment costs and strict technical requirements, with the continuous progress and innovation of technology, pre-vacuum cleaning machines will be advanced in terms of intelligence, energy conservation and environmental protection, and technological integration