388 results about "Wet cleaning" patented technology

The invention relates to a surface cleaning device for wet cleaning a surface, comprising a guide part which extends longitudinally between a proximal end and a distal end and is designed for manually guiding the surface cleaning device over the surface, a base part which is connected to the distal end of the guide part, a tool device which is arranged on the base part and is designed to act on the surface, a fluid dispenser which is designed to dispense fluid onto the surface, a fluid receptacle which is designed to receive fluid from the surface which has been delivered to the surface by means of the fluid dispenser, a fluid path which fluidically connects the fluid receptacle to the fluid dispenser for the return of fluid received by means of the fluid receptacle, and a conveying device which is designed to convey fluid along the fluid path.whereby fluid absorbed from the surface by means of the fluid intake can be released onto the surface by means of the fluid discharge. The invention also relates to a fluid tank for such a surface cleaning device, a surface cleaning system, and a method for wet cleaning a surface.

The present embodiment relates to a control method for a cleaning robot and a related device. The method comprises: acquiring a contaminant type and a contaminated area of a floor to be cleaned, wherein the contaminant type comprises a liquid contaminant; when there is the contaminated area having the liquid contaminant on the floor to be cleaned, turning a body of the cleaning robot around and driving the cleaning robot to perform a cleaning operation in a reversing posture, so as to use a wet cleaning member to clean the liquid contaminant in the contaminated area. The present invention solves the problem that a dry cleaning member of the cleaning robot is easily wetted when cleaning the liquid contaminant, improving the cleaning effect on the floor having the liquid contaminant.

A surface cleaning apparatus includes an upright body and a base adapted for movement across a surface to be cleaned, a fluid delivery system, and a recovery system. The surface cleaning apparatus can be configured to clean multiple surfaces, including hard and soft surfaces, and for different cleaning modes, including wet cleaning, dry vacuum cleaning, and self-cleaning. Methods for self-cleaning a surface cleaning apparatus are also provided.

The invention belongs to the technical field of photovoltaic equipment, and particularly discloses a solar photovoltaic panel cleaning device which comprises a transverse moving square frame, mounting rods are symmetrically and fixedly arranged on the lower sides of the two ends of two long beams of the transverse moving square frame, and first rolling wheels and second rolling wheels which are perpendicular to each other are rotationally arranged at the inner ends of the mounting rods; longitudinal moving driving mechanisms are arranged at the two ends of the transverse moving square frame in the length direction, a double-layer square frame is arranged above the transverse moving square frame in parallel, an alternate cleaning mechanism is arranged on the lower layer of the double-layer square frame, a washing brush mechanism is arranged above the alternate cleaning mechanism, and a water collecting tank is arranged in the alternate cleaning mechanism. A reciprocating type alternate overturning driving mechanism is arranged at one end of the alternate cleaning mechanism, and a cleaning power mechanism is arranged at the other end of the alternate cleaning mechanism. An alternate cleaning mode is adopted, one cleaning assembly cleans the photovoltaic panel while the other cleaning assembly is cleaned, the cleaning assemblies do not need to be replaced frequently, and meanwhile, a semi-wet cleaning mode is adopted, so that sewage diffusion or flying dust pollution is avoided.

The invention relates to the technical field of solar power generation, in particular to a self-cleaning solar tower type power generation reflector. Comprising a reflector, the reflector comprises a supporting column, a rotating platform and a mirror surface, the rotating platform is rotationally arranged on the supporting column, the mirror surface is installed at the top of the rotating platform and used for reflecting sunlight, a water tank is installed on the supporting column, and guide rod frames are symmetrically arranged on the rotating platform. Through cooperation of the water tank, the electric roller, the cleaning cotton, the connecting pipe, the water pump, the water conveying pipe and the moving mechanism, the cleaning cotton can be automatically wetted through clean water, then the mirror surface of the reflector is wiped through the wetted cleaning cotton, and therefore the mirror surface of the reflector is automatically cleaned, time and labor are saved, the efficiency is high, and the practicability is high. And through cooperation of a backflow pipe, a filtering mechanism and a cleaning mechanism, clear water in the connecting pipe can flow back and be filtered, backflow water is recycled, and therefore the purpose of saving water resources is achieved.

The invention relates to an obstacle cleaning method, a cleaning robot and a computer readable storage medium. The method is applied to the cleaning robot, the cleaning robot comprises a chassis and a wet cleaning part connected with the chassis, and the method comprises the steps that obstacle information is recognized, when the height of an obstacle is larger than a first threshold value, an obstacle avoidance cleaning strategy is executed, and when the height of the obstacle is smaller than a second threshold value, a low obstacle cleaning strategy is executed; the obstacle avoidance cleaning strategy is to clean obstacles along the edges; according to the low obstacle cleaning strategy, the upper surface of the obstacle is kept clean by adjusting the lifting height of a chassis of the cleaning robot and / or the lifting height of a wet type cleaning piece. By adopting the method, the cleaning coverage rate and the cleaning effect are improved.

The utility model provides a cleaning brush as well as cleaning equipment and a cleaning system comprising the cleaning brush, and belongs to the field of cleaning equipment. The cleaning brush is used for being installed on the cleaning equipment so as to clean a surface to be cleaned, and the cleaning brush comprises a rolling brush support, a rolling brush and an isolation mechanism. The rolling brush is rotationally mounted on the rolling brush bracket; the isolation mechanism is connected with the cleaning equipment and / or the rolling brush bracket and has a first state and a second state; wherein in the first state, the isolation mechanism enables the rolling brush to be in contact with a surface to be cleaned so as to carry out first cleaning operation; and in the second state, the isolation mechanism enables the rolling brush to be isolated from the surface to be cleaned so as to carry out second cleaning operation or carry out second cleaning operation after the corresponding rolling brush is dried, and the technical problem that an existing cleaning brush is poor in compatibility of dry-state cleaning and wet-state cleaning can be solved.

The invention relates to a control method of cleaning equipment, the cleaning equipment and a computer readable storage medium. The method comprises the steps that obstacle information on a working face can be accurately and timely acquired through a detection system, and when a target obstacle is recognized, a shielding piece can be timely controlled to be switched to a shielding state, so that closing of an opening of a containing cavity is achieved, and the working efficiency is improved. Water in the rotary wet-type cleaning piece rotatably arranged in the containing cavity is prevented from being scattered on the working face, the cleaning effect is prevented from being affected, and the cleaning quality is improved; the shielding piece of the cleaning equipment can comprise the shielding state and the avoiding state, switching between the shielding state and the avoiding state is carried out in time based on the detected obstacle information, and the use scene of the cleaning equipment is expanded.

A cleaning device and methods for cleaning are provided. In one embodiment, the cleaning device includes a head assembly, a body assembly, and a handle assembly. The cleaning device also includes components that enable the cleaning device to operate in dry cleaning modes and wet cleaning modes. Dry cleaning modes can employ a vacuum assembly, including a motor, tubing, and a fluid recovery tank in order to draw in debris and waste into a fluid recovery tank. Wet cleaning modes can further employ a fluid supply tank, a pump, and tubing in order to supply fluid to a brushroll to aid in a cleaning process.

A cleaning device for cleaning a surface is described. The cleaning device includes at least one cleaning element and a wetting system to supply a cleaning liquid to the at least one cleaning element. The wetting system is operable in one of at least one normal operation mode and a boost operation mode involving an increased supply rate of the cleaning liquid with respect to the at least one normal operation mode. During start-up of the cleaning device in a wet cleaning mode thereof, a start-up operation mode of the wetting system is determined to be one of the normal operation mode or the boost operation mode on the basis of assessment of an actual value of at least one parameter that is indicative of whether or not the at least one cleaning element is in a wet cleaning condition.

The invention provides semiconductor cleaning equipment which is characterized in that a dry cleaning cavity and a wet cleaning cavity are integrated in one cleaning equipment, a wafer transfer cavity is arranged, photoresist on a wafer is removed in the dry cleaning cavity through dry cleaning, and then the wafer transfer cavity is arranged in the wet cleaning cavity; and then the wafer transfer cavity is utilized to quickly transfer the wafer subjected to dry cleaning into the wet cleaning cavity for wet cleaning, so that the photoresist can be efficiently removed, the time interval between the dry cleaning process and the wet cleaning process of the wafer is improved, the cleaning efficiency and effect of the wafer are improved, and in addition, the wafer transfer cavity is utilized to quickly transfer the wafer subjected to dry cleaning into the wet cleaning cavity for wet cleaning. A mixed solution of sulfuric acid and hydrogen peroxide is used as a cleaning solution for wet cleaning, a rotating device and a spraying device are arranged in a wet cleaning cavity, and the rotating device is arranged to drive the wafer to rotate while the spraying device sprays the cleaning solution to the wafer, so that the cleaning solution is uniformly distributed on the wafer; and the wet cleaning effect is further improved.

Systems, devices, and methods for stain detection and cleaning using robotic cleaners are disclosed. An example robotic cleaning system may include a robotic cleaner. The robotic cleaner may include a housing, at least one wet cleaning element including at least one cleaning surface on an underside of the housing, at least one sensor, and at least one processor. The processor(s) may be programmed or configured to detect at least one stain on a surface to be cleaned based on sensor data from the at least one sensor and perform at least one cleaning operation based on the at least one stain.

The invention discloses a photovoltaic panel impurity removal device and a using method thereof, and belongs to the technical field of photovoltaic panel impurity removal. An eccentric movable assembly is driven to move through a driving assembly, so that the eccentric movable assembly can shake after being in transmission with a rack, an adjustable cleaning assembly shakes along with the eccentric movable assembly, and therefore the cleaning effect of a cleaning plate on a photovoltaic structure can be improved; in addition, before cleaning of the cleaning plate, floating dust on the photovoltaic structure can be blown away in advance through the exhaust assembly, the risk of friction damage of the cleaning plate and the photovoltaic structure is reduced, then cleaning is conducted through the cleaning plate, attached impurities are blown away through airflow after cleaning, the cleaning effect is improved, the number of the water outlet heads is two, and after the floating dust is blown away preliminarily, the cleaning effect is improved. And water spraying cleaning can be carried out through the water conveying assembly according to needs, then wet cleaning is carried out through reciprocating movement of the cleaning plate, stubborn dirt can be conveniently removed, finally, flushing is carried out through the water outlet head, and the photovoltaic structure cleaning effect is better.

The invention belongs to the technical field of wastewater recovery, and discloses a cleaning fluid recovery device for wet cleaning of semiconductor wafers, which comprises an evaporation tank, a feed pipe fixedly arranged on the side surface of the evaporation tank, and a discharge pipe fixedly mounted at the bottom of the evaporation tank, the valve is arranged on the discharge pipe, the mounting bracket is fixedly arranged outside the evaporation tank and the condensation tank, and one side, close to the evaporation tank, of the condensation tank is fixedly connected with a transmission pipe communicated with the evaporation tank; the cleaning mechanism is arranged in the evaporation tank and used for cleaning the inner wall of the evaporation tank, and through cooperation of a heater, a scraping plate, a cleaning plate and other structures, the interior of the evaporation tank can be conveniently and rapidly heated and cleaned; the problems that when an existing cleaning liquid recycling device is used for removing and recycling impurities through distillation, a large amount of impurity scale is prone to remaining in a distillation chamber, and cleaning is not easy are solved.

A cleaning apparatus, comprising: a mobile platform (100), which is configured to autonomously move on an operating surface; and a wet cleaning module (200), which is arranged at the bottom of the mobile platform (100) and is configured to clean at least part of the operating surface in a wet cleaning manner, wherein the wet cleaning module (200) comprises: a driving assembly (230), which is used for outputting a driving force in a first working mode; and a cleaning assembly (2000), which comprises a first cleaning assembly (210) and a second cleaning assembly (220), the first cleaning assembly (210) being configured to move in a reciprocating manner in the first working mode of the driving assembly (230) so as to clean at least part of the operating surface, the second cleaning assembly (220) being configured to continuously rotate in the first working mode of the driving assembly (230) so as to clean at least part of the operating surface, the second cleaning assembly (220) being arranged at an edge position of a projection surface of the mobile platform (100), and cleaning surfaces, which come into contact with the operating surface, of the second cleaning assembly (220) and the first cleaning assembly (210) being approximately located in the same horizontal plane.

The utility model discloses a cleaning robot and a cleaning system. The cleaning robot comprises a machine body, driving wheels, a fabric wet type cleaning assembly, a water tank assembly and a suction assembly. The driving wheels are arranged at the bottom of the machine body and used for driving the machine body to move. The fabric wet-type cleaning assembly is connected with the machine body and used for conducting wet-type cleaning on the fabric products, and the fabric wet-type cleaning assembly is provided with a liquid spraying hole and a dirt suction opening; the water tank assembly is provided with a clear water cavity and a sewage cavity which are separated from each other, the clear water cavity communicates with the liquid spraying hole, and the sewage cavity communicates with the sewage suction port; the suction assembly comprises a suction source installed on the machine body, and the suction source is used for being communicated with the sewage cavity so that garbage can be sucked into the sewage cavity from the sewage suction opening. The cleaning robot can automatically clean the cloth products, and the cleaning effect is good.

The present invention belongs to the technical field of photovoltaic equipment, and specifically discloses a cleaning device for a solar photovoltaic panel, which includes a horizontally moving square frame. At the lower sides of both ends of the two long beams of the horizontally moving square frame, mounting rods are symmetrically and fixedly provided. At the inner ends of the mounting rods, a first roller and a second roller perpendicular to each other are rotatably provided. At both ends in the length direction of the horizontally moving square frame, a longitudinal movement driving mechanism is provided. Above the horizontally moving square frame, a double-layer square frame is arranged in parallel. An alternating cleaning mechanism is arranged at the lower layer of the double-layer square frame. Above the alternating cleaning mechanism, a flushing brush mechanism is provided. A water collecting tank is arranged inside the alternating cleaning mechanism. At one end of the alternating cleaning mechanism, a reciprocating alternating flipping driving mechanism is provided. At the other end of the alternating cleaning mechanism, a cleaning power mechanism is provided. The present invention adopts an alternating cleaning method, while one cleaning component cleans the photovoltaic panel, the other cleaning component is being cleaned, realizing that there is no need to frequently replace the cleaning component. At the same time, a semi-wet cleaning method is adopted to avoid the diffusion of sewage or dust pollution.

The utility model provides equipment for wet cleaning and etching. The equipment comprises a liquid conveying pipeline, a box body, a heating device and a spraying device, one end of the liquid conveying pipeline is connected with a chemical solution supply device, the other end of the liquid conveying pipeline is connected with the box body, and the chemical solution supply device conveys a chemical solution into the box body through the liquid conveying pipeline; the heating device is used for heating the chemical solution in the box body; and the spraying device is connected with the box body and is used for spraying the heated chemical solution to the wafer. According to the utility model, the box body is arranged between the spraying device and the liquid conveying pipeline to store the chemical solution, and the heating device is utilized to heat the chemical solution in the box body, so that the chemical solution sprayed to the wafer by the spraying device reaches a set temperature value, the rate of chemical reaction is guaranteed, and the chemical reaction efficiency is improved. And the condition of non-uniform etching or incomplete cleaning is avoided.

An autonomous cleaning device, includes: a mobile platform, configured to move autonomously on a cleaning surface; and a cleaning module, disposed on the mobile platform and including a wet cleaning module, configured to clean at least part of the cleaning surface in a wet cleaning mode.

The embodiment of the invention provides a control method of a cleaning robot and the cleaning robot, and the method comprises the steps that in the process that the cleaning robot executes a cleaning task in a first cleaning mode along a preset cleaning path, the cleaning robot judges whether at least one part of a wet type target object is in contact with a dry type cleaning assembly of the cleaning robot or not; if the cleaning robot judges that at least one part of the wet type target object is in contact with the dry type cleaning assembly of the cleaning robot, the cleaning robot stops executing the cleaning task along the original preset cleaning path; the cleaning robot is controlled to execute a first cleaning strategy, and the first cleaning strategy comprises the steps that at least one part of the wet type target object is cleaned in a wet type cleaning mode or the cleaning robot is made to bypass the wet type target object. According to the cleaning robot, the current cleaning mode can be stopped in time when an emergency occurs in the cleaning path and the cleaning assembly is in contact with the unmatched target object, an emergency cleaning strategy is switched, and secondary pollution accidents are avoided.

A handheld extraction cleaner system includes a wet cleaning head including a wet suction nozzle, a dry cleaning head including a dry suction nozzle. A handheld base includes a modular receiver configured to interchangeably couple to the wet cleaning head and the dry cleaning head. A suction source is configured to generate a suction air stream through the wet suction nozzle when the wet cleaning head is coupled to the modular receiver and through the dry suction nozzle when the dry cleaning head is coupled to the modular receiver. A fluid delivery system includes a fluid distributor configured to dispense a cleaning solution on a surface to be cleaned, where at least one of the handheld base and the dry cleaning head is configured to at least partially prevent the fluid delivery system from dispensing the cleaning solution when the dry cleaning head is coupled to the modular receiver.

The invention discloses a wet drying method for a wafer with a graphic structure, which comprises the following steps of: carrying out wet cleaning on the wafer with the graphic structure, and after the wet cleaning is finished, filling a cleaning solution in an interval region between the graphic structures. The flowing supercritical gas is adopted to dry the wafer, and in the drying process, the included angle between the flowing direction of the supercritical gas and the extending direction of the graphic structure ensures that the supercritical gas can smoothly flow from one side of the interval area to the other opposite side, so that the cleaning liquid in the interval area is completely replaced. According to the method, the effect of replacing the cleaning liquid in the interval areas between the pattern structures can be improved, complete replacement of the cleaning liquid is achieved, and meanwhile it is guaranteed that the pattern structures are not collapsed or damaged.

The utility model discloses a combined belt conveyor wet-type cleaning device with water mist assistance, which is applied to a belt conveyor body, vertical rods are symmetrically arranged at the top of the belt conveyor body, adjusting mechanisms are arranged on one sides of the vertical rods, a concave frame is arranged between the adjusting mechanisms, a conveying mechanism is arranged in an inner cavity of the concave frame, and the conveying mechanism is connected with the belt conveyor body. A conveying mechanism is arranged on the front surface of the vertical rod, a cleaning mechanism is arranged below the conveying mechanism, a spraying mechanism is arranged in the middle of the front surface of the vertical rod, and the multiple mechanisms such as the adjusting mechanism, the conveying mechanism, the cleaning mechanism, the spraying mechanism, the supplying and conveying mechanism and the scraping mechanism are matched in an assisting mode; the cleaning efficiency is remarkably improved, the combined cleaning structure enables the cleaning efficiency to be improved to 99% or above, the residue amount is smaller than 50 g / m < 2 >, the efficiency is far higher than 85% of a traditional cleaning device, adaptability is high, various viscous materials (such as wet coal and ore pulp) can be treated, and the problem that the traditional cleaning device cannot thoroughly clean the high-humidity and high-viscosity materials is solved.

The invention provides a reworking method of an MIM upper pole plate, which comprises the following steps: providing an MIM structure of the upper pole plate to be reworked, the upper pole plate is a TiN layer, and a dielectric layer is formed below the upper pole plate; the TIN layer is removed through APM wet etching; carrying out dry etching on the dielectric layer, and then carrying out wet cleaning treatment twice; carrying out dry etching on the dielectric layer again, and then carrying out wet cleaning treatment twice; performing film thickness detection and defect detection; in response to film thickness detection and defect detection, regrowing to form a dielectric layer and a TiN layer; and carrying out a subsequent process flow, and carrying out a WAT test after the subsequent process flow is completed. The method is used for reworking the wafer when the MIM upper electrode plate is abnormal, wet etching is carried out on the upper electrode plate, dry etching and wet etching are carried out on the dielectric layer for multiple times, after film thickness detection and defect detection pass, the dielectric layer and the upper electrode plate are formed through regrowth, the problem that the MIM upper electrode plate is abnormal is solved, the reworking success rate is increased, and the reworking efficiency is improved. And the device yield is improved.

A cleaning device includes: a housing; a drive device for automatically moving the cleaning device in a movement direction; and a wet-cleaning module accommodated in the housing, the wet-cleaning module including a moveable cleaning element for wet cleaning of surfaces. The cleaning element is belt-shaped. In an embodiment, the wet-cleaning module has three positions for the belt-shaped cleaning element: a cleaning position, in which the cleaning element is configured to contact a surface to be cleaned with a cleaning surface; a parking position, in which the cleaning element is at a distance from the surface to be cleaned; and a regeneration position located between the cleaning position and the parking position, or a regeneration position located in the parking position in which the cleaning element is regeneratable. The wet-cleaning module has a transport mechanism for moving the cleaning element into its cleaning, parking, and regeneration positions.

The application discloses a typeable soft shaft electric cleaning brush and a control method, relates to the technical field of cleaning tools, and the cleaning brush comprises a handle, a typeable soft shaft waterproof sealing structure and a quick-change brush head; the handle is internally provided with a lithium battery, a driving motor and a control module, and an outer wall is provided with a button switch; the typeable soft shaft is internally provided with a steel wire transmission soft shaft, is matched with a double-layer waterproof sleeve and a front end sealing head, and can be arbitrarily bent and shaped; the conversion head and the brush head are respectively locked and transmitted through a jacking screw, and each component is modularized and can be disassembled; the control method comprises the steps of matching and assembling the brush head, bending and shaping the soft shaft, single-key starting and stopping and speed adjusting and washing, and long-pressing stopping, disassembling, washing and maintaining. The application can be extended into a special-shaped small cavity for dry and wet cleaning, the whole machine is waterproof, convenient to disassemble and assemble, and can effectively adapt to multiple complex cleaning scenes.

Device (1), preferably in the form of a wet scrubber, for cleaning a gas stream of gaseous, liquid and solid impurities, which has a gas inlet (3), at least one first washing section (6) for cleaning the gas stream with a washing liquid, a gas outlet (5) and gas supply lines (24), characterized in that the device (1) further has several gas inlets (3) for different gas streams, wherein the supply lines (24) connected to the gas inlets (3) have a continuous gradient towards the device (1) and preferably a liquid trap (14) upstream of the gas inlets (3), and the device (1) has a pre-wash chamber (16) with at least one spray nozzle (10) and, between a first washing section (6) and a second washing section (7) in the connecting line or after the washing section (6), at least one packing (9) with a specific surface area of ​​at least 400 m² / m³, preferably in the form of a textile packing.and has a spray nozzle (10) above the packing (9), whereby the washing liquid for the packing (9) and the gas flowing through the packing (9) flow in the same direction, and wherein the gas flow is directed from the upper end of the first washing section (6) via the preferably textile packing (9) downwards in the connecting line to the lower end of the second washing section (7) or to the gas outlet (5).

A cleaning robot includes a main body; a wheel to move the main body; a pad holder, the pad holder being rotatable and to which a wet cleaning pad is attachable; a motor to rotate the pad holder; a floor sensor; a controller connected to the wheel, the motor, and the floor sensor; and a lifting assembly to lower the pad holder toward the floor, or to raise the pad holder toward the main body, wherein the controller is to: identify a type of the floor based on a detection signal transmitted from the floor sensor, determine whether a dry cleaning is required based on the type of the floor, and control the motor to rotate the pad holder in the reverse direction such that the pad holder is raised toward the main body, by the lifting assembly, based on the dry cleaning being determined as required.

The invention discloses a preparation method of a vertical channel hole, and the method comprises the steps: S10, providing a semiconductor structure which comprises an etching stop layer and a to-be-etched layer; s20, forming a patterned mask layer on the semiconductor structure by using a photoetching process; s30, taking the patterned mask layer as a mask, and forming an initial channel hole vertically penetrating through the to-be-etched layer through a dry etching process; s40, performing wet cleaning on the initial channel holes, and measuring to obtain the average aperture of the channel holes subjected to wet cleaning; s50, determining wet etching process parameters based on the average aperture, performing wet etching on the channel holes, and measuring the average aperture of the channel holes after wet etching; s60, judging whether the measured average aperture of the channel holes is smaller than a set aperture lower limit value or not; and if yes, repeating the step 50 and the step S60 until the average aperture of the channel hole measured after wet etching again is not smaller than the set aperture lower limit value. According to the preparation method, the stability of the aperture of the channel hole can be remarkably improved.

Embodiments of the present disclosure provide a wet cleaning device and a wet cleaning system, which relate to the technical field of semiconductor equipment and are used for saving liquid consumption of lubricating devices. The display panel comprises a conveying device, a cleaning device and a liquid storage device. The conveying device is used for conveying target objects. The cleaning device comprises a cleaning port and a liquid discharge port. The cleaning port is used for outputting a first liquid to the target objects to clean the target objects. The liquid discharge port is used for discharging a second liquid, which is formed after the target objects are cleaned by the first liquid. The liquid storage device is connected with the liquid discharge port of the cleaning device to store the second liquid. The liquid storage device can also output the second liquid to the conveying device to lubricate the conveying device. The wet cleaning device is used for recycling the liquid used for cleaning the target objects.