35results about "Paper material treatment" patented technology

This utility model discloses a papermaking tail pulp recovery device, relating to the technical field of tail pulp recovery equipment. It includes a primary separation cylinder, a pulp inlet pipe, and a primary overflow pipe. A separating cylinder, corresponding to and connected to the inlet end of the primary overflow pipe, is fixed on the inner wall of the top of the primary separation cylinder. It also includes a reinforced buffer mechanism to reduce the impact of the tail pulp on the separating cylinder. The reinforced buffer mechanism includes a damping plate attached to the wall of the separating cylinder, an mounting part for conveniently assembling the damping plate to the cylinder body, and a reinforcing part for increasing the connection strength between the separating cylinder and the inner wall of the top of the primary separation cylinder. The pulp inlet pipe corresponds to the damping plate. This utility model, through the installation of the damping plate, can effectively suppress the shaking caused by tail pulp scouring, reduce the stress at the connection between the separating cylinder and the primary separation cylinder, and reduce the risk of the separating cylinder falling off due to long-term impact.

The application belongs to the field of comprehensive utilization of biomass, and relates to a method for preparing nanocellulose based on dissociation of biomass in an ionic liquid / water system. Cellulose fibers are added to a binary system composed of ionic liquid and water, and are heated and stirred under high pressure to obtain a cellulose dispersion liquid, which is regenerated and dried to obtain nanocellulose. Compared with the prior art, the process provided by the application is simpler, greener and more efficient. The raw material used in the application belongs to renewable resources, and the nanocellulose prepared therefrom can be widely applied in medicine, fine chemical industry and preparation of new materials, thereby providing a new method for efficient utilization of renewable resources.

This utility model relates to the field of insulating paper production technology and discloses a pulp filtration device for insulating paper production, including a support frame, a recycling frame placed on the inner wall of the support frame, a filter frame fixedly installed on the inner wall of the support frame, a filter screen disposed in the filter frame, and a control component disposed in the support frame. In this pulp filtration device for insulating paper production, when the output shaft of the motor drives the circular plate to rotate on the side of the support frame, the movable rod hinged to the surface of the circular plate can be folded and push the connecting rod to move longitudinally on the surface of the vertical rod. During the movement of the connecting rod, the support frame fixed at the bottom of the connecting rod and the support rod can simultaneously be longitudinally squeezed within the filter frame, applying pressure to the pulp. This can push the free water and some bound water in the pulp to quickly pass through the filter screen, thereby breaking the bottleneck of the filter cake layer that hinders water penetration and avoiding the impact of increased resistance on filtration efficiency.

This invention discloses a method for the stepwise extraction of single components from high-purity insoluble dietary fiber, belonging to the field of chemical separation and extraction technology. The method specifically includes: (1) Lignin extraction: reacting high-purity insoluble dietary fiber with a eutectic solvent at high temperature, filtering to obtain filtrate and precipitate one, and then concentrating, settling, washing and drying the filtrate to obtain lignin; (2) Hemicellulose extraction: adding acetone to precipitate one and stirring and centrifuging to obtain precipitate two; then adding alkaline solution to precipitate two, stirring and settling to obtain precipitate three and supernatant; then subjecting the supernatant to alcohol precipitation and freeze-drying to obtain hemicellulose; (3) Cellulose extraction: washing and freeze-drying precipitate three to obtain cellulose. Through the above method, the stepwise extraction of single components from insoluble dietary fiber can be achieved with high purity; in addition, the raw materials used are inexpensive, and waste can be utilized at high value, reducing resource waste.

The application discloses high-whiteness lignin-rich cellulose nanofiber and a preparation method and application thereof. The method comprises the following steps: pretreating wood fiber raw materials by dilute sulfuric acid, removing at least part of hemicellulose and amorphous carbohydrates in the raw materials, relatively enriching lignin in the solid phase; then, performing bleaching treatment by alkaline hydrogen peroxide, reducing the content of color groups in the lignin and retaining more lignin structure; finally, performing mechanical nanofibrillation treatment, obtaining high-whiteness lignin-rich cellulose nanofiber with a lignin content of 15% to 30% and a whiteness of 60 to 90. The obtained nanofiber has the ultraviolet shielding capability in the 200-400 nm wave band while improving the whiteness and maintaining a high lignin content, and when about 5% of the nanofiber is added into a sunscreen composition, the sunscreen index of the sunscreen composition is 34-40, and the nanofiber has the dispersion performance in a non-polar solvent. The material can be used for preparing a barrier film, an ultraviolet shielding film and a sunscreen composition.

This utility model relates to a siphon for papermaking. When pulp needs to be transported, the siphon is installed above the pulp tank via a frame, and the inlet end of the siphon body extends into the pulp tank. Then, the siphon body is operated, allowing the pulp in the pulp tank to enter the siphon body through the inlet end and then be discharged through the outlet end. Before the pulp enters the inlet end, large particles in the pulp are isolated by a filter cover. The finer pulp enters the filter cover through the filter holes and is then sucked in by the siphon body. Because the particles in the pulp are sticky, they easily stick to the outside of the filter cover, affecting the pulp's entry into the filter cover through the filter holes. The washing component can be operated to wash the filter cover in the pulp tank, thereby removing the particles that were originally stuck to the filter holes, allowing the pulp to enter the filter cover for siphoning more effectively. This reduces the chance of siphon clogging and allows the siphon to transport pulp more efficiently.

The utility model discloses a convenient to clean's net front centrifugal screen, including base, the base is fixed with the box, the inside rotation of box is equipped with centrifugal cylinder, the upper end opening of box is equipped with the filter box for carrying out the filtration to the paper pulp to the top of box, the filter box is equipped with the funnel shape's feeding opening of penetration, be equipped with the filter mechanism in the feeding opening, the filter mechanism includes the filter screen of detachable setting in the feeding opening, compared with prior art, the utility model has the beneficial effects that: the utility model discloses a convenient to clean's net front centrifugal screen through design detachable filter screen and lifting mechanism cooperation, effectively avoided the paper pulp waste and greatly simplified the cleaning process of centrifugal cylinder and screen cloth, and the design of the crushing knife and the scraper is combined, not only improves the filtration effect of the paper pulp, but also prevents the filter screen from being blocked, the overall optimization paper pulp processing efficiency and quality, reduces the maintenance cost.

This utility model discloses a screening device for screening pulp, including a screening barrel. A screening screen for screening the pulp is installed in the middle of the screening barrel. A cleaning component for cleaning impurities on the surface of the screening screen is installed on the upper part of the screening screen. The cleaning component includes a stepper motor mounted on the upper part of the screening barrel. A rotating shaft is installed at the output end of the stepper motor to drive several sets of brush blocks to rotate. The output ends of the brush blocks are all attached to the upper surface of the screening screen. An air supply pipe for conveying airflow is installed on the upper part of the screening screen. Several nozzles for spraying airflow onto the surface of the screening screen are installed at the output end of the air supply pipe. Through the coordinated operation of all parts of the cleaning component, impurities trapped on the surface of the screening screen can be quickly cleaned, effectively preventing screen clogging. Compared with manual cleaning of the screening screen, this method has higher cleaning efficiency and can ensure the working efficiency of the entire screening device.

The present application relates to the field of packaging materials, and discloses a method for extracting cellulose from soy sauce residues for preparing food packaging film. The preparation process uses soy sauce residues as raw materials, and after the processes of desalting, drying, degreasing, decoloring, alkalization, acetylation modification, plasticization modification and film preparation, an excellent food packaging material is prepared. The food packaging film prepared by the method retains the environmental protection advantages of biodegradability of natural cellulose and has high safety. Meanwhile, through modification, the aggregation structure of cellulose itself is greatly improved, and glyceryl tri(ethylhexanoate) further reduces the hydrogen bond interaction between cellulose molecules, so that an excellent food packaging film material with smooth and transparent appearance, strong compression plasticity and high tensile strength is prepared.

This invention relates to a method for unclogging or cleaning screens in a continuous kraft paper digester process, wherein the continuous kraft paper digester includes a plurality of screens, each screen having a side facing the digester zone and a side facing the digester wall, the plurality of screens being arranged in a screen ring, the screen ring having at least one screen outlet exiting the digester and at least one screen inlet entering the screen ring; the at least one screen inlet entering the screen ring provides cleaning fluid to the screens for: unclogging, alkalization, or both without stopping the system.

The utility model discloses a kraft paper slurry filtering device relates to all kinds of kraft paper technical field, including device body, the device body inner wall is rotationally arranged with the material discharge reel and the material receiving reel to be provided with the rotating mechanism of driving material discharge reel and material receiving reel rotation, the material discharge reel outside fixed winding has the filter screen, the filter screen movable end is fixedly connected with material receiving reel side wall, the device body upper portion and be located the just above filter screen center place is provided with the feed inlet, one side of device body is provided with the discharge gate and the liquid discharge, the discharge gate is located the above one side of filter screen, this kraft paper slurry filtering device, through setting material discharge reel and material receiving reel, so when filter screen is blocked or wears seriously, can through the release filter screen spare part and the winding filter screen need replacement part, thereby effectively improve the replacement efficiency of kraft paper slurry filtering device and its work efficiency.

This invention is a method for the graded utilization of all components of Arundo donax through segmented fiber crushing. This method, through the coordinated design of front-end and back-end processes, systematically couples customized agronomic front-end processes, differentiated component separation paths, and a shared environmentally friendly purification platform to achieve the joint production of multiple series of high-value products from a single Arundo donax raw material. The method includes the following steps: customized production and supply of targeted raw materials; differentiated separation and pretreatment of whole-plant components; and high-value conversion of components based on the shared purification platform: high-value conversion of leaves to obtain high-purity Arundo donax flavonoids and Arundo donax leaf powder; separation and derivatization of the three culms to obtain xylose / syrup and high-purity lignin, as well as further derivatization to prepare various bio-based chemicals and bio-based materials, including lactide, polylactic acid resin, nanocellulose, and bamboo-based plastic composite materials. This invention achieves efficient, clean, and high-value utilization of all components of Arundo donax, forming a complete industrial chain.

The utility model provides an improved multi -net pulp thickener, including thickener body, its characterized in be that a plurality of filter plates are fixedly connected on the thickener body respectively, and the both sides of each filter plate are provided with pulp storage groove, and the inside of each pulp storage groove is provided with scraping mechanism, and the one side of each pulp storage groove is provided with pulp feeding pipe, and each pulp feeding pipe is connected with pulp storage tank after converging, and the lower part of thickener body is provided with water storage tank, and the lateral wall of water storage tank is provided with water outlet pipe, and the top of thickener body is provided with pulp inlet pipe, through setting cleaning mechanism, and the cleaning mechanism is only set on the filter plate of the upper part and the middle part of thickener body, when filtering a certain time, there is the problem of filter hole blockage, at this moment, through starting electric push rod A, makes it drive water sump and scraper brush to move back and forth on the filter plate, starts water pump to send water to water sump through elastic water pipe and sprays through water spray hole, realizes the integrated structure of cleaning and flushing.

This utility model relates to a scraper for papermaking. When it is necessary to scrape off impurities adhering to the inner wall of the filter cylinder, a screw jack can be operated to drive the scraper downward through the pressure plug. This allows the pulp inside the filter cylinder to be better discharged from the outside of the filter cylinder under the pressure of the pressure plug. At the same time, the scraper scrapes the inner wall of the filter cylinder, causing the impurities on the inner wall to move downward towards the scraper assembly along with the pressure plug and the scraper below the pressure plug. After the pulp is filtered, the pressure plug also scrapes the impurities into the lower scraper assembly. Then, the lower scraper assembly is operated to discharge the impurities to the outside of the device through the lower scraper assembly. Then, the screw jack is operated to reset the pressure plug. At the same time as the pressure plug is reset, the scraper above the pressure plug scrapes the inner wall of the filter cylinder again until the pressure plug is reset to the upper scraper assembly. The scraped impurities are discharged through the upper scraper assembly. Then, the pulp feeding mechanism is operated to filter the next batch of pulp.

The present invention relates to a dilution process for a pressure sorter (100, 200) comprising a rotor (40) rotating within and spaced apart from the screen (60), wherein the supplied material (F) is fed to a sorting area (10) formed by the distance between the rotor (40) and the screen (60), wherein a portion of the supplied materials (F) passes through the screen (60) into the good material zone (30) and forms the good material (A), and the remaining supplied materials (F) are discharged in a reject zone (20) as a reject stream (R), wherein the amount of dilution water (D) added to the reject stream (R) is 0.8 to 3.5 times the amount of the reject stream (R).The present invention further relates to a pressure sorter (100, 200) with a device for adding dilution water, which is suitable for directly adding dilution water (D) into the reject zone (R) of the pressure sorter (100, 200), wherein the amount of dilution water (D) added to the reject stream (R) is 0.8 to 3.5 times the amount of the reject stream (R).

The present application relates to papermaking machinery technical field, disclose a kind of papermaking machinery pulping filtering device, including shell, arc screen plate, feeding mechanism, high-pressure flushing mechanism.Arc screen plate discharge side is equipped with multiple groups of reflection unit, each group of reflection unit includes an arc elastic baseband and the reflection plate rotatably arranged on its two sides by connecting assembly.The end of each reflection unit is connected with horizontal support rod by elastic suspension assembly.Horizontal driving mechanism drives support rod to move horizontally, and the power source of this mechanism is derived from the falling water flow of impact impeller.When working, the falling water flow impacts the reflection plate to produce upward splashing, and continuously scours the back of arc screen plate;When reflection unit moves horizontally, reflection plate can be close to the back of arc screen plate for auxiliary physical cleaning.The present application realizes the recycling of wastewater kinetic energy, forms continuous, dynamic composite self-cleaning, and significantly improves the anti-clogging ability.

A cleaner system for removing solid debris and contaminants from a feed slurry includes a cleaner operable to separate a feed slurry into an accepted slurry and a reject slurry, the reject slurry including the solid debris and contaminants. The cleaner system further includes a dilution device fluidly coupled to a reject outlet of the cleaner. The dilution device includes a dilution water hydrocyclone having a dilution water inlet, a cyclonic flow section, an underflow outlet at a downstream end of the cyclonic flow section, and a reject slurry inlet in a top of the dilution water hydrocyclone. The dilution water hydrocyclone further includes a flow director disposed between the dilution water inlet and the reject slurry inlet and operable to direct the flow of dilution water from the dilution water inlet in at least an axial direction towards the cyclonic flow section.

The utility model discloses a kind of paper pulp board pulping and deslagging devices, including box, the both sides of the box are penetrated by bearing and have installation cover, and two groups of installation cover are equipped with filter screen pipe, the inside of the box is provided with gas reservoir, the side of the box is equipped with cover, and the side of cover is equipped with driving motor and servo motor, the output end of driving motor is fixedly sleeved with main gear, the side wall of left side one group of installation cover is fixedly sleeved with driven gear, the side of left side one group of installation cover is penetrated by bearing and has installation shaft, and the side wall of installation shaft is equipped with multiple groups of stirring vane, the output end of servo motor is connected with installation shaft by shaft coupling. Advantageous effect: the utility model has adopted installation cover and filter screen pipe, by installation cover and filter screen pipe set, without the aid of screw structure, just can realize the deslag work to paper pulp liquid, bring guarantee for the continuous use of paper pulp board pulping and deslagging device.

This utility model discloses a kraft paper pulp filtering device, relating to the technical field of pulp processing equipment. It includes a filter box with a feed pipe fixedly connected to its top. A fixed box is fixedly connected inside the filter box, and two movable seats are rotatably connected inside. Filter screens are embedded inside the movable seats. Pulp is injected into the filter box through the feed pipe, and the pulp is filtered through the filter screens inside the movable seats. The pulp remains on the outer surface of the filter screens. After the water drains, a flipping mechanism drives the two movable seats to flip towards the fixed box, causing the two filter screens to press against two scraper plates. A sliding lifting plate scrapes off the pulp remaining on the filter screens and collects it inside the fixed box. After cleaning, the flipping mechanism drives the filter screens to flip back to their original position for reuse. This device is easy to operate and improves the efficiency of pulp collection.

This utility model discloses a pulp impurity cleaning device for paper product production, relating to the field of paper product manufacturing technology. The utility model includes a housing, a backflush anti-clogging component, and an automatic impurity cleaning component. A filter screen is fixedly connected between the two sides of the inner cavity of the housing, and a discharge pipe is connected to the right side of the housing. The backflush anti-clogging component includes a backflush hood. This utility model utilizes the intermittent high-pressure gas generated by a pulsed airflow delivery mechanism, combined with a rotatable backflush hood, to impact the mesh of the filter screen. This causes small particles of impurities clogging the filter screen pores to be instantly blown away by the high-pressure airflow, ensuring that blockages in different areas of the filter screen are effectively removed. This avoids the localized residue problems caused by traditional unidirectional cleaning. The electric cylinder-driven squeezing block further reinforces the positioning of the backflush hood, enhancing the stability of the concentrated airflow injection and significantly reducing the frequency of filter screen clogging.

The utility model discloses a toilet paper repulping filtering mechanism which comprises a paper pulp pool, a pulp filtering half cylinder and an impurity scraping plate, a supporting block is fixedly installed on the inner wall of the paper pulp pool, a filtering screen is fixedly installed on the arc-shaped bottom face of the pulp filtering half cylinder, the pulp filtering half cylinder is placed on the supporting block, installation plates are symmetrically and fixedly installed on the paper pulp pool, and the supporting block is fixedly installed on the installation plates. A rotating shaft is mounted between the two mounting plates, one end of the rotating shaft is connected with the output end of a servo motor, mounting blocks are symmetrically and fixedly mounted on the rotating shaft, mounting grooves are formed in the mounting blocks, and mounting connecting rods are symmetrically welded to the bottom surface of the impurity scraping plate. The automatic cleaning device has the advantages that the paper pulp pool, the pulp filtering half cylinder and the impurity scraping plate are arranged, impurities intercepted on the filter screen can be automatically cleaned under the condition that the machine is not shut down for a long time, the working efficiency is higher, and the automatic cleaning device is more reliable to use, not prone to breaking down and higher in practicability.

The application relates to a radial pulp distributor with a centrifugal degassing function and relates to the field of papermaking equipment. The pulp distributor comprises a pulp distribution cylinder, a cover body fixed to the top of the cylinder, a cylinder coaxially arranged at the center of the bottom end of the interior, a spiral flow guide plate, a feeding pipe and a plurality of discharging pipes. The spiral flow guide plate is connected between the inner wall of the cylinder and the outer wall of the cylinder and extends from bottom to top, and jointly forms a spiral channel; the feeding pipe is communicated with the lower half of the cylinder, is connected in a tangent direction and is communicated with the bottom inlet of the spiral channel; the discharging pipes are uniformly distributed on the upper half of the cylinder, and a degassing port is arranged on the cover body. The application realizes gas-liquid separation by utilizing the centrifugal force generated by the fluid kinetic energy of the pulp itself through the bottom oblique cutting feeding and the internal spiral channel, integrates the centrifugal degassing and the pulp distribution in situ, eliminates the huge front independent degassing equipment and the additional mechanical power, effectively shortens the flow pipe, saves the floor area and reduces the overall energy consumption of the system.

The invention relates to a hydrocyclone device (1) for centrifugal separation of solids from a suspension, having at least one first hydrocyclone (2.1) and at least one second hydrocyclone (2.2), and a common outlet (7) for the lean suspension fraction of the at least one first hydrocyclone (2.1) and the at least one second hydrocyclone (2.2), wherein the common outlet (7) is arranged within a common inlet housing (10) of the hydrocyclone device (1), a deflection device (8.1, 8.2) arranged within the inlet housing (10) is provided for the first upflow pipe (6.1) of the first hydrocyclone (2.1) and the second upflow pipe (6.2) of the second hydrocyclone (2.2), respectively, the deflection device being designed to deflect the axially discharged lean suspension fraction in a direction having a radial directional component, so that the lean suspension fraction is introduced into the common outlet (7) with said radial directional component, respectively.

The application discloses aile lyocell fiber, a preparation method and application, wherein the preparation method comprises the following steps: obtaining ailao powder from fresh ail leaves; under fermentation conditions, the ailao powder is fermented by microorganisms to selectively degrade lignin and hemicellulose in the ail leaves, and an ail leaf cellulose pulp rich in active ingredients is obtained; the ail leaf cellulose pulp is subjected to auxiliary hydrolysis by sodium chlorite and sodium hydroxide to obtain purified ail leaf cellulose; the purified ail leaf cellulose is dissolved in N-methyl morpholine-N-oxide aqueous solution, an antioxidant and an alkaline adjusting agent are added, and a spinning dope is obtained; and the spinning dope is subjected to post-treatment to obtain the ail lyocell fiber. The application provides the ail lyocell fiber, the preparation method and the application, adopts a microbial fermentation technology as a core, and realizes efficient extraction of cellulose and in-situ reservation of natural active ingredients under mild conditions by screening of efficient composite microbial flora for directional degradation of lignin and hemicellulose in the ail leaves.

The utility model relates to a kind of single-cycle pulping system based on automatic control of paper pulp molding, it is related to paper pulp molding production technical field, including the machine table mechanism of top one-way opening, the top of machine table mechanism is hung and is connected with the mounting mechanism of U-shaped structure, it is solved that pulp used by forming machine is recycled, however, when model repairing, machine repairing operation is carried out in forming machine, product dark point is easily increased, a forming machine appears problem and is repaired, the impurities etc. generated can pollute the whole pulping system problem, through pulping system using single-cycle mode, through liquid level module real-time monitoring machine table mechanism inner liquid level, and data transmission is given to external control equipment and is regulated, can accurately control pulp quantity, avoid impurity mixing into pulp due to liquid level anomaly, reduce product dark point generation, simultaneously, under single-cycle mode, each machine table mechanism independently operates, the impurities generated when a device is repaired cannot spread into the pulp of other equipment.

This utility model discloses a slag removal device for improving the quality of kraft paper pulp, relating to the field of kraft paper production technology. It includes a slag removal cylinder, a discharge pipe fixed to the bottom edge of the cylinder, a conical platform fixed to the bottom center of the cylinder's inner cavity, a support column fixed to the bottom of the cylinder, a drive motor fixed to the bottom center of the cylinder, and an installation cylinder fixed to the end of the drive motor's output shaft. A filter cylinder is connected inside the installation cylinder, and a disassembly / assembly mechanism is provided on the outside of the filter cylinder. This slag removal device for improving the quality of kraft paper pulp utilizes the disassembly / assembly mechanism. By pulling a pull plate, a connecting plate moves, causing a locking block to retract into the shrinkage cavity. This allows the filter cylinder to be pulled, disassembling it entirely and facilitating the removal of all filter residue inside. This makes removal simpler and more convenient, saving time and effort, and improving the practicality of the device.

TITLE. Asymmetrical Foil or Blade Shutter Device. The present invention relates to a shutter device (1) for closing an orifice (21) of a fluid supply nozzle (2). The device (1) consists of a rotor (3) having at least one blade (4) carried by a shaft whose axis of rotation (5) is parallel to the axis (22) of the nozzle. The blade, as it rotates, alternately opens and closes the orifice of the supply nozzle. The blade comprises a closing face (6) and an opening face (7) of the orifice (21). The closing face is formed by the edge of the blade that first comes into contact with the nozzle when it closes, while the opening face is the edge of the blade opposite the first edge of the blade constituting the closing face. According to the present invention, the blade (4) has an asymmetrical design. Fig. 3

Sorter with a sieve element of essentially rotationally symmetrical shape, open at both its ends (inlet and outlet) and with a sorting element-carrying rotor whose axis of rotation is the same as the axis of rotational symmetry, wherein the sieve elements have different diameters between the inlet and outlet in order to maintain a differential velocity between the sorting elements and the circumferential velocity component of the material to be sorted up to the outlet, characterized in that at least two rotor sections (3A, 3A'; 3B, 3B') with different diameters and associated diameter-matched sieve elements (2A, 2A'; 2B, 2B') are arranged in the axial direction, and are rigidly connected to each other in the axial direction via an adapter (A, A') between the two sieve elements (2A, 2B; 2A', 2B').

This invention provides a waste paper recycling and paper-plastic separation device, belonging to the technical field of pulp separation equipment. It includes a separation device, a separation chamber, a pulp filtration chamber, a filter plate, and filter holes. Multiple deformation grooves are formed around the circumference of the filter holes, creating multiple movable parts. A bracket is installed inside the pulp filtration chamber, and multiple electromagnet modules are mounted on the bracket to create multiple arc-shaped magnetic fields on the outer side of the filter plate. This invention, by creating multiple deformation grooves around the filter holes, forms multiple elastically deformable movable parts. Simultaneously, electromagnet modules that can reciprocate along the length of the filter plate are arranged on the outer side. The magnetic field generated by the electromagnet modules can generate a magnetic attraction force on the movable parts, causing them to deform towards the electromagnet modules. This increases the inner diameter of the filter holes, allowing clogged materials to be discharged, achieving a cleaning effect.