In the event of heavy rain, the little umbrella cannot withstand the torrential rain. Not only the shoes and socks are soaked, but even the love bag is also suffered. If the bag has been exposed to rain, if it is not disposed of immediately, it means that the moldy day is not far from you! Here are five key points for maintaining and storing leather handbags:
Wipe dry with water
Not all leather bags are coated with waterproof paint. If your bag is spilled with water, wipe it off immediately with a dry cloth. If it is a non-smooth fabric made of suede, it is recommended to use point pressing to avoid damaging the fiber surface of the leather. Try not to wipe the bag with tissue paper, because the tissue paper will be crumbs and difficult to remove completely. A lighter cloth should be used. If it is rubbed excessively for cleaning, it will cause secondary damage to the bag.
Ventilation hanging upright
Bags that are not in use or splashed with water should be placed in a well-ventilated place. For leather products, keep away from high temperature, do not expose to the sun, and do not use a hair dryer in case of water. Because the temperature will damage the leather surface, causing cracks or even direct damage.
Good dust protection, good use of white paper
Bags that will not be used for a long time, please wrap them in dustproof bags and store them in a moisture-proof cabinet. Before storing, you can put white newspaper in the bag, on the one hand, to avoid deformation, on the other hand, you can use the white newspaper to absorb the moisture in the air. Do not use ordinary newspapers, as black ink may leave marks on the bag due to friction.
Clean the leather bag regularly
The luster of the leather will fade over time. Regularly dusting, wiping the surface with a dry cloth and a small amount of petroleum jelly or leather maintenance oil can keep the leather bright and beautiful. If it gets dirty, be sure to remove it with a special cleaner.
What to do if the bag is moldy
If there are only long spots on the surface, you can wipe it with a dry cloth first, then spray alcohol on another clean cloth, and then wipe it again. Be sure to air dry after cleaning. If the mildew cannot be wiped off, you have to take it to a professional leather maintenance shop.
Everyone has seen or used an excavator bucket, so how is an excavator crusher bucket made? Why is it so strong, and what material is it made of?
The first is cutting
Cutting is to cut and shape the steel plate used to make the excavator bucket. Generally, Q345B steel plate and HQ60 steel plate are used for the excavator bucket. Now, more and more manufacturers are starting to use wear-resistant steel plates or Swedish hardox steel plates as the main material of buckets. After the material arrives at the factory, flame plasma cutting is usually used. After the material is cut, it is pressed into a certain shape using a forging press.
Followed by earboard team
Ear plate team refers to the combination of cut and forged steel plates according to the requirements of the drawing to form the shape of the ear plate. According to different excavator models, the assembly drawings are different, which is related to whether the bucket is suitable for the excavator. After the ear plate is assembled according to the drawing, it must be sent to the welding area and welded on the welding positioner, which can improve the accuracy and reduce the deformation.
Then finishing
After welding, the ear plate will be finished on the boring machine to make the ear plate hole more suitable. After that, the bucket is installed according to the mold and the ear plate group. Different types of excavator buckets have different mold sizes. After rough welding, the assembled bucket is placed on the welding positioner and welded to ensure the quality of welding.
Finally, it is painted
After welding, the bucket also needs to be shot blasted to remove the oxide scale on the surface and eliminate welding internal stress. After the shot blasting, the bucket will become smooth and tidy. The finished bucket is sent to the painting workshop, and after leveling by putty, primer coating, topcoat coating, the beautiful finished bucket is thus produced.
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The three-level maintenance includes: daily maintenance of the equipment, primary maintenance and secondary maintenance. The three-level maintenance system is a mandatory maintenance system in which the operator is mainly responsible for the protection of the livestock sorting equipment and the warranty is important. The three-level maintenance system relies on the masses and gives full play to the enthusiasm of the masses. It implements an effective method of group management, group integration, and equipment maintenance.
Daily maintenance of the equipment, generally have daily maintenance and weekly maintenance, also known as daily maintenance and weekly insurance.
1. Daily insurance
The daily maintenance is carried out by the equipment operators on duty, and the four things in front of the class, the five notes in the class and the four things in the class are earnestly carried out.
(1) Four things before the class Digest the pattern data and check the handover record. Wipe the equipment and lubricate as required. Check that the handle position and manual operation are correct and flexible, and that the safety device is reliable. Check the transmission for normal operation at low speed, and whether lubrication and cooling are smooth.
(2) Class 5 pay attention to the operation sound, equipment temperature, pressure, liquid level, electrical, hydraulic, pneumatic system, instrument signal, safety insurance is normal.
(3) Four things after the shift Turn off the switch and put all the handles to zero. Remove iron filings, dirt, and clean the oil on the rail and sliding surfaces of the equipment and refuel. Clean the workplace, organize attachments and tools. Fill in the shift record and the record of the operation desk, and go through the handover procedure.
2. Weekly insurance
The weekly maintenance is carried out by the equipment operators every weekend. The maintenance time is: general equipment 2h, fine, large and rare equipment 4h.
(two) primary maintenance
The first-level maintenance is based on the operator, the maintenance worker assists, partially disassembles and inspects the equipment according to the plan, cleans the specified parts, clears the oil circuit, pipeline, replaces or cleans the oil line, felt, oil filter, and adjusts the various parts of the equipment. Fit the gaps and tighten the various parts of the equipment.
The time for primary maintenance is 4-8h. After the completion of the first maintenance, records should be made and the defects that have not been cleared should be recorded. The workshop mechanics will organize the acceptance. The scope of a guarantee shall be that the enterprise is fully equipped, and the key equipment shall be strictly implemented.
The main purpose of the first insurance is to reduce equipment wear, eliminate hidden dangers, extend the service life of the equipment, and provide equipment protection for the production tasks during the next insurance period.
3.Secondary maintenance
The secondary maintenance is mainly based on maintenance workers, and the operators are involved to complete. Secondary maintenance is included in the equipment maintenance plan, partial disassembly inspection and repair of the equipment, replacement or repair of worn parts, cleaning, oil change, inspection and repair of electrical parts, so that the technical status of the equipment fully meets the requirements of the required equipment integrity standards. The time taken for secondary maintenance is about 7 days.
The three-level maintenance system highlights the status of maintenance in equipment management and planned maintenance work, and further clarifies the requirements of “three good” and “four meetings” for operators, and improves the knowledge and skills of operators to maintain equipment.
The three-level maintenance system broke through the relevant regulations of the former Soviet Union's planned pre-repair system, and improved some shortcomings in the planned pre-repair system, which is more realistic. In the implementation of the three-level maintenance system, he also learned to absorb some of the military's management of weapons, and emphasized the group management.
The three-level maintenance system has achieved good results and experience in the country, and the implementation of the three-level maintenance system has effectively improved the integrity of the equipment, reduced the equipment accident rate, extended the equipment overhaul cycle, and reduced the equipment maintenance period. Livestock sorting equipment overhaul costs have achieved good technical and economic results.
Daily maintenance of the equipment, generally have daily maintenance and weekly maintenance, also known as daily maintenance and weekly insurance.
1. Daily insurance
The daily maintenance is carried out by the equipment operators on duty, and the four things in front of the class, the five notes in the class and the four things in the class are earnestly carried out.
(1) Four things before the class Digest the pattern data and check the handover record. Wipe the equipment and lubricate as required. Check that the handle position and manual operation are correct and flexible, and that the safety device is reliable. Check the transmission for normal operation at low speed, and whether lubrication and cooling are smooth.
(2) Class 5 pay attention to the operation sound, equipment temperature, pressure, liquid level, electrical, hydraulic, pneumatic system, instrument signal, safety insurance is normal.
(3) Four things after the shift Turn off the switch and put all the handles to zero. Remove iron filings, dirt, and clean the oil on the rail and sliding surfaces of the equipment and refuel. Clean the workplace, organize attachments and tools. Fill in the shift record and the record of the operation desk, and go through the handover procedure.
2. Weekly insurance
The weekly maintenance is carried out by the equipment operators every weekend. The maintenance time is: general equipment 2h, fine, large and rare equipment 4h.
(two) primary maintenance
The first-level maintenance is based on the operator, the maintenance worker assists, partially disassembles and inspects the equipment according to the plan, cleans the specified parts, clears the oil circuit, pipeline, replaces or cleans the oil line, felt, oil filter, and adjusts the various parts of the equipment. Fit the gaps and tighten the various parts of the equipment.
The time for primary maintenance is 4-8h. After the completion of the first maintenance, records should be made and the defects that have not been cleared should be recorded. The workshop mechanics will organize the acceptance. The scope of a guarantee shall be that the enterprise is fully equipped, and the key equipment shall be strictly implemented.
The main purpose of the first insurance is to reduce equipment wear, eliminate hidden dangers, extend the service life of the equipment, and provide equipment protection for the production tasks during the next insurance period.
3.Secondary maintenance
The secondary maintenance is mainly based on maintenance workers, and the operators are involved to complete. Secondary maintenance is included in the equipment maintenance plan, partial disassembly inspection and repair of the equipment, replacement or repair of worn parts, cleaning, oil change, inspection and repair of electrical parts, so that the technical status of the equipment fully meets the requirements of the required equipment integrity standards. The time taken for secondary maintenance is about 7 days.
The three-level maintenance system highlights the status of maintenance in equipment management and planned maintenance work, and further clarifies the requirements of “three good” and “four meetings” for operators, and improves the knowledge and skills of operators to maintain equipment.
The three-level maintenance system broke through the relevant regulations of the former Soviet Union's planned pre-repair system, and improved some shortcomings in the planned pre-repair system, which is more realistic. In the implementation of the three-level maintenance system, he also learned to absorb some of the military's management of weapons, and emphasized the group management.
The three-level maintenance system has achieved good results and experience in the country, and the implementation of the three-level maintenance system has effectively improved the integrity of the equipment, reduced the equipment accident rate, extended the equipment overhaul cycle, and reduced the equipment maintenance period. Livestock sorting equipment overhaul costs have achieved good technical and economic results.
Geotextile, also known as geofabric, is usually a water-permeable geosynthetic material made of synthetic fibers by needle punching or weaving processing way. Geotextile belongs one of new geosynthetics materials. The finished permeable geotextile product is cloth-like, usually with a width of 1-6 meters and a length of 50-200 meters. Geotextiles are divided into woven geotextiles and non-woven geotextiles.
Permeable Geotextile characteristics
1. High strength. Due to the use of plastic fibers, it can maintain sufficient strength and elongation in dry and wet conditions.
2. Corrosion resistance, long-term corrosion resistance in soil and water with different pH.
3, Good water permeability with fine openings between fibers.
4. Good biological resistance.
5. Easy installation because permeable geotextile is light and soft, which makes it convenient to transport, lay and install.
6. Wide specification range: width up to 6 meters, mass per unit area: 100-1000g /m2
Geotextile Application
Separation
Permeable geotextile is used to separate construction engineering materials with different physical properties, so that two or more materials are not be lost or intermixed. Thus, the overall structure and function of each material are maintained, which of loading capacity is strengthened.
Filtration
When the passage of liquid flows from the fine soil layer into the coarse soil layer, the good air permeability and liquid permeability of the permeable geotextile (usually is nonwoven geotextile) are used to pass the liquid flow and effectively prevent the loss of soil particles, fine sand, small stones, and so forth to keep soil and liquid engineering structure stable.
Drainage
Permeable geotextile has good water drainage property. It can form drainage passages inside the soil and discharge excess liquid and gas in the soil structure.
Reinforcement
Permeable geotextile is used to enhance the strength and anti-deformation ability of the soil body, to enhance the stability of construction structure by improving soil performance.
Protection
When water flow scours soil, permeable geotextile effectively diffuses, transfers or decomposes the concentrated stress to protect the soil from being damaged by external forces from water flow.
Puncture-resistance
Permeable geotextile can be composited with geomembrane to form a composite waterproof and anti-seepage material, which plays the role of puncture prevention.
Main Geotextile Types
1.Non-woven geotextile
The main raw material is polyester or polypropylene fiber. And in construction field, needle punching nonwoven geotextile is most widely used because it has five primary applications (separation, filtration, drainage, reinforcement and erosion control) which are commonly designed and required in the civil engineering structures of construction industry.
2.Woven geotextile
Woven geotextiles are obtained by polymer fibers, then spun into threads, and weaving on a loom to form a cloth with a regular organization. Because of their interlaced structure, they usually have higher strength than same material and density nonwoven geotextiles. But in the other aspect, they usually have lower properties in filtration and drainage of nonwoven geotextiles.
Pet Woven Geotextile
3.Geotextile Composites
① Needle-punched non-woven permeable geotextile composited with PE film Ordinary specification is one nonwoven geotextile with one film and two nonwoven geotextiles and one film. The main purpose of using this geotextile composite material is to prevent Infiltration, to enhance its anti-shear property and to improve the plane drainage performance between this liner and its overlying & underlying materials in the same time. They can be applied in railway, highway, tunnel, subway, airport, dams, reservoirs and other civil engineering projects.
② Non-woven and woven composite geotextiles
Needle punched non-woven geotextile and woven geotextile can be composited to one compound material. This compound material can provide excellent reinforcement and permeability coefficient property.
Polyester Nonwoven and Woven Composite Geotextiles
③ Geotextile and geogrid composites
Permeable nonwoven needle punched geotextile and woven geogrid can be compounded to make a composite geosynthetic material which provides both reinforcement and permeability applications.
Geotextile and Geogrid Composites
Shanghai Yingfan Environmental Engineering Co., Ltd., is specialized in R&D, manufacture, sales and installation services of geotextiles and other geosynthetic lining products. Certified by ISO 9001, 14001, OHSAS18001, our company provides top quality products and professional installation service.
Semiconductors are divided into: intrinsic semiconductors and impurity semiconductors. An intrinsic semiconductor is a semiconductor that is pure and contains no impurities. An impurity semiconductor refers to a semiconductor containing impurities. What we usually mean by semiconductors is impurity semiconductors.
The structural characteristics of semiconductors are covalent bonds. Covalent bonds have a strong binding force, allowing atoms to be regularly arranged to form crystals.
Intrinsic semiconductors are composed of semiconductor silicon and germanium, and their outermost electrons (valence electrons) are four. In silicon and germanium crystals, atoms form a crystal lattice according to a tetragonal system. Each atom is located at the center of a regular tetrahedron, while four other atoms are located at the apex of the tetrahedron. Each atom is formed between the atoms adjacent to it Covalent bond, sharing a pair of valence electrons.
The two electrons in the covalent bond are tightly bound in the covalent bond, which is called a bound electron. At room temperature, it is difficult for bound electrons to escape from covalent bonds and become free electrons. There are very few free electrons in intrinsic semiconductors, so the intrinsic semiconductors have very poor electrical conductivity.
When T=0K and no external excitation, the valence electrons are completely bound by covalent bonds. There are no movable charged particles in the intrinsic semiconductor, and its conductivity is 0, which is equivalent to an insulator. At room temperature, due to thermal excitation, some valence electrons get enough energy to escape from the covalent bond and become free electrons. At the same time, a vacancy is left on the covalent bond, which is called a hole. The higher the temperature, the higher the carrier concentration.
In intrinsic semiconductors, there are two types of carriers, namely free electrons and holes, and one electron has one hole.
Under the action of an external electric field, holes attract nearby electrons to fill them. This result is equivalent to the migration of holes, and the migration of holes is equivalent to the movement of positive charges. Therefore, holes can be considered as carriers.
In an intrinsic semiconductor, the current consists of a current generated by free electron movement and a current generated by hole movement. Its conductivity depends on the concentration of carriers. Due to the low carrier concentration, the conductivity is generally poor. However, the carrier concentration depends on the temperature. The higher the temperature, the higher the carrier concentration, and the stronger the conductivity of the intrinsic semiconductor.
Impurity semiconductors are divided into N-type semiconductors and P-type semiconductors. Semiconductors doped with certain trace elements in the intrinsic semiconductor are called intrinsic semiconductors. N-type semiconductor refers to a semiconductor doped with a pentavalent impurity element such as phosphorus, and the free electron concentration is greatly increased. P-type semiconductor refers to a semiconductor doped with a trivalent impurity element (such as boron), and an impurity semiconductor having a greatly increased hole concentration.
In N-type semiconductors, free electrons are majority carriers, which are mainly provided by impurity atoms; holes are minority carriers, which are formed by thermal excitation. Pentavalent impurity atoms that provide free electrons become positive ions because they are positively charged, so pentavalent impurity atoms are also called donor impurities. In P-type semiconductors, holes are majority carriers, which are mainly formed by doping; free electrons are minority carriers, which are formed by thermal excitation. Holes can easily trap electrons, making impurity atoms negative ions. Trivalent impurities are therefore also called acceptor impurities.
On the same semiconductor substrate, P-type semiconductors and N-type semiconductors are separately manufactured. After the carrier diffusion, a PN junction is formed at their interface. In the space-charge region, due to the lack of multiples, it is also called a depletion layer. When the applied voltage causes the potential of the P region in the PN junction to be higher than the potential of the N region, it is called plus forward voltage, referred to as forward bias; otherwise it is called plus reverse voltage, referred to as reverse bias.
When the forward voltage is applied to the PN junction:
1.Low resistance
Large forward diffusion current
When reverse voltage is applied to the PN junction:
High resistance
Very small reverse drift current
Unidirectional conductivity of PN junction:
When the reverse voltage of the PN junction increases to a certain value, the reverse current suddenly increases rapidly. This phenomenon is called reverse breakdown of the PN junction. Thermal breakdown is irreversible. Both Zener breakdown and avalanche breakdown are electrical breakdowns, which are reversible.
RGB LED Diode parameters:
1. The maximum rectified current IF refers to the maximum forward average current allowed to flow through the diode when it is used for a long time.
2. The reverse breakdown voltage VBR and the maximum reverse working voltage VRM refer to the voltage value when the diode reverse breakdown. The reverse current increases sharply during breakdown, and the unidirectional conductivity of the diode is destroyed or even overheated and burned out.
3. The reverse current IR is the reverse current when the diode plus reverse peak working voltage. The large reverse current indicates that the tube has poor unidirectional conductivity, so the smaller the reverse current, the better. Reverse current is affected by temperature. The higher the temperature, the greater the reverse current.
4. Forward voltage drop VF
5.Capacitor CB or maximum working frequency