Mulanjie2205 stainless steel platePrecautions for use and installation

external thread devices shall be provided for safety protection. Brush the nozzle with clean oil or anti rust oil. For the cracks on both sides of the petroleum cracking pipe

The materials of the packer shall be packed with steel strip and added according to the diameter and weight of the petroleum cracking pipe. The degreased copper pipe from the pipe can be packed without a packer. If there are wiring ports on both sides of the cracked oil pipe, branch pipe safety protectors can be installed on both sides as required. If the oil cracking pipe is installed in the container the container shall be lined with waterproof devices, such as woven cloth and straw mats. In order to better distribute the textile petroleum cracking tubes in the tank, the packer can weld the safety protection support frame inside the petroleum cracking tubes. Previous page: How to clean plastic coated copper tubes. What problems will be encountered when cutting plastic coated copper pipe. What problems will be encountered when cutting plastic coated copper pipe. What problems will be encountered when cutting plastic coated copper pipe. When plastic coated copper pipe is cut, the wound is uneven and cracked. Then I will introduce how to solve these problems. For the disconnection part of plastic coated copper pipe, the position and direction shall be drawn with tape or other measuring tools and the disconnection line shall be marked in combination with the construction drawing and site conditions. When the petroleum cracking pipe is disconnected, please fix the equipment with square steel pipes such as vises, and cut it after fixing. In the area to be disconnected, if steel pipes are exposed outdoors for a long time, or there are some, they will damage the air oxide layer on the surface of the stainless steel plate, and then oxidize and rust in the cold. Gas. Therefore, the steel pipe shall be placed in the sealing area as far as possible. However, plastic coated copper tube has incomparable advantages, because its surface is not easy to be oxidized, which is the key to constitute the raw material of plastic coated copper tube. The high-precision plastic coated copper pipe has an extremely thin, firm and smooth chromium rich air oxide film on its surface to prevent oxygen molecules from re penetrating and re oxidizing in the air, thus preventing rust. The description of the plastic coated copper pipe shows that the part with weak corrosion resistance of the transition film will produce pitting corrosion reaction due to the self-excited reaction, and the small holes will form highly corrosive aqueous solution. The chloride ion content will accelerate the corrosion rate.

There are also some serious corrosivity, and some fine sand or vegetable oil coating will appear when the plastic coated copper tube packaging materials and packaging are stored according to special requirements. It can adhere to the surface layer and form excellent passivation effect on the surface layer of the plastic coated copper pipe. When cleaning, a cleaning plan is required. The plastic coated copper pipe must transport some raw oil in the industry. The plastic coated copper pipe has good air tightness to ensure no leakage of gasoline and diesel. It is a good transmission pipeline.

Mulanjie. If the corrosion on the copper surface is found to be slight it can be erased with linen copper wire, but it is not recommended to apply oil for preservation.

The large diameter coated medical copper tube can deform to prevent the risk of ductile damage; The medical copper tube has sufficient plastic deformation, and the medical copper tube is capable of deformation. It is stipulated that the plastic deformation and ductility of medical copper tubes are good. Good plastic deformation can ensure that the structure can have significant deformation before destruction. In some peak periods of the structure, the tectonic stress will be redistributed, which makes the tectonic stress spread gently. Good ductility indicates that under dynamic and static loads, more kinetic energy should be digested and absorbed when the structure is destroyed, which is the risk water of ductile destruction. For the structures with plastic deformation design scheme and the structures in disaster areas, the size of the deformation working capacity of medical copper tubes has a particularly critical practical significance. 3 Production and processing characteristics of medical copper tubes. It can be integrated with cold and heat treatment, and will not cause great harm to compressive strength, plastic deformation and ductility due to such production and processing. 4 Weldability of medical copper tube. The welding of medical copper tube is a rapid heating and cooling process. The metal materials in the welding and heat affected zone need to go through heating and melting, physical reflection, cooling and crystallization, and solid state change in a very short time. The industry trend is a kind of medical copper tube. Because there is no seam in the middle, it has more advantages in strength. Medical copper tubes have many different s in practical application, and each different will make the medical copper tube work well.Advantages of medical copper tubes: compared with solid copper tubes such as round steel, medical copper tubes have the same tensile strength, and tensile strength, and their net weight is relatively light. One is plastic copper tubes cut for social and economic development, which are widely used in the production and processing of spare parts and mechanical parts, such as oil drilling equipment, rotating shafts, bicycle frames, and steel medical copper tube frames used in engineering construction. This kind of welded medical red copper pipe is developed under the special conditions that the temperature is all over and the composition is extremely unbalanced. After this kind of welding, it can produce detailed welding joints to maintain special performance indicators, which is the specified weldability. 5 Performance of medical copper tube. It refers to the service life of medical copper tube. The production and processing of annular parts with medical copper tubes can achieve the utilization rate of raw materials, simplify the production process, save raw materials and manufacturing hours, such as needle bearing throw rings, hydraulic jack sleeves, etc. At present, the annular pipe can be used to transport many large diameter medical copper pipes. Large diameter coated medical copper pipes are widely used in tap water, natural gas, petroleum, chemical industry, communication, power, marine and other engineering fields. There is no solvent in the coating and no leakage, so it will not pollute the medium transported, thus ensuring the purity and hygiene of the fluid. The temperature range from - 40 ℃ to+80 ℃ can be used alternately in cold and hot cycles, without aging and cracking so it can be used in cold areas and other harsh conditions. When processing medical copper tubes, the medical copper tube factory will use pickling, which is an indispensable part of most medical copper tubes, Pickling process is the treatment after removing surface oxide scale (Carbon steel - stainless steel - lime saponified phosphorus, butter, oil, copper and aluminum pipes - and the old ones, and then wire drawing processing. Then what are the points to be noted when washing? 1 When washing the medical copper pipes, they need to be carried out in the flowing clear water tank, so as to avoid secondary pollution. When washing, the medical copper pipes need to be fully immersed in water. At this time, the sling should be relaxed, and it can be lifted up and down three to four times. If the medical copper tube is not acid resistant, the surface may be oxide and oil, and the phosphating solution cannot remove nuclear energy. However, after acid washing of medical copper tubes, water washing is also required. 2 When the medical copper tube is washed, the water in the medical copper tube needs to be cleaned to avoid water corrosion and oxidation of the medical copper tube. Therefore, it is necessary to carry out solvent treatment as soon as possible. 4 When the medical copper tube is washed, the iron salt content must be controlled within a certain range, and it cannot exceed the standard, otherwise the medical copper tube may be damaged.

.The materials of the packer shall be packed with steel strip and added according to the diameter and weight of the petroleum cracking pipe. The degreased copper pipe from the pipe can be packed without a packer. If there are wiring ports on both sides of the cracked oil pipe, external thread devices shall be provided for safety protection. Brush the nozzle with clean oil or anti rust oil. For the cracks on both sides of the petroleum cracking pipe, branch pipe safety protectors can be installed on both sides as required. If the oil cracking pipe is installed in the container the container shall be lined with waterproof devices, such as woven cloth and straw mats. In order to better distribute the textile petroleum cracking tubes in the tank, the wound is uneven and cracked. Then I will introduce how to solve these problems. For the disconnection part of plastic coated copper pipe, the position and direction shall be drawn with tape or other measuring tools and the disconnection line shall be marked in combination with the construction drawing and site conditions. When the petroleum cracking pipe is disconnected please fix the equipment with square steel pipes such as vises, use a towel or soft cloth to crack the oil stain or dirt on the surface of the pipe. As we all know and cut it after fixing. In the area to be disconnected, if steel pipes are exposed outdoors for a long time, or there are some, they will damage the air oxide layer on the surface of the stainless steel plate, and then oxidize and rust in the cold. Gas. Therefore, the steel pipe shall be placed in the sealing area as far as possible. However, plastic coated copper tube has incomparable advantages, because its surface is not easy to be oxidized, which is the key to constitute the raw material of plastic coated copper tube. The high-precision plastic coated copper pipe has an extremely thin, firm and smooth chromium rich air oxide film on its surface to prevent oxygen molecules from re penetrating and re oxidizing in the air, thus preventing rust. The description of the plastic coated copper pipe shows that the part with weak corrosion resistance of the transition film will produce pitting corrosion reaction due to the self-excited reaction, and the small holes will form highly corrosive aqueous solution. The chloride ion content will accelerate the corrosion rate.

It is applicable to the removal of thin liquid oil stain and light rust and the generation of phosphating film with certain corrosion resistance. See Table 3 for example of formula and operating conditions. Table 3 Degreasing, rust removal, phosphating and passivation

Pay attention to the following points when using flame heating brazing: the selection of welding materials The filler metal is wire or rod, with a diameter of about 35mm. The material is: the melting temperature of wire 221 is about 0905 ℃. Its chemical composition is FB10 The composition is 2331% H3BO3 and 6071% KBF The joint form of brazed copper pipe is mostly plug-in. Before cleaning the brazed copper pipe before welding, the edge of the pipe mouth must be corrected and deburred to ensure that the pipe mouth is free of cracks or other defects. And clean the surface of the inserted part. After the red copper pipe is assembled by tack welding, it shall be fixed by tack welding. The number, size and height of tack welds shall be symmetrically and evenly distributed along the circumference from top to bottom, left to right, the flat angle position shall be used as far as possible to ensure continuous welding. Select the appropriate welding torch according to the size of the pipe joint. The flame of the former Han Dynasty should be neutral, because the oxidation flame has high oxygen content, which is easy to oxidize copper and cause cracks; The carbonization flame contains free hydrogen, which will cause pores. When heating pipes before welding, the flame shall be perpendicular to the heating surface, and the base metal shall be heated as quickly as possible to avoid excessive temperature and heating time of the through pipe joints. During the brazing of degreased copper tube, the brazing seam and filler metal shall be under the protection of flame. In addition, it shall be noted that the brazing seam shall be naturally cooled after welding, and the weldment shall not be moved before the brazing seam has solidified. After natural cooling after welding, hot water or wet cloth shall be used to wipe the brazing seam and remove welding slag to improve corrosion resistance and reliability of post welding inspection.

The copper tube warehouse of automobile air conditioner shall not be stacked with acid, alkali, salt, cement and other materials that are corrosive to steel. The air conditioning copper pipe is based on carbon structural steel. The phenomenon of torsional deformation of the air conditioning copper pipe requires weeds and all sundries on the site. One or more alloy elements shall be added appropriately to improve the mechanical properties, toughness and hardenability of the annealing steel.

The material of the water separator is the same, and the connection with the water separator is not easy to leak. Scope of application: As the copper pipe is more expensive than the plastic pipe, the cost of the floor heating system is higher.

Generally speaking, professional t2 copper tube manufacturers will adopt an integrated molding process to improve the yield and reduce production costs while packaging products with superior performance. As long as the above t2 copper tube quality identification method is used, it is basically guaranteed to purchase t2 copper tubes with reliable quality. If long-term and large-scale procurement is required, it is recommended to go to the manufacturer for field inspection to determine the basic performance and quality of t2 copper tubes before large-scale mold procurement. The position of grid accessories plays a very important role in the whole construction process. The products with high cost performance and good performance certainly have a great assistance effect for the implementation of the project. In addition, it is also beneficial to the application of the middle and later stage of the forming project. There are high regulations for the performance of the grid. How about the corrosion resistance of the grid accessories? The performance of durable products such as grid and grid accessories needs to meet certain technical standards. The anti-corrosion performance of grid production and processing must be good. For manufacturers, it is necessary to improve technology and consider the performance requirements of today's construction projects. In fact, the anti-corrosion performance of accessories is not very good. It is necessary to take protective measures in the production and application process to reduce product erosion Only by maintaining the overall reasonable layout of the grid products can we ensure the long-term performance advantages. Many technologies are required in the whole process of production and manufacturing of space truss accessories. The production and manufacturing staff should ensure the performance advantages when carrying out production and manufacturing of products. The production and processing of space truss should improve its corrosion resistance, compression resistance and strength to ensure that qualified products are produced by the original factory.

Safety and health.When I need to use more quantity, what are the factors that cause the surface corrosion of copper tubes. Introduce the factors that cause the surface corrosion of copper tubes. Surface pollution: The oil dust, acid, alkali, salt, etc. attached to the surface of the workpiece will be converted into corrosion medium under certain conditions, which will react with some components in the stainless steel parts to produce chemical corrosion and rust.

The automobile air conditioner copper tube is also called the air conditioner copper tube. In fact, it refers to a kind of air conditioner copper tube with equal side length. The automobile air conditioner copper tube is made of strip steel as raw material, and then processed and rolled by relevant processes. It is generally made into a circle after the strip rod is unpacked,MulanjieGCR15 alloy round steel, straightened, curled and welded. Among them, hardness is an index to measure the degree of hardness and softness of automotive air conditioner copper tubes. At present, the commonly used hardness method for measuring product hardness in production refers to the use of an indenter with a certain geometric shape to measure the hardness value of the metal surface being tested under a certain load according to its degree of coverage. The air conditioner copper pipe in the automobile air conditioner copper pipe is also divided into weld and seamless. Seamless air conditioner copper pipe is a metal material formed by directly using seamless round pipe. The plasticity of the air conditioner copper pipe refers to the ability to deform under a certain load without its original performance. The copper pipe for automobile air conditioner is a hollow and square section. The light thin-walled copper pipe for air conditioner is also known as steel cold-formed profile. It is a square section steel made of strip or coiled plate after processing in the cold bending area and high-frequency welding. In addition to being used in the automobile industry, the air conditioning copper pipes are used in construction, machinery manufacturing, steel construction and other projects, shipbuilding, solar power generation support, steel structure engineering, electric power engineering, power plants, agricultural and chemical machinery, glass curtain walls, boiler construction, highway railings, housing construction, pressure vessels, oil tanks, bridges, power station equipment, lifting and transportation machinery and other high load welding structures. In addition to the thickening of the wall, the size and external straightness of the extra thick wall air conditioning copper tube can both exceed the water content of the resistance welded cold formed air conditioning copper tube. Therefore, this kind of automobile air conditioning copper tube has better comprehensive mechanical properties and has the advantages of hot processing, cold processing, weldability and corrosion resistance.

Handle carefully to prevent damage and scratches. 2 When installing the keel, avoid collision between the basket and the keel. When installing the external wall hanging plate, protect it from impacting the medical copper pipe. 3 After the installation of thermal insulation curtain wall, in order to prevent personnel from approaching, special personnel should check the distance from the ground curtain wall. 4 For each process close to the curtain wall, some temporary protective measures should be taken to achieve the effect of later use. 3 On the premise of considerable cohesiveness, the exterior wall external thermal insulation decorative integrated board of high-rise buildings should meet the principle of flexible gradual change, and disperse and absorb seismic stress as far as possible to reduce the impact on medical copper pipes. 4 The medical copper pipe shall be made of waterproof and moisture permeable external insulation materials to avoid damage to the wall caused by water or steam migration. 5 Under the action of negative wind pressure, the volume expansion of the air layer in the insulation layer will damage the insulation layer. The aging of medical copper pipe will affect the use of building materials to a certain extent. When it reaches its service life, it needs to be replaced to prevent the trouble of aging in life. 6 The thermal expansion and cold contraction caused by the temperature difference change will cause the volume change of the non structure of the medical copper tube. Such medical copper tube has a shorter service life than the plate in normal use, and needs regular maintenance according to regulations.

Pay attention to the following points when using flame heating brazing: the selection of welding materials The filler metal is wire or rod, with a diameter of about 35mm. The material is: the melting temperature of wire 221 is about 0905 ℃. Its chemical composition is FB10 The composition is 2331% H3BO3 and 6071% KBF The joint form of brazed copper pipe is mostly plug-in. Before cleaning the brazed copper pipe before welding, the edge of the pipe mouth must be corrected and deburred to ensure that the pipe mouth is free of cracks or other defects. And clean the surface of the inserted part. After the red copper pipe is assembled by tack welding, size and height of tack welds shall be symmetrically and evenly distributed along the circumference from top to bottom, left to right, and the tack welds shall be melted into the whole weld during brazing. When brazing the copper pipe, the flat angle position shall be used as far as possible to ensure continuous welding. Select the appropriate welding torch according to the size of the pipe joint. The flame of the former Han Dynasty should be neutral, because the oxidation flame has high oxygen content, which is easy to oxidize copper and cause cracks; The carbonization flame contains free hydrogen, the flame shall be perpendicular to the heating surface, the pipe joints shall be heated evenly, and the base metal shall be heated as quickly as possible to avoid excessive temperature and heating time of the through pipe joints. During the brazing of degreased copper tube, the brazing seam and filler metal shall be under the protection of flame. In addition, it shall be noted that the brazing seam shall be naturally cooled after welding, and the weldment shall not be moved before the brazing seam has solidified. After natural cooling after welding, hot water or wet cloth shall be used to wipe the brazing seam and remove welding slag to improve corrosion resistance and reliability of post welding inspection.

quality.Copper tube has good bearing capacity. For example, in large cities, road bridges and undersea bridges often appear. Most road bridges are built with plastic coated copper pipes. With plastic coated copper pipes, engineering construction in large cities will become stronger and stronger. The actual operator shall carry out the actual operation of the heating furnace, yze the materials of the heating furnace, determine the cleaning, and select the type and concentration of cleaning solution. Pay attention to the cleaning time and temperature to develop more effective solutions and also develop some safety protection measures. An obvious feature of plastic coated copper pipe is heat resistance, because this kind of seamless steel pipe for heating furnace is mainly used for machining parts. Because the seamless steel pipe must be heated at high temperature during production and processing. What are the plastic coated copper tubes to prevent wear. What are the plastic coated copper tubes to prevent wear. We all know that all objects will wear in application, so how to prevent the wear of oil cracked pipes. Now let's introduce it to you. The packaging of petroleum cracking tubes shall be able to prevent and damage during normal loading, unloading, transportation and storage. If the Demander has special requirements for packaging materials and packages of petroleum cracking tubes, it shall be indicated in the contract; If it is not marked, the supplier shall select packaging materials and packaging. Packaging materials shall comply with relevant requirements. If the material is not packaged, it should be suitable for the intended use and avoid obvious and natural purification. If the customer stipulates that the surface layer of the cracked tubing should not be damaged by bumps, it can be considered to repair and install the cracked tubing in the middle. Rubber sleeves, tree trunks, straw ropes, fiber cloth, pipe caps, etc. can be used for maintenance and installation. The thick wall petroleum cracking pipe can choose the internal fulcrum or external structure. Because thick walled tubes are thin. The supporting frame and frame are made of steel, which is inconsistent with the plastic coated copper pipe. If the customer needs a packer, the petroleum cracking tube can be weighed in a decentralized way. However, the specification must be 159MM500MM.

The outer package can prevent surface scratches, cracks and other damages.

The large diameter coated medical copper tube can deform to prevent the risk of ductile damage; The medical copper tube has sufficient plastic deformation, and the medical copper tube is capable of deformation. It is stipulated that the plastic deformation and ductility of medical copper tubes are good. Good plastic deformation can ensure that the structure can have significant deformation before destruction. In some peak periods of the structure, the tectonic stress will be redistributed, which makes the tectonic stress spread gently. Good ductility indicates that under dynamic and static loads, more kinetic energy should be digested and absorbed when the structure is destroyed, which is the risk water of ductile destruction. For the structures with plastic deformation design scheme and the structures in disaster areas, the size of the deformation working capacity of medical copper tubes has a particularly critical practical significance. 3 Production and processing characteristics of medical copper tubes. It can be integrated with cold and heat treatment, and will not cause great harm to compressive strength, plastic deformation and ductility due to such production and processing. 4 Weldability of medical copper tube. The welding of medical copper tube is a rapid heating and cooling process. The metal materials in the welding and heat affected zone need to go through heating and melting, physical reflection, cooling and crystallization, and solid state change in a very short time. The industry trend is a kind of medical copper tube. Because there is no seam in the middle, it has more advantages in strength. Medical copper tubes have many different s in practical application, and each different will make the medical copper tube work well.Advantages of medical copper tubes: compared with solid copper tubes such as round steel, medical copper tubes have the same tensile strength, torsional strength, and tensile strength,MulanjieQ345D alloy round steel, and their net weight is relatively light. One is plastic copper tubes cut for social and economic development which are widely used in the production and processing of spare parts and mechanical parts, such as oil drilling equipment, rotating shafts bicycle frames, it can produce detailed welding joints to maintain special performance indicators and steel medical copper tube frames used in engineering construction. This kind of welded medical red copper pipe is developed under the special conditions that the temperature is all over and the composition is extremely unbalanced. After this kind of welding which is the specified weldability. 5 Performance of medical copper tube. It refers to the service life of medical copper tube. The production and processing of annular parts with medical copper tubes can achieve the utilization rate of raw materials, simplify the production process, save raw materials and manufacturing hours, such as needle bearing throw rings, hydraulic jack sleeves, etc. At present, medical copper tubes have been widely used for production and processing. Disadvantages of medical copper tubes: medical copper tubes are also indispensable raw materials for various strategies. Drums must be produced and processed by medical copper tubes. Medical copper tubes can be divided into round medical copper tubes and profiled steel according to their different cross-sectional areas. Due to the large circle area under the same diameter specification, the annular pipe can be used to transport many large diameter medical copper pipes. Large diameter coated medical copper pipes are widely used in tap water, natural gas, petroleum, chemical industry, communication, power, marine and other engineering fields. There is no solvent in the coating and no leakage, so it will not pollute the medium transported, thus ensuring the purity and hygiene of the fluid. The temperature range from - 40 ℃ to+80 ℃ can be used alternately in cold and hot cycles, without aging and cracking, so it can be used in cold areas and other harsh conditions. When processing medical copper tubes, the medical copper tube factory will use pickling, which is an indispensable part of most medical copper tubes, Pickling process is the treatment after removing surface oxide scale (Carbon steel - stainless steel - lime saponified phosphorus, butter, oil, copper and aluminum pipes - and the old ones, and then wire drawing processing. Then what are the points to be noted when washing? 1 When washing the medical copper pipes, they need to be carried out in the flowing clear water tank,Mulanjie310s stainless steel coil, so as to avoid secondary pollution. When washing, the medical copper pipes need to be fully immersed in water. At this time, the sling should be relaxed, and the phosphating solution cannot remove nuclear energy. However, water washing is also required. 2 When the medical copper tube is washed, the water in the medical copper tube needs to be cleaned to avoid water corrosion and oxidation of the medical copper tube. Therefore, it is necessary to carry out solvent treatment as soon as possible. 4 When the medical copper tube is washed, the iron salt content must be controlled within a certain range, and it cannot exceed the standard, otherwise the medical copper tube may be damaged.

Mulanjie.Handle carefully to prevent damage and scratches. 2 When installing the keel, protect it from impacting the medical copper pipe. 3 After the installation of thermal insulation curtain wall, in order to prevent personnel from approaching special personnel should check the distance from the ground curtain wall. 4 For each process close to the curtain wall, the medical copper pipe shall be temporarily protected before construction and can be covered with fiberboard. Even after the construction is completed, some temporary protective measures should be taken to achieve the effect of later use. 3 On the premise of considerable cohesiveness, the exterior wall external thermal insulation decorative integrated board of high-rise buildings should meet the principle of flexible gradual change, and disperse and absorb seismic stress as far as possible to reduce the impact on medical copper pipes. 4 The medical copper pipe shall be made of waterproof and moisture permeable external insulation materials to avoid damage to the wall caused by water or steam migration. 5 Under the action of negative wind pressure, the volume expansion of the air layer in the insulation layer will damage the insulation layer. The aging of medical copper pipe will affect the use of building materials to a certain extent. When it reaches its service life, it needs to be replaced to prevent the trouble of aging in life. 6 The thermal expansion and cold contraction caused by the temperature difference change will cause the volume change of the non structure of the medical copper tube. Such medical copper tube has a shorter service life than the plate in normal use, and needs regular maintenance according to regulations.

The utility model relates to a connecting structure, in particular to a connecting structure of a copper tube and an aluminum row. At present, most of the copper aluminum transition joints have not been effectively protected. In this way, under the condition of long-time electrification and heating and affected by the water vapor or corrosive gas in the air, the parts at the connection point are more likely to be oxidized, resulting in the reduction of the effective contact area of the connection point, the increase of the contact resistance, and the excessive heating or even burning of the connection point.

For the production and processing of sculpted copper tubes, the sheet metal shall be first opened in the sheet metal workshop according to the dimensions shown in the drawings, and then use the bending machine to form the edge according to the drawing forming diagram. The shaped copper pipe shall also be installed with reinforcing ribs as required, and the four corners of the shaped plate shall be welded well. The welded parts shall be sent to the grinding workshop, and the spraying surface shall be polished and the welding interface shall be polished and leveled. The polished modeling copper pipe is then sent to the spraying workshop for processing. Before spraying the surface of the sculpted copper pipe shall be chrome treated and the process hole shall be drilled, so as to ensure that the sculpted copper pipe can be hung on the spraying line well, and the painting can be smooth without flow marks, and the color is consistent without color difference. After that, according to customer demand