Product Description
Recycling PET bottles Plastic twin screw Extruder machine price
Product model for your choosing:
(Notes: Different raw materials, the output is different, please tell me what’s the material you want to produce, I will recommend you the correct model.)
| Type | TSH-20 | TSH-35 | TSH40 | TSH52 | TSH65 | TSH75 | TSH95 |
| Screw Diameter (mm) product-list-1.html | 22 | 35.6 | 41 | 51.4 | 62.4 | 71 | 93 |
| Screw Speed (rpm) | 600 | 600 | 600 | 600 | 600 | 600 | 600 |
| Motor Power (kW) product-list-1.html | 4 | 18.5 | 30 | 55 | 90 | 132 | 315 |
| L/D | 32-60 | 32-68 | 32-68 | 32-68 | 32-68 | 32-68 | 32-68 |
| Output (Kg/h) | 2-15 | 15-95 | 70-120 | 155-255 | 255-400 | 450-750 | 950-1600 |
Product details:
1. Twin screw main extruder: Main motor: Imported “WEG”or “SIEMENS” Variable frequency motor(The frequency converter will automatically change the frequency to reduce the frequency of the motor. The operating current will always run between 80%, 50%, and 30% of the rated power. This will greatly reduce the motor’s operating current and achieve the effect of saving electricity).
2. Gearbox: Warranty: 3 years; (2)Concentricity deviation of output shaft and input shaft: within 0.2mm; (3)Both output shaft radial bearings are imported “IKO”and “NSK” bearings;
3. Electric cabinet box: (1)Inverter: Imported Switzerland”ABB”, Japan”TOSHIBA”,”FUJI”; (2)PLC: Imported “SIEMENS” brand; (3)Main electrical controller:”Schneider” brand; (4)Display of electric current:Japan “OMRON” brand; (5)Temperature instruments: Japan “OMRON” brand;
4. Twin-screw Barrel
Bimetal wear-resistant and corrosion-resistant material, the base material is 45# steel, after multiple forging, quenching and tempering treatment; the cylinder is inlaid with α-101 wear-resistant and corrosion-resistant alloy bushing, which has better wear resistance and corrosion resistance than general alloy bushings.
5. Screw elements
(1)Material is W6Mo5Cr4V2 (high speed tool steel) with the best wear resistance, the whole adopts vacuum quenching treatment, hardness is 60 ~ 62HRC; (2)Designed by the building block principle, and the screw element and the screw shaft are connected by an involute spline, and the screw combination can be adjusted according to the process requirements; The screw elements are all made by CNC machining center, with good identity and strong process repeat-ability,which is benefit for changing;
6. Screen changer+Die-head: Quick open die-head, convenient and fast, short flow path of the machine head and less material storage can significantly reduce the
deterioration of the material’s physical properties, yellowing, black spots
Machine applications:
(Notes: Our machine can be applied in the production of different plastics, such as color masterbatch, filler masterbatch, engineering plastics, reinforced materials, recycling plastics, biodegradable materials and so on.)
Our certificates:
Tengda has obtained High-tech Enterprise and National High-tech Enterprise award.
We have passed ISO,TUV,CE Certifications, more than 30 patents.
Our customers:
Related products:
product-list-1.html
| After-sales Service: | 7*24 Hours Online Service |
|---|---|
| Warranty: | Gearbox: 3 Years; Extruder: 1 Year |
| Raw Material: | PP PE Ect. High Filler Masterbatch |
| Screw: | Double-Screw |
| Inverter: | Inverter |
| Electromagnetic Heater: | Without Electromagnetic Heater |
| Samples: |
US$ 50/Set
1 Set(Min.Order) | |
|---|
| Customization: |
Available
| Customized Request |
|---|
Screw Shaft Types
A screw shaft is a cylindrical part that turns. Depending on its size, it is able to drive many different types of devices. The following information outlines the different types of screws, including their sizes, material, function, and applications. To help you select the right screw shaft, consider the following factors:
Size
A screw can come in a variety of shapes and sizes, ranging from a quarter to a quarter-inch in diameter. A screw is a cylindrical shaft with an inclined plane wrapped around it, and its main function is to fasten objects together by translating torque into a linear force. This article will discuss the dimensions of screws and how to determine the size of a screw. It is important to note that screw sizes can be large and small depending on the purpose.
The diameter of a screw is the diameter of its shaft, and it must match the inner diameter of its nuts and washers. Screws of a certain diameter are also called machine screws, and they can be larger or smaller. Screw diameters are measured on the shaft underneath the screw head. The American Society of Mechanical Engineers (ASME) standardized screw diameters in 3/50-inch to 16 (3/8-inch) inches, and more recently, sizes were added in U.S. fractions of an inch. While shaft and head diameters are standardized, screw length may vary from job to job.
In the case of the 2.3-mm screw group, the construct strength was not improved by the 1.2-mm group. The smaller screw size did not increase the strength of the construct. Further, ABS material did not improve the construct strength. Thus, the size of screw shaft is an important consideration in model design. And remember that the more complex your model is, the larger it will be. A screw of a given size will have a similar failure rate as a screw of a different diameter.
Although different screw sizes are widely used, the differences in screw size were not statistically significant. Although there are some limitations, screws of different sizes are generally sufficient for fixation of a metacarpal shaft fracture. However, further clinical studies are needed to compare screw sizes for fracture union rates. So, if you are unsure of what size of screw shaft you need for your case, make sure to check the metric chart and ensure you use the right one.
Material
The material of a screw shaft plays an important role in the overall performance of a screw. Axial and central forces act to apply torque to the screw, while external forces, such as friction, exert a bending moment. The torsional moments are reflected in the torque, and this causes the screw to rotate at a higher rate than necessary. To ensure the longevity of the screw, the material of the screw shaft should be able to handle the bending moment, while the diameter of the shaft should be small enough to avoid causing damage.
Screws are made from different metals, such as steel, brass, titanium, and bronze. Manufacturers often apply a top coating of chromium, brass, or zinc to improve corrosion resistance. Screws made of aluminum are not durable and are prone to rusting due to exposure to weather conditions. The majority of screw shafts are self-locking. They are suited for many applications, including threaded fasteners, C-clamps, and vises.
Screws that are fabricated with conical sections typically feature reduced open cross-sectional areas at the discharge point. This is a key design parameter of conical screw shafts. In fact, reductions of up to 72% are common across a variety of applications. If the screw is designed to have a hard-iron hanger bearing, it must be hardened. If the screw shaft is not hardened, it will require an additional lubricant.
Another consideration is the threads. Screw shafts are typically made of high-precision threads and ridges. These are manufactured on lathes and CNC machines. Different shapes require different materials. Materials for the screw shaft vary. There are many different sizes and shapes available, and each one has its own application. In addition to helical and conical screw shafts, different materials are also available. When choosing material, the best one depends on the application.
The life of the screw depends on its size, load, and design. In general, the material of the screw shaft, nut body, and balls and rollers determine its fatigue life. This affects the overall life of the screw. To determine whether a specific screw has a longer or shorter life, the manufacturer must consider these factors, as well as the application requirements. The material should be clean and free of imperfections. It should be smooth and free of cracks or flaking, which may result in premature failure.
Function
The function of a screw shaft is to facilitate the rotation of a screw. Screws have several thread forms, including single-start, double-start and multi-start. Each form has its own advantages and disadvantages. In this article we’ll explore each of them in detail. The function of a screw shaft can vary based on its design, but the following are common types. Here are some examples of screw shaft types and their purposes.
The screw’s torque enables it to lift objects. It can be used in conjunction with a bolt and nut to lift a load. Screws are also used to secure objects together. You can use them in screw presses, vises, and screw jacks. But their primary function is to hold objects together. Listed below are some of their main functions. When used to lift heavy loads, they can provide the required force to secure an object.
Screws can be classified into two types: square and round. Square threads are more efficient than round ones because they apply 0deg of angle to the nut. Square threads are also stronger than round threads and are often used in high-load applications. They’re generally cheaper to manufacture and are more difficult to break. And unlike square threads, which have a 0deg thread angle, these threads can’t be broken easily with a screwdriver.
A screw’s head is made of a series of spiral-like structures that extend from a cylindrical part to a tip. This portion of the screw is called the shank and is made of the smallest area. The shank is the portion that applies more force to the object. As the shaft extends from the head, it becomes thinner and narrow, forming a pointed tip. The head is the most important part of the screw, so it needs to be strong to perform its function.
The diameter of the screw shaft is measured in millimeters. The M8 screw has a thread pitch of 1.25 mm. Generally, the size of the screw shaft is indicated by the major and minor diameter. These dimensions are appended with a multiplication sign (M8x1).
Applications
The design of screws, including their size and shape, determines their critical rotating speeds. These speeds depend on the threaded part of the screw, the helix angle, and the geometry of the contact surfaces. When applied to a screw, these limits are referred to as “permissible speed limits.” These maximum speeds are meant for short periods of time and optimized running conditions. Continuous operation at these speeds can reduce the calculated life of a nut mechanism.
The main materials used to manufacture screws and screw shafts include steel, stainless steel, titanium, bronze, and brass. Screws may be coated for corrosion resistance, or they may be made of aluminium. Some materials can be threaded, including Teflon and nylon. Screw threads can even be molded into glass or porcelain. For the most part, steel and stainless steel are the most common materials for screw shafts. Depending on the purpose, a screw will be made of a material that is suitable for the application.
In addition to being used in fasteners, screw shafts are used in micrometers, drillers, conveyor belts, and helicopter blades. There are numerous applications of screw shafts, from weighing scales to measuring lengths. If you’re in the market for a screw, make sure to check out these applications. You’ll be happy you did! They can help you get the job done faster. So, don’t delay your next project.
If you’re interested in learning about screw sizing, then it’s important to know the axial and moment loads that your screws will experience. By following the laws of mechanics and knowing the load you can calculate the nominal life of your screw. You can also consider the effect of misalignment, uneven loading, and shocks on your screw. These will all affect the life of your screw. Then, you can select the right screw.
editor by CX 2023-11-22
China Twin Screw Compounding Extruder Screw Shaft Screw Elements with Low Price threaded end shaft
Product Description
Product Description
We manufacture barrels for co-rotating twin screw extruders ranging from 12 mm to 350 mm and over. Our manufacturing specializes in barrels for twin screw extruders and is optimized for flexible order handling.
Bloom supplies cylinder barrel suitable for the following extruder products lines :
-APV -KOBE -OMC
-Buhler -KraussMaffei -Theysohn
-Buss -Berstorff- -Toshiba
-Clextral -Labtech -USEON
-Lantai – others
-JSW -Leistritz
-Keya -Maris
Range of Work
Diameter of 12-350mm
Types of Barrels
Standard for classification: Design geometry Standard for classification: With inner or not
* Feeding barrel * Solid barrel
* Closed barrel * Barrels with inners
* Vent barrel
* Combi barrel
* Extended degassing barrel
* Combi barrel with backward venting
We offer a broader choice of materials:
Solid barrels
*Nitrided steel barrels *Tooling steel barrels *Bimetallic
Barrel with installed inner
* made of PM-HIP solid *WR13
By working closely with customers in choosing optional materials,we can minimize wear and tear and associated costs.
Our Main Materials and Their Application:
For Wear Application:
Tool Steel: W6Mo5Cr4V2
PM-HIP Materials: SAM10, SAM26, SAM39, CPM10V, CPM9V
For Corrosion Application:
Nitrided Steel: 38CrMoAlA
PM-HIP Materials: SAM26, SAM39, CPM10V, CPM9V
For Wear & Corrosion Application:
PM-HIP Materials: SAM26, SAM39, CPM10V, CPM9V
Other Materials: 316L HC276 etc.
|
Standard Barrel Parameter Table (selection table) |
|||
|
Model |
Size(mm) W*H*L |
Hole Diameter(mm) |
Distance(mm) |
|
BM-20 |
115*105*132 |
φ23 |
18.4 |
|
BM-30 |
135*115*120 |
φ30.6 |
26 |
|
BM-35 |
140*120*140 |
φ36 |
30 |
|
BM-36 |
160*140*150 |
φ36 |
30 |
|
BM-40 |
175*145*160 |
φ41.6 |
34.5 |
|
BM-50 |
190*150*190 |
φ51 |
42 |
|
BM-52 |
200*155*210 |
φ52 |
43 |
|
BM-53 |
210*160*220 |
φ53.3 |
48 |
|
BM-58 |
220*175*240 |
φ58 |
48 |
|
BM-60 |
210*170*240 |
φ60 |
52 |
|
BM-65 |
210*170*240 |
φ63 |
52 |
|
BM-75 |
260*200*290 |
φ71.8 |
60 |
|
BM-85 |
280*215*320 |
φ81.9 |
67.8 |
|
BM-92 |
310*240*360 |
φ92 |
78 |
|
BM-95 |
310*240*360 |
φ94 |
78 |
|
BM-110 |
330*240*420 |
φ109 |
91.5 |
|
BM-125 |
390*290*500 |
φ125 |
98 |
|
BM-135 |
370*300*410 |
φ134 |
110 |
Company Profile
Bloom(HangZhou) Materials Co., Ltd ,which located in the beautiful city of HangZhou , HangZhou, speically produce alloy materials and machined parts. We are alibaba verified Chinese alloy material factory.Our main business is selling various of special alloy and some of stainless steel besides the alloy materials, we also developed some of machinning parts, such as spot welding machined parts and extruder screw machined parts. All of our products comply with international quality standards and are greatly appreciated in a variety of different markets throughout the world. If you are interested in any of our products or would like to discuss a customized order, please feel free to contact us. We are looking forward to forming successful business relationships with new clients around the world.
Products Scope of Bloom Alloy
Insulation Alloy(KCF alloy)
Xihu (West Lake) Dis. Pins and Sleeves for bolts and nuts.
Low Expansion Alloy(4J36 36 alloy)
Duplex Steel and other Precision Alloy
Machined Parts for Twin Screw Extruder
FAQ
FAQ:
Q1. What‘s your MOQ?
1PC or SET
Q2. Can I place the customized order for different sizes, materials, structure….?
Yes, all customized orders are welcomed.
Q3. Could I get a QC report before delivery?
Yes, the specific QC reports will be sent to you before delivery.
Q4. Can I have our own logo or label on our product?
Yes,we can laser your logo or code number on your product.
Q5. How long is your guarantee?
1year,2 years,5 years base on different requirement.
Q6. How to reach you for other questions?
Please feel free to contact us through E-mail, call or visiting our factory.
|
US $20-100 / Piece | |
10 Pieces (Min. Order) |
###
| After-sales Service: | 1 Years |
|---|---|
| Warranty: | 1 Years, 1 Years |
| Standard: | GB |
| Technics: | Casting |
| Feature: | Recycle |
| Material: | Stainless Steel |
###
|
Standard Barrel Parameter Table (selection table)
|
|||
|
Model
|
Size(mm)
W*H*L
|
Hole Diameter(mm)
|
Distance(mm)
|
|
BM-20
|
115*105*132
|
φ23
|
18.4
|
|
BM-30
|
135*115*120
|
φ30.6
|
26
|
|
BM-35
|
140*120*140
|
φ36
|
30
|
|
BM-36
|
160*140*150
|
φ36
|
30
|
|
BM-40
|
175*145*160
|
φ41.6
|
34.5
|
|
BM-50
|
190*150*190
|
φ51
|
42
|
|
BM-52
|
200*155*210
|
φ52
|
43
|
|
BM-53
|
210*160*220
|
φ53.3
|
48
|
|
BM-58
|
220*175*240
|
φ58
|
48
|
|
BM-60
|
210*170*240
|
φ60
|
52
|
|
BM-65
|
210*170*240
|
φ63
|
52
|
|
BM-75
|
260*200*290
|
φ71.8
|
60
|
|
BM-85
|
280*215*320
|
φ81.9
|
67.8
|
|
BM-92
|
310*240*360
|
φ92
|
78
|
|
BM-95
|
310*240*360
|
φ94
|
78
|
|
BM-110
|
330*240*420
|
φ109
|
91.5
|
|
BM-125
|
390*290*500
|
φ125
|
98
|
|
BM-135
|
370*300*410
|
φ134
|
110
|
|
US $20-100 / Piece | |
10 Pieces (Min. Order) |
###
| After-sales Service: | 1 Years |
|---|---|
| Warranty: | 1 Years, 1 Years |
| Standard: | GB |
| Technics: | Casting |
| Feature: | Recycle |
| Material: | Stainless Steel |
###
|
Standard Barrel Parameter Table (selection table)
|
|||
|
Model
|
Size(mm)
W*H*L
|
Hole Diameter(mm)
|
Distance(mm)
|
|
BM-20
|
115*105*132
|
φ23
|
18.4
|
|
BM-30
|
135*115*120
|
φ30.6
|
26
|
|
BM-35
|
140*120*140
|
φ36
|
30
|
|
BM-36
|
160*140*150
|
φ36
|
30
|
|
BM-40
|
175*145*160
|
φ41.6
|
34.5
|
|
BM-50
|
190*150*190
|
φ51
|
42
|
|
BM-52
|
200*155*210
|
φ52
|
43
|
|
BM-53
|
210*160*220
|
φ53.3
|
48
|
|
BM-58
|
220*175*240
|
φ58
|
48
|
|
BM-60
|
210*170*240
|
φ60
|
52
|
|
BM-65
|
210*170*240
|
φ63
|
52
|
|
BM-75
|
260*200*290
|
φ71.8
|
60
|
|
BM-85
|
280*215*320
|
φ81.9
|
67.8
|
|
BM-92
|
310*240*360
|
φ92
|
78
|
|
BM-95
|
310*240*360
|
φ94
|
78
|
|
BM-110
|
330*240*420
|
φ109
|
91.5
|
|
BM-125
|
390*290*500
|
φ125
|
98
|
|
BM-135
|
370*300*410
|
φ134
|
110
|
Screw Shaft Types
If you’re looking for a screw shaft, but aren’t sure which type to buy, you’re in luck. In this article, we’ll talk about the different types, including Threaded shank, Round head, and Machined. Once you’ve read it, you’ll know which type to buy. Then, you can decide whether you want a ball screw nut or a threaded shank.
Machined screw shafts
Besides the standard stainless steel shaft, manufacturers also provide a variety of other materials, such as titanium, bronze, and brass. In addition to stainless steel, manufacturers also provide a variety of top-coating options, including zinc, brass, and chromium. Aluminum screws are not particularly durable and are easily affected by weather. Most screw shafts feature self-locking mechanisms. They are especially useful in C-clamps, vises, and screw-top container lids.
For applications where accuracy is vital, a ball screw shaft needs to be annealed. A heat treatment can be performed on the ball screw shaft to ensure that both ends are heated evenly. In this process, the shaft will be more durable, while maintaining its high-precision properties. These screw shafts are a key component in computer-controlled motion-control systems, wire bonding, and other industries that require high-precision and high-quality performance.
Depending on the material used, screw shafts can be made of stainless steel or titanium. High-precision CNC machines and lathes are typically used to manufacture screw shafts. Various shapes and sizes are available, each with a specific application. Whether you need a small or large screw, you can find one to fit your needs. And since each size requires a different material, your choice of material is important as well.
In general, the materials used for machining screw shafts are steel, stainless steel, titanium, brass, bronze, and aluminum. Metals that resist corrosion are also commonly used. Other materials for screw shafts are Teflon, nylon, and nylon. You can also find threaded screw shafts in materials such as porcelain, glass, and ceramic. If you want to use your screws in a unique material, consider purchasing a customized one.
Ball screw nuts
If you have a screw shaft, the last thing you want to worry about is the ball nut slipping off. To prevent this, you can place a temporary stop in the shaft’s grooves to ensure that the ball nut does not slide off. When you remove the stop, you can then install the ball screw nut. But, before you can install the ball screw nut, you have to make sure that you have a good grip on the shaft.
When selecting ball screw nuts, it’s important to consider how much preload you need to apply to avoid excessive backlash. Preloading eliminates this problem by making the ball nut compact. It also prevents backlash, which is lost motion caused by clearance between the ball and nut. Backlash disrupts repeatability and accuracy. This is where spacer preloading comes in. You can insert a spacer between the two ball nuts to transmit the force to the nut. However, you should keep in mind that this method reduces the load capacity of the ball screw.
The critical speed of a screw is the maximum rotating speed before it whips. This critical speed is influenced by several factors, including the diameter of the screw shaft, the number of support elements, and the material. By adjusting these factors, you can reduce the number of components used and the amount of time it takes to assemble the screw shaft. In addition, you can also reduce the number of components and avoid stacking tolerances. However, the critical speed of plastic nuts is limited due to sliding friction.
The ball screw nut has several characteristics that make it unique. Its most prominent feature is the presence of ball bearings. These balls help reduce friction between the screw nut and the shaft. Without ball bearings, the friction would be too high to function properly. Another important characteristic is the groove profile of the nut and ball. These two features ensure that the ball and the nut meet at two points. You’ll be amazed by the results of the work of these ball screw nuts.
Threaded shank
Wood screws are usually not fully threaded because the shank has an unthreaded portion at the top. This shoulder part forces the screw to compress two pieces of wood, which prevents the screw from overheating and compromising the materials strength. As the screw is threaded partially up, it is not as difficult to remove as a fully threaded screw. However, it is important to note that a wood screw will not hold as tightly as one with a fully threaded shank.
In addition to being universal, screw threads can be of different sizes. For example, a M8 screw has a thread pitch of 1.25 mm. To avoid confusion, screw thread pitches are commonly given with a multiplication sign. For example, M8x1 means that the screw is eight mm in diameter but has a thread pitch of one mm per 360-degree rotation. Those who are not familiar with these dimensions may find it confusing.
The OD of the threaded portion of a bolt is generally smaller than the OD of the nut. If the shank is too deep for the nut to fit, the threads may bottom out. This is why it’s important to use a thread-cutting bit with a small thread diameter. You can use a micrometer or caliper to measure the thread diameter. This tool will also allow you to easily identify which screw size fits where and how well.
The metric system is the most widely used. Fasteners with DIN numbers are generally metric in size. This makes them very useful for industrial settings. You can find metric-sized screws anywhere, as long as you buy them from a reputable manufacturer. These fasteners also come with a dog point, which is used for safety wire. If the screw needs to be replaced, the shank can be drilled with a hole for a safety wire or for a dog-point.
Round head
A round head screw is the most common type used for machine screws. Other common types include truss head, flat head, and hexed head. Each has a different profile and are used for different purposes. A round head screw is typically wider than a flat or a hexed head, and has a slightly rounded surface. These screws are useful for projects involving sheet metal or sheet-metal parts. Round heads are usually slightly wider than a hex head screw, and they may also be used as a substitute for washers in certain applications. However, truss heads are not necessary for every project.
A wood screw has a smooth shank that protrudes above the surface of the material it is attaching. A metal screw has a threaded shaft that is fully threaded from head to point, and a fully threaded shaft provides more bite. Two common head styles are round head and pan head. If the task requires the screw to be flush or countersunk, the round head will be the best choice.
Another type is the Reed & Prince screw drive. These are similar to Phillips screws but have a 75-degree V shape. They are commonly used in marine hardware and are also known as BNAE NFL22-070. This type is also used for steel plate hangers. In addition to round head and pan head screws, there are a variety of other screw types. You can even get a head with a slotted head if you know where to look.
Screw diameters are specified according to the ISO 261 or ISO 262 standards. An M8 screw has a diameter of 8.25 mm. The M8 screw has a pitch of 1.25 mm, which is equivalent to one mm per 360 degrees. There are several other standard screw sizes and thread diameters available. You can find them all by consulting the relevant standards. But remember, the metric system is the most popular.
Self-locking mechanism
A self-locking mechanism for a screw shaft is a device that secures the screw to its supporting member in a failure position. The locking mechanism provides a positive connection between the screw shaft and the control surface during normal operation, and locks the screw to its supporting member when the screw fails. Previous attempts to solve this problem have typically used secondary nuts with free play on the screw, which were intentionally designed to jam when loaded. However, such a device can be unreliable, which is why the present invention offers a more robust and reliable locking mechanism.
The self-locking function of a screw depends on several factors, including its pitch angle and the coefficient of friction of the threads. The angle of friction must be less than the tangent of the material pairing to prevent untightening of the screw. Screws with self-locking mechanisms have an efficiency e lower than 50%, which is less than half. Self-locking screws also have the benefit of being less efficient than a standard screw.
Unlike a normal screw, a self-locking screw can be turned in either direction. The nut 22 rotates with the screw shaft, and the member 23 is translated in an axial direction. Regardless of the direction of the rotation of the screw, this axial translation will result in the opposite moment to that input moment. While screw self-locking mechanisms are typically less expensive, they are more reliable and durable.
Another important feature of self-locking screws is that they are not susceptible to independent loosening. The screw cannot rotate without a certain amount of torque. In addition, a self-locking screw shaft must have a small wedge with a smaller half-angle than the arctangent of the static friction. This means that the torque applied by the driver must be greater than the torque needed to overcome the friction.
editor by czh 2022-11-26