Application methods
Polyurethane cuffs are used in various hydraulic cylinders to seal gaps between the cylinder and rod walls. They are widely used in food, agriculture, construction and many other areas.
There is a manual for each hydraulic motor, which shows how to use and change the seals. But there are general recommendations:
- first you need to visually inspect the cuff for external defects;
- examine the installation site of the seal, there should also be no damage, dents there;
- then you need to remove dirt and grease residues from the seat;
- carry out installation in a special groove, avoiding twisting.
The production process of polyurethane cuffs in the video below.
Cuff manufacturing technology
There are two methods for making cuffs: classic (this is casting) and turning from a workpiece.
For casting, a shape is required that repeats the appearance of the future cuff. Liquid polyurethane is poured into it through a hole under pressure. Spreading in shape, it displaces air through the second window. After the mixture has filled the workpiece, it cools down and takes the form of the desired product.
For the production of polyurethane seals in this way, a special machine is required - an engineering injection molding machine capable of performing injection molding. For this purpose, injection molding machines are used, since they are able to manufacture products of any shape and size in huge quantities.
The advantages of this technology:
- the ability to control the process of selecting the hardness and temperature of polyurethane, compatibility;
- reduced material consumption;
- the ability to release in large batches with high quality workmanship.
There are also disadvantages - this is the high price of the mold, which depends on the complexity of the future product. On average, the cost ranges from 1 to 4 thousand dollars.
Turning is used when the number of parts is from one piece to one thousand, and this is turning on CNC machines. The workpiece is installed in a numerically controlled lathe, and then, in just a few seconds, the desired part is obtained.
The machine contains a huge number of programs, and having measured the desired cuff, you can immediately repeat it. An employee just needs to choose and set a program, and then everything happens without his participation - in automatic mode.
What it is?
Polyurethane is an artificial material that is used to replace sealing products made of rubber, rubber, leather. In almost all cases, its use is more expedient due to its improved properties. Its primary purpose is to be used as a sealing element to prevent leakage of working fluid or gas in hydraulic or pneumatic equipment.
One very remarkable property of polyurethane cuffs is the so-called mechanical memory. After the load ceases to act on the seal, its original shape is restored. This allows the cuffs to work with a high degree of efficiency in any equipment and withstand even high pressures.
Compared to cuffs made of other materials, polyurethane cuffs have the following advantages:
- extended service life: due to their increased wear resistance, they can be used 3 times longer than rubber;
- high elasticity: can stretch twice as much as rubber;
- increased resistance to all types of fuels and oils;
- reliability;
- stably withstand high loads;
- chemically resistant to acids and alkalis;
- there is a possibility of application in the temperature range from -60 to +200 degrees Celsius;
- do not conduct electric current.