What does a lubricant do? What is the role of a lubricant?

Lubricant is a lubricating medium used to reduce frictional resistance and slow down the wear of friction, and can also play a role in cooling, cleaning and preventing pollution on friction.

Lubricating oil was first used in clinical medicine to examine the human body, and many medical devices will cause different degrees of mechanical damage when they penetrate into the human body, and lubricating oil can minimize the damage to body tissues and mucous membranes.

In the early days, human lubricants were mainly composed of glycerin and hydrophilic substances, and later improved with sodium hyaluronate, ethylcellulose, carbomother and other components were added to reduce viscosity and balance pH, so that it was as similar as human body fluids as much as possible, reducing the incidence of allergic symptoms.

What is the role of lubricating oil? Star Awareness Project

It is a lubricating medium that can reduce the frictional resistance of the friction pair and slow down its wear. Lubricants also cool, clean and prevent contamination of friction pairs.

In order to improve lubrication properties, suitable additives can be added to some lubricants. When selecting lubricants, it is generally necessary to consider the movement of the friction pair, the material, the surface roughness, the working environment and working conditions, and the performance of the lubricant. In mechanical equipment, most of the lubricants are delivered and distributed to the parts that need to be lubricated through the lubrication system.

Advantages: Since the beginning of the 21st century, with the improvement of people's awareness of environmental protection, the development of lubricants has gradually developed to high efficiency and environmental protection, and water-based stamping lubricant technology is the product of scientific development. It is a composite that combines the advantages of a variety of lubricating ingredients. Better lubrication performance, especially good cooling performance, good permeability and low environmental pollution, is the direction of the development of stamping lubricants.

It is mainly used in punch drawing, punching, punching, bending and other processes in the process of workpiece forming, and can complete the most difficult deep drawing punch drawing. After a large number of experiments conducted by IRMCO, a global professional stamping lubrication technology and product research and development institution, the advantages of environmentally friendly water-based stamping lubricants over ordinary greases have been obtained

1. Increase the life of the mold.

2. High-strength steel forming.

3. Reduce the cost of raw materials.

4. Save energy.

5. Efficient production and increased added value.

The function of lubricants is to reduce the friction between plastic macromolecules, improve the fluidity of polymers, reduce the friction between polymers and processing machinery, avoid adhesion between them, and reduce the surface roughness of products. According to the role of lubricants, they can be divided into two categories: internal lubricants and external lubricants. Internal lubricant refers to the good compatibility with the resin added to the resin, which can improve the fluidity of the melt and reduce the friction between the melts.

External lubricant refers to the purpose of adding to the resin to reduce the temperature of the plasticized melt, reduce the friction between the melt and the surface of the equipment, and prevent the melt from sticking to the metal surface of the equipment. Internal and external lubrication is not absolute, in fact, many lubricants have the role of both types of lubricants, such as metal soaps. The common thermoplastics that need to be lubricated are PVC, PP, PE, PS, PA, ABS, etc., among which rigid polyvinyl chloride is the most prominent.

There are four commonly used lubricants: metal soaps, saturated hydrocarbons, fatty acids and their derivatives, and fatty acid salts. Such as stearic acid (octadecanoic acid), liquid paraffin wax (white oil), polyethylene wax (low molecular weight polyethylene), stearic acid amide, oleic acid amide.

The following issues should be paid attention to when selecting lubricants.

1) The lubricant should have good compatibility with resins and other additives.

2) The lubricant can be evenly dispersed in the resin without affecting the performance of plastic products.

3) It has no effect on the quality of plastic molded products, and is conducive to improving the appearance quality of products and reducing the surface roughness of products; It does not decompose, does not deteriorate, and is not affected by temperature changes.

4) Lubricants with the same performance should be selected with low and abundant material sources.

Lubricant is used to reduce friction resistance, slow down its wear of the lubricating medium, but also play a role in cooling, cleaning and preventing pollution, when choosing, generally consider the material, surface roughness, working environment and working environment and the performance of the lubricant and other factors, in mechanical equipment, most of the lubricant through the lubrication system to the parts that need to be lubricated.

The role of lubricants is to reduce friction and wear, so that the friction surface is not in a state of friction. The lubricant forms a kind of film between the friction surfaces, so that the micro-convex bodies on the friction surface are in contact with or without contact as much as possible, so as to achieve the purpose of reducing friction or even no damage. If you have any questions and needs, please feel free to consult Zhuhai Zhengfang Electromechanical Equipment.

The "compatibility" of the lubricant with the resin is a key factor in determining whether the lubricant acts as an internal or external lubricating agent.

What is the role of lubricating oil? Star Awareness Project

The role of PVC lubricants is to reduce the friction between the polymer and the device, as well as the internal friction between the polymer molecular chains. The former is called external lubrication, and the latter is called internal lubrication. It has external lubrication such as silicone oil, paraffin, etc., and has internal lubrication such as monoglycerides, stearyl alcohol and esters.

As for metal soaps, it's a bit of both. In addition, it should be noted that the statement of internal and external lubrication is only a habitual name for us, and there is no obvious boundary, some lubricants play different roles in different conditions, such as stearic acid, at low temperature or a small amount, it can play an internal lubricating role, but when the temperature rises or the amount increases, its external lubrication effect gradually prevails, and there is a special case of calcium stearate, which is used alone as an external lubricant, but when it is used in conjunction with hard lead and paraffin, it becomes an internal lubricant to promote plasticization.

In rigid PVC plastics, excess lubricant can lead to a decrease in strength and also affect process operations. Peeling can occur in the case of injectable products, especially in the vicinity of the gate. For injection products, the total dosage of stearic acid and paraffin is generally in parts

Extruded products generally do not exceed 1 part.

In soft product formulations, too much lubricant can cause frosting and affect the strength of the product and the high-frequency welding and printability. Too little lubricant will stick to the roller, and for blown film, too little lubricant will stick to the mold, which is easy to make the plastic coke in the mold. At the same time, in order to improve the stickiness of the blown film, it is advisable to add a small amount of monoglycerides, an internal lubricant.

In the production of PVC soft products, the amount of lubricant added is generally less than 1 part.

The most basic function of lubricants is to reduce friction and wear, so that the friction surface is not in a state of friction. The lubricant forms a thin film between the friction surfaces, so that the micro-convex bodies on the friction surface are in contact with as little as possible or are not in contact, so as to achieve the purpose of reducing friction or even no damage.

When the friction surface is completely separated by the liquid lubricating oil film, there is no wear, and the friction only occurs between the molecules inside the liquid, which is fluid lubrication, and the viscosity of the lubricating oil is the decisive factor. The formation of the load-bearing oil film can be formed automatically by the relative motion of the friction surface (hydrodynamic lubrication), or by the forced formation between the friction surfaces by pressure (fluid net pressure lubrication). The state of Kaiyan lubrication, which is between fluid lubrication and dry friction, is boundary lubrication.

Using the oiliness and extreme pressure of lubricating oil, a physical and chemical adsorption film or reaction film is formed on the metal surface to protect the metal from adhesion. However, direct metal contact cannot be completely avoided, and there is a certain amount of wear.

In summary, try to keep the friction pair in a fluid lubricated state, and minimize wear even when boundary lubrication occurs. Therefore, it is particularly important to choose the most suitable lubricant according to the actual situation.

Lubricants have other auxiliary and sometimes important functions. First of all, lubricating oil can be used as a coolant to dissipate heat and cool down in circulating lubrication. Secondly, it can carry away abrasive debris or other impurities, or act as a seal to prevent impurities from entering the system.

Thirdly, it prevents metal corrosion and maintains its stability in appearance. Finally, it allows the mechanism to operate over a wide range of temperatures.

The main function of the internal lubricant is to weaken the interaction force between the internal chain segments of the polymer, so that the polymer molecules are easy to slide, improve the fluidity of the polymer melt, such lubricants are compatible with the polymer molecules, and can be evenly distributed around the polymer molecules, such as common processing aids: stearic acid.

Stearic acid diagram. The main purpose of the external lubricant is to make the surface gloss of the product good, the product is easy to demold, and prevent the surface of the product from sticking. The general amount of external moisturizing agent should not be too much, too much is easy to make the surface frosty or sticky.

For example, polyethylene wax.

Lubricant is to achieve the effect of reducing friction and damage caused by gear through lubrication.

The materials that must be added before tableting can increase the fluidity of the particles (or powders) and reduce the friction between the particles (or powders) and the die and the internal friction, and have a lubricating effect are called lubricants.

Reduces the coefficient of friction and reduces friction.