Selection and use of cooling lubricants for stone sawing

1The mechanism of action of cooling lubricant

Cooling lubricant can fully improve the cutting conditions of stone, mainly composed of emulsifier and base oil, so it is also called lubricant.

The substance is generally in an emulsified state after being dissolved in water, and is also called an emulsified rinse. The mechanism of stone cutting processing cooling lubricant is more complicated.

There are different ways of cooling lubricant for different objects, both physical and chemical.

1.1 Mechanism of action on diamond

(1) Lowering the temperature of the diamond-rock sawing interface

A cooling lubricant is a surfactant that adsorbs on the surface of a diamond-like rock to form a lubricating film that enhances the diamond interface.

Lubricity, reducing frictional resistance, resulting in the lowest heat during sawing, which reduces the interface temperature, or reduces diamond oxidation or

The graphitization speed is beneficial to maintain the hardness and strength of the diamond. According to the indoor measurement, the cooling lubricant with a content of 0.2% makes the diamond-rock boundary

The friction coefficient is reduced by more than 60% compared with water. In addition, due to the directed adsorption of cooling lubricant molecules on the surface of diamond and rock

The film is lubricated to reduce frictional resistance. The strength of the adsorption capacity and the strength of the lubricating film are related to the molecular structure of the cooling lubricant and the adsorption of the gene.

.

(2) Speed ​​up the thermal diffusion rate of the diamond-rock sawing interface

Diamond has oleophilic, hydrophobic properties. The surface tension of the cooling lubricant aqueous solution is low, only 32.5X10-3N/cm, less than water

50%. It has good wettability to diamond and low surface tension, which can effectively improve the thermal diffusion speed of the interface and shorten the heating of diamond.

The time of action reduces the degree of diamond oxidation or graphitization, improves the working environment of diamond, and helps to reduce its wear and tear.

And the life of the diamond is improved.

1.2 Mechanism of action on metal bond

The diamond block (cutting head) is made by mixing and sintering diamond and various metal powder binders. After the various powders are sintered into blocks,

The effect of the diamond inlaid on the diamond becomes the embryo body. During the sawing process, the new diamond is exposed due to the continuous wear of the metal mixture (embroid body).

In order to continue the sawing process, the wear and tear of the bonding agent is also an important factor affecting the life of the saw blade.

(1) Cooling lubricant reduces the frictional resistance of the binder-rock boundary

The coolant slip agent can not only adsorb on the diamond surface, but also adsorb on the surface of the binder metal, thereby improving the binder-rock.

The lubricity of the surface reduces the frictional resistance of the boundary and helps to reduce the wear of the bonding agent. Laboratory tests prove: when using 0.2% cooling lubrication

Agent, the wear of the binder on the rock can be reduced to 1/10 using clean water. This creates favorable conditions for the binder to protect the diamond.

(2) Cooling lubricant accelerates the precipitation of stone powder in the coolant and discharges as soon as possible

The cooling lubricant contains a certain amount of polymeric precipitant. It quickly aggregates the powder particles, causing them to coalesce into a mass and settle quickly. therefore,

The concentration of stone powder in the coolant is greatly reduced, which reduces the wear of the coolant during the recycling process, and ensures the bonding agent and diamond.

The synchronous wear does not cause the diamond to fall off prematurely, which prolongs the service life of the cutter head. According to the measurement, for 20μm diameter quartz particles, 1g

It can adsorb 0.1mg of cooling lubricant molecules, and the quartz particles below 5μm can absorb more than 0.8mg. Produced during these stone cutting processes

The carbon powder can be discharged sooner or later under the coolant flushing, reducing the repeated crushing of the rock powder.

1.3 Mechanism of reducing the deflection of the saw blade base

During the sawing process, the saw blade can be severely deflected, resulting in an increase in the current of the device and the inability to continue sawing. There are two reasons for this: First, the saw

The deformation of the substrate is yawed, mainly because the slit width is too large, which can be solved by correcting the substrate; the second is due to the saw blade base and the cut

The friction between the rock walls on both sides of the seam is mainly manifested as the normal width of the slit, the mechanical operation is normal when the upper part is sawed, and the current value is positive.

Often, when deep sawing is performed, it is necessary to reduce the feed concentration or the left and right travel speed of the saw blade. In the second case, the use of a cooling lubricant can

Effectively solved, the cooling lubricant produces physicochemical adsorption on the sawing interface (base and rock sawing surface) to form a layer of thick

Lubricating film. The friction coefficient is as large as 0.38 or more; while the cooling lubricant having a content of 0.2% is used, the friction coefficient can be immediately reduced to about 0.1.

That is, after the cooling lubricant is used, the frictional resistance of the base and the rock wall slit can be reduced by more than 70%. Saw blade due to reduced sawing resistance

The condition of the film is improved. The yaw and vibration of the saw blade base are controlled to extend the life of the saw blade.

2 cooling lubricant composition

The complete stone cutting processing lubricant should be composed of emulsifier, lubricating oil and precipitant. In some cases, only emulsifier and sink should be used.

A precipitant, or a lubricating oil and a precipitant. There are many types of each of the three components, and the performance of the different types is also different.

(1) Emulsifier

It is mainly composed of a surfactant. The molecule of the surfactant consists of two parts, a lipophilic group and a hydrophilic group.

Greatly reduce the surface tension of the solvent (usually water) or the liquid-solid interface tension, changing the interface state of the system. According to the type of hydrophilic structure and it

They are each soluble in the ionic state of water, which can be divided into four categories: anionic cooling lubricants (alkyl sodium sulfonate, alkyl sulfonic acid)

Sodium salt, sodium alkyl sulfate sulphate, sodium alkyl phosphate sulphate); cationic cooling lubricant (secondary amine salt, secondary amine salt, tertiary amine salt, quaternary ammonium salt)

Amphoteric cooling lubricant (amino acid type, betaine type); nonionic cooling lubricant (polyethylene glycol type polyol type). Emulsifier master

To lubricate and cool.

(2) Lubricating oil

Lubricating oil can be summarized into three categories: one is motor oil, usually animal oil and vegetable oil; the second type is mineral oil, mainly petroleum products;

Learn synthetic oils. Among them, mineral oil has sufficient sources, low cost, wide practical range, and good stability, so it is the most widely used. Because of animal and vegetable oils

More stearic acid, poor chemical stability, and limited source, not much use. Synthetic oil is a new type of lubricant made by chemical synthesis.

It can meet certain characteristics that mineral oil can't meet, but it has a narrow practical range, high cost and less general applications. The main part of the component

Dispersion and cooling.

(3) Precipitant

As a auxiliaries in the cooling lubricant, the precipitant can flocculate the stone powder produced during the cutting process into a mass and further precipitate it to make the coolant

The concentration of the stone powder in the tube is greatly reduced, thereby reducing the repeated wear on the cutter body and facilitating the life of the cutter head. Precipitant precipitated stone

The principle of action of powder can be divided into inorganic precipitant and organic precipitant. 1 inorganic precipitant is mainly composed of inorganic electrolytes (such as NaCl,

Na2SO4); etc.) class composition. Its principle of action is to neutralize the electrical properties of the surface of the stone powder by the cations (such as Na+) ionized by the inorganic electrolyte.

The repulsive force between the stone powders is reduced and the hydration layer on the surface of the stone powder is thinned, and then coalesced by thermal motion. Precipitated object after electrolyte coalescence

The product is smaller and more solid. 2 The organic precipitant is mainly composed of a polymer (such as polyacrylamide). Its principle of action is based on polymer

The adsorption group on the daughter strand is simultaneously adsorbed on two or more stone powder particles, and a "bridge" is built between them, and then the macromolecule is curled.

These stone powder particles are suspected and finally lose sedimentation stability. The stone powder after flocculation from the polymer is relatively loose and bulky.

3 cooling lubricant selection

3.1 Selection of cooling lubricant type

There are many types of materials that can be used as cooling lubricants, but this does not mean that we can choose any material as a cooling lubricant.

Because we have a lot of factors to consider when formulating stone cutting cooling lubricants, such as the difficulty of raw material sources, the quality of cooling lubricants,

The size of the consumption and whether the price is cheap or so.

(1) Selection of cooling lubricant material

The object of stone processing is mainly granite. Relevant research has confirmed that the surface of granite powder is negative under the condition that the pH value of the solution is more than 3.6.

Electrical, if we choose cationic cooling lubricant, due to the positive and negative electric attraction, the stone powder will attract a large amount of cooling lubricant.

The unnecessary consumption of the coolant causes the coolant to fail. Non-ionic cooling lubricants do not produce ionization in water, and both indoor and field tests have proven to be easy to

Stone powder produces physical adsorption that reduces the quality of cooling lubrication. The material of the anionic cooling lubricant can overcome these shortcomings, it is electricity in water

Separated, it exists in an anion state. Due to the principle of reciprocal repulsion, it will repel the adsorption of stone powder in the coolant, thus reducing its own elimination.

Consumption, while playing its cooling lubrication.

More importantly, whether a cooling lubricant can play a good role depends on whether it can reduce diamond-granite and carcass.

The friction coefficient of the two pairs of gangs and the degree of reduction. Among the commonly used anionic cooling lubricants, sodium alkylate

The salt solution has the lowest friction reduction coefficient, which can effectively reduce the frictional resistance between the diamond saw blades during the process of cutting the stone and reduce the cutting process.

The heat generated in the steel ensures the hardness and strength of the diamond and greatly increases the life of the saw blade. Therefore, when formulating stone cutting cooling lubricant

Alkyl fumarate sodium salt should be preferred as the main material. Because it has a wide source, low price, good cooling and anti-friction characteristics, and consumption.

Low comprehensive advantages.

(2) Selection of precipitant materials

Both inorganic and organic precipitation have the effect of precipitating stone powder. Which one to choose from depends on the specific situation. If you choose NaCl as the inorganic

Precipitant, when the concentration of stone powder in the sedimentation tank is high, only when the content of NaCl in the cooling lubricant is high, effective precipitation can be achieved.

However, the indoor preparation shows that the NaC1 content in the cooling lubricant cannot meet the requirements at all, because less than this concentration, the cooling lubricant has already been produced.

Severe floc separation and loss of stability. Therefore, it is not acceptable to add an inorganic electrolyte as a precipitant to the cooling lubricant. For ease of use

The polymer can be selected as a precipitant. Polyacrylamide is an ideal one. It is non-ionic and will not appear in the cooling lubricant.

It is stable to the coolant, and its guanamine group (-CONH2) has a strong polarity, so the water solubility is also good. When the stone meets stone powder

The guanamine group adsorbs the stone powder particles on the macromolecular chain of polyacrylamide by hydrogen bonding, and the result is as if many stone powder particles are erected.

The bridge then flocculates a large number of stone powder particles into a mass by the crimping action of the polymer macromolecular chain, thereby causing the stone powder to lose its sedimentation stability.

Qualitative and eventually precipitated quickly.

3.2 Selection of cooling lubricant quality

It is not enough to choose the type of cooling lubricant correctly, but also to choose a quality product. The first choice is to choose the qualified products produced by regular manufacturers.

Product, to ensure the reliability of the use of cooling lubricants. Check the three certificates at the time of purchase and produce a shelf life. Second, pay attention to the safety of the cooling lubricant. cold

However, the lubricant itself should not have adverse effects such as adverse effects or hazards on the environment, stone materials and human body, but some may be improperly formulated or other factors, and may also

Brought adverse effects. Therefore, you should pay attention to the purchase, you can use the nose to smell, odorless or no other odor, then you can observe its shape, the upper layer

Do not have any size foam or other solid floats. When the coolant is dissolved in water and is not formulated into a working fluid, it should be milky white. pH detection

It is weakly acidic and must not be acidic or strongly alkaline. Only by choosing a coolant with no side effects or side effects can we effectively protect our

The environment guarantees the physical and mental health of the on-site staff.

Cooling can greatly increase the grinding ratio and the square of the sawnable. But the harder the stone, the larger the grain and the higher the quartz content, the effect of the coolant

The smaller the fruit.

4 use of cooling lubricant

When using cooling lubricants in stone cutting, it should be equipped with corresponding implementation. Generally, the use of cooling lubricants requires two conditions:

(1) There is a circulating water system and sedimentation. The size of the sedimentation tank depends on the annual output of the plate. The volume of the sedimentation tank required for an annual output of 3,000 m2 should not be

Less than 20m3. The sedimentation volume required for an annual output of 6000 m2 of wool board is not less than 80 m3. The volume of sedimentation tank required for an annual output of 10,000 m2 of wool board is not to be less than

150m3. The sedimentation volume required for an annual output of 10,000 m2 of wool board should be greater than 200 m3 to ensure that the stone powder has sufficient time to settle down and treat the stone powder.

How much, regularly clean up the sedimentation tank.

(2) Because the cooling lubricant affects the grinding effect of the grindstone, the grindstone grinding cooling water contains a large amount of ca2+ and Mg2+, which affects the grinding effect, so

The grinder is required to have a separate drainage system. Pay attention to the following when using cooling lubricants:

4.1 Master the amount of lubricant. For the first use, add 0.3 to 0.5%, and add 3 to 5 kg of lubricant to 1 m3 of clean water.

Add to the clear water pool and use. If the concentration is too high, it will only accelerate the consumption and waste of the cooling lubricant, which is not much help for improving performance.

help. If the quality of the cooled lubricant is poor, the water content is too high (up to 90%), even with a larger concentration of action, the effect

It is also not good.

4.2 Regularly replenish the lubricant. Cooling lubricant has a certain consumption during use, mainly due to the adsorption of cooling powder by stone powder.

The second thing is that the stone powder produced in the cutting is very fine and has a large specific surface area. Due to the van der Waals force, it and the cooling lubricant molecules

Physical adsorption occurs between the micelles and the cooling lubricant is consumed. The prepared coolant does not have to be replaced regularly, it can be used continuously, only on a regular basis.

Add freshly prepared coolant. Under normal circumstances, sawing 1m2 hairboard needs to add 0.7~1kg, you can add it once a day, and it must be timely

.

4.3 Control the pH of the solution. The pH of the cooling lubricant is too low, and the stone powder is bound to absorb a large amount of cooling lubricant, resulting in unnecessary consumption.

And the coolant is disabled. Therefore, the pH of the cooling lubricant should be controlled, and the pH value of the solution can be measured by pH test paper. Generally, the pH is required to be maintained at 7.0 to 7.5.

. If the pH of the cooling lubricant is too low, some anionic cooling lubricant material may be added to the solution for neutralization.

4.4 Maintain a suitable solution concentration. Although the used coolant has a high concentration, the cooling and lubricating properties are not improved, but the rust is prevented.

The performance is very poor, which is caused by impurities mixed in the outside world or the balance of the components has been destroyed. If the concentration of the cooling lubricant is large, a small amount should be added.

After the water is diluted, it is added to the sedimentation tank.

4.5 Pay attention to the water quality of the dilution water. If the water of the lubricant is hard water, it is best to first softwareize the water to reduce the cooling lubricant consumption.

To improve its use. Because the hardness is too high, it not only promotes the corrosion of the cooling lubricant, but also causes cooling due to the loss of fatty acids.

Lubricant performance is degraded. It is strictly forbidden to mix soluble substances (such as cement, lime, etc.) of high-valent ions such as Ca2+ and M92+ into the circulating cooling lubricating fluid.

So as not to affect the effect of use.

5 Conclusion

The sawing process phenomenon is mostly related to various friction phenomena during the sawing process. After adding the lubricating cooling cutting fluid, the cutting fluid penetrates into the diamond.

After the contact surface of the stone saw blade, the diamond saw blade and the stone surface are subjected to extreme pressure resistance, which reduces the friction between the diamond saw blade and the stone.

The number, which reduces surface roughness, extends the life of the diamond saw blade. The reasonable composition of the hard stone sawing and processing coolant, right

It is very important to improve production efficiency and reduce production costs. Select the lubricating component in the coolant and the appropriate amount of use, must

According to the stone material, the quality of the ginge group stone and the water quality conditions, while reducing the wear of the diamond and the binder, the diamond has a suitable

blade. The method of water softening and compounding nonionic surface active bud can be used to improve the calcium resistance of the coolant. Using high-molecular flocculants and inorganic electricity

Decomposition and flocculation of precipitated rock powder can obtain better results.  

Plastic Push In Fittings

Plastic Push In Fittings, Pneumatic Plastic Push In Fittings, Plastic Pneumatic Fittings, Plastic Push Fittings, Pneumatic Airline Fittings, One Touch Tubing Fittings

Cixi Air-Fluid Pneumatic Components Co.,Ltd , http://www.air-fluidfittings.com