How to replace the sandblasting nozzle
Some customers always ask whether there are some nozzle models that are not mass-produced, such as nozzles with an inner diameter of 7.5MM / 6.5MM, an outer diameter of 13MM / 17MM, a length of 55MM / 57MM or 75MM, and the order is very urgent, these goods are basically There is no inventory on board,
No manufacturer is willing to squeeze a bunch of goods that are difficult to sell, unless it is the original manufacturer of the sand blasting machine, because their blasting machines have always been sold with these nozzles, the purpose is to hold the customer in. Let the customer make it, the customer Not willing to order so much at once, causing both parties
All came to nothing, customers did not get the low cost they wanted, and the merchants did not sell the goods.
In response to this problem, I need to express my personal opinion. Basic spray guns, nozzles, and nozzle sleeves have 2-3 specifications. These specifications are basically universal and have little effect on the sand blasting effect. They can basically be used instead. Be sure to match the original.
I hope the above views can help customers using sandblasting machines and save some replacement costs for customers. Of course, my views may not be all correct. I hope that the industry can provide some more valuable and professional Recommended for manufacturers using sandblasting machines
Greater benefits from replacement parts:
Sandblasting nozzle <BR> I. Type of nozzle
First of all, let's look at the types of sandblasting machine nozzles from the structural form :
The structure of the nozzle is divided into a straight hole nozzle and a venturi nozzle
1.Straight hole nozzle :
Its internal structure has only a constricted section (commonly known as the bell mouth) and a straight section.It is simpler to make and is much cheaper than a nozzle.It can be made of ceramics, tungsten steel, silicon carbide, boron carbide and other materials.It is currently the most versatile. Nozzle form, as shown below:
Straight hole nozzle mechanism diagram
The boron carbide nozzles produced by our factory are manufactured in accordance with the national standard. The wall thickness of the bell mouth is 2MM, and the depth of the mouth is 9-11mm. For example, the depth is 11mm.
The wear resistance of the nozzle is not much different than the nozzle with a depth of 9MM. In fact, the wear resistance of the nozzle is mainly determined by the purity of the material and material and the calcination method. Now some boron carbide nozzles on the market are very low in price, and many customers In order to bargain, I want to remind customers,
After all, the price is a bit related to the quality. Some of these ultra-low-priced boron carbide nozzles are caused by the following reasons. If not, congratulations, you have bought cheap and good products.
1) Sandblasting nozzle made of silicon carbide:
Silicon carbide has the characteristics of light weight, black color, and looks similar to boron carbide on the surface. Unfamiliar customers are really difficult to distinguish. In fact, the actual boron carbide nozzle is still lighter, and the luminosity of boron carbide is relatively light. Weak, a little weak light feel, while made of silicon carbide
The product is black and shiny, and the reflectivity is very strong.Of course, the nozzles with oil applied are difficult to distinguish.The only thing to do is to wash the oil and blow it off before distinguishing it.
The characteristics of silicon carbide nozzles are low wear resistance, and they are more wear-resistant than tungsten steel nozzles. It is 1 / 3-1 / 2 life of hot-pressed sintered boron carbide nozzles. The advantage is that the price is close to that of tungsten steel nozzles. Shaping all kinds of special-shaped nozzles, which have special shape requirements and resistance to
Milled products are a good choice.
2) Boron Carbide Blasting Nozzle:
The real boron carbide is a black diamond hexahedron that is formed after smelting in a high-temperature furnace (about 4000 degrees high temperature) for a long time. It is a hot-pressed sintered product. Extrusion molding, high-temperature sintering, and cooling mold release require a certain time, sometimes To ensure the quality, the cooling time must be one day, before and after
It takes almost 3 days to make a nest of nozzles (about ten), so the cost is high.
Atmospheric pressure sintered boron carbide nozzles do not require special extrusion molding and calcination of high-temperature and high-pressure boilers. A large number of molds can be used. One mold can manufacture dozens or even hundreds of molds at a time, and the cost is low. Nozzles are characterized by lower hardness and abrasion resistance
Not high, harder than silicon carbide, but less than half the life of a hot-pressed sintered boron carbide nozzle. From the surface, this nozzle has more honeycomb holes or pores.
3) Sandblasting nozzle combined with boron carbide and silicon carbide:
This kind of sand blasting nozzle is better in quality than ordinary pressure sintered boron carbide nozzles, and inferior to high pressure sintered pure boron carbide nozzles. The addition of silicon carbide is to increase the nozzle's toughness during extrusion molding and calcination, reduce the damage rate, Suitable for shaping some simple shaped boron carbide products,
The surface of this nozzle is bright and the color is uniform.If the manufacturer's technology is mature, the quality is even better than the quality of boron carbide nozzles produced by ordinary manufacturers.
If you buy the nozzles of 1) and 2) above, I think it is better to buy more pure boron carbide. If you buy the nozzle of 3), then you can make money.
In addition, there is a high-pressure sandblasting nozzle (gun), which has the same appearance as the venturi nozzle with a single inlet, but the inside is really a straight-hole sandblasting nozzle, but it is longer and the outer diameter is increased. Nozzle is used for high pressure open blasting machine, suitable for some blasting strength, speed,
Sandblasting projects that are not large, such as ordinary steel blasting, jeans blasting,
2.Venturi nozzle :
The structure is divided into three parts: the shrinking section, the straight section and the diffusion section. The production is more complicated. Under the same pressure conditions, the venturi nozzle speed and sand blasting area can be more than doubled compared to the straight hole nozzle. Straight hole nozzles are much taller.
Secondly, we summarize the types of sandblasting nozzles from the manufacturing materials :
The nozzle materials currently on the market are ceramic nozzles \ alumina nozzles \ tungsten carbide nozzles (also known as tungsten steel nozzles, hard alloy nozzles) \ silicon carbide nozzles \ boron carbide nozzles (also known as artificial diamond nozzles), etc.
Use the following blast test data to compare the service life of various nozzles.
Nozzle reference life obtained through tests: (unit: hour)
Nozzle Material Steel Shot Quartz Sand Brown Corundum Alumina Ceramic 20-40 10-30 1-4
Tungsten Carbide 500-800 300-400 20-40
Silicon Carbide 600-1000 400-600 50-100
Boron carbide 2000-2500 1000-1500 500-1000
We can see that the service life of boron carbide nozzles is the highest, basically the aging time is more than 5-10 times that of tungsten steel nozzles. It has gradually replaced the nozzles of other materials, and its price is not much higher than that of cemented carbide nozzles. The service life is increased several times!
1) Ceramic nozzle features:
The abrasion resistance is not high and the service life is not long, but because of its low cost, simple production, and die-casting by means of a mold, many special-shaped nozzles use composite ceramic materials. For example, stepped nozzles, A-type nozzles, Flared nozzle, 9 / 10MM outer diameter nozzle, etc.
Especially for those blast guns that require special-shaped nozzles for the design of the gun, ceramic nozzles are sometimes necessary.
2) Tungsten carbide nozzle:
Also known as tungsten steel nozzle, hard alloy nozzle, high hardness, strong wear resistance, compared to boron carbide, there is still a gap, but the price is moderate, it is the best-selling sandblasting nozzle in previous years. For not long time every day For customers who continuously use sand blasting machines, save inventory costs, tungsten steel blasting
Mouth is a good choice.
3) Silicon carbide nozzle:
The wear resistance of silicon carbide nozzle is better than that of tungsten steel nozzle, but the wear resistance is far worse than that of boron carbide nozzle, because it has the characteristics of light weight, black color, and the surface is similar to the characteristics of boron carbide. So many customers Cheap and frequent when buying boron carbide nozzles
Repeated strokes. Because the quality of silicon carbide nozzles is not much different from tungsten steel nozzles, the price is much more expensive than tungsten steel nozzles, and the price is not much cheaper than boron carbide nozzles, but the wear resistance is much worse. Most sandblasting machine manufacturers believe that Silicon carbide nozzles are not recommended. Except for boron carbide
Unable to meet the shape requirements, silicon carbide must be used to make shaped products.
4) Boron carbide nozzle:
First explain what is boron carbide ?
Boron Carbide (B4C) is a kind of carbide of boron. It is a black diamond hexahedron formed by smelting in a high temperature furnace (about 4000 degrees high temperature). Boron carbide is one of the hardest man-made materials. Hardness second only to diamond and cubic boron nitride, with
It has the characteristics of light weight, semiconductor physical properties, neutron absorption, high grinding efficiency, and no reaction with strong acids and alkalis. Mohs hardness is 9.36, micro hardness is 5400-6300 kgf / mm2, density is 2.52 g / cm3 The melting point is 2450 degrees Celsius.
Boron carbide is a non-metallic material with important physicochemical properties.It is the hardest boron compound after boron nitride.
Use range :
Suitable for drilling, grinding, grinding and polishing of hard materials, such as hard materials such as hard alloys, precious stones, and ceramic wear-resistant parts, including wear-reinforced plates, pump parts, bearings, faucet pieces, nozzles, and valve parts engineering Ceramics (including structural, environmental and process
Ceramics), bioceramics, nuclear reactor core blocks, lightweight bulletproof armor materials, etc.
Boron carbide and its products are widely used in machinery, petroleum, chemical, shipbuilding, metallurgy, automotive, aerospace, military, atomic energy and other industrial fields. Sand blasting nozzles, seals, wire drawing dies, slide blocks made of boron carbide and silicon carbide , Measuring probes, bearings,
Products such as bulletproof vests, armor plates, and neutron absorption blocks are widely used in industrial technical fields such as spraying, sealing, drawing, casting, protection, corrosion protection, and measurement.
The boron carbide nozzle made of boron carbide powder has all the above characteristics of boron carbide and is the most durable nozzle of sand blasting machine at present. Because of its characteristics, it is destined not to be processed into special-shaped products at will, but only simple grinding or laser. Cutting.
Boron carbide nozzle has all the characteristics of boron carbide and is the most commonly used wear-resistant blast nozzle
Second, the replacement and purchase of boron carbide nozzles and spray guns .
First you need to understand the principle of nozzle spraying :
Ordinary sand blasting machines generally use suction sand blasting (normal pressure siphon sand blasting machine), that is, the use of compressed air flowing at high speed in the spray gun to form a negative pressure to induce ejection. The abrasive in the cyclone separator tank is sucked through the sand pipe. Inside the spray gun, sand and compressed air pass through the sand
The tube and the air pipe enter the spray gun separately, and after they are combined inside the spray gun, they enter the bell mouth of the nozzle. After being accelerated in the nozzle straight tube, they are ejected from the nozzle outlet to the surface of the workpiece. The impact of sand on the surface of the object changes the mechanical properties of the surface of the workpiece, forming a specific Surface effect
To the purpose of sandblasting.
There is also a pressure blasting machine (pressure feed blasting machine)
The pressure type sand blasting machine uses a pressure tank.Compressed air is divided into two before entering the pressure tank. A group of pressure blasting machines (sand cylinder) combines with the abrasive in the cylinder to form a hybrid power. It enters from the bottom of the sand pipe through the sand regulating valve. Sand tee, another set of compressed air directly through the pipe
Blowing toward the sand tee, combined with the abrasive power down from the sand cylinder to form a whole, which is directly ejected from the sand blasting gun through the sand tube movement, and hits the surface of the object at high speed and high pressure to form a sand blasting effect.
According to the size of the sand tube used in the pressure type sandblasting machine (usually a small sand tube with an internal diameter of 19MM and a large sand tube with an internal diameter of 32MM), ordinary straight-hole sandblasting guns (nozzles) and Venturi high-speed spraying guns with single inlet and double inlet are used. (mouth).
Here we focus on the straight hole nozzle of the ordinary pressure blasting machine.The following issues are related to the blasting effect and to the replacement of the nozzle .
1) Spraying speed : the longer the nozzle, the higher the spraying speed, the more concentrated the abrasive spraying; the greater the air pressure, the greater the speed;
2) Spraying distance : the farther the spraying distance is, the smaller the intensity of the spraying is, and the larger the spraying range is, the weaker the effect is;
3) The angle of the spray : the vertical spray strength is the largest, and the smaller the angle, the weaker the spray effect. Normally, the sand is blasted at an angle of 30-45 degrees.
A ): You can change the model of the non-mass production nozzle that comes with the original blasting machine .
: Replaced with some nozzle models that can be bought at any time on the market or replaced with shorter nozzles, one is cheaper by dozens of dollars, which can save costs. In fact, many manufacturers in order to make their products different from other manufacturers, Also for regular users
Households generally use accessories that are not commonly seen on the market, so customers have no way to replace them themselves, and can only spend more money to buy specific products from manufacturers.
In addition, many manufacturers do not produce spray guns, nozzles, sand pipes, and air compressors. Most of these are ordered back, and the cost of natural sales will be higher. If the manufacturer of the sand blasting machine does not affect the sand blasting, If it is effective, replace it with one that is easy to buy on the market
Standard accessories, then the cost of procurement is naturally reduced.
Two ): You can replace the shorter nozzle with a cheaper price .
When replacing, you need to consider the effect of sandblasting and what kind of objects to spray. Generally, it is considered that the length of the replacement should not be too large within 20mm. For example: 55MM long nozzles can be replaced with 45MM, and 45MM long nozzles can be replaced with 35MM. Because it is replaced with a shorter spray
After the mouth, you can adjust the air pressure to achieve the effect of using the long nozzle before, and at the same time: You can reduce the spray distance to achieve the effect of using the long nozzle before.
C ): The inner diameter of the nozzle can be changed .
The size of the sand material to be used and the force range of the object to be sprayed need to be considered. For some spraying ranges that require special accuracy, try to keep the variation range of the nozzle's inner diameter as small as possible. It should be no more than 2mm, because whether the nozzle can produce sand depends on the gas Core aperture size.
For example: the inner diameter of 8.5MM can be replaced with 8mm, the use of 7.8mm can be replaced with 7mm or 6mm, and the use of 7mm can also be replaced with 8mm, the effect of spraying is very small.
Of course, special-purpose nozzles should be determined by actual work requirements.For example, the nozzle for engraving and lettering must have a small inner diameter and there is no need to replace it.
Special tips :
If the sand material used is small and can pass the inner diameter of 7mm, the inner diameter of 7mm and 8mm should be considered at the same price. The 7mm should be considered because when the inner diameter loss is ground from 7mm to 8mm, the aging effect is already much more.
Summary : For the nozzle, the size and length of the nozzle pipe ( inner diameter ) are mainly affected by the blasting effect .
The nozzle length determines the speed of the spray , which can be controlled and compensated by adjusting the pressure ;
The size of the inner diameter of the nozzle is determined by the particle size of the sand material, and the size of the inner hole of the air core of the spray gun must be considered . The size of the pipe determines the size of the spray range . The smaller the range , the smaller the spray range and the more concentrated the spray .
When replacing the nozzle, the difference between the inner diameters of 1-2 mm has no effect on the general blasting effect.If the replacement gap is too large, the sand material will not be concentrated or uneven, and the particle size of the sand material must be considered .
The requirements for sand blasting are relatively low , and the deviation of 10-20mm has little effect.This can be compensated by pressure adjustment and distance adjustment .
Company Name: Magin Dongguan Humen Meijun Wear-resistant Sandblasting Equipment Store
Address: No. 69, Longan 5th Road, Longyan Industrial Zone, Humen, Dongguan