How to test product quality?
Today we will talk about how the finished product is inspected.
After the production of CNDOME’s abrasive disc is completed, professional inspectors need to conduct quality inspections on each piece.
First of all, inspectors need to check the appearance of the abrasive disc, such as whether the edges are neat, whether there are burrs, the neatness of the mesh, and the aesthetics of the layout.
Second, do a static balance test. The balance is the basic standard of the abrasive disc.
The last and most critical step is the cutting test. This is the most important test of the quality of the abrasive disc. Each batch of our goods will be spot-checked on a fixed proportion of cutting performance, because we are responsible for each piece of abrasive disc.
Quality factors and control points of grinding wheel slippage and less network
Leakage net—part of the built-in net of the grinding wheel leaks out.
Less net—The net is not placed in the grinding wheel as required.
Leaked network, external network—visual inspection.
Built-in network-the next station operator visual inspection.
1. Lost the net: (1) Affect the appearance of the grinding wheel, and the product has no market competitiveness.
(2) The abrasive grains at the leaked mesh have poor cohesiveness and are easy to sand out.
(3) In use, the safety is poor. In severe cases, the grinding wheel ruptures, causing personal injury.
2. Less network: the strength of the grinding wheel cannot meet the safety requirements of the design, and the grinding wheel breaks directly when the worker is in use, causing personal injury.
1. The coarse particles of the mixture cause difficulty in spreading and leak through the net.
2. The scraper is not adjusted well or the spreading speed is fast, which leads to partial failure and slippage.
3. The mesh is not well compressed during pre-compression: the mesh is not flattened or compacted, and the mesh partially floats during the spreading process, causing the internal mesh to leak.
4. Too much waxing will cause wax masses to be formed in the spread to suppress, and form a slip through the net after hardening.
5. The operation is not careful, and the material mass is not processed in time.
6. Less network:
(1) The program design of the automatic unwinding device is unreasonable, and no automatic shutdown is detected when the net is not released.
(3)The operator is not serious, and the net has not been put out and has not been checked out.
Definition: unload the wheel without cooling to room temperature.
Inspection method: hand sensing
1.Slicing products are prone to severe distortion, deformation and bulging.
2.Affect the delivery period.
3. After long-term aluminum plate pressing and flatness are qualified, the product performance attenuation is difficult to restore to the designed performance.
1. The unloading personnel do not perform as required and are not aware of the seriousness of heat unloading.
2. Insufficient stacking of aluminum plates, and inadequate coordination of the production plan of the management personnel, to meet the use of the previous process, it is discharged before being cooled to normal temperature.
3. The spring-loaded large slice product has a long cooling time and needs to be improved.
Changzhou Dome Abrasives Manufacture Co., Ltd founded in 1997,it is a leader abrasive disc manufacturer in China with more than 120 employees, the daily production capacity reaches 300,000 pieces.
The factory located at Changzhou City, Jiangsu provice,China, which is 150 kilometers from Shanghai. It is very convenient to ship the goods from Shanghai or Ningbo sea ports, also convenient send the goods to Yiwu warehouse.
At present, our factory can produce 3” to 16” different size cutting disc, the thickness from 1.0mm to 4.0mm with T41 flat and depressed center T42 types. 4” to 9” grinding wheels wiht thickness 6.0mm to 7.0mm with double nets or three nets for your choice. Most of our products already past CE and Germany MPA certificates. We also have BSCI certificate.
The products widely export to North and South American countries, Europe countries, East and South East Asia countries, Africa and Middle East countries.
Welcome to chose our factory cutting and grinding wheels.
Analysis of common quality problems of sand wheels:
Reason for serial number problem/solution measure
1 The size of the material does not match, and the hardness does not match. Calculate the ingredients strictly according to the ingredient list, review is the key program
2 In the process of mixture and mixture, we can clean up the tooling appliances. Before the ingredients, check the various raw materials for impurities
3 The mixing mixing is mixed according to the process requirements. Replace the mixing machine parts with too large wear at any time. Powder resin should be sieved according to the sieve and number of sieves and times according to the process
4 Organization unevenness, uneven hardness and unevenness adjust the dry and humidity of the mixture, so that it has good molding. The stalls and scraping operations are performed according to the process requirements. Put the iron at the process according to the process requirements to maintain the accuracy of the stress machine; the stalls are unevenly scraped when the feeding, the mix is humid, or the feed group, unevenly submitted, the mold wear, the leakage is severe, the mold needs to be replaced, you need to replace the mold, you need to replace the mold.
5 The temperature of the fissure of the body is too high, the product is cold and hot, and the temperature is too low when the core is removed. The core should be removed in time.
The following four crack prevention measures:
The plasticity of the mixture is well -adjusted, and the molding mold mold must not exceed the prescribed wear standards. The template and iron pads maintain a good flat degree. The thickness of the iron pad should be consistent.
6 -end fissure forming material has poor plasticity, and the method of removing the mold is improper. The molding mold bottom plate or the pads are not parallel to too large
7. The split module around the surrounding area is severely worn.
8 Pores and diameter cracks are low in strength, too much vibration when the mold is removed, the core rod is too large or the taper is too small.
9 The spring cushion of the diagonal cracks, the elasticity is inconsistent, which causes the mold to be compressed by diagonal. The suppression speed of the fine material mill is too fast, the pressure time is short, and the gap between the mold is too large
10 Two ends to keep the accuracy of the pressure padding table, operate in accordance with the process specifications
11 Surface uneven workwear maintenance within the accuracy range of the required accuracy
12 The hardness of the molding mold does not match the required inspection of the first piece, and each batch of spot checks is not less than 30%.
13 Bridge landscape cooling needs to be uniform; the “warning” on the surface of the parts is called bridge landscape. This is caused by uneven cooling, which causes inconsistency of the component or the pads of the furnace. Mostly from thin sliced sand wheels and fine -grained thin products. When the chip wheels are cooling too fast, it is easy to produce bridge lace waste products
14 Bubbles control the temperature and hardening according to the product specification hardening curve, and strictly control the quality of the mixed materials; the molding temperature is too high or too low, and the temperature needs to be adjusted. The curing temperature is too high, and the temperature of the furnace is out of control. The binding agent is wrong; the ultra -hard grinding vertical surface is protruding deformation or the entire surface swells, and it is resin luster, and some turtle cracks appear.
1 The temperature of the temperature is too fast or the temperature fluctuates large, which is easy to foam and expand the particle size, high hardness, and tight tissue. Because these products contain a large number of binding doses or small pores, if the temperature control is inaccurate, the heating rate is too fast, which will cause a fierce reaction of the binding agent, the amount of volatile substances increases sharply, and the gas pressure inside the blank body will make the product foam and swell.
2. The mixing of the type of material is uneven, and there are bonding agents or lower boiling points in the material (such as ethanol, acetone).
3 The errors of the mixing and molding processes increase the binding dose of the parts, increase the single weight, and increase the pressure.
15 Deformation and collapse are carried out in accordance with the process regulations and temperature control operations. The ratio between filling should be strictly controlled and adjusted, and there is interaction between filling. Insufficient pressure will deform when cutting slices.
The reasons for the deformation and collapse of super hard abrasives during the hardening process are:
1 When the furnace is installed, the body is exposed to the outside of the pad or squeezed the body of the body to each other, and the pads are not tilted.
2 High -thickness parts do not permeate papers in accordance with the process regulations.
3 Natural drying time is short or without low temperature drying, directly entering the furnace hardening.
4 The temperature is too fast, and the binding agent is melted sharply to soften the body and collapse.
16 Red Heart Hardrobic Volume exhaust system needs to be unblocked. According to the hardening curve of product specifications, it is properly controlled. The liquid resin is used to use porous pad or ceramic pads; Unexpected hardness is easy to break.
1 The hardening equipment exhaust system is poor, and the exhaust gas is difficult to discharge.
2 The hardening curve is unreasonable, and the heating speed is too slow.
3 The pads of liquid resin pieces have poor breathability.
4 The content of liquid resin has a high content of liquid deoxol, and the solid content is too low.
17 The hardness of the hardening and the rotation rupture is correctly controlled by the hardening curve. The hardening of the pink resin blank must be stamped or buried. During the installation and unloading process, avoid shocking. The super -hard abrasive has ruptured during inspection, which is caused by the low -intensity or grinding with cracks.
The cause is:
1 The hardening temperature is too high, and the binding agent has some carbonization reduced the strength of the abrasive gear.
2 The mixing material is wrong, such as more abrasives, less binding agent, or the poor quality of the binding agent itself decreases.
3 The mold unloading, transportation, and furnace are shaking severe vibration, causing the parts to be damaged by mechanical and dark cracks inside.
4 The tissue of the sand wheel is uneven, and the unbalanced gram is too large.
5 Severe bias or pores are too large.
18 During the use of use, the quality of the cutting slices of the mesh resin lipid and the mesh should be qualified. The process formula should be reasonable, and there is basically no problem with the above problems. Some broken particles, tissue looseness, and lack of binding agents will be separated from the grid cloth. The production of these defects is related to the improper manufacturing process.
19 The hardness and strength of the finished product do not meet the quality of the resin, and the content of the lipphenols of the resin is high and low. The so -called free phenol is the phenol that remains in the resin. The molecular formula is C6H5OH. Long -term heating can crack the resin after hardening and affect the strength of the wheel.
2 The resin powder is unevenly mixed with Ulot. The scientific name of Uloto is hexal metharine (CH2) 6n4. It affects the strength and hardness of the wheel; if the content is too high, the excessive Ulot products are not combined with the resin, which will be volatile and volatilizes in the hardening process, increasing the pores of the sand wheel, and reducing its strength and hardness.
3. The binding agent particles are too thick, and the particle size of the binding agent is appropriate, which is conducive to the distribution of the binding agent evenly, and it is conducive to the sufficient contact of the hardening agent. If the particle size is too thick, the molding material is not easy to mix and uniform, affecting the hardness and strength of the wheel. Even for the thick -grained resin slice cutting the sand wheel and the rigid sand wheel, the particle size of the binding agent (resin powder) should be thinner than 320#. Create fine -grained sand wheel products, the particle size requirements of the binding agent are several microns.
20 The side and the corner should be carefully operated after the molding until it is hardened to ensure that the edge of the brake is intact and avoid mechanical damage. Most of the drops and corners are caused by accidental furnaces, and accidentally taken during transportation. For workers who are unskilled, they should strengthen training and improve their skills. The resin mill body’s dampness strength should be transferred or put in a flippiculation method, and the blank body cannot be moved directly by hand.
Product Quality Inspection
How to test product quality?