How to adjust the air marks of injection molding machine products, and how to adjust the air marks o

Shooting lines, bubbles.

The formation of the injection pattern is generally due to the injection starting too quickly, so that the air in the front section of the mold cavity.

It cannot be suppressed and eliminated by the melt of the rubber compound, and the air is mixed in the rubber material, making the surface of the product bright.

The uneven color is the so-called shooting pattern, which constantly affects the appearance and makes the finished product.

The mechanical strength is much reduced. Therefore, it is necessary to find out the cause of this defect in order to avoid it.

and improve it.

The formation of the jet pattern, since it is due to the gas contained in the melt plastic, then ** this.

1) The plastic itself contains water or oil:

As the plastic is exposed to air during the manufacturing process, inhalation of water vapor or oil agents, or.

When mixing, some wrong proportional components are mixed to make these volatile substances melt.

, gas is produced when heated.

2) Thermal decomposition of raw materials:

If the temperature, back pressure and melting speed of the screw barrel are adjusted too high, or the molding cycle is too long, it will be used for heat-sensitive materials such as PVC

Plug steel, PC, etc., are easy to decompose due to high temperature heating to produce gas.

3) Air. The plastic pellets contain air between the pellets if the screw barrel is at the inlet.

If the temperature is adjusted too high, the surface of the plastic will melt and stick together without being compressed, and the air between the plastic particles will not be completely removed.

Therefore, the plastic should be dried, and the appropriate melting temperature and speed should be used.

When the back pressure, you can get the ideal plastic product. In addition, mold design is also very important.

of the link. Usually the mold with a large flow channel and a small injection port has the opportunity for gas to enter the mold cavity.

It will also be reduced. In injection molding technology, there is a method to prevent the formation of injection marks. Make the mold.

The structure includes pressurized equipment and a compressed air inlet hole. After clamping, the void is compressed.

The air enters the mold, so that the air pressure in the mold increases.

When the molten plastic enters the high-pressure mold, the pores of the mold begin to vent, and a certain pressure is maintained in the mold cavity, increasing the air in the mold.

pressure, which can indeed avoid the chance of shooting marks. For example, when the common injection method deals with the moisture content of ABS, the ejaculation appears; Gradually increasing the air pressure in the mold can process ABS with a high moisture content without the appearance of jets.

The following table lists the causes of the appearance of a shot pattern (for reference).

Cause of the failure. Solution:

The temperature of the feed tube inlet is too high.

Reduce the temperature of the inlet.

The injection speed is too fast.

Reduces the rate of fire and increases the pressure of fire.

The raw material contains moisture.

The ingredients are dried thoroughly.

The mold temperature is too low.

Increase the mold temperature. The gate is too small.

Readjust the pore size or temperature.

There is air in the barrel.

The temperature of the section is lowered and the pressure is increased.

The coarse and fine particles of the raw material are uneven.

Use raw materials with uniform granules.

Other additives in the raw material are not mixed evenly.

Mix thoroughly.

Additives such as dyes are decomposed by heat.

Use a substitute with a higher temperature resistance.

One: see if the material is dry.

Two: see if the back pressure is too small.

Three: whether the injection speed is too fast.

In fact, it is difficult to find out the root cause of the problem from the defects of the product alone, the usual practice is to eliminate them one by one, and the defects such as wave lines, silver wires and other defects are usually unreasonable in the position of the gate opening, if the mold is no problem, then look at whether the parameter settings of the machine are reasonable, speed, adjust up and down to see the situation changes in the position of the waves, anyway, the factors that may cause the waves to try one by one, if the experienced people see the position of the waves, they can also accurately judge the reason. If you are inexperienced, take your time and eliminate the problems one by one!

In the injection molding process of injection molding products, due to various reasons, defects such as air marks may occur, which affects the quality of products. Here are some common adjustment methods to solve the problem of air marks in injection molded products.

1.Adjust the parameters of the injection molding machine. Parameters such as pressure, speed, and temperature of the injection molding machine will affect the quality of the injection molding product.

For the problem of air marks, it is generally necessary to appropriately increase the pressure of the injection molding machine and increase the injection molding time so that the gas can be discharged during the filling process. In addition, the barrel temperature of the injection molding machine can be appropriately increased to improve the melt fluidity, reduce the melt viscosity, and facilitate gas elimination.

2.Adjust the mold structure. The structural design and manufacturing accuracy of the mold have a great impact on the quality of the product.

If the air marks are concentrated in a certain location, the flow channel and exhaust hole at that location can be appropriately increased to better discharge the air inclusions. In addition, it can also increase the amount of cooling water in the mold cavity, reduce the mold temperature, reduce the curing time of the melt, and facilitate gas removal.

3.Adjust raw materials. The composition and quality of raw materials also have a great impact on the air mark problem of the product.

If the air marks are due to volatile components in the raw materials, you can try changing the raw materials or adjusting the formulation. In addition, the drying time of the raw material can be increased to reduce the moisture and volatile components in the raw material.

4.Other adjustment methods. In addition to the above methods, you can also adjust the injection speed, pressure, nozzle position and other parameters of the injection molding machine, or add some special additives, such as antioxidants, defoamers, friction reducers, etc., to improve the gas mark problem of the product.

It should be noted that different gas scar problems may have different solutions, and the specific adjustment methods need to be comprehensively analyzed and judged according to the actual situation. In addition, during the adjustment process, each adjustment needs to be recorded and tracked so that problems and improvements can be identified in a timely manner.

Hello dear, the injection molding machine product has air lines can be adjusted like this: Hu Xiangjian 1, adjust the pressure in the plastic mold, so that the pressure between the molds has a good balance, so as to avoid the appearance of gas banquet key lines. 2. Adjust the speed of screw movement and move slowly so that the product can be injected accurately.

3. Regularly inspect the plastic mold and check whether there is dirt in the runner pants to prevent the appearance of gas lines caused by blockage. 4. Check the internal temperature of the plastic mold to ensure that it is not too high, so as to avoid gas streaks.

1.Characteristics of defects in injection molded parts.

It is usually related to the gate area: its surface is dull and sometimes streaks are visible.

2.Possible causes of problems.

1).The melting temperature is too high.

2).The mold fills too fast.

3).The temperature is too high.

3.Remedy.

1).Reduce the temperature in the first two zones of the injection cylinder.

2).Reduce the injection molding speed.

3).Reduced injection pressure.

4).Reduce the mold temperature.

5).Most of the parts produced with PE will have shooting patterns, which can be used according to the requirements.

Modify the inlet location.

How to solve the problem of air streaks on injection molded products:

Appropriately increase the temperature of the barrel to make the gas easy to escape, but the temperature of PC ABS plastic can not exceed 270 to prevent high temperature decomposition and affect the performance of PC ABS plastic.

Appropriately reduce the injection pressure and injection speed so that the gas has sufficient time to discharge. It should be noted that the injection pressure and the injection speed are interrelated, and the adjustment cannot be made in such a way that both can be changed at the same time, because it is not possible to determine whether the cause of the streaks is too much injection pressure or too much injection speed.

The correct way to do this is to select one of the parameters to adjust and then see how it works, and then decide what to do next.

Increasing the back pressure and increasing the melting speed can make the air wrapped in the raw material and the gas generated by the volatile phase of the raw material itself fully discharged from the back section of the barrel.

Improve the venting of the mold. Ensure that all kinds of gases generated when the material is filled into the mold during the injection molding process are smoothly discharged from the mold.

The raw materials should be fully dried, it is recommended to be 70 80, the drying time is not less than 4h, and moisture-proof measures should be taken (especially in rainy days) to prevent the influence of water vapor.

Summary. If you make a mistake, how to adjust the air pattern at the inlet of the transparent PC, you can adjust the mold temperature a little higher, and then the injection speed is a little faster, and then the pressure holding time can be kept a little longer.

Process: the speed is slower, and the pressure is greater if you can't rush.

On the mold: increase the mold temperature, which side has air lines to add the mold temperature, generally about 100 degrees. If possible, change the inlet to a larger one.

Material: Be sure to remember to dry, there will be gas streaks if you don't dry.

Be sure to see whether it is stress lines or air lines.

Combined with the above, it should be able to be done.

What are the skills of adjusting the air pattern of the injection molding machine.

If you make a mistake in how to adjust the air pattern at the mouth of the transparent PC glue, you can adjust the temperature of the mold world a little higher, and then the injection speed is a little faster, and then the pressure holding time can be kept a little longer. Process: the speed is slower, and the pressure is greater if you can't rush.

On the mold: increase the mold temperature, which side has air lines to add the mold temperature, generally about 100 degrees. If possible, change the material of the inlet to a larger point:

Be sure to remember to dry late, and there will be gas streaks if you don't dry. Be sure to see whether it is stress lines or air lines. Combined with the above, it should be possible to do the search for a clear circle.

Air streaks at the inlet of the glue.

The general solutions to the gas pattern at the inlet of plastic products are: 1. If there is a recycled material added, stop using it first. 2. Dry the raw materials thoroughly, and do not let them get damp again while waiting.

3. The raw materials must be completely melted in the melting section, the compression ratio of this section is large, it is easy to exhaust, and it will be difficult to discharge the gas when entering the homogenization section. Raise the temperature of the melting section appropriately. 4. Increase the back pressure, which is obviously to increase the exhaust pressure, which is conducive to pressing out the gas in the raw material in the melting section.

5. The air pattern at the inlet is likely to be caused by supplementing the feed during the final pressure holding, so as to reduce the temperature of the homogenization section of Huaiqin to prevent degradation. 6. The injection speed is reduced during pressure holding. 7. If the parting surface passes through the glue inlet, try to loosen the mold.

8. If the process measures are ineffective, try to enlarge the gate size and open an exhaust groove near the glue inlet.

If there are gas marks in the injection molding machine, it is necessary to reduce the injection speed, reduce the injection temperature, reduce the mold temperature, increase the mold exhaust depth, and increase the number of gates. The formation of gas marks in the injection molding machine is generally due to the rapid injection start, so that the air in the front section of the mold cavity cannot be suppressed and eliminated by the rubber melt, and the air is mixed in the rubber material, so that the surface gloss and color of the product are not uniform.

Injection molding machines are also known as injection molding machines or injection molding machines. It is the main molding equipment for making thermoplastics or thermosets into plastic products of various shapes using plastic molding molds. The injection molding machine heats the plastic and applies high pressure to the molten plastic, causing it to be injected and fill the mold cavity.

According to the arrangement of the injection device and the clamping device, it can be divided into vertical, horizontal and vertical compound type.

The injection molding machine has the ability to form plastic products with complex appearance, precise size or dense texture with metal inserts at one time, and is widely used in national defense, electromechanical, automobile, transportation, building materials, packaging, agriculture, culture, education and health and people's daily life in various fields.

Today, with the rapid development of the plastic industry, injection molding machines occupy an important position in terms of quantity or variety, and their total production accounts for 20%-30% of the entire plastic molding equipment, thus becoming one of the fastest growing and largest production models in the plastic machinery.

The huge potential of China's plastic processing industry has opened up a broad space for the rapid growth of the injection molding machine industry. At present, 83% of plastic processed products are injection molded. In recent years, due to the growing demand for injection products in automobile, construction, household appliances, food, medicine and other industries, the development and improvement of injection molding technology has been promoted.