TECHINCAL
時間：2020.08.18
Questions and answers of ZTL automatic air pressure leak detector
FAQ of ZTL automatic air pressure leak detector:
1、 Q: under what circumstances should a leak detector be used?
Answer: the leak detector can detect the small leakage of the hollow container reliably, high speed and stability, so as to ensure the quality of the detected products. After adding the leak detection process, the problems of can leakage, production interruption and leakage pollution caused by defective products entering the next process can be avoided. Therefore, the leak detector will be used for the containers, bottles, boxes and various pipe fittings that need to be sealed well.
2、 Q: why is air pressure leak detection better than water pressure leak detection?
A: one of the most important advantages of using air pressure for leak detection is the objectivity of the detection process. This means that the results can be obtained repeatedly and can be used for statistical analysis. Generally, water pressure can detect leakage, but it is easily affected by human factors and takes a long time to obtain the results. So the problem is how to determine the length of time the sample is tested underwater. Most of the leaks detected are "significant" leaks, such as large ones. Electronic instruments can detect very small leaks very quickly. Other problems with underwater testing include moisture content, spillage, and product damage or damage.
3、 Q: what are the advantages of pressure drop leak detection?
Answer: pressure drop leak detection can be effectively used for leak detection of relatively small volume products. The product is pressurized with air, and the instrument monitors the negative change of pressure. If there is a pressure drop, there is a leak. This method only takes a few seconds to get the results, so it is widely used in large industries, such as automobile products, castings, medical equipment and consumer goods.
4、 Q: what kind of occasions do you use the double check function?
A: there may be a small amount of false detection in the detection process due to external interference. The double detection function makes the system completely avoid the occurrence of false detection caused by external interference by detecting the detected products twice and synthesizing the detection results. For some industries, such as pesticide, chemical industry, dangerous goods and other packaging containers, the quality requirements of detection bottles are high, so it is recommended to use this function.
5、 Q: how many products can be tested each time?
A: the number of products that can be detected at the same time is determined by the number of channels of the leak detector. For example, 2 channels can detect two products at the same time. ZTL series leak detector can provide 6-channel model at most.
Summary of PET production problems (for reference only)
Key points of PET bottle embryo production technology
Analysis and solution of some defects of PET bottle grade chips in the process of injection molding
1. If there is a problem with the installation and concentricity of the mold, the order of the installation and concentricity should be confirmed. If necessary, it needs to be re installed.
2. There is a problem with the machining accuracy of the mold parts. Confirm whether the normal mold parts are used. For the machining accuracy, please ask the mold manufacturer.
3. It is suggested to replace the worn parts and carry out routine inspection and oiling operation again.
Demoulding phenomenon:
Injection molding is a phenomenon that may occur due to poor mold. The main causes and solutions are as follows:
1. It is suggested to solve the problem of burr.
2. The cooling of bottle embryo is not enough. It is suggested to check the cooling pipeline, including the internal cooling circuit of the mold and the operation of the chiller, so as to reduce the temperature of the cooling water.
3. Pet drying is insufficient, it is recommended to check the operation of dehumidifier dryer and the property of PET raw materials.
4. The melt temperature is too high, it is recommended to reduce the temperature of barrel (front and middle).
5. It is recommended to replace the damaged parts due to the damage of die parts (bending of die core, etc.).
6. If the demoulding structure is unreasonable or the position is improper, check the demoulding structure and position.
7. If the mold temperature is too high, reduce the mold temperature properly.
8. If the injection pressure is too high, reduce the injection pressure properly.
9. Use release agent.
Condensation
Condensation during injection molding is a possible phenomenon. The main reasons and solutions are as follows:
There are water drops in the injection core, and the formed bottle embryo is closely connected with it, which is caused by poor demoulding. It is suggested to increase the temperature of cooling water properly and check the operation of the mold dehumidifier.
Analysis and solutions of the defects in PET bottle embryo production
Intersection fracture
The gate fracture of bottle embryo is a common phenomenon in injection molding, which is the cause of nozzle blockage and short injection. The main causes and solutions are as follows:
1. The temperature of hot runner nozzle is too low. It is suggested to increase the temperature of hot runner nozzle.
2. The pressure used for holding pressure is too high, so it is recommended to reduce the pressure used for holding pressure.
Partial albinism
Local whitening of bottle embryo is a possible phenomenon during injection molding. The main causes and solutions are as follows:
1. The former gate debris flowed into the bottle embryo and caused white people. In this case, no special treatment is required. If it is abnormal for a certain period of time, or the mold should be cleaned.
2. When the temperature of the hot runner nozzle is low, it is recommended to reduce the pressure used for pressure holding.
wire drawing
The main reasons and solutions are as follows:
1. The over temperature of hot runner nozzle is too high, so it is suggested to reduce the temperature of hot runner nozzle.
2. If the resin temperature is too high, it is suggested to reduce the temperature of hot runner nozzle.
3. The pressure used for holding is too low, so it is recommended to increase the pressure for holding.
4. If the holding time is too short, it is suggested to extend the holding time.
5. The resin is dry and enough. It is recommended to check the dryer.
