In the production of plastic products in the injection molding industry, the finished products often have many problems such as shrinkage, silver streaks, bubbles, cracks, flow marks, and weak transparency. The main reason for these defective products is that the plastic products are not extruded. Due to the lack of thorough drying treatment before, a dehumidification dryer must be used for dehumidification and drying treatment. Then, our custom injection molding companies will teach you how to choose a more suitable industrial dehumidification dryer:
There are generally two types of industrial dehumidification dryers commonly used at present: freeze dehumidification dryers and rotary dehumidification dryers. The refrigerated dehumidification dryer has high dehumidification efficiency and strong economy, and is suitable for most environments. However, the freeze dehumidification dryer should not be used in a low temperature environment of ≤5°C, and it is difficult to reduce the humidity below RH30%. Therefore, if the temperature of the dehumidifier is required to be lower than ≤ 5°C, or the humidity is required to be reduced, the RH refrigeration dehumidification dryer is not suitable for use below 30%. The dehumidification effect of the wheel dehumidification dryer is less affected by the ambient temperature and humidity, and it is a very stable and reliable dehumidification equipment. Compared with the freeze dehumidification dryer, the price of the rotary dehumidification dryer is several times higher. Generally speaking, the rotary dehumidification dryer is mainly suitable for the following two environments: one is low-temperature environments such as cold storage and chocolate packaging workshops; the other is environments with humidity requirements ≤ RH30%, such as pharmaceuticals and chemicals.
The dehumidification capacity refers to how much water needs to be liquefied from the air to a certain space in order to achieve the target humidity, and is generally expressed in "liter/hour". The calculation of dehumidification is generally through the air entropy table or special calculation software, the moisture content of the unit air under the ambient humidity minus the moisture content of the unit air under the target humidity. The final dehumidification capacity should also be adjusted according to the ambient temperature and sealing conditions.
After calculating the required dehumidification capacity, we also need to find a balance between the number of dehumidification dryers and the dehumidification capacity of a single machine. If a space is equipped with too many dehumidification dryers, it will affect the use of the space and cause inconvenience.
a. The casing of the plastic product dehumidification dryer must be effectively grounded to ensure safe use.
b. The relative humidity of the dehumidifying dryer for plastic products should be ≤85%RH, and there should be no corrosive gas around, no strong vibration source and strong electromagnetic field.
c. There is no explosion-proof and anti-corrosion treatment in the working room of the dehumidification dryer for plastic products, and the vacuum dryer must not place flammable, explosive, or corrosive gas-prone items.
d. The vacuum pump cannot work for a long time. Therefore, when the vacuum degree meets the requirements of the plastic product dehumidification dryer, the vacuum valve should be closed first, and then the power of the vacuum pump should be closed. When the vacuum degree is lower than the requirements of the dehumidification dryer for plastic products, open the vacuum valve and the power supply of the vacuum pump to continue vacuuming to prolong the service life of the vacuum pump.
e. If the items in the dehumidification dryer for plastic products are wet, it is best to add a filter between the vacuum box and the vacuum pump to prevent the wet gas from entering the vacuum pump and causing the vacuum pump to malfunction.
The above is the way to buy a more suitable industrial dehumidification dryer. Price is also one of the major factors when buying a dehumidifier dryer. First of all, a budget should be made, and then the price range of the dehumidification dryer should be determined according to the budget.