Injection molding machine drying principle and common faults

An injection molding machine dryer is a device specifically designed for drying plastic pellets in injection molding machines. The following is a detailed introduction to injection molding machine dryers:

I. Working Principle
Plastic dryers on injection molding machines generally operate based on hot air circulation, working as follows:

Air heating: A heating system heats the air.

Hot air circulation: The hot air circulates to evaporate and dry the plastic pellets.

Moisture evaporation: When wet plastic pellets enter the dryer's hopper, the hot air within the barrel is evenly blown onto the surface of the pellets, where it fully contacts them and transfers heat to the pellets, rapidly evaporating the moisture on the surface. The evaporated water is carried out of the dryer through the exhaust vents with the hot air.

Drying completion: When the moisture is completely evaporated and the plastic pellets are dry, the dryer stops. The dryer then continues drying the next barrel of pellets, waiting for them to enter the injection molding machine for the next step.

In addition, the dryer features an intelligent temperature control system that effectively manages temperature differences. This system adjusts parameters based on the drying requirements of the plastic pellets to avoid overheating and energy waste. The equipment also heats up quickly and retains the temperature during the heating process, minimizing heat loss. The hopper is constructed of double-walled stainless steel with an insulating layer in between to lock in heat, resulting in low power consumption and excellent drying results.

II. Instructions
When using the injection molding machine dryer, follow these steps:

Equipment Inspection: Before using the plastic dryer, ensure the equipment is in good working condition. Check the appearance of the equipment, ensure the power connection is secure, verify that the power cord is properly connected, that the drain is unobstructed, and that the filter is clean.

Setting Parameters: Set the temperature and time based on the type and moisture content of the plastic pellets.
Starting the Equipment: Start the plastic dryer and allow it to operate. After turning on the power switch, the equipment will draw the plastic raw material into the hopper for drying.
Monitoring Operation: During the drying process, check the operating status of the plastic dryer, such as the temperature display and operating status. If any abnormalities are detected, stop the dryer immediately and conduct an investigation and repair.
Shutting Down the Equipment: When the drying time is up, shut down the plastic dryer and wait for it to cool down. Common Dryer Problems
1. Poor Drying Performance
Possible Causes:
Improper drying temperature setting. When the temperature is too low, moisture evaporates slowly, making it ineffective in removing moisture from the plastic. Excessively high temperatures may damage the plastic's properties, reducing its strength and toughness.
Insufficient air flow. Air is a crucial medium for removing moisture. If the air flow is low, moisture cannot be removed from the dryer promptly, accumulating inside and affecting drying efficiency.
Aging equipment can reduce the efficiency of heating and ventilation systems.
Solution:
Set the drying temperature appropriately based on the type of plastic and drying requirements.
Regularly inspect and maintain the dryer's ventilation system to ensure adequate air flow.
Replace or repair aging equipment to improve its efficiency.
2. Excessive Energy Consumption
Possible Causes:
Aging equipment can lead to decreased heating element performance, requiring more heat to maintain the set drying temperature.
Improper operating mode, such as prolonged continuous high-power operation without intelligent adjustment based on the actual drying needs of the plastic.
Solution:
Perform regular equipment maintenance and servicing, including inspecting and replacing aging heating elements. Adjust the dryer's operating mode appropriately based on actual production needs to reduce energy consumption.

III. Equipment Failure
Common Failures and Possible Causes:
Dryer fails to start: Power failure, blown fuse, damaged control panel cable, etc.
Dryer overheats: Incorrect temperature setting, control system malfunction, etc.
Dryer vibrates or makes noise: Instable equipment installation, worn mechanical components, etc.
Dryer leaks: Loose air pipe connections, valve malfunction, etc.
Dryer clogs: Blocked feed inlet, clogged air duct, etc.
Solution:
Check the power cord, fuse, and control panel cable to ensure proper power supply and secure connections.
Check the temperature setting to ensure it meets process requirements and adjust it. If the control system is damaged, replace or repair it.
Reinstall the equipment and ensure stability, secure the fan blades, and replace worn mechanical components.
Ensure secure air pipe connections, replace worn cylinder seals, and repair or replace faulty valves.
Clear any obstructions in the feed inlet and air duct to ensure they are unobstructed. 4. Improper Maintenance
Possible Issues:
Dust and dirt accumulate during dryer use, affecting the equipment's heat dissipation and operating efficiency.
Insufficient or contaminated lubricating oil can cause increased wear on mechanical components.
Solution:
Regularly clean dust and dirt from the heater, fan, container, interior and exterior of the drying chamber, cylinder, and control cabinet.
Regularly check and replace the lubricating oil to maintain lubrication and cooling of mechanical components.