Rubber calender is one of the most important equipment used in the processing of rubber and plastic products. It is heavy-duty and high-precision machinery used in the rubber and plastic industry. This detailed guide will cover the structural composition, working principle, classification methods, parameter indicators, operation points, and maintenance of rubber calenders.

Rubber calender consists of several key components:

• Working Roller
• Frame
• Machine Base
• Transmission Device
• Speed and Distance Adjustment Device
• Roller Heating and Cooling Device
• Lubrication System
• Emergency Stop Device

The heated and mixed rubber is squeezed and stretched through the gap between two or more rotating rollers placed horizontally, forming semi-finished products such as films. During this process, the molecular structure of the rubber changes, improving its plasticity, and the rubber's dimensions are fully controlled.

Rubber calender can be divided into different types:

• Classification by the number of rollers:
  • Two-roll calender
  • Three-roll calender
  • Four-roll calender
• Classification by process use:
  • Sheeting calender
  • Rubber rubbing calender
  • General calender
  • Profile calender
  • Laminating calender
  • Steel wire calender

There are several parameter indicators of rubber calender:

• Roller Linear Speed
• Speed Range
• Speed Ratio

Some important operation points of rubber calender:

• Preparation before starting
• Feeding operation
• Adjustment of the calendering process
• Stop operation

The maintenance of rubber calender can be divided into three parts:

• Daily maintenance
• Regular maintenance
• Troubleshooting

The operation process of the rubber calender involves preparation before starting, start-up operation, calendering process operation, and shutdown operation. Here's a detailed breakdown of the process:

Before starting the calender, some essential preparations must be taken:

1. Equipment inspection:
   • Check the various components of the calender, such as rollers, transmission systems, spacing devices, temperature control systems, etc. Ensure that the components are well-connected, and there is no looseness or damage.
   • Check the surface of the roller and clean it if there is debris or damage.
2. Material preparation:
   • Prepare the rubber raw materials to ensure that their formula is accurate and mixing is uniform.
   • Prepare auxiliary materials such as additives and fillers required for production.
3. Parameter setting:
   • Set roller speed, roller spacing, working temperature and other parameters in the control system.
   • For example, when producing rubber sheets, the roller spacing needs to be set, and the appropriate working temperature needs to be determined for different types of rubber.

The start-up operation involves:

1. Starting the transmission system: This is done to ensure that the roller starts to rotate slowly. It is essential to observe whether the roller rotates smoothly and detect any abnormal sounds or vibrations.
2. Preheating the roller: The temperature control system is started to preheat the roller according to the set working temperature. During the preheating process, the temperature changes are monitored to ensure that the temperature rise is uniform and stable.

The main operations to be carried out during the calendering process are:

1. Feeding: Prepared rubber raw materials are fed slowly and evenly into the feed port between the rollers. The feeding speed should be moderate to avoid any issues.
2. Calendering adjustment:
   • Check the molding of rubber products, observe the flow of rubber between the rollers and adjust the speed ratio of rollers, and other necessary parameters.
   • Continuously check the quality of the calendered rubber products, including appearance, and dimensional accuracy, among others.

The shutdown operation process entails:

1. Stop feeding: When current production tasks are completed or production needs to be suspended, first stop feeding the rollers, and let the remaining rubbers be calendered until all rollers are sent out.
2. Cooling Roller: Turn off the heating function of the temperature control system and allow the roller to gradually cool down; the cooling function can be turned on as necessary.
3. Stop the transmission system: After the roller has cooled down and the rubber has been fully delivered, stop the transmission system of the calender to stop the roller from rotating.
4. Equipment cleaning: Clean the calender thoroughly, remove the rubber, and other debris remaining on the roller surface, feed port, discharge port, and other parts of the equipment in preparation for the next start-up.