Maintenance methods for extrusion molds and cooling conditions for rubber extruders

Common maintenance methods for extrusion molds:

1, Pressure maintenance methods:

Maintain the pressure at the inlet and outlet of the extrusion mold, maintain the supply pressure of lubricating oil and sealing oil, and maintain the pressure of cooling water.

2, Mechanical maintenance methods:

Displacement, shaft vibration, and rotor overspeed of the extrusion mold rotor shaft.

3, Temperature maintenance method:

Maintenance of inlet temperature between extrusion mold cylinder and section, working temperature of bearing shell, inlet temperature of lubricating oil and sealing oil, oil temperature of oil tank, etc.

Preparation before dismantling the extrusion mold:

1, Master the operation of extrusion molds and prepare the necessary data and drawings.

2, Prepare maintenance tools, cranes, measuring tools, materials, and accessories, and wear labor protection equipment.

3, Cut off the connection between the extrusion mold equipment and the power supply to the system, hang a warning sign on the power control box of the maintenance pump, discharge the medium inside the pump, and ensure that the maintenance conditions and equipment stability are met.

4, The maintenance personnel need to close the front and rear gate valves of the extrusion mold and check whether the pressure gauge at the inlet and outlet of the extrusion mold is faulty.

The heating of the barrel of a rubber extruder is to supply heat for plasticizing the material inside the barrel, while the cooling of the barrel is to prevent excessive heat from increasing the temperature of the material during kneading and friction plasticization. The alternating use of heating and cooling ensures that the heat of the rubber extruder barrel is controlled within the process temperature range required for material plasticization, ensuring that the rubber extruder can produce continuously and normally. Heating methods for the barrel: resistance heating, electric induction heating, and heat carrier heating. There are two cooling methods: water cooling and air cooling.

The heating and cooling device of the rubber extruder is a necessary condition for the rubber extrusion process to proceed.

1, Nowadays, rubber extruders usually use electric heating, which is divided into resistance heating and induction heating. The heating element is installed in the body, neck, and head of the machine. The heating device heats the plastic inside the external heating cylinder to achieve the temperature required for process operation.

2, The cooling device is set up to ensure that the plastic is within the temperature range required by the process. Specifically, it is to eliminate the excess heat generated by the shear friction of the screw rotation, in order to avoid excessive temperature that may cause plastic decomposition, burning, or difficulty in shaping. Barrel cooling can be divided into two types: water cooling and air cooling. Generally, air cooling is more appropriate for small and medium-sized rubber extruders, while large ones often use water cooling or a combination of both forms of cooling; Screw cooling mainly adopts central water cooling, aiming to increase the solid material conveying rate, stabilize the adhesive output, and improve product quality; But the cooling at the hopper is twofold: firstly, to increase the conveying effect on solid materials and prevent plastic particles from sticking and blocking the feeding port due to temperature rise; secondly, to ensure the normal operation of the transmission part.

The function of the transmission system is to drive the screw and supply the torque and speed required by the screw during the extrusion process. It is usually composed of an electric motor, a reducer, and bearings.

With the increasing demand in various product markets, such as optical fibers, medical catheters, audiovisual film substrates, photographic film substrates, and projection films, the requirements for detailed extrusion molding equipment and technology are also constantly increasing. For some special processing and molding, such as the processing of dangerous and poor materials, reaction extrusion processes, etc., strict control of process parameters such as temperature, pressure, material residence time and distribution, as well as heat transfer between reaction materials and the outside world, are required. Ordinary extruders are often unable to handle these tasks. Fine extrusion molding machines provide the necessary equipment conditions for various complex reaction extrusion processes.

In actual production, the temperature of the equipment is directly related to the pressure inside the extruder barrel, so the temperature control system of the equipment has strict requirements. When selecting rubber extruder equipment, we need to choose the equipment configuration and production process based on the actual precision and structure required by the product.

Rubber extruders play a role in the production of rubber products by extruding and shaping. Extrusion molding is a processing method with good speed, continuity, low cost, and wide adaptability. However, people mistakenly believe that extrusion molding is a low precision and low added value processing method.