1. Feed machinery and equipment accessories film cover product introduction

In the pelletizing process of feed production, the film cover is one of the key protective and auxiliary parts of the pelletizing machine. Although it does not directly participate in the feed molding process, it plays a vital role in ensuring the smooth progress of pelleting operations, improving the quality of feed particles and extending the service life of the core components of the pelleting machine.

2. Structural characteristics

Hood shape and size

The film cover is usually cylindrical or nearly cylindrical structure, and its diameter and height are determined according to the model of the granulator, the size of the die and the production process requirements. In general, the diameter of the cover body should be slightly larger than the outer diameter of the die to ensure that the die can be completely covered and a certain space is reserved for the flow of materials and heat dissipation. For example, in common small feed pelletizing machines, the diameter of the film cover may be between 300-500 mm and the height is about 200-300 mm; The size of the film cover of the large feed pelletizing machine will increase accordingly, with a diameter of more than 1000 mm and a height of 500-800 mm. The two ends of the cover body are usually open design, one end is connected with the body of the granulator or other fixed parts, and the other end is adapted to the material feeding or discharging device to ensure that the material can smoothly enter and exit the working area inside the pressure film cover.

Connecting and fixing the structure

There are many kinds of connections between the film cover and the granulator, the common ones are bolt connection, clamp connection, etc. Bolt connection The corresponding bolt holes are arranged on the film cover and the pelletizer body, and the two are firmly connected together using bolts, nuts and washers. This connection method has the advantages of reliable connection and high stability, and is suitable for large granulators or occasions with high connection strength requirements. The clamp connection is to use the clamping force of the clamp to fix the film cover in the specific part of the granulator, which is convenient to install and disassemble, and is often used in small granulator or need to frequently replace the film cover. In the connection part of the film cover, there is usually a sealing structure, such as rubber sealing ring or sealing gasket, to prevent material leakage and dust escape, to ensure the cleaning of the pelleting machine working environment and the safety of the production process.

Observation and inspection window

In order to facilitate the operator to carry out real-time monitoring of the granulation process and timely maintenance when the equipment fails, the film cover is generally provided with an observation window and an inspection window. The viewing window is usually made of transparent plexiglass or tempered glass, and is installed in the appropriate position of the cover body, so that the operator can clearly see the operation of the die, the press roll and the material. The size and number of observation Windows are determined according to actual needs, which should ensure sufficient viewing field without affecting the overall strength and tightness of the film cover. The service window is generally designed with a removable cover plate, such as a metal cover plate that is hinged or bolted. When it is necessary to overhaul, maintain or clean the internal parts such as the die and roll, you can easily operate by opening the inspection window. The location of the inspection window is usually selected in a place where it is easy to access key components, and when closed, ensure that the seal with the hood is good to prevent material and dust leakage.

Internal structure and diversion design

The inside of the diaphragm is not a simple cavity, but has a certain structural design to optimize the flow of materials and granulation process. A guide plate or vane may be provided in the area inside the cover near the die. The role of these conductive structures is to guide the material evenly distributed to the surface of the die, so that the material can be more fully in contact with the die and the roll, and improve the efficiency of granulation and the quality of the particles. For example, the baffle can divert the material entering from the feed port according to a certain Angle and direction, so that it forms a uniform material layer on the surface of the die to avoid material accumulation or local lack of material. In addition, there may be a ventilation channel or heat sink inside the film cover to dissipate the heat generated during the pelleting process to prevent the die and roll from being damaged due to overheating and ensure the stable operation of the equipment.

3. Material characteristics

Metal material

Carbon steel: Carbon steel is one of the more commonly used metal materials for the manufacture of film covers, such as Q235 carbon steel. It has the advantages of low cost and high strength, and can meet the basic strength requirements of the general feed pelletizing machine. The pressed film cover of carbon steel material can improve its corrosion resistance and appearance quality to a certain extent after appropriate surface treatment, such as spray painting or galvanizing. In some small feed processing plants or equipment cost control is more strict occasions, Q235 carbon steel film cover is widely used. For example, in some small granulators that produce ordinary livestock and poultry feed, the Q235 carbon steel press film cover can operate stably, effectively protect the internal components, and provide a good working environment for feed pelleting.

Stainless steel: Stainless steel materials such as 304 stainless steel and 316 stainless steel are also used in the manufacture of pressure film covers. Stainless steel has excellent corrosion resistance, oxidation resistance and hygiene properties, especially suitable for occasions with high requirements for feed hygiene, such as the production of aquatic feed and pet feed. 304 stainless steel can resist the erosion of water, acid and alkali components and microorganisms in the feed, to ensure that the pressure film cover will not rust or corrosion during long-term use, so as to ensure the quality and safety of feed products. 316 stainless steel has greater corrosion resistance and is suitable for use in harsher environments or when handling special feed formulations. In some high-end pet feed production enterprises or export-oriented aquatic feed processing plants, stainless steel film covers are the preferred accessories to meet strict hygiene standards and product quality requirements.

Aluminum alloy: Aluminum alloy materials such as 6061 aluminum alloy can also be used in some cases to manufacture film covers. Aluminum alloy has the characteristics of low density, high strength, good thermal conductivity, etc., so that the pressure film cover can ensure a certain strength while the weight is light, easy to install and disassemble. Its good thermal conductivity helps to dissipate heat during the granulation process, which can reduce the working temperature of the die and the press roll to a certain extent. However, the corrosion resistance of aluminum alloy is relatively weak, and special surface treatment, such as anodizing treatment, is required in some environments where corrosive media exist to improve its corrosion resistance. In some pelletizing machines that require equipment weight or work in relatively dry, non-corrosive environments, aluminum alloy press-film covers can play their unique advantages.

Non-metal material (optional)

In some special application scenarios or in order to meet specific performance requirements, the pressure film cover may also be partially non-metallic. For example, in some cases where enhanced thermal insulation performance is required, insulation materials such as ceramic fiber insulation panels or polyurethane foam insulation can be added to the inner or outer walls of the pressed film cover. Ceramic fiber heat insulation board has the characteristics of high temperature resistance and good heat insulation performance, which can effectively reduce the heat loss to the external environment during the granulation process, reduce energy consumption, and protect the operator from high temperature burns. The polyurethane foam insulation layer has better heat insulation and sound insulation effects, and can play a certain role in noise reduction in some granulators that require noise control. In addition, for the observation window and some sealing parts, often use rubber, plexiglass and other non-metallic materials, rubber is used for sealing, to ensure good sealing performance, plexiglass provides a clear view of the field of view.

4. Performance advantage

Protection and sealing performance

One of the main functions of the film cover is to protect the core components such as the die and roll of the pelletizer, prevent impurities such as materials and dust from entering other areas inside the equipment, and also avoid the operator from accidentally contacting the high-speed rotating parts, ensuring the normal operation of the equipment and the safety of personnel. Its good sealing performance is achieved by the sealing structure of the connecting part and the overall design of the cover body. Whether using rubber sealing ring or other sealing methods, it can effectively prevent material leakage and dust escape, keep the pelletizer working environment clean, reduce material waste and environmental pollution. For example, in the feed granulation process, the powder material is squeezed through the die hole under high pressure, if there is no effective protection and sealing of the pressure film cover, the material may splash around, not only affecting the production environment, but also leading to material loss and equipment failure.

Optimized granulation process

The inlet structure and ventilation design inside the diaphragm can optimize the granulation process. The guide plate distributes the material evenly to the surface of the die, so that the die and the roll can be stressed evenly when working, and the molding quality and production efficiency of the feed particles are improved. Ventilation channels and heat sinks help dissipate the heat generated during the pelleting process to avoid problems such as material bonding, die hole blockage or component damage caused by overheating of die and roll. When producing feed particles in a high temperature environment, the heat dissipation function of the film cover is particularly important, which can ensure that the press die and the press roll work within the appropriate temperature range, ensure the continuity and stability of the pelleting operation, and produce feed particles with uniform quality and in line with the standard.

Material compatibility and durability

The variety of material choices of the film cover enables it to adapt to different feed production environments and process requirements. Carbon steel material low cost, high strength, suitable for general environment; Stainless steel material has excellent corrosion resistance and hygiene performance to meet the production needs of high hygiene standards; Aluminum alloy material light weight, good thermal conductivity, has advantages in certain conditions. Moreover, through the corresponding manufacturing process and surface treatment, the pressure film cover has good durability, can maintain good performance in the long-term use process, reduce the cost and trouble of frequent replacement parts, and provide reliable equipment support for feed production enterprises.

5. FAQ

Q: What is the main material of the film cover?

A: The pressed film cover is usually made of high-strength steel or alloy steel to ensure that it has sufficient strength and wear resistance. These materials can withstand high loads and long periods of use.

Q: What are the surface treatment processes of the film cover?

A: The common surface treatment processes of the pressed film cover include quenching, carburizing and nitriding. These processes can improve the hardness and wear resistance of the surface and extend the service life.

Q: How to ensure the transmission efficiency of the diaphragm?

A: In order to ensure the transmission efficiency of the film cover, the matching accuracy between the shaft and the film cover should be ensured, and the lubrication system should be checked and maintained regularly to keep the lubricating oil clean and appropriate.

Q: How long is the replacement cycle of the film cover?

A: The replacement cycle of the pressure cover depends on the frequency of use, the working environment and the operating condition of the equipment. In general, when it is found that significant wear, deformation or can not be effectively driven, a new pressure film cover should be considered.

Q: What are the special requirements of the film cover in different application scenarios?

A: In different application scenarios, the pressure film cover may have different special requirements. For example, pressure film covers used in high temperature environments need to have high temperature resistance; For use in corrosive environments, corrosion-resistant materials are required.