Research on the life and replacement cycle of the main components of the injection molding machine

In the field of injection molding production, injection molding machines are the core equipment, and their stable operation is directly related to the continuity of production and product quality.The main components of the injection molding machine, such as the template, tie rod, connecting rod, pin shaft, barrel, screw, etc., are like the key organs of the human body. Their respective service life and reasonable replacement cycle are the main points that every injection molding practitioner must be familiar with.
1. Template: durability of solid support
As the key structure of the bearing mold, the template usually has a life span of 8-15 years under normal use and maintenance.The template made of high-quality steel has good rigidity and fatigue resistance, and can withstand thousands of mold opening and closing shocks.During daily maintenance, the surface of the template is cleaned regularly to prevent the accumulation and corrosion of plastic debris; the installation bolts are fastened and checked to ensure that the template is positioned accurately, which can effectively extend the service life.If the surface wear and deformation of the template are found to cause the mold installation to not fit, which affects the molding accuracy of the product, replacement needs to be considered. Generally, the accuracy deviation exceeds 0.1mm as the reference threshold.
2. Tie rod: the backbone of the stable frame
The tie rod is responsible for connecting the fixed template and maintaining the stability of the overall structure of the injection molding machine.Under normal working conditions, its service life is about 10-18 years.The tie rod can withstand the tensile and compressive stress of the opening and closing mold for a long time, and the high-quality alloy steel material guarantees its toughness and strength.During maintenance, it is essential to apply anti-rust grease to avoid rust of the tie rod and reduce the mechanical properties; at the same time, monitor the straightness of the tie rod. Once the bending deformation is found to exceed 0.05mm, it may affect the smooth opening and closing of the template. At this time, even if the service life is not reached, it should be replaced in time to prevent more serious mechanical failures.
3. Connecting rod: the key link of power transmission
The connecting rod plays a key role in transmitting power in the mold closing mechanism of the injection molding machine, converting hydraulic energy into mechanical movement.Normal use and proper maintenance, the life span is roughly 7-12 years.The joints of the connecting rods are easy to wear, and lubricating oil is added regularly to ensure the flexible operation of the joints, which can reduce the wear rate.When the connecting rod is obviously loose, abnormal noise, or wear causes the motion accuracy to decrease, making the mold closing force uneven, which is reflected in the defects such as flying edges and missing materials on the product, and the adjustment is fruitless, it is a signal to replace the connecting rod. Usually, after every 5 million mold opening and closing actions, key inspections are required.
4. Pin shaft: consideration of the life of flexible joints
As the connecting “joint” of many mechanical structures, the pin shaft works in frequent rotation and swing, and its normal life span is 5-10 years.Due to its harsh working environment and high-load friction and impact, the selection of high-strength and wear-resistant materials is the basis.Daily maintenance needs to clean up the impurities around the pin shaft in time to prevent foreign objects from accelerating wear and tear; regularly check the mating gap between the pin shaft and the bushing. When the gap exceeds 0.1mm, it is easy to cause mechanical vibration and motion deviation. Replacement should be arranged to avoid small problems turning into major failures.
5. Barrel: the key container for plastic melting
The barrel is a place where plastic raw materials are heated and melted and pushed by the screw. When it is normally produced and well maintained, the service life is about 6-10 years.The inside of the barrel should be subjected to high temperature, high pressure and erosion of plastic materials, and it is made of alloy materials with high temperature resistance and corrosion resistance.In daily operations, strictly control the heating temperature range to prevent deformation of the barrel due to overheating; clean up the residual material in the barrel in time to avoid carbonization of the accumulated material and affect the heat transfer efficiency.When the inner wall of the barrel is severely worn, resulting in uneven plasticization of the plastic, unstable product color and performance, or obvious hidden dangers of cracks and leaks, it must be replaced in time to ensure production safety and product quality.
6. Screw: the core component of material conveying
The screw and the barrel work together to convert the solid plastic into a uniform melt and deliver it accurately.Under normal use, the screw life is usually 5-8 years.The screw head and thread edges are areas with high wear, which will reduce the plasticizing capacity and conveying efficiency after wear.During maintenance, avoid idling and overloading of the screw; clean up the plastic attached to the surface of the screw in time after shutdown.Once the screw wear causes the plasticization time to be extended by more than 20%, the product weight fluctuates by more than 5%, or serious damage such as thread peeling occurs, the screw should be replaced to ensure that the injection molding process is stable and efficient.
The service life and replacement cycle of the main components of the injection molding machine are not fixed, but are closely related to the daily use specifications and maintenance fineness.Only by in-depth understanding of the characteristics of each component, careful care, and timely replacement of the components when they show signs of aging or damage can the long-term stable operation of the injection molding machine be guaranteed, and a steady stream of power will be injected into the production of the enterprise, and it will move forward steadily in the fierce market competition.