The study of the gradual deterioration in the performance or condition of an injection moulding machine over time. Many failures are preceded by omens, known as potential failures, whose identifiable physical parameters indicate that functional failure is imminent, and functional failures indicate the loss of specified performance criteria for the moulding plastic machine.
The pattern of change in the failure rate of plastic injection machine over time is often referred to as the bathtub curve. The change in the failure rate of an injection molding equipment over time can be roughly divided into three phases: the early failure phase, the episodic failure phase and the wear and tear failure phase.
Early failure period
Injection moulding machine is in the early failure period, the beginning of the failure rate is very high, but with time the failure rate decreases rapidly, the early failure period for mechanical products is also known as the break-in period. The length of this period varies depending on the product, system design and manufacturing quality. Failures that occur during this period are mainly due to design and manufacturing defects, or caused by improper use of the environment.
Occasional failure period
In the random failure period of injection molding machine, the failure rate is generally stable and tends to a fixed value. During this period, the failure occurs randomly. During the episodic failure period, the failure rate of the hydraulic plastic moulding machine is the lowest and most stable. It can therefore be said that this is the optimum condition period or the normal operating period of the injection moulding machine. This period is called the useful life.
Failures during the period of occasional failure are mostly due to design, improper use and poor maintenance. Therefore, by improving the design quality, improving the use of management, monitoring and diagnosis, and maintenance work, the failure rate can be reduced to the lowest level.
3Wear and tear failure period
In the late stage of the injection moulding machine, the failure rate starts to increase. This is due to the wear and tear of plastic injection machine parts, fatigue, ageing, corrosion and so on. By overhauling at the inflection point, i.e. at the beginning of the wear and tear failure period, the failure rate can be reduced economically and effectively.The three stages of the injection moulding machine failure rate curve change, a true reflection of the moulding plastic machine from break-in, debugging, normal operation to overhaul or scrap failure rate changes in the law, strengthen the injection moulding machine daily management and maintenance, can extend the occasional failure period. Accurately find out the turning point, can avoid excessive repair or repair scope expansion, to get the best investment benefit.
