A Case Study of Heat Transfer from Hot Runner Mould to the Fix Platen of the Injection-moulding Machine

In an injection moulding process, the parallelism b et ween the tie bars of the injection moulding machine is very important as it will affect the mould closing and clamping system. In recent years, more and more ho t runner systems are being applied in the moulding industry to save material and decrease the losses of injection pressure. Heat transfer from hot runner system from the fixed half which is secured in the fix machine platen could transmit s o much heat that it may cause high temperature differential between the machine fix platen and moving platen. This will cause the tie bar to become unparallel. Part quality will be compromised and the wear of the tie bar will be excessive. Overhaul of the tie bar may be necessary after a short period of time which is c ostly. This raises the need to analyze the heat transfer from the hot runner sys tem to the machine fix platen and the methods of isolating or minimizing the hea t transfer. In this case study, a photo lens article mould was used. The mould w as built with a direct hot runner nozzle system. Heat conduction from hot runner and machine screw to machine fix platen were studied based on either using high temperature heat insulating plate put in placed between the mould and the mould ing machine fix platen or drill cooling channels in the front mould clamping pla te. The high temperature insulator is very costly as it is made out of glass re inforced polymer composite material. Experimental results were obtained and anal yzed to find the best method to minimize the unwanted heat transfer using the ch eapest and most effective method.

Automated process parameters tuning for an injection moulding machine with soft computing

In injection moulding production,the tuning of the process parameters is a challenging job,which relies heavily on the experience of skilled operators.In this paper,taking into consideration operator assessment during moulding trials,a novel intelligent model for automated tuning of process parameters is proposed.This consists of case based reasoning (CBR),empirical model (EM),and fuzzy logic (FL) methods.CBR and EM are used to imitate recall and intuitive thoughts of skilled operators,respectively,while FL is adopted to simulate the skilled operator optimization thoughts.First,CBR is used to set up the initial process parameters.If CBR fails,EM is employed to calculate the initial parameters.Next,a moulding trial is performed using the initial parameters.Then FL is adopted to optimize these parameters and correct defects repeatedly until the moulded part is found to be satisfactory.Based on the above methodologies,intelligent software was developed and embedded in the controller of an injection moulding machine.Experimental results show that the intelligent software can be effectively used in practical production,and it greatly reduces the dependence on the experience of the operators.