How does iQ weight control plus simplify injection moulding?

For many years, we have been successfully using iQ weight control for closed loop control of fluctuations in the injection process, such as those caused by changing material batches or temperature fluctuations. The system compares each injection curve with a reference in real time and corrects it automatically.

However, production requests are increasing and the demands placed on individual production lines are becoming increasingly specific. For example,

• more complex tools are more difficult to phase out, or

• processes with a high proportion of recycled material are more difficult to control.

In the latter case, the material behaviour changes more significantly during operation, for example by fluctuating plastic viscosity. Companies are often unable to exploit their full potential due to a lack of expertise. This is exactly where iQ weight control plus comes in.

First of all, we make process settings easier than ever before. Instead of time-consuming optimisation of an injection profile with up to 40 practice parameters, process determination with iQ weight control plus works thanks to pressure-controlled process control via the variation of only 2 parameters:

• Injection pressure

• Switchover time.

The ideal injection profile is automatically determined. This is intuitive, comprehensible and quick to learn. Especially with new moulds or little routine on the machine, it saves time and minimises sources of faults.

This is precisely one of the most important advantages of iQ weight control plus.

With classic, volume-based injection moulding using iQ weight control, the process is controlled to a fixed volume specification. If one or more cavities fail in an injection moulding tool with, for example, 48 cavities, the machine still injects the full volume. This leads to overmoulding and rejects.

With iQ weight control plus, injection is pressure-controlled. The machine automatically reacts to an early increase in filling resistance by slowing down the injection speed.

The result:

• The component weight remains constant and

• Rejects are avoided.

• And entirely without manual intervention.

This is an enormous gain in stability, especially at high-cavity moulds or when overmoulding inserts.

This was actually done in the past until Closed loop speed control gained importance due to progress in measurement technology. It enabled finer control, but at the expense of simplicity. In times when there was sufficient skilled personnel, this was not a problem. But today we are experiencing a shortage of skilled workers first-hand.

At the same time, ENGEL now has iQ weight control plus, a system that automatically compensates for the previous weaknesses of pressure closed loop control. Specifically, this is sensitivity to fluctuations in plastic material viscosity.

It is important to note that both injection types, speed-controlled and pressure-controlled, have their merits. Which type is more suitable always depends on the component and the respective process.

• Significantly simpler operation: two process parameters instead of over 40 for injection moulding. This greatly simplifies the settings. Ideal for new tools, frequently changing personnel or short starting times.

• Robust in the face of material fluctuations: even with batch or plastic viscosity fluctuations, the system automatically adjusts – as with classic iQ weight control. This ensures reliable part quality under changing conditions.

• Process stability, even in the event of cavity failure: the pressure-controlled system automatically detects changes in filling and dynamically adapts the injection. The weight of the injection-moulded component remains constant and rejects due to overmoulding are avoided. This is particularly valuable for high-cavity moulds or sensitive applications.

• Ensuring productivity despite a shortage of skilled workers: with the simple logic of pressure and time, the injection moulding process can be reliably controlled even without in-depth expert knowledge. This means that the know-how remains in the process and not just in the heads of experienced employees.

It is an extension of the possibilities. With iQ weight control plus, our customers are free to make decisions:

• classic speed-controlled or

• new pressure-controlled.

The optimal method is selected depending on the application, moulded part, material or personnel structure. It is not a question of "either/or", but of greater flexibility and less complexity.