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How SLG ensures stable injection moulding production despite varying material properties

Optimising production

How SLG ensures stable injection moulding production despite varying material properties

SLG demonstrates how the iQ weight control plus digital assistance system compensates for material fluctuations and enables stable injection moulding production. The result: improved component quality, less waste and energy savings of up to 10%.

23 June 2026

Image shows employees from SLG and ENGEL in front of a duo 2-platen injection moulding machine

Author

Eva Wörnhörer

Marketing

Tag

digital solutions
technical moulding

Stable processes are crucial in industrial injection moulding production. Fluctuations in material, mould or environment can quickly lead to quality issues, rejects or unnecessary energy consumption.

Plastics processor SLG Kunststoff GmbH from Buggingen presents how in a current production project digital assistance systems can solve these challenges.

With ENGEL, SLG tested the production version of iQ weight control plus under real production conditions. The results were impressive: greater process stability, improved part quality and measurable energy savings.

The challenge: stable quality with complex moulds in injection moulding production

Amongst other things, SLG produces large-volume packaging components for the household sector using family moulds. In a current project, tray and lid components (2,100 g / 700 g) for a storage box were produced on a duo 1700 two-platen injection moulding machine.

Technical plastic injection-moulded parts such as these present typical challenges:

fluctuating material viscosity
changes in the mould’s filling behaviour
high demands on weight consistency and surface quality
rising pressure on energy efficiency and production costs
small process deviations can lead to rejects or unstable injection moulding production

The solution: pressure-controlled injection with iQ weight control plus

iQ weight control plus provides injection moulders with an assistance system that intelligently controls the injection process. During production, the software analyses the pressure curve of each individual shot and automatically adapts the injection volume to the current plastic viscosity. This immediately compensates for fluctuations in the process.

A key innovation: pressure-controlled injection moulding.

Instead of a complex injection profile with numerous adjustment parameters, only two values need to be defined in the injection moulding process:

injection pressure
switchover time

The system automatically generates the optimal injection profile from these. The result: a significantly more stable process in injection moulding production, combined with reduced setup effort.

Real-world results: How does SLG benefit from iQ weight control plus?

The practical test at SLG took place under real production conditions. The aim was to increase quality and efficiency without changing the cycle time.

1. Improved component quality

By means of pressure-controlled injection moulding, several typical quality issues have been eliminated.

The improved quality is evident in practice:

no flash formation on the components
consistent part quality also by material variations
reliable production restart after standstill

The system automatically responds to changes in the mould’s filling resistance and dynamically adapts the process.

2. Lower injection pressure

A particularly interesting effect was observed with regard to injection pressure: a reduction of around 300 bar compared to the standard process.

This not only means low mechanical load on the mould and machine, but also more efficient processing.

3. Measurable energy saving of around 10%

Next to quality improvements, significant energy savings were also achieved.

A before-and-after comparison of energy consumption illustrates the effect:

before: 0.407 kWh/kg
after: 0.383 kWh/kg

This corresponds to an energy saving of around 10% with no change in cycle time.

Image shows a project planner at SLG Kunststoff GmbH

It is particularly helpful that the process is much easier to set up. With iQ weight control plus, we achieve stable results in injection moulding production without having to constantly readjust. This significantly reduces the workload for our production staff.

Aytac Hatkoy, Project Planner at SLG Kunststoff GmbH

4. Economic benefits for injection moulding companies

In addition to technical improvements, the project demonstrates above all the economic added value of intelligent assistance systems.

Initial calculations at SLG show that a single machine alone offers annual savings potential in the five-figure range.

The important economic benefits:

less rejects
lower energy consumption
more stable processes across shifts
less time spent on set-up
less reliance on expert knowledge

Particularly in these times of skills shortages and rising energy prices, this combination is becoming a decisive competitive advantage for many processors.

5. More process reliability, also by using recycled material

Injection moulders benefit from iQ weight control plus, particularly when processing demanding materials.

Fluctuations in plastic viscosity, such as those caused by recycled materials or batch changes, can be automatically detected and compensated for within the same shot. This ensures that part weight and quality remain consistent.

The opening up of new possibilities for cost-effective, sustainable and stable injection moulding production.

Conclusion: iQ weight control plus enables stable injection moulding production

The use of iQ weight control plus at SLG illustrates how material fluctuations in injection moulding can be specifically compensated for and processes stabilised in the long term.

The important advantages at a glance:

Higher component quality – The digital software automatically reacts to changes in the mould’s filling resistance and dynamically adapts the process. The component weight remains constant and flash formation is prevented.

Reduced process complexity – In the injection moulding process with iQ weight control plus, only two injection moulding parameters are set instead of over 40. This simplifies operation and the training of new colleagues.

Measurable energy savings – SLG was able to save up to 10% in energy without changing the cycle time.

Stable injection moulding production across shifts – With the simple logic of just two machine settings, injection pressure and switchover time, machine operators can reliably control the injection moulding process even without in-depth expert knowledge.

With the iQ weight control plus digital assistance system, process stability in injection moulding production is not determined by chance or experience any longer, but by intelligent algorithms.

Read more about iQ weight control plus in an interview with development engineer Matthias Hüttler: How does iQ weight control plus simplify injection moulding?.

Less parameters, greater stability – find out in a personal consultation how iQ weight control plus also optimises your injection moulding production.

FAQ

iQ weight control plus analses the flow time during each injection process and detects changes in material viscosity in real time. Based on this, the system automatically adapts the injection pressure in the next cycle. This compensates for fluctuations, ensuring consistently high part quality and stable injection moulding production, even with varying material properties or recycled materials.

With pressure-controlled injection, only two parameters need to be defined: injection pressure and switchover time. The injection speed profile is determined automatically. Compared to conventional processes with numerous machine settings, this results in fewer sources of faults, faster set-up, greater process stability and reduced reliance on the operator’s experience.

The set injection pressure is not exceeded during the filling process, and pressure peaks are reliably avoided. This reduces energy consumption and allows the required clamping force to be lowered. In practice, savings of up to 10% are possible by maintaining the same cycle time. Furthermore, rejects, machine load and set-up time are reduced, leading to noticeable cost savings and more efficient production overall.