TAGS: Part Design & Manufacturing Polymers for Compounding
In the last few years, a new concept has emerged strongly in the industrial world - industry 4.0. It has been wrongly identified as the internet of things since this denomination is already included in the general term of industry 4.0.
Industry 4.0 can be defined as the transformations of the current production systems due to the integration of digital technologies and internet. To reach this modification, a group of existing technologies has been defined to boost the inter-connectivity between man and the industrial process, or even different equipment.
This boost in inter-connectivity will help to obtain the maximum amount of information about:
- Processing
- Storing, and
- Managing
All this together will ensure the best quality and productivity.
The final goal of industry 4.0 is not to create a new system for controlling the process, but to improve the effectiveness of the companies, by:
- Reducing time to market
- Improving innovation, and
- Saving money in resources (workforce and/or energy) among other things
Pillars of Industry 4.0
The defined technologies are considered, 'enabling technologies of industry 4.0' and are also called the 'pillars of industry 4.0'. These technologies are:
- The cloud
- Big data
- Additive manufacturing
- Internet of things
- Cybersecurity
- Autonomous robots
- Augmented reality
- Simulation, and
- Process integration
Between these technologies, there are ones that are:
- More directly linked with compounding and the improvement of productive processes, and
- More related to data storage, managing and administrative issues
Companies, depending on their priorities, can choose the technologies from industry 4.0 they want to integrate. It is not mandatory to incorporate all nine pillars, but originally those pillars were thought as complementary to obtain the maximum yield in the companies.
So that, technologies like simulation, advance sensoring, big data, augmented reality or
additive manufacturing could relatively be applied easier to the production of compounds, reactive extrusion, and masterbatches of
PVC formulation.
Now, let's learn how these selected technologies can improve the processes in terms of productivity and quality.
Process Simulation
Process simulation is a very interesting way of understanding and foreseeing what would happen, especially while trying to:
- Develop a new compound
- Modify existing ones
- Scale up to industrial process, and
- Increase productivity
The direct economic impact would be the shortening of time to market and the savings in raw materials.
In the last decades, different simulation software for Co-rotating twin screw extrusion has appeared in the market (
Ludovic®,
TXS®,
Akro twin or Sigma etc.). They can give information about how different settings of our machine can influence the process. For example:
- Melt temperature evolution
- Degree of filling
- Residence time
- Specific mechanical input
- Torque consumption and shear among others
This forecast software can help us design more robust processes and can save time in the compound development stages. This software can also be helpful while designing/assembling new screw profiles.
Unlike Finite elements simulation software that required very powerful hardware and quite some time to simulate (mold filling in injection molding), most of the simulation software for co-rotating twin screw extruders are called “
1D software”. This simplifies a lot the calculations and shortens the simulation times.
The simulation will not give absolute values but is a scientific way to evaluate tendencies with the most promising strategy or approach. Also, it can help evaluate the factors affecting final properties or productivity.
Nevertheless, it is important to have knowledge of the process to set up the right boundary conditions and to understand the response of the software to extract good conclusions. In most of the cases,
…the more and complete information we have about the polymer or compound
normally in terms of viscosity evolution Vs temperature, the better the results of simulation
Ludovic Screenshoot of Melt Temperature Evolution
Modifying Processing Parameters
Simulation can be a useful tool to know in advance what can happen inside of our extruder. But another way of understanding, what is happening inside of our “
black box” (Co-rotating twin screw extruders) is to increase the sensing capacity. To do this, we can increase the number of melt pressure or temperature sensors for controlling the melt evolution better inside the barrel especially in mixing zones where pressure and temperature of the melt can be inexpertly higher.
On the other side, we also can incorporate inline or online measurement of final properties, where:
- Inline refers to - measuring in continuous in the flow direction of the extruder
- Online refers to - measuring in continuous parallel to the flow direction
This is done to modify our processing parameters and to obtain a variation of the property that we are looking for without waiting to prepare specimens and the further testing in the labs. Electrical conductivity can be a good candidate for inline measurement, for instance. Viscosity has been traditionally the most measured online property.
Solutions for Accurate Measurements
It would be interesting to monitor dispersion, mechanical properties or even flame retardancy using inline measurements. But there are important challenges related to it.
It is important to underline that these inline measurements would have to be confirmed at testing labs. But initially, during processing, we would have had determined which trials needed to be measured, saving time and workforce.
Based on the readings and by means of artificial intelligence (neural networks), we can train our extruder to learn what are the processing parameters that can improve the final properties of the compounds we are processing. Of course, more complex control software would be necessary to work in that way -
machine learning is another interesting concept that floats around industry 4.0. Further to sensoring, it is needed to store the big amount of values that can be generated.
It is very important to decide:
- The response variables that we want to record, and
- The frequency of recording
So that not too much data is accumulated, which can affect the part of the hardware.
Normally we can record response variables like: temperature and pressure melt, torque and Specific mechanical input (SMI) to ensure process stability and quality.
- The part of recording or data collection is the first part
- The second part will be data treatment, where by means of multiple regression, we can conclude which processing parameters (screw profile, screw speed, throughput etc.) affect most the quality or productivity
Another important monitoring that can be performed is the energy consumption per compounding line.
To understand the energy cost and to examine the effectiveness of working procedures, we can also follow the production times, the stops, the changeover times, maintenance tasks, etc. This will help apply corrective measures to shorten these dead times.
Advancing Technologies of Industry 4.0
#1. 3D Printing
One of the most important technologies is additive manufacturing. Many techniques can be found nowadays, but the most used at domestic and industrial level is
fused deposition modelling (FDM), also known as
3D printing. This technology is an enabler of the industry 4.0, but at the same time as FDM is based on plastic materials for printing, and as via compounding we can modify these materials,
compounding can be considered a technology that enables industry 4.0.
Nowadays, 3D printing is another way to convert polymers like through:
Injection molding or
extrusion. But, one of the biggest differences is the relatively few materials or compounds that we can find for 3D printing as compared to injection molding or extrusion. This scenario opens the possibility for the development of a huge number of compounds, especially if the natural evolution of 3D printing is to obtain tools or spare parts or final parts with special functionalities, besides prototypes.
#2. Augmented Reality
The last technology from the technical point of view that can help us to improve our process is augmented reality (AR). This technology needs two important things:
- A device that will show us some scenario where we want to operate, and
- Software that will add the information required to help us proceed in this scenario
AR can be confused with virtual reality (VR). But, while AR shows us a scenario in real time by merging the real world with extra information, which most of time overlaps in one device (like mobile phones, glasses or tablets),
VR recreates this given scenario by means of design software.
The most known applications for AR are:
- Touristic
- Medical
- Military, or
- Gaming
- More related to industry maintenance operations
With AR, assembling and disassembling equipment or tutorials to failure detection can be followed in real time meanwhile we are looking the device to be fixed.
Conclusion
As it has been said previously, there are more technologies that will complete our factories to the total industry 4.0 adaptation but are not in the background of the writer. Other experts will be needed in terms of cybersecurity, robots, the cloud etc.
Companies can choose the different technologies they want to implement at their facilities. These technologies might not be integrated and they can be different depending on the type of production they have. Industry 4.0 will be a reality in the next coming years and the compounding companies would need to adapt to this new production model in order to react faster to new market changes and regulations. Also, this would help bring the compounds to market faster than competitors at a cheaper cost while maintaining high standards.