Why do we need to perform maintenance frequently?
In the world of plastics, there are countless processes to transform raw materials into finished products for various applications. Companies acquire PVC equipment that allows them to meet their production targets and ensures a finished product that complies with market demands.
Under the understanding that the PVC equipment should be running all the time, as the opposite entails a cost for the company; they are under constant wear and tear and therefore a regular maintenance shutdown is something that must be planned well in advance, unless it is an urgent repair.
In some companies, preventive maintenance programs do not even exist, and only essential or routine repairs are carried out to keep the equipment running. What is often overlooked is that, without thorough maintenance, operational activity becomes more complicated over time, making it harder for the production manager to meet objectives. Since these repairs are not considered urgent and involve high costs, the common saying applies: “If it works, why fix it?”
What does PVC do to our equipment?
In the case of PVC, we should be aware that this is a highly corrosive material due to the hydrochloric acid (HCl) it emits, and that depending on the formula used, it can cause significant wear due to friction in the equipment. For example, there are different types of mineral fillers used to give the PVC structure, ductility and cost reduction, where hardness and particle size play an important role in the wear of machinery.
In a rigid PVC formulation for DWV pipe, the space between the screw and the barrel inside the extruder typically widens over time, hindering proper material fusion. When the PVC equipment is not in good condition, the company has to reinforce the formulation with lubricants that improve fusion, but this in turn increases formulation costs. It would certainly be of interest to the production manager to compare the cost of more frequent, major maintenance against the additional costs of formulation adjustments.
Of course, there are tricks to minimize the aforementioned problem. It's common to see customers reduce the extrusion speed to increase the residence time of the material in the equipment. Adding screen packs to compensate for the compression required in the process is also common.
Another very common issue is that injection and/or extrusion equipment lacks ammeters or pyrometers to guide the operator and ensure they are working within ideal parameters. This not only complicates the operator's task due to frequent machine stoppages and constant adjustments to process conditions, but also significantly increases scrap.
To make matters worse, many companies acquire used equipment and continue these poor practices, which only complicate operations. Furthermore, the failure to perform thorough and proper maintenance raises the possibility of latent defects that even the company is unaware of.
In summary, we recommend implementing a preventive maintenance program for your PVC equipment and identifying unplanned repairs to strengthen this area. This will help reduce hidden costs and improve the profitability of your operations.
At Chemical Additives, our technicians recommend conducting on-site trials with our clients to anticipate any such issues, communicate them effectively, and provide a product that is tailored to their needs and process.
We invite you to learn more about PVC HERE.
Chemical Additives de México, S.A. de C.V.
