The issue:

The screw on a plastic injection moulding machine, which is a key component in the production process, is fully enclosed. As part of the manufacturing process, the barrel encapsulating the screw is heated to very high temperatures in order to melt the plastic fed into the machine. In many cases abrasive plastic material feed can cause friction and wear to the internal screw, which causes a number of challenges;

• If undetected, a worn screw can significantly reduce the quality of injection moulded parts resulting in unnecessary waste product.
• Worn screws require more energy to process the polymer mix and therefore result in unnecessary and increased energy usage.
• There was no way to gain real-time visibility of screw and barrel wear to allow for predictive maintenance.
• Unplanned production downtime, of up to two days, was sometimes needed to replace a worn screw, resulting in exponential profit loss.
• Long lead times on replacement parts also mean if unplanned maintenance occurs, production lines can experience even more extensive periods of downtime until replacement parts are sourced.

Our Objective

The aim was to develop a monitoring solution that a technician could easily and safely set up and use within minutes to accurately evaluate the condition of the injection moulding machine’s screw and determine if it needed replacing.

What we did

• Developed a custom Screw Wear Monitoring System providing real-time access to wear measurement data.
• The ultrasonic sensing solution is housed within external casing which ensured the solution was non-invasive and can be fitted easily onto the existing equipment.
• The Screw Wear Monitoring System can be permanently embedded onto the injection moulding machine or it can be used as a portable device.
• A high temperature ultrasonic transducer, a key component within the Screw Wear Monitoring System, sends waves to a pulser receiver which, in turn, records and measures any changes to the wear on the screw.
• A custom algorithm was developed to calculate the gap between the injection moulding machine’s screw and barrel.
• Our team worked closely with ENGEL to evaluate the System in a range of scenarios, testing a wide variety of feed plastics.

How we did it

Collaborative workshops allowed our team to conduct a detailed investigation to pinpoint the challenges ENGEL were facing. This information was used to determine the scope of the project and the exact product requirements.

Tribosonics developed an early-stage concept, created a range of prototypes and conducted thorough field testing which enabled the team to develop the initial concept all the way through to a fully functioning Screw and Barrel Wear Monitoring system.

The Impact

• Transformed the maintenance cycle for ENGEL’s customers, reducing the downtime, it previously took to measure the screw wear, from two days to just one hour.
• Significant costs have been saved from unnecessary or unplanned maintenance.
• Real-time data driven decisions have increased machine availability and enabled machines to run in a fully optimised state. This has increased processing productivity and allows machines to operate with optimum energy efficiency.
• Machine operators previously involved in the manual stripping and measuring process are now upskilled in intelligence based decision-making to monitor and plan maintenance.
• The Screw and Barrel Wear Monitoring system is an Industrial Internet of Things (IIOT) solution which has further supported ENGEL’s 4.0 initiative to enable the next generation of SMART factories.
• ENGEL can now offer the value-added service to new customers and retrofit older machines, offering further opportunity to maximise revenues.