Pentagon Plastics have been processing polymers for over 54 years. Throughout that time the organisation has grown, adapted, and flexed to become the injection moulder of choice that they are today. Specialising in technical injection moulding for components from 0.5 grams to 450 grams shot weight, they provide a rich pool of manufacturing expertise.

Plastic injection moulding is the process of injecting raw thermoplastic material into a mould to produce a finished component. The granular form raw material is funnelled from the hopper into a screw and barrel unit, the barrel is heated along its length to melt the plastic at staged temperatures, allowing the material to liquify and move along the screw. The screw rotates, moving the material forward with the selected process setting parameters of dosage, pressure, and speed determined by the Setter Technicians to fill the cavity.

Material is injected into the mould through the nozzle situated in front of the screw to the feed channels of the tool. The feed channels allow this material to flow into the open cavity which forms the shape of the finished product and the mould tool is then held at a constant temperature to ease the flow of material, avoiding moulding stress and to draw out the heat from the product after injection to form a solid shape.  After the required cooling time is reached, the tool will open and the part(s) will be ejected from the press.

Coupled with well-crafted tooling solutions, the ‘process settings’ of a product are the key to successful repeatable production and overall ROI. As referenced above, the settings will vary depending on material behaviours, tooling configuration, and product design. It is important that theses settings are optimised and recorded for future production to ensure repeatability.

Mould settings are determined in the trial phase of a project, the full trial process for a new injection mould tool involves validating that the tool functions correctly and produces parts within specifications. This is typically known as a T0 (first trial) and subsequent optimisation trials T1, T2 and beyond follow as required.

The trial involves preparing the machine, running the required material, optimising parameters (speed, pressure, temperature), and inspecting part quality.

 Adjustment is made to parameters like injection speed, holding pressure, temperature, and cooling time to achieve a visually and dimensionally acceptable product within the defined parameters of processing the material efficiently, and getting the cycle to the estimated time to meet the part price quoted.

Within this initial process inspection and quality control will measure dimensions and inspect the component appearance to ensure that the part meets engineering requirements. Looking to detect common moulding issues such as flash, air traps, sinkage, and visual defects allows for troubleshooting and finalisation to fix any moulding defects identified, through modifying cooling channels, improving venting, or adjusting gate sizes. Areas are sometimes left metal safe to allow for post-trial modification to meet tight tolerance areas on the cavities/cores where appropriate.

This structured trial process ensures that the tool is fully optimised before moving to mass production, therefore reducing risks of future tool repair and potential production delays.

Process optimisation is where Pentagons Setter Technician team consistently deliver outstanding results using their accumulative processing expertise. With a rich mix of experience in the processing and behaviours of high engineering grades of thermoplastics the team can control and process even the most challenging of materials.

Further supported by the in-house quality team who are heavily involved in new project from infancy through to repeat production to ensure the components produced meet the customers exacting specifications.

Many of the products that are manufactured at Pentagon are made from high-engineering grades of thermoplastics, engineered to withstand extreme environments, chemically resistant and for mechanical strength. These materials can be used as a metal replacement so that components become lighter and more effective for end use with long term durability. Materials such as Peek (Polyetheretherketone), Nylon (Polyamide), and Ultem (Polyetherimide) are amongst a range of materials that will always be found in Pentagons material stores.

With the uncertainty of the on-going conflicts and concerns over supply through the Strait of Hormuz Pentagon are fully anticipating longer term impact on polymer prices and supply. In anticipation for this and to support customers supply requirements the team are pro-actively working with material suppliers to ring-fence longer term supply than usual. Paul Edwards, managing director says ‘’ how we look after our customers is truly reflective of the organisational culture. Supplying their products is our priority, and we will always do whatever we can to be a supportive and pro-active provider of their injection moulding and tooling needs.’’

If you are looking to achieve exceptional part detail, flexibility in terms of volume, exacting repeatability, and rapid production, not to mention material versatility then plastic injection moulding is the manufacturing solution you need for your component.