What price can you put upon a stopped production line? Sometimes the inconvenience and embarrassment to your reputation can far outweigh the moulding machine down time.
Boddingtons good manufacturing practices ensure that this scenario is never entertained. For example, the company maintains at least one spare screw and barrel for every injection moulding machine deployed on site.
All injection moulding machines at Boddingtons have a duplicate screw and barrel – for quick tool changes, fast lead times and preventative maintenance .
Boddingtons operates moulding screws in the 20mm to 100mm size range and performs some three to four injection barrel changes per week.
The majority of these screws are through hardened; effectively abrasion and corrosion resistant in order to reduce wear. The hardened metal offers some 30% improvement in performance and screw lifetime. And since the replacement spare policy was introduced at Boddingtons, the company has not yet needed to replace a single screw or barrel.
The spare screws and barrels are cleaned using heated sandblasting technology (at 430 – 850 C) via equipment supplied by the Schwing company. All post production contaminants and residues are effectively carbonised through this process. Once the unit cools then these materials can simply be brushed off.
Wayne Allen, Boddingtons Production Manager notes that ‘post heating and cleaning all items are then measured and records are kept of each screw and barrel – all numbered – so that we can monitor for any wear and tear. Wear can really affect the process and therefore quality of the part’.
Boddingtons ensures precision measurement and maintenance for all the company’s hardened injection moulding screws.
The cleaned screw and barrel units are then left on the shelf, ready for action – either when changing to a clean or colour critical/high cosmetic production or in the case of any breakage or emergencies.
‘Importantly,’ says Wayne, ‘these units are supplied fully assembled to the machine on the production line, and ahead of any changes. This approach reduces the machine set up time considerably and thence the overall downtime of the machine.’ Wayne acknowledges that ‘some traditional moulders would remove the screw during set up and clean it down by hand. However, our view is that this is an ad hoc method, takes much too long, implies heath and safety issues and frankly does not do as good a job as the heated silica solution.’
‘When it comes to plant maintenance,’ notes Wayne, ‘prevention is always the best cure,’ notes Allen. ‘You know that your production line needs to be operational at all times, so why take the risk of something going wrong. A snapped screw replacement for some jobs could take weeks to arrive; holding up production and payment and jeopardising customer relationships. None of our work at Boddingtons is worth that risk.
