Productivity, and ways for the UK manufacturing industry to increase its levels to remain competitive, is a topic of increasing importance. But how can the plastics industry benefit and can you increase productivity without major investment? In the following article, Craig Forrester of Stäubli UK argues that in many cases, the maximum gain comes from the lowest investment.

Productivity, namely what we produce for the amount of work it takes to do it, and solving the issue of it flatlining in the UK in recent years, is a hurdle the manufacturing industry must jump in order to remain competitive.

Noise around overcoming the UK’s ‘productivity puzzle’ has been getting louder of late, with solutions pointing at working smarter, not harder, with investment essential to secure future success. However, it is possible for plastics manufacturers can see huge returns from only a small investment. As a company, we’ve seen how small changes and integrating new technologies can make a big difference to not only productivity, but also efficiency, safety and, ultimately, a company’s bottom line.

Connecting with connectors

A good example of such is connectors; the plastics market has been involved with and have regularly been the pioneers of new technologies such as ‘straight through’, restriction-free couplings, valved connectors for increased safety and multi connection systems either for single or multi media. The plastics industry is an ideal environment to realise the benefits of Quick Release Couplings, providing an important step in the relentless ongoing demand for faster and safer mould changes.

The process of speeding up mould changes should ideally be approached methodically. Starting with the basics; significant benefits can be gained at very little expense, quick release couplings on a mould can often reduce tool change over from hours to just minutes.

A good example of such is connectors; the plastics market has been involved with and have regularly been the pioneers of new technologies such as ‘straight through’, restriction-free couplings, valved connectors for increased safety and multi connection systems either for single or multi media.

The next step is to consider the benefits of putting all connectors together by using one of a range of standard multi-couplings plates. This process often then leads on to a bespoke multi-coupling plate, specifically designed for a specific application, on which additional connectors and even electrical and signal circuits can be included. Consideration of mould clamping, mould transfer and loading should then follow. These are all tasks that need to be addressed to fully optimise productivity.

Considering clamping

When it comes to consideration and evaluation of quick mould clamping, companies should consider the benefits of mechanical, hydraulic and magnetic systems; there will be an appropriate technique for any specific application.

Mechanical systems are very often easy to install since they require no hydraulic or electrical connections. They can be readily fitted to most injection moulding machines below a maximum closing force of 300 tonnes. However, the selection of the mechanical system cannot be made on the size of the machine alone; the quantity of moulds deployed in the machine is also a very important economic factor. As a general rule the higher the quantity of moulds the more consideration should be given to magnetic clamping. In the case of larger machines, either hydraulic or magnetic systems will be necessary, the choice depending on the quantity and variation of moulds. Magnetic systems have the flexibility to clamp a wide range of mould sizes and normally require no modifications to the mould and no additional back plate, which represents a significant cost saving. Hydraulic systems require a standard back plate to be fitted to each mould which, dependant on the quantity of moulds, substantially increases the investment. Not to be forgotten when choosing between magnetic and hydraulic technologies is the increased safety and data storage capabilities of the magnetic systems.

Software is available that provides a step-by-step guide to help evaluate the options and select the most suitable system. The choice for any given application is far from straight forward, and, the user should give really close consideration to both their current and, perhaps even more importantly, their future needs.

Plastic moulders are increasingly insisting that injection moulding machine manufacturers incorporate clamping systems in their machines. This demonstrates that across the sector use and knowledge of the benefits of these types of systems is increasing, which in turn creates demand to retrofit systems to existing machines. Although it must be stressed that clamping is only a part of the quick mould change process, in the vast majority of applications, the most beneficial savings can come from reducing the time taken to disconnect and connect the thermal regulation lines. It is absolutely true that in many cases the maximum gain comes from the lowest investment.

As styrene-based polymers react to market fundamentals, what is likely to happen with other polymers?

In the process of speeding up mould changes, mould transfer and loading can often be a neglected area, many even regarding it as a luxury. This is not always the case. Simple mould transfer and loading carts can be very economical, serving a range of machines and giving a payback on investment of just a few months. Handling moulds securely and preventing costly damage while improving operator safety are significant added benefits. Where restrictions on workshop height preclude the use of cranes, side loading of moulds using transfer systems often provide an attractive solution.

For heavier moulds, systems right up to fully automated rail mounted carts are an option; individually designed to suit the specific application and user needs. Pre-heating stations can be included to ensure that the mould is at operating temperature ready for immediate use, again helping to minimise downtime.

The selection of the correct technology and the correct processes are imperative to maximise return on investment. The aim should always be to chose the most suitable system, one capable of operating safely and securely over many years, meeting the financial and productivity goals established at the outset. That is the essence of productivity.

Understanding productivity: Demonstrations at Interplas

The demands of working smarter to increase productivity and capitalise upon the benefits for business is the theme of Stäubli’s presence at Interplas, the UK plastics industry show, taking place from 26-28 September at Birmingham’s NEC. On Stand E12 in Hall 4 there will be an interactive and operational injection moulding cell demonstrating Single Minute Exchange of Die (SMED), complete with mould connections, mould clamping, handling and loading as well as robotics. The robots will demonstrate their ability to work safely alongside operators within the production cell.

On Stand L10 in Hall 4, several new products will be on show, including robust quick release connectors capable of working safely at the higher temperatures being used in injection moulding and secure reliable electrical multi connectors capable of handling all the electrical circuits on a moulding tool. Stäubli engineers will be on hand to discuss specific requirements and explain the technology behind these innovative developments.