Moulds for medical technology: satisfying the growing demand for productivity in the field of medical consumables

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Stack moulds double output and reduce waste

In the field of medical consumables, the productivity requirements that must be met by manufacturers are constantly rising. Manufacturers find themselves caught between the conflicting priorities of everincreasing demands from customers in terms of quality and reliability, and the constant pressure to reduce unit costs. In recent years, manufacturers have countered this trend with an increased demand for stack moulds. At one Swiss mould manufacturer, the proportion of stack moulds produced is now more than 30%.


The growth of the world’s population, increasing urbanisation, ageing societies, and increasing selfmedication are among the reasons that the demand for medical consumables constantly continues to rise. At the same time, manufacturers have limited production space, and the costs of this space are always rising. This is particularly the case in countries where production costs are already relatively high, but has also become an important cost factor in growth markets such as China.

This has created a demand for increased productivity per square foot of production space, coupled with higher demands in terms of production volumes and output.

These requirements are met by stack moulds, which use two mould-parting surfaces within a single mould, doubling the capacity of an injection moulding machine. These systems are able to achieve this with the same mould mounting surface and almost the same clamping force as a non-stack mould.

Complex systems


Stack moulds are complex systems, and as such they have a demanding set of maintenance requirements. Schöttli, a Husky company based in Diessenhofen, Switzerland, supports its customers across the world in the use, commissioning, and maintenance of stack moulds. Following several years of providing customer training, the mould manufacturer recently opened its own academy to satisfy the increasing demand for training. Maintenance is always preferential to repair, so customers are specifically trained to perform the required maintenance measures in a timely manner. This results in a seamless production process and higher system availability, which in turn reduces unit costs.

Form alignment

As with conventional moulds with very deep mould halves, the alignment of the individual mould segments in stack moulds is crucial to the quality of the injection-moulded parts and the lifespan of the mould. At the commissioning stage, the manufacturer shows customers how they can align moulds to achieve an optimum production flow.

The moulds include systems that support the customer, helping them to precisely configure and check the moulds, and to continually monitor the production process and make adjustments: monitoring systems with sensors, for example, help to ensure that both mould halves are optimally aligned during the injection moulding process. The sensors continuously record and evaluate data to detect possible deviations at an early stage. In addition, Husky provides a stack mould carrier with harmonic linkage, ensuring accurate mould alignment and making it easy to install, remove and service the mould.

The centre section carrier and moving platen travel on linear bearings located on the machine base, allowing for fast, clean operation.

Electrical drives

The trend towards electrification in the injection moulding process is especially noticeable in the medical market, with an increasing proportion of fully electrical machines.


The use of electrical drive concepts is also increasing for moulds. Clearly defined pathways within moulds allow for quick, efficient, and repeatable sequences. The advantages are clear -- in the sensitive medical market, many systems operate in clean rooms where oil-free moulds contribute to a reliable, particle-free production process. Furthermore, electrical drives require less energy and can be integrated into existing control systems. Programmable control devices allow movements to be triggered independently and in parallel. Using the shortest possible reach and stroke distances within the moulds leads to a reduced cycle time.

The possibility to limit the load and monitor torque reduces wear and tear and increases the service life of the mould.

About Schöttli, a Husky company

Schöttli, a Husky company, is a globally-positioned specialist in the development and manufacture of high-precision and high-performance moulds, as well as integrated system solutions for the volume production of plastic injection mould parts in the medical, closures, and thinwall packaging industries. Schöttli was acquired by Husky Injection Molding Systems in December 2013.

About Husky Injection Molding Systems

Husky Injection Molding Systems is a leading supplier of injection molding equipment and services to the plastics industry.


The company designs, manufactures and integrates the industry’s most comprehensive range of injection moulding equipment, including machines, moulds, hot runners, auxiliaries, and integrated systems. Its value added services include preform development, factory planning, customer training, systems integration and complete asset management. With more than 40 service and sales offices and employing approximately 4,000 people worldwide, Husky supports customers in over 100 countries.

PRA interviewed Paul Commisso, Global Marketing and Communications Manager, Husky Injection Molding Systems

  • What current global trends (example, contracting markets, low product exports in some economies, and cost cutting measures, energy efficiency and automation in manufacturing, etc.) will Husky focus on in its machinery offering; and could weigh in on strategies for the company?

  • Husky consistently looks to global trends to help influence our strategy on product design and development, along with routinely learning from our customers how we can design solutions that solve their key business challenges. We are particularly interested in intelligent tooling and further integration of our systems; from sharing digital processing data to the integration of Husky production IT with partners downstream, Husky is committed to bringing intelligent factories to life. Husky’s latest production systems take advantage of steady data flow from auxiliaries, moulding machines and tooling, and feed this digitised process chain through Shotscope servers for business insights and to optimise system performance.

  • Husky is a leader in innovation. Is it a challenge to keep up with this “brand” or identity, amid other companies also vying to lead the innovation arena?

  • Husky has always focused on nurturing our strong culture of innovation to drive continuous improvement in the markets we serve. We have been very successful at anticipating trends within the industry (i.e. the recent launch of our self-cleaning mould technology).

  • There is competition in every industry. This is what keeps a business and the industry healthy. It also helps increase our speed-to-market for innovative solutions. We are focused on developing solutions that meet our customers’ key business challenges, with a particular emphasis on a regular cadence of renewal in our products to ensure we are able to offer the latest engineering solutions to our customers.

  • Are there new emerging segments/industries/applications that Husky will be breaking into or focusing on this year?

  • We are continuing to focus on applications for every volume, weight, capacity and design – looking at our innovative value-added capabilities like part design, mould flow simulations, and factoryplanning in order to break into adjacent markets that we may not have previously served, and to expand our reach within our current markets and customer-base.

  • Additionally, our more recently-formed Medical and Specialty Packaging business unit allows us to focus our attention on the medical market and combine our capabilities in other areas of our business with the precision manufacturing of Schöttli to offer medical customers an integrated solution for even the most complex applications.

  • Does Husky view Asia as a growing market for all-electric machinery, are hydraulics on the way out or hybrids a tie-in? And with competitors from Taiwan, Japan and Europe, what is the vantage point Husky has with its allelectrics?

  • All-electrics are a viable option for moulders, but not an indication that hydraulics are on the way out. The question of all-electric versus hybrid (electric and hydraulic) is dependent upon the application and end-user requirements – the key is to have a solution that delivers the right performance and consumer experience.

  • Compared to technologies from a decade back, all-electrics are more energy efficient, cleaner, quieter, and obviously don’t have the need for infrastructure to handle hydraulic oil, but this often comes at the expense of cycle time and output. This is why all-electric systems are generally preferred for low-volume applications, which helps to serve markets like China where there may be excess capacity for certain applications.

  • Husky’s H-PET AE effectively meets these lower-volume demands, without any compromise in quality of the preforms or shot-to-shot consistency. For high-output manufacturing hybrid machines (electric and hydraulic) are the preferred alternative because they are capable of delivering high productivity with optimal specific energy consumption.

  • Currently, Husky has facilities in China and India in Asia, are there any expansion plans to other Asian countries, in terms of branch/office set-ups; manufacturing facilities or representations?

  • We are always looking carefully at our global footprint to ensure that we continue to provide the best products and services to our customers, by operating in a way, and in locations, that best meet their needs. In some cases this means consolidating facilities, and in others it means further investing in existing or additional facilities. While we have no immediate plans for additional manufacturing facilities in Asia, we review needs on an ongoing basis in order to make the decisions that best serve our customers and their markets.

  • With the acquisition of Schöttli in 2013, Husky has set up the Medical and Specialty Packaging business as a focus of growth for the company. Are there any expansion plans/new product introductions in line with the new division this year?

  • Our Medical and Specialty Packaging business unit is definitely a focus of growth for us; the market potential within consumer packaged goods, home care products, and of course medical is quite significant.

  • We are looking at an outside view in – determining what the market and consumer trends are, and using that to help shape the products we develop for our core markets. With this approach, we can be better organised to provide the products and services that serve the trends in the marketplace.

  • Currently, we are the only company in the specialty closures and medical markets that can offer a complete injection moulding system (including mould, machine and hot runner), and we will continue to develop solutions with this line of thinking. The ability to buy an integrated system is valuable to our customers, particularly in emerging markets where having one touchpoint is key.

  • Medical product manufacturers demand reliability, and having one supplier with a focus on consistency in part quality and reliability in operation helps to bring the total cost of ownership down, and ensures less risk in their operations.


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