GPE responded to sharply increased customer demand during the coronavirus pandemic and contributed to professional patient care.
As a TIER ONE supplier, GPE developed stable manufacturing processes and ensured the perfect interaction of a wide range of components and materials.
Unique development and manufacturing expertise in plastic and liquid silicone injection moulding and complex system assembly.

Breathing system for anaesthesia/ventilation of adults, paediatric patients and neonates

Its complexity is nearly impossible to surpass – just like the value of each individual life.

Protective lung ventilation thanks to ‘Great Performance Engineering’: The breathing system for anaesthesia/ventilation of adults, paediatric patients and neonates helps to safely ventilate the patient – and as a reusable item, it is autoclavable at 134 °C. GPE developed a stable manufacturing concept in accordance with the highest standards of quality, assumed responsibility for supplier management and assembled the individual parts into a highly complex module, as well as performing testing and packaging in a class 9 clean room according to DIN EN ISO 14644-1. In addition – GPE can deliver in a highly reactive manner.

The Task

A trusted advisor to the customer during the development of a new breathing system: in close collaboration between the customer and the project teams, GPE was tasked with overseeing and implementing the developments and planned improvements to the breathing system.

This included the design of the injection moulding tools, consulting in the selection of materials and supplier management as well as the subsequent assembly of components through to customer-specific packaging solutions, including logistics services.

The customer was specifically looking for advice on an optimum production concept and the best possible technological solution using plastic injection moulding; the focus was on designing components that could be manufactured from plastic, taking into account the technical requirements and specifications, including the mould concepts for the respirator system.

The Challenges

As a reusable item, the hospital needed to be able to detach and sterilise the breathing system after use by the patient. Both steam sterilisation at 134°C and the required service life of the breathing system placed special demands on the choice of materials for the various components – the raw materials need to meet special mechanical, thermal and electrical requirements and possess particular characteristics. These include high resistance to moisture absorption, heat stabilisation for low warping tendency, chemical resistance, autoclavability, EMI shielding properties, be flame retardant in accordance with the UL 94 V-0 fire protection class, etc.

In addition, the individual injection-moulded parts had to meet the highest customer requirements in terms of tolerances, distortion and flatness. A total of 20 different materials are used, including PPS with 20% carbon fibre content, PPS with 40% glass fibre reinforced, PA12 with 30% glass bead reinforced, PPSU, LSR, steel and TPE. Strict quality assurance agreements are in place with the raw material suppliers and GPE to audit the mechanical and flow properties of each batch of material. The processing temperature sometimes exceeds 300 °C. The following production technologies were required: Plastic injection moulding, liquid and solid silicone injection moulding under class 8 clean room conditions to DIN EN ISO 14644-1, high-speed machining, laser marking, induction welding, assembly, 100% inspection, labelling and packaging in a class 9 clean room to DIN EN ISO 14644-1.

The Solution

GPE assumed responsibility for designing the 12 injection moulds for the functional components, enabling the compatibility of the items both individually and with each other to be achieved very quickly. The breathing system consists of 170 different components and 12 subassemblies. All of the individual parts must meet the highest standards of quality before they can even be fitted into the final assembly. Each breathing system is subjected to a full mechanical, optical and pneumatic functional check using customer-specific testing equipment. The breathing system’s main assemblies are laser-marked with UDI codes using order-related serial and production numbers. This ensures that every single functional assembly in the breathing system is fully traceable.

Supplier management for all of the assembly’s components, right down to the packaging material, is fully handled by GPE. Sealing and packaging the parts in antistatic ESD PE pouches, including label printing with a LOT no. and Data Matrix code, is carried out under class 9 clean room conditions to DIN EN ISO 14644-1. Complete documentation of incoming purchased parts and outgoing deliveries of saleable breathing systems is stored for each batch by GPE using a CAQ system, including test certificates.

Project realisation by GPE meets the highest standards with respect to plastic-compatible component design and tooling concepts with inspection of functionally relevant test dimensions for each part during production, e.g:

  • Flatness < 0.20 mm
  • Plane parallelism < 0.20 mm
  • Tolerances in some cases < 0.10 mm
  • Stress cracking resistance
  • Impermissible, open-pored surface structures, voids or vacuum voids

GPE developed special injection moulds for processing the high-performance plastic PPS-CF20 for the breathing system’s two large parts (the cover and housing). In the process, GPE demonstrated its unique capabilities in numerous details:

  • Due to the very high abrasive influences and processing temperatures of the raw material, corresponding basic tooling requirements are standardised at GPE. In addition to special screw geometries to ensure the melt is conveyed smoothly and homogeneously, these include fully armoured and thus wear-resistant injection units and screw fittings.
  • Due to the extreme demands on service life, the abrasive and highly aggressive influences on the raw material as well as the extremely high heat effect of centrally integrated heating systems, the individual injection moulds are made of specially tempered steels.
  • In addition, specially developed special coatings inside the injection moulds prevent the raw material from sticking to the cavity and at the same time facilitate the removal of gases during the mould filling process. Here, the advantages of a superior and low-stress demoulding, mould venting (gas accumulation = burner) and the prevention of deposits (mould fouling) are clearly evident.
  • Multiple temperature sensors in combination with impulse cooling (using air as the medium) selectively regulate the thermal equilibrium in the mould during the injection process, enabling significantly shorter residual cooling times to be achieved compared to liquid media thanks to the targeted dissipation of heat during the cooling and solidification phase of the melt within the cavity. This process also makes it possible to produce parts with low stress and thus to meet customer requirements for flatness and dimensional accuracy – a clear advantage over processes that use water and oil tempering. The cavity pressure system calculated and integrated via pressure simulation produces an automatically controllable, extremely constant and reproducible injection moulding mass production process.
  • Thanks to the use of a built-in, pneumatically controlled valve gate system, it is possible to substantially reduce raw material and production costs by eliminating sprue connections and removing them later. The associated positive environmental aspects are standard at GPE.

GPE developed a smart production concept for component assembly according to customer specifications, met the highest quality standards of quality with respect to the assembly of the individual parts to one another, and carried out the assembly, testing and packaging in a class 9 clean room according to DIN EN ISO 14644-1. Each module was fully tested with regard to flow rate, seal and overpressure. GPE assumed responsibility of the complex process of managing the suppliers of purchased parts (secondary parts) including packaging materials; this also included several certified suppliers specified by the customer. GPE integrated itself into the customer’s existing supply chain abd handled the complete quality documentation (DIN-ISO documentation) of the final product – from the raw material to labelling. Batch traceability of all components back to the raw material used is also guaranteed by means of laser marking with UDI coding.

The Added Value

In close collaboration with the customer, GPE developed and defined well-engineered and stable manufacturing processes and assumed responsibility for managing the suppliers of purchased parts, including smart scheduling. GPE carries out the process of harmonising the plastic and silicone parts with each other, thus eliminating the need for the customer to coordinate with multiple suppliers. They achieve maximum quality with respect to the assembly of the breathing system, because in this case the most important aspect is the interaction of the wide variety of materials and component tolerances in each drawing. If a relevant functional test dimension in a single component is not accurate, the complete assembly of the breathing system may fail the final test. A highly complex subassembly production process is carried out, from the raw material to the fully tested and documented subassembly. UDI coding of the various components enables traceability back to the raw material for each batch. The customer receives the quantities required from GPE in a highly responsive, forecast-driven process, for example in the form of saleable packaged assemblies for the spare parts business, but also in returnable packages of 15 units each, delivered directly to the production line every day – known as the ‘ship to line’ logistics model.

The breathing system can be disassembled and prepared for sterilisation (autoclaving) in ten simple steps by the nursing staff. It is easy to handle, can be easily connected, disconnected and opened thanks to quick-release fasteners on the cover. It thus plays an important role in improving clinical processes.


Ventilators for intensive mechanical ventilation and lung monitoring are more in demand than ever as a result of the coronavirus pandemic. The breathing system described represents a sophisticated contribution to invasive and non-invasive ventilation, in neonatology and paediatrics.

The breathing system ensures the patient remains safe via protective lung ventilation in the operating theatre, thus helping to avoid post-operative pulmonary complications (PPC), one of the most common afflictions of the respiratory system under general anaesthesia.

The breathing system is used to generate a pressure or flow rate with the blower and thus ensure that the patient is properly ventilated. The newly developed breathing system can be used in the anaesthesia of adults, paediatric patients and neonates.

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