The manufacture of high-volume plastic parts is commonly achieved through the process known as plastic injection moulding. This is because, in the case of simple structures of considerable size, the costs and production times are low since the costs associated with the amount of material do not have a significant impact compared to 3D printing. However, when the structural complexity of a part increases and its size decreases, plastic injection moulding is not the most suitable method for manufacture. For the production of parts with plastic injection, moulds are required; which is why, when dealing with complex parts (such as a impeller or turbine), manufacture is practically impossible unless they are produced in pieces and then assembled, given the demoulding requirements.

In these cases, additive manufacturing is the solution. With this method, complexity does not determine the price of production since a design with demoulding is not required. Additive manufacturing, or 3D printing, allows the complete production of parts as complex as turbines. It is necessary for this part to be manufactured as a whole, and not in pieces, in order to increase its performance and optimize its mechanical strength. 3D printing allows not only the production of complex parts, but also the simultaneous production of moving parts within fixed parts, which has mechanic and even electronic advantages. Finally, an optimization of the structure to be manufactured allows elements such as sensors and turbines to be integrated without external connection elements, thereby saving on size and assembly costs.

 

In general, 3D printing allows the manufacture of small, complex components at a lower cost than plastic injection moulding, as it reduces assembly labour, overall equipment size and the number of parts, as well as the initial investment, giving flexibility and freedom to the entire design process and reducing time to market. So much so that, when the complexity of a part is doubled, the price of production using conventional methods is multiplied by a factor of eight. In contrast, by using additive manufacturing, the price merely doubles when complexity is doubled. Comparing the two cases, and with a good design, you get a product four times cheaper with the latter method, as the cost of production is no longer directly proportional to the increase in complexity.

 

The information presented can be corroborated by the work carried out at TBIOM, where AIRESS has been designed — a low-cost biomedical device ideal for the COVID era, which replaces mouth-to-mouth resuscitation, whose manufacturing process has been so optimized that it consists of only 13 parts with an assembly time of less than ten minutes. This is an achievement compared to its closest competitor, which has more than 100 pieces and an assembly time of one hour.

 

This device is now functional, fully designed, has been tested on animals and with top medical equipment, evaluated by doctors and industrially tested. The project is currently in the phase of obtaining the CE marking, and in the funding round, in order to conclude the project.

 

Adalid Guzmán Alá, Biomedical Engineer.

For more information you can consult our website: www.tbiom.com or call 934621196