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How 3D printing is beneficial to the medical sector.

How 3D printing is beneficial to the medical sector.

3D Printing in the Medical Sector: Innovation and Life-Saving Applications

In recent years, 3D printing has revolutionized the medical sector, providing customized solutions and contributing to improved clinical outcomes for patients.

This innovation has paved the way for a range of life-saving applications that address critical medical challenges, radically transforming the production of devices and prosthetics.

Customized Prosthetics for Maxillofacial Surgery

An emblematic example of life-saving use of 3D printing is found in maxillofacial surgery. In this field, the technology allows for the creation of titanium prosthetics perfectly tailored to the individual needs of the patient.

These prosthetics, used in complex procedures, restore the patient’s facial structure, giving them new confidence and improving their quality of life even after highly impactful surgeries.

Polymeric Materials for Life-Saving Applications

In addition to metals, 3D printing successfully utilizes polymeric materials.

An example is the 3D bronchial stent made of polycaprolactone, developed by our team in collaboration with Bambino Gesù Hospital in Rome and currently undergoing certification.

This technology has found application in the healthcare sector, enabling the production of customized, high-quality medical devices in small batches.

This makes otherwise expensive or complex solutions accessible, improving efficiency and reducing production times.

3D Printing in Healthcare: Innovation and Accessibility

Thanks to the optimized design made possible by 3D printing, lighter and more efficient solutions are achieved, helping to reduce costs and improve the overall quality of medical devices.

This is particularly evident in orthopedic surgical procedures, where 3D printing enables the production of customized prosthetics and surgical guides.

These tailored solutions reduce surgical times and improve outcomes for patients, increasing precision and reducing the risk of complications.

Photo courtesy of Prototal Damvig

Photo courtesy of 1zu1

Advanced Support for Customized Medical Solutions

Prototal Group, with its centers of excellence (cleanrooms) and specific certifications for medical device production, is committed to supporting companies in need of advanced solutions.

By collaborating with industry experts and adopting the latest technologies, we are able to provide personalized and high-quality solutions to meet the needs of our clients in the medical sector.


Photo courtesy of Prototal Sweden

Photo courtesy of Castomade

Design tolerances in 3D printing

Design tolerances in 3D printing

Tips & Tricks: What are design tolerances?

Exploring design tolerances in SLS 3D printing

Design Tolerances

Let’s continue our journey into the world of tolerances, this time delving into the concept of design tolerances.

What are they, and how should they be managed? In this exploration, we will unveil the crucial role of tolerances in engineering, design, and the production of mechanical components.”

Why using tolerances?

The use of tolerances is a common practice in various industries, and their role becomes particularly evident in ensuring the flawless coupling of components.

But what exactly are design tolerances?

When designing or manufacturing a component, achieving precise dimensions in every unit produced can be a challenge.

Materials, subject to variations in temperature and other factors, can expand or contract. This is where tolerances come into play, defining the limits within which a specific dimension can vary without compromising the functionality of the part.

Prosilas Contribution

At Prosilas, our expertise in manufacturing processes, tolerances, and materials allows us to provide valuable input during the design phase.

Our targeted advice supports engineers and designers in achieving optimal results, ensuring the proper functioning of the parts

Managing Tolerances in 3D Printing

When dealing with the 3D printing of two parts intended to mate, recommended tolerances typically range around one-tenth to two-tenths of a millimeter. These targeted specifications ensure precise mating/fitting, eliminating potential issues of unwanted play.

If the component involves movable sections or joints and requires integrated printing, suggested tolerances increase to around three-tenths of a millimeter.

This distance takes into account the presence of unsintered powder between surfaces and the heat generated by the machine, preventing unintended fusions between moving parts.

Dimensional Tolerances

Dimensional Tolerances

Tips & Tricks: What are Dimensional Tolerances?

Dimensional Tolerance in SLS 3D Printing: Management and Control by Prosilas



Dimensional Tolerances

3D printing has revolutionized the way products and components are manufactured, offering unprecedented flexibility and customization.

Even in this innovative technology, dimensional precision is a crucial aspect, and Selective Laser Sintering (SLS) stands out for its ability to produce parts with remarkable precision.

Dimensional tolerance refers to the possible deviation within which the printed part can vary from the original geometry.

Specifically, we are talking about +/- 0.3 millimeters for parts up to 100mm and +/- 0.3% for larger dimensions.

Photo courtesy Protototal Industries

Thermal Expansion

This difference between the nominal dimensions in the 3D file and the printed part is due to thermal expansion, an intrinsic phenomenon in SLS technology.

This printing methodology involves heating the materials to their melting temperature, such as 170°C in the case of polyamide.

During the subsequent cooling process, the part transitions from the melting temperature to room temperature, contracting by approximately 3%.

Our Approach

The parts are initially processed with larger dimensions, using scaling factors specific to each machine and material.

The determination of these factors occurs through the periodic production of samples, a practice that allows monitoring and maintaining control over the dimensional tolerances declared to customers

L'approccio di Prosilas consiste nel produrre parti inizialmente con dimensioni maggiori, utilizzando fattori di scalatura specifici per ciascuna macchina e materiale.

To achieve the highest level of precision, we incorporate this element during the job preparation stage.

Quality Standards

Thermal shrinkage is not entirely constant; hence, an average of the results is calculated and applied.  This phenomenon can vary depending on various parameters, such as cooling times, part orientation, shape, and thickness.

To ensure maximum precision, we integrate this aspect during the job preparation phase. Geometries are carefully modified in the software, taking into account the inevitable dimensional variations that occur during material cooling.

This proactive practice demonstrates our commitment to providing 3D-printed components that strictly meet the quality standards required by our customers.

Per garantire  il massimo della precisione, integriamo questo aspetto durante la fase di preparazione dei job.

The software undergoes meticulous modifications to the geometries, considering the inevitable dimensional variations occurring as the material cools.

What are the NDAs?

What are the NDAs?

NDA: The Value of Confidentiality Agreements at the Heart of a Trust Relationship Between Service Providers and Manufacturing Companies

Confidentiality Agreements, commonly known as NDAs (Non-Disclosure Agreements), are legally significant in the manufacturing industry as they are designed to protect confidential and sensitive information.

NDA contracts are widely used in both the industrial and technological sectors, as well as in research and development, with the explicit goal of preventing the disclosure of sensitive data to third parties without the explicit consent of the information owner.

Managing Industrial Secrets at Prosilas

Prosilas works closely with companies, contributing to the development of projects intended to launch in the market within the next three years. In this context, safeguarding information plays a critical role.

Therefore, we provide support for both prototype component production and mass production, utilizing a comprehensive range of technologies, ranging from complex additive manufacturing and 3D printing methodologies to more traditional injection molding techniques.

Within the Prototal Industries group, we have privileged access to diverse technological resources, occasionally collaborating with external suppliers. This is precisely why it is crucial to extend confidentiality throughout the production chain when exchanging information with colleagues and partners.


Cybersecurity: Protecting Information Online

Information communication occurs through digital platforms or by transmitting files via email, emphasizing the relevance of cybersecurity issues.

In this regard, Prosilas consistently invests in enhancing its cybersecurity systems, ensuring adequate monitoring and protection of exchanged information.

Our staff also undergoes continuous specialized training to maintain high-level expertise in this field.

Dedicated Spaces: Protecting “Offline” Projects

Confidentiality is a fundamental pillar of our operations and is ensured through the use of NDAs. However, there are circumstances where a higher degree of secrecy is required. We have dedicated specific spaces within our laboratories, providing access exclusively to authorized personnel. Information security is an indisputable priority to preserve the trust and respect of our clients.


STL File : the most common errors

STL File : the most common errors

Normal lines inverted, holes and multiple shells

In this article, we will discuss the most common errors found in STL files, which usually involve inverted normals, presence of holes, and multiple shells.

These errors often result from mistakes during part modeling or during the export and conversion process to the STL file format using CAD software. These defects need to be corrected in order for the part to be suitable for printing.

As highlighted in the previous post, the STL file, necessary for 3D printing a part, represents a three-dimensional geometry composed of triangles oriented in space.

Normal line inverted

Each triangle is described not only by the coordinates of its vertices, but also by the normal, which is a vector perpendicular to the plane on which the triangle is positioned, and its orientation defines the outer side. In some cases, the normal of these triangles can be inverted, mistakenly identifying an outer side as the inner side and vice versa. Such a situation can lead to errors during the printing process.

Example of a normal line inverted 

Example of a normal line corrected

Hole in the STL file

The second most common error encountered is the presence of holes, which can be caused by missing surfaces or misalignment between triangle vertices.

These holes need to be manually corrected if they are of considerable size, or automatically using specialized software if they are smaller. The presence of holes can compromise the quality and functionality of the printed part.

The presence of holes can compromise the quality and the realization of the part printing.

Holes in a STL file

STL file corrected

Shell Multiple

Lastly, we encounter the issue of multiple shells. A shell refers to a group of connected triangles. The presence of multiple shells in a part indicates the presence of separate groups of triangles. In this case, the inner shell overlaps with the outer shell.

Resolving this type of error is necessary to avoid anomalies during the slicing of the model into layers or incorrect surface generation, as well as to prevent printer jams. It is important that all shells are properly joined to achieve a coherent and functional printed part.

This situation can also occur when, in the design phase, the shapes that make up the CAD model are not properly integrated into the rest of the shell, but remain separate.

It is crucial to ensure that all components of the model are correctly integrated into the main shell to avoid printing issues and ensure the quality of the final product.

Example of Multiple shells

Example of Multiple shells

Multple shells fixed 

When we receive the files. stl from our customers, it frequently occurs the need to make changes and corrections before proceeding with the production.

STL correction requires specific skills and the use of dedicated software to repair imperfections and ensure that the part is ready for printing.

Our team is fully committed to making such corrections with the utmost precision and timeliness, in order to ensure that the printed parts reach high quality standards and fully meet customer expectations.

What is an STL file?

What is an STL file?

An Overview of the Three-Dimensional Representation for 3D Printing

Today, we delve into the analysis of the STL file extension and its crucial role in the realm of additive manufacturing. If you are interested in the world of 3D printing, you are likely already familiar with this extension and its unique characteristics.


STL file

Essentially, the STL file represents a three-dimensional geometry through a combination of triangles arranged in three-dimensional space. This representation simplifies more or less complex surfaces, modeled using CAD software, into a series of planar triangles described by the Cartesian coordinates of their vertices.


The primary reason for the widespread use of the STL fileformat in the field of additive manufacturing lies in its ability to translate the language of CAD software, which is based on mathematical functions, into a format understandable by all 3D printing technologies on the market (SLS, SLA, FDM, etc.). This simplified format is based on a three-dimensional coordinate system, which represents a more accessible and immediate language for different printing technologies.

Export of  STL file

We often encounter the receipt of files with different extensions, such as .iges or .step, or even proprietary files from modeling software, each with specific characteristics. However, in order to materialize them through 3D printing, they need to be transformed into the STL file format. This conversion process simplifies the 3D models but may involve some modifications, such as approximating cylindrical or spherical parts and the presence of facets that do not accurately reflect the originally designed surfaces.

Example of 3D modelled file

Example of correctly exported file in STL with good resolution

Example of file exported in STL with incorrect resolution. Note the inside of the hole that has lost its initial sphericity.

STL file resolution

It is directly related to the number and size of the triangles that make up the model. A large number of triangles implies a higher resolution.

However, it is important to emphasise that a large file size does not necessarily mean significant advantages. Rather, it is preferable to adapt the size of the triangles to the printing resolution of the machine used. For example, our SLS machines operate with a resolution of about 5 hundredths of a millimetre. Therefore, it is vital to have a correctly adapted .STL file in order to guarantee optimum surface resolution.


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