Rapid prototyping services and prototype construction from plastic

Rapid prototyping is the fast production of sample components or small batches originating from a digital 3D model. In product development, it ensures quick design testing, under real conditions using additive manufacturing or 3D printing technologies.

• Design prototype: This type of prototype is constructed to check whether the realised object meets the visual requirements and fits into the overall concept. These models do not yet have any functionality and can be made from ordinary plastic.
• Geometric prototype: Geometric prototypes already correspond to the exact dimensions of the application and can be assembled to check whether further changes need to be made to the fit. In this way, the requirements for the material needed can also be checked and concretised.
• Functional prototype / functional prototype: Functional prototypes depict the central functionalities of the planned component and can be tested directly in the application. At this point, a small series of sample components is recommended in order to test them under different conditions
• Technical prototype: Once the final geometry and material have been finalised, the finished application is tested in use with the technical prototype. The model already corresponds completely to the end product in terms of material, mechanical behaviour and geometry.
• Industrial prototyping: Before a product goes into mass production, small series are often produced, particularly in the automotive industry, e.g. for pre-series vehicles, so that the new model can be tested by customers. At this stage of product development, it is often the case that changes need to be made to the material.

The process used for prototype production depends primarily on the requirements of the application. The mechanical specifications of a sample are determined not only by the material, but also by the printing process and the specific realisation. The time and quantity of prototypes to be produced also influence the choice of printing process.

SLS (selective laser sintering)

This process is very well suited to the production of individualised single parts and series of up to 10,000 pieces. In this process, a laser melts a thermoplastic powder layer by layer, creating the specified model. Prototypes produced using this manufacturing process are characterised by a particularly high load-bearing capacity. It is the most commonly used additive manufacturing process at igus®, as strength, precision and component price are superior. Various finishes, such as colouring or smoothing, are also offered.

FDM (Fused Deposition Modelling)

Based on special plastic filaments, this process produces particularly robust components in small quantities. A major advantage of the FDM process is the large selection of materials for special requirements such as high temperatures or food contact, as well as the comparatively uncomplicated combination of different materials in the production of a prototype. However, complex geometries cannot be modelled as flexibly with this process as with the SLS process.

Rapid Tooling (print2mold®): Injection moulded parts from additively manufactured injection moulding tools

For industrial prototyping, the high-volume production of functional prototypes and for special material requirements, it is often worthwhile using additively manufactured tools for injection moulding. In this way, a larger selection of materials can be used, as not every plastic is available as a 3D printing material. On the one hand, this technology makes it possible to produce technical prototypes that are largely identical to the end product; on the other hand, the special features of the injection moulding process limit the freedom of design in contrast to prototypes from the 3D printer. The injection moulds are made of metal or synthetic resin using the stereolithography (SLA) process, depending on the requirements and the number of units needed.

Subtractive processes: bar stock

Prototypes made from bar stock are also characterised by the fact that both the material and the mechanical specification can already be reproduced and tested in their full functionality at the test stage. In this process, material is removed mechanically, for example with a milling machine, in order to produce the required workpiece from the raw material. The advantage of this technology is that, unlike 3D printing, there are no specific restrictions, such as the minimum wall thickness. The choice of material for prototyping with bar stock is also greater than in additive manufacturing. The cost advantage of this process lies in the production of large-volume or particularly simple parts.

Rapid prototyping is important because it gives engineers freedom to experiment with different materials and manufacturing processes without the costs of tooling, set up charges and restrictions.