The combination of textile surfaces with additively printed, three-dimensional elements enables functional optimization and integration as well as a high degree of design freedom. In the AddiTex project new plastic compounds with material properties are developed that meet the requirements of the 3D printing process as well as (those of) the applications, e.g. in protective and functional clothing.
Additive manufacturing processes (3D printing) play a decisive role as an automated manufacturing technology for the production of high-performance components. This will also open up unique opportunities for textile and clothing companies in the future to increase competitiveness and save resources (new products, dismantling of supply chains, reduction of CO2 emissions), which are not available with conventional production methods.
In the project, polymer materials for additive manufacturing on textiles were initially developed. Based on this, textile composites with geometries and properties that were previously unimaginable were created. Examples of applications include UV and noise protection or functional and protective clothing.
Using the 3D printing technology of Fused Deposition Modeling (FDM), plastics are applied layer by layer and three-dimensional structures are created. FDM printing on textiles has so far not been used commercially due to the lack of availability of suitable polymer materials. The filaments available on the market have insufficient additives for the special industrial requirements. By establishing a holistic manufacturing system in which new functional materials (compounds) and joining and connecting technology including structuring and surface technology (3D printing) are coordinated with each other, the special requirements of the industry are to be taken into account and new textile composite materials produced.
At the same time, the material properties specified by the application led to problems during processing using FDM, which meant that the surfaces of the filaments had to be modified. A further challenge was the permanent adhesion to the textile: the printed plastic should form a firm bond with the textile and at the same time be sufficiently flexible to be able to follow the movement and stretching of the base. A flexible, flame-retardant compound with a Shore hardness of 70A was developed for this purpose. This is particularly suitable for applications in the field of textile sun protection and sound insulation and has already been successfully tested for its suitability in tests customary in the industry. Materials in this Shore hardness range are currently not available on the market as FDM filament.
In addition, a stiff, glass-fibre reinforced compound has been developed which is particularly suitable for the direct printing of plug connections or form reinforcement for protective and functional clothing. This should save production steps and reduce costs. In future, the researchers also plan to test biobased plastics for the production of textile composites and develop further applications.
Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT