#Research & Development

2025-01-23

Textile daylight management when the winter sun is at an angle

When the sun is currently shining, shading textiles face particular challenges. On the one hand, they should allow as much daylight as possible into the rooms during the dark season. On the other hand, the angle of incidence of the sun's rays is so low that the light is particularly dazzling - much more so than in summer. The German Institutes of Textile and Fiber Research (DITF) are using special light measurement techniques to research suitable shading textiles.

Daylight enhances well-being and has many advantages over artificial lighting. Sensible daylight management can therefore increase the ability to perform and concentrate. As less artificial light is required and solar gains and losses are used for room air conditioning, daylight management also saves energy.

Scheme for determination of the cut-off angle with 1 light source, 2 diffuser, 3 measurement sample on motorized rotating stage, 4 collimating lens, 5 spectrometer. Drawing: DITF

Textile daylight systems influence the incidence of light and are mainly designed to be movable. Internal systems include, for example, roller blinds, folding blinds and curtains. External systems are external venetian blinds, awnings and screens that are guided in front of the façade. The DITF can precisely measure daylight behavior in its light and dark laboratories - even beyond existing standardized test methods.

A test method developed in Denkendorf allows the glare control of solar protection devices to be re-evaluated and has been included in the standard to determine the cut-off angle. This cut-off angle describes the extent to which a solar protection device can block the transmission of direct light from a certain angle of incidence. In the currently valid standard, glare control is quantified using the two characteristics of normal and diffuse light transmittance. For solar protection devices with an openness coefficient of 1-3 %, a higher glare control class can be achieved. This applies to cut-off angles of 65° or less. The cut-off angle is determined by an angle-dependent measurement of the direct light transmittance. During the test, the solar protection textile is rotated in a modified test sample holder from the zero point until the direct light transmittance falls below a defined threshold value. This process is repeated after a gradual azimuthal rotation of the test sample, in other words a rotation of the textile in the test sample holder. Depending on the symmetry properties of the sample, up to 29 individual measurements may be required to determine the cut-off angle.

At the DITF, testing and development facilities for other photometric requirements such as incident light, self-luminous textiles and light-conducting textiles are available for industrial product developments.

The direct transmission of a textile screen when changing the angle of incidence and the specific angle of rotation. Photos: DITF

Towards a circular and sustainable textile industry in Europe: BioFibreLoop has been started

The German Institutes of Textile and Fiber Research Denkendorf (DITF) are coordinating the research project, which is funded as part of the European Union's Horizon Europe research and innovation program. The aim of BioFibreLoop is to develop recyclable outdoor and work clothing made from renewable bio-based materials. The kick-off event took place in Denkendorf on June 26 and 27, 2024.

Closing the Loop in the Textile Industry: Value Creation in the State of Brandenburg

How can the state of Brandenburg benefit from a circular textile industry? This question is addressed in the new policy paper "Closing the loop in the textile industry: Value creation in the state of Brandenburg." Based on the „TexPHB“ feasibility study funded by the Brandenburg Ministry of Climate Protection, it shows how textile waste can be integrated into new value chains.

Better, faster, bio-based: Functional new Plastic alternatives

How can new bio-based and biohybrid materials with improved features be developed faster? Six Fraunhofer institutes are jointly exploring this question in the SUBI²MA flagship project, using an innovative bio-based polyamide developed by Fraunhofer researchers as a model. Its specific properties make it a promising alternative to fossil-based plastics.

A smarter way to verified Chemical Compliance

Hohenstein and GoBlu Drive Innovation in Sustainable Supply Chain Management As regulatory demands, customer expectations, and sustainability goals continue to grow, the ability to manage chemical compliance and data across complex supply chains has become critical. Hohenstein and The BHive® by GoBlu are initiating a strategic partnership to enhance chemical management in the textile sector. The collaboration delivers more than just a service – it provides an integrated, future-ready solution for brands, manufacturers and suppliers seeking trusted chemical management and credible sustainability.

Rieter reports stable order backlog and strategic progress – outlook for 2025 adjusted

In its Investor Update 2025, Rieter announced an order intake of CHF 203.9 million in the third quarter and CHF 559.3 million after nine months, reflecting a continued cautious investment climate in the textile machinery sector. Sales totaled CHF 121.5 million in the third quarter and CHF 457.7 million for the first nine months of the year, while the order backlog stood at around CHF 590 million as of September 30, 2025.