In the architectural segment, MEHLER TEXNOLOGIES®
multilayered composite materials have special densely woven low-wick yarns in
the base fabric. The double thread woven fabric, commonly described as “Panama”
weave, varies depending on the mechanical resistance requested by the
customers. The different membrane materials are graded by weight, strength,
lacquering system and translucency. There is a great MEHLER TEXNOLOGIES® range,
but especially in this segment it is crucial that selected product fits to the specific
project needs and the particular defined use.
A specific analysis of your needs and mechanical/static load properties is therefore recommended.
The textile industry is constantly improving the existing materials. Low & Bonar as a pioneer fabric producer, is continuously increasing and perfecting those materials in every aspect. For engineering tensile structures, the most common choices are PVC coated polyester cloth materials. High quality low-wick treated PVC polyester fabrics generally achieve a structural lifespan in excess of 20 years. In ordinary materials, the plasticizers in the PVC migrate towards the surface over a period of time making the surface harder to clean. The PVC coating contains additives that include UV stabilisers, fire retardants, colouring and fungicidal agents. MEHLER TEXNOLOGIES® quality known under the brand name VALMEX® MEHATOP F1 are a selection of protective PVDF (fluorinated polymer) lacquers that enhance the ability to clean the PVC membrane. To improve this and maintain translucency, we offers a range of products including PVDF lacquer on both material sides, which are perfectly weldable. The choice of a suitable material is dictated by many characteristics, ranging from technical and mechanical properties to the aesthetical appearance resulting from physical material properties.
Low & Bonar, a pioneer in PVC-PES coatings, introduced the weldable PVDF coated membrane more than 14 years ago. In our opinion, the textile industry should provide products to the market, which can perform without the need to be modified, ground or manipulated by the fabricator.
The industry should assume full responsibility of the material properties and not delegate it to additional substances, manipulation of the surface, uncontrolled machine operation capability or simply to human factors. It is wrongly assumed that the weldability of a PVDF coated material is determined by the percentage of PVDF included into the top coat.
Our PVDF coated fabrics incorporate a primer between the top coating lacquer and the PVC coating, including 5 components in the structure of the product (see schematic view of Valmex Mehatop F ). Other manufacturers use between 3 and a maximum of 4 components (base fabric, adhesion layer (some), coating and lacquer).
This is the reason why our fabric is weldable, easy to manufacture and stable (non-peeling).
MEHLER TEXNOLOGIES® is essentially ”pre-stressed” with different force grades in both directions. The warp direction (length of the material roll) has less stretch to stabilise elongation in this sense. The weft direction (the width side of the material roll) has more stretch in order to absorb the orthogonal tension more readily during the distensile installation process.
Professionals like to manouver the compensation ratio of the fabric material during the patterning process in order to generate ad-hoc geometries and unique smooth surfaces. This process is generally considered “top secret” to most of them and is also the key to the well qualified textile architecture engineer or specialized manufacturer.
This requires a certain kind of technical information generated by computer analysis, simulation and testing processes, generated case by case for each project. We can provide the customer with biaxial results for each produced batch of material. The tests are carried out upon client request by external accredited laboratories based on the MSAJ/M-02-95 procedure.
A good example of the use of the VARIO STRETCH system is the asymmetrical curvature shapes of the sunshades structure in Ningxia, China.
The use of natural resources in buildings for purposes of functionality is considered to be “intelligent architecture”. The reason for this is to fully understand the needs for energy savings, and therefore environmental protection.
In normal use, a space with a general, diffuse light transmission of 5% is appropriate to carry out everyday tasks at home and work (e.g. reading a newspaper). Lower transmission grade fabrics may need to be artificially illuminated or, in contrast, spaces with too much light (UV) transmission can be found to be unpleasant by the public. The grade of natural transmission has to be carefully analysed “case by case” as this can have dramatic consequences on the final results and depends very much on the intended application of such a building.
For example, a sport complex company was planning to install tennis
court covers a few years ago. The architects preferred to integrate
arch supported tensile coverings into the surrounding area in a light
green shade. The aesthetical look of the covering was very attractive but it led to the tennis player being disturbed by
green shadows on the tennis court.
In reality, anyone can feel
uncomfortable underneath a highly transparent covering when the sun is
shining. The quantity of natural light and the high UV transmission
causes this space to become very warm and consequently may disrupt normal
tasks that may have to be carried out by people while in the
confines of this construction.
Our products allow for different grades of transmission from 2% to 15% (HFT pigmented), also depending on the strength of the material, the thickness of the coating and the colour of the coating. It is important to note that our material translucency is as well measured at 550 nanometres of light spectrum intensity (daylight intensity that is very close to the frequency to which the human eye is most sensitive). This is the range where we detect light intensity changes; some other material producers use higher light intensity references to increase their values. For particular uses (for example, a circus tent) a material with full block-out may be most suitable, because they are practically impermeable to external light and can be produced in combined and different (external/ internal) colours.