In April 2013 the German Quality Assurance Association RAL Gütegemeinschaft Kunststoff-Fensterprofilsysteme adopted the new Quality Mark RAL-GZ 716. What is new about this Quality Mark is that it focuses on the assessment of the profile system as a whole. What does the new Quality Mark involve in terms of commitment and what opportunities does it offer for the system suppliers and their component suppliers? These questions were explored within the film manufacturer RENOLIT SE, located in Worms, by a group of experts consisting of Business Unit Manager Stefan Friedrich, Head of R&D Dr. Dirk Heukelbach and Product Manager Franz Josef Weber.
In May 2013 the new Quality Mark replaced the former approval mark for window profiles that had come into effect in 1998 and was modified in 2008. The Quality Assurance Association has now provided an assessment instrument taking into account all component parts of a window system provided that all single components of the system are previously assessed according to the same approach. The risk for the profile manufacturers will thus remain calculable because “after all, they will assume full responsibility for the entire system”, emphasizes Stefan Friedrich and points out the intricate circumstances. “In turn, the window manufacturers can rely on a high level of security – provided they do not modify the system. If they do so, a re-examination by the association Verband Fenster + Fassade (VFF) according to RAL-GZ 695 would be required”.
Each component must be certified
With view to the wide product range, RAL-GZ 716 provides a rather differentiated structure. It applies to plastic profiles only and in its first section differentiates between profile and surface versions. In its second section the testing requirements for the single components and the lamination process are stipulated. The decisive progress compared to the old test mark is essentially based on the details Dirk Heukelbach describes: “The requirements to lamination film and adhesives were either enhanced or – in the case of adhesive bonding – established as an additional feature”. In light of durability, the entire component system consisting of film, adhesive and profile is nowadays tested over a period of six weeks under a temperature of 70 degree Celsius and a relative humidity of 98 per cent.
In weathering tests the films must at least comply with the conditions of M20, corresponding to an exposure period of 10,000 hours under special Xenon lamps or to absorption of 20 Gigajoule per square metre. Additionally, the test specimens are irrigated at regular intervals. In another test the specimens may not heat up to more than 66 degree Celsius under defined laboratory conditions. “Standardised measuring procedures for the determination of surface temperatures are imperative in order to achieve reproducible and thus objectively comparable results”, underlines Franz Josef Weber the necessity of such standards.
RAL-GZ 716 has been introduced with a three-year transitional period ending on 31 December 2016. Up to this date so-called old systems formerly approved according to RAL-GZ 716/1 may be awarded the new Quality Mark after undergoing a system test. All systems using new components must be tested according to the new guidelines.
Further expansion of current high level
For RENOLIT the altered regulations with view to the new Quality Mark do not require major adjustments because “We owe our success to two timeless virtues – quality awareness and striving for perfection. For our standard product RENOLIT EXOFOL MX we have already been exceeding the stipulated minimum requirements and are rather ranging on the higher level of weathering class M30”, as Stefan Friedrich puts it.
Since RAL Quality Marks only refer to the German market products are only certified to the classifications M20 and M30. However, the product lines RENOLIT EXOFOL PX and RENOLIT EXOFOL FX are specifically designed for demanding conditions that only prevail outside of Germany. RENOLIT EXOFOL PX is able to resist 40 Gigajoule per square metre, theoretically corresponding to M40. RENOLIT EXOFOL FX even resists 50 Gigajoule per square metre and is exposed more than 25,000 hours to artificial weathering. Thanks to its additional PVDF layer this exterior film meets the requirements for M50 and thus exceeds the standards set by RAL-GZ 716 by 2.5 times.
Technical expertise in demand
These strengths are combined with various other features surpassing the requirements of RAL as mentioned by Franz Josef Weber: “Proven processability, high level of security in handling as well as outstanding product resistance against environmental influences”. In view of the new RAL standards, these attributes also provide additional reliability because the individual components of a profile system are tested by neutral testing institutes independently from one another. This provides the window manufacturer with a complete package of tested components, increasing the reliability of the entire system.
Because of the manifold variety of components it is not possible to test all thinkable combinations in advance. Stefan Friedrich recommends: “System suppliers are well advised to consider potential interactions and to consult the experts of their business partners should there be the slightest doubt”. Moreover, both professional circles and end users have access to all kinds of information on the systems and their components. In spite of RAL being restricted to the coordination of processes on the German market it enjoys a high reputation also on the international level.
The RENOLIT Group is an international leader in the manufacture of high-quality plastic films and related products for technical applications. This independent family-owned business, which has been setting benchmarks for quality and innovation for over 65 years, now employs a workforce of approximately 4,500 employees at more than 30 production sites and sales entities. In the fiscal year 2014, the Group generated a turnover of EUR 915.8 million.
In Xenotests RENOLIT traditionally sets high criteria and its premium product RENOLIT EXOFOL FX exceeds the RAL-GZ 716 standard by 2.5 times.
Under the Xenon arc lamp the RENOLIT films must withstand up to 50 Gigajoules per square metre.
Natural weathering forms part of the compulsory programme of long-term weathering tests in order to measure all kinds of weather influence.
Monitoring the quality of printing and embossing requires an experienced eye.
With their wide range of décors RENOLIT EXOFOL products set architectural standards.
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