When defining the technical specifications for an outdoor stadium or sports venue\u2014whether from the design desk of an architectural practice, the standards\u2011driven calculations of an engineering consultancy, or the feasibility assessment carried out by the contractor and the asset owner\u2014UV resistance is a critical variable to ensure long\u2011term project success.<\/p>\n
The question \u201cDoes it have UV protection?\u201d is no longer enough. What is really required is verifiable evidence: how it is demonstrated<\/strong>, which standard<\/strong> supports it, and what impact it has on service life, colour, safety (brittleness\/impact) and replacement cost<\/strong>.<\/p>\n It is also important to differentiate between two concepts that are often confused:<\/p>\n Below we answer, directly, the questions that most frequently arise when technical teams assess outdoor seating<\/strong>, and we share key points<\/strong> to safeguard quality through design, engineering calculations and life\u2011cycle planning.<\/p>\n <\/p>\n 3 key takeaways<\/strong>:<\/span><\/p>\n <\/p>\n <\/p>\n Three key factors<\/strong> determine performance against UV radiation:<\/p>\n <\/p>\n <\/p>\n In our seats, the UV stabiliser is added as another additive in masterbatch form<\/strong>. This enables better dispersion of the additive<\/strong> when mixed with the rest of the material that will form the seat.<\/p>\n Injection moulding machines operate with a dosing unit that adds each component at the desired percentage. Once added, mixing and homogenisation of all components take place in the plasticising chamber and along the injection screw, so that this additive (and the rest) are fully integrated when entering the moulding stage to form the seat.<\/p>\n Technical conclusion<\/strong>: the UV\u2011stabilising additive is bonded into the material prior to moulding, therefore it is present throughout the entire mass of the seat (not only on the surface).<\/p>\n<\/div>\n <\/p>\n Injection moulding and blow moulding<\/strong> are different processes and require pigments suitable for each process<\/strong>. A pigment suitable for injection moulding may not be recommended for blow moulding, and vice versa. For this reason, processability<\/strong> and UV performance<\/strong> must be verified in each case.<\/p>\n Once behaviour has been verified, the expected performance should be equivalent<\/strong>, provided that pigment, formulation, geometry and process<\/strong> are correctly optimised.<\/p>\n <\/p>\n <\/p>\n Important point for engineering \/ design<\/strong>: beyond the pigment, seat geometry also matters<\/strong>. Blow\u2011moulded seats typically incorporate a double wall and an air cavity<\/strong>, which manages the thermal stress<\/strong> associated with solar radiation differently compared with a monobloc injection\u2011moulded part. This difference can affect how the seat absorbs and dissipates heat and, therefore, how it ages.<\/p>\n <\/p>\n <\/p>\n For seating in sports facilities, the main reference is UNE\u2011EN 13200\u20114<\/strong>.<\/p>\n This standard requires the material to be verified by an accelerated ageing chamber test<\/strong> lasting 2,300 hours<\/strong>, and then evaluated for:<\/p>\n <\/p>\n<\/div>\n Objective measurement of colour stability (CIE La<\/em>b* and \u0394<\/strong>E)<\/strong>\u00a0 \u00a0To avoid subjective interpretations of colour loss, colour variation is assessed using standardised colourimetric parameters in the CIE La<\/em>b* colour space<\/strong>. This system allows the colour difference between an initial sample (before testing) and an aged sample (after UV exposure) to be quantified objectively, by calculating the \u0394<\/strong>E (Delta E)<\/strong> value as an overall indicator of colour change.<\/p>\n CIE La<\/em>b* system parameters<\/strong> The \u0394<\/strong>E<\/strong> value integrates the combined variation of these three parameters and is used as an acceptance criterion according to the project\u2011defined requirements. The lower the <\/strong>\u0394<\/strong>E value, the smaller the perceptible colour variation.<\/strong><\/p>\n In this way, colour stability ceases to be a visual or subjective criterion and is assessed using a reproducible technical indicator<\/strong>, enabling objective comparison of materials, formulations and solutions after the accelerated ageing test in accordance with UNE\u2011EN 13200\u20114<\/strong>.<\/p>\n<\/div>\n <\/p>\n It is the manufacturer\u2019s responsibility to carry out the tests and quality controls required to guarantee these properties. Daplast seating technical documentation explicitly states UV light protection in accordance with UNE\u2011EN 13200\u20114<\/strong>.<\/p>\n Safety and liability<\/strong>: A UV\u2011related failure is not only an aesthetic issue<\/strong>. A polymer embrittled by solar radiation can lose elasticity and impact resistance, compromising spectator safety under dynamic loads or vandalism. Therefore, strict compliance with the tests under UNE\u2011EN 13200\u20114 (and its linkage to use levels supported by UNE\u2011EN 12727) is the objective basis for defining technical specifications with confidence.<\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n There is no single answer<\/strong>, because it depends (among other factors) on:<\/p>\n Environmental variability<\/strong> has a direct impact on the project life cycle<\/strong>: a selection based only on the initial cost can lead to premature replacements (logistics, removal\/re\u2011installation, partial shutdowns), increasing OPEX<\/strong> and total cost of ownership (TCO).<\/strong><\/p>\n <\/p>\n <\/p>\n It affects both. UV radiation causes degradation of the seat material<\/strong>, which is why UNE\u2011EN 13200\u20114 requires mechanical properties to be assessed after accelerated ageing (2,300 h). These test hours should not be interpreted as a direct equivalence to years in service<\/strong>, but as a standardised comparative criterion.<\/p>\n Key conclusion for structural validation<\/strong>: UV stabilisers do not only protect colour; they also help protect the base material<\/strong> against degradation and embrittlement, sustaining mechanical performance.<\/p>\n <\/p>\n <\/p>\n Daplast internally qualifies all materials and pigments before they are introduced to the market. The process includes:<\/p>\n Accelerated ageing chamber tests<\/strong>, as part of our internal comparative studies and material selection, can exceed 8,000 hours<\/strong>, enabling long\u2011term behaviour analysis and selection of the best solution for each project.<\/p>\n <\/p>\n<\/div>\n <\/p>\n <\/p>\n Solar radiation is not homogeneous globally<\/strong>, and this variability has a direct impact on the long\u2011term behaviour of seats installed outdoors.<\/p>\n To quantify this difference, the Kilo\u2011Langley (KLy)<\/strong> is used\u2014a unit that specifically measures exposure to ultraviolet radiation<\/strong> per square metre over the course of a year.<\/p>\n This indicator makes it possible to compare objectively the severity of the environment to which a seat will be exposed:<\/p>\n<\/div>\n <\/p>\n These differences significantly influence the expected service life of each colour and formulation<\/strong>, because the higher the accumulated radiation, the greater the demand on the material, pigments and UV\u2011stabilising additives.<\/p>\n From the perspective of economic planning and the project life cycle<\/strong>, a choice based solely on the seat\u2019s initial cost<\/strong>\u2014without considering the actual radiation level (KLy)\u2014can lead to premature degradation<\/strong>. This may force reinvestment in removal, logistics and re\u2011installation<\/strong> within a few years, noticeably increasing the venue\u2019s OPEX<\/strong> and total cost of ownership.<\/p>\n Good practice<\/strong>: in high\u2011insolation projects<\/strong>, it is advisable to request specific technical guidance <\/strong>from the manufacturer on the most suitable colours and pigments for the site, taking into account accumulated solar radiation values and the project\u2019s durability objectives.<\/p>\n <\/p>\n <\/p>\n Daplast has more than 50 years of experience working in regions with high UV radiation<\/strong>. Since our beginnings, we have worked on sports venue projects in Southern Spain, with high levels of solar radiation.<\/p>\n Our experience installing seats in countries in North Africa and Central America has shaped our quality processes and materials research so that our seats are highly resistant to ultraviolet light<\/strong>.<\/p>\n To reinforce technical control, we combine:<\/p>\n This approach enables us to cross\u2011check controlled laboratory data with empirical validation under real conditions<\/strong>, and to select materials and pigments with the best behaviour against UV\u2011driven ageing for each project.<\/p>\n <\/p>\n <\/p>\n UV resistance in stadium & arena seating<\/strong> should not be treated as a simple \u201cyes\/no\u201d attribute, but as a verifiable set of material, formulation and process decisions<\/strong>.<\/p>\n To specify with confidence, always request test evidence in accordance with UNE\u2011EN 13200\u20114<\/strong> (and associated tests). Discuss the most suitable\/recommended colours<\/strong> with the manufacturer based on their experience and review the warranty scope<\/strong> in writing\u2014it must be reliable and consistent<\/strong> with the analysed data.<\/p>\n This approach helps minimise the risk of colour change<\/strong>, premature brittleness<\/strong> and mid\u2011term replacement costs<\/strong>.<\/p>\n<\/div>\n <\/p>\n\n
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<\/strong><\/strong>2) <\/strong><\/strong>\u201cReal\u201d UV protection<\/strong>: stabilisation must be integrated through the material (in\u2011mass)<\/strong>, not as a surface coating.
3) <\/strong><\/strong>It\u2019s not only aesthetic<\/strong>: UV radiation can affect mechanical safety<\/strong> (brittleness\/impact), not just colour.<\/div>\n<\/blockquote>\n<\/div>\n1) What factors influence a seat\u2019s UV resistance?<\/strong><\/h3>\n
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2) Is the UV stabiliser \u201cin the mass\u201d or is a surface coating?<\/strong><\/h2>\n
\u00a0<\/h3>\n
3) Are there differences in UV resistance between injection-moulded and blow-moulded seats? <\/strong><\/h3>\n
\u00a0<\/h3>\n
![\"Important](\"https:\/\/daplast.com\/wp-content\/uploads\/2025\/07\/1-2-300x300.png\" "\\"\\"")
<\/p>\n<\/div>\n4) Which European standard governs UV resistance for stadium & arena seating?<\/strong><\/h3>\n
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\u2022 L*: lightness (black to white)
\u2022 a*: green\u2013red axis
\u2022 b*: blue\u2013yellow axis<\/p>\n5) What is the difference between UNE\u2011EN 13200\u20114 and UNE\u2011EN 12727 when evaluating a seat?<\/strong><\/h3>\n
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![\"mechanical](\"https:\/\/daplast.com\/wp-content\/uploads\/2024\/11\/maquina-resistencia-sittem-azul__fondo_BN-300x200.png\" "\\"\\"")
<\/p>\n\n\n
\n \u00a0 UV Risk Factor<\/strong><\/td>\n What does the technical test evaluate?<\/strong><\/td>\n Project Impact<\/strong><\/td>\n Decision\u2011making Priority<\/strong><\/td>\n<\/tr>\n \n \u00a0 Aesthetic degradation \u00a0<\/strong><\/td>\n Colour stability and uniform gloss change.<\/td>\n Visual appearance of the seating bowl and fidelity to the original concept.<\/td>\n \u00a0Architecture \/ Design management<\/td>\n<\/tr>\n \n \u00a0 Mechanical degradation<\/strong><\/td>\n Retention of properties and impact resistance after 2,300 h.<\/td>\n Spectator safety and resistance under severe use or vandalism.<\/td>\n \u00a0Engineering \/ Safety consultancies<\/td>\n<\/tr>\n \n \u00a0 Environmental uncertainty<\/strong><\/td>\n Real ageing under site\u2011specific conditions.<\/td>\n Budget deviations due to future maintenance costs.<\/td>\n Contractors \/ Clubs \/ Local authorities<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n \u00a0<\/h3>\n<\/div>\n
\u00a0<\/h3>\n
6) How many years will the colour remain \u201cwithout significant visual deterioration\u201d?<\/strong><\/h3>\n
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7) Does UV radiation affect only colour, or also impact performance\/brittleness?<\/strong><\/h3>\n
8) What UV resistance testing does Daplast carry out?<\/strong><\/h3>\n
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![\"UV](\"https:\/\/daplast.com\/wp-content\/uploads\/2026\/05\/maquina-xenon-test-resistencia-UV-web-297x300.png\" "\\"\\"")
<\/p>\n9)<\/strong> How does geographic location influence UV performance?<\/strong><\/h3>\n
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![\"Solar](\"https:\/\/daplast.com\/wp-content\/uploads\/2021\/08\/kilolangley-world-map-300x160.jpg\" "\\"\\"")
<\/p>\n10) What resources does Daplast use to improve and guarantee UV behaviour?<\/strong><\/h3>\n
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Conclusions:<\/strong><\/h3>\n
\u00a0<\/h4>\n
Are you defining technical specifications, calculating safety requirements or planning the life cycle of your next seating bowl?<\/strong><\/h3>\n<\/div>\n