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A queen with conscience

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					greenhousejournal                                                                                                                 PRofitable GRowth undeR acRylic                               May 2007




     A queen with a
     conscience
     Against the backdrop of rising energy costs and the ongoing debate about
     CO² emissions, companies that squander energy will probably have a hard
     job staying in the market. Energy will account for an increasing share of
     the overall costs of running a greenhouse.
     Growing orchids consumes a great deal of energy, so orchid growers keep
     a keen eye on costs. That's why more and more greenhouses, especially
     in the Netherlands, are glazed with PLEXIGLAS® because its excellent heat
     insulation offers significant benefits.




[Keynote] —        Grace, purity, elegance        PLEXIGLAS® when it comes to converting           adding another 6,800 square metres of                      Haussmann says. “The crucial factor is that
and beauty are the attributes of a queen.         existing greenhouses or building new ones.       greenhouse capacity.”                                      we can provide these leading global plant
So it's no wonder orchids are seen as the         The insulating air cushions in the double             “The Netherlands is our most                          specialists with exactly what their plants
aristocrats of pot plants. They also call         or triple-skin sheets offer particularly high    important market at present, and one                       need.”
for right royal treatment during their            thermal resistance and are therefore more        the whole world is watching. A total                             For Eric Moor, that means PLEXIGLAS
cultivation. Lavishly tended, nurtured and        suitable than single glazing. The more           greenhouse area of 200 hectares are glazed                 RESIST ® double-skin sheet. The Dutch
checked, they feel happiest at 27 degrees         layers of air, the better the heat insulation.   with PLEXIGLAS ® in the Netherlands.                       horticulturalist produces flowering
Celsius.                                          Greenhouses are normally built with two          This is where trends are set,” Michael                     Phalaenopsis orchids in Europe's most
       Not exactly the average temperature        skins at most, to retain                                                                                                    modern greenhouse. His
in the Netherlands, the world's largest
supplier of orchids. To thrive in Europe,
                                                  the highest possible light
                                                  transmission.
                                                                                     Energy saving: how PLEXIGLAS® compares                                                   colleagues, who grow
                                                                                                                                                                              Phalaenopsis seedlings,
these tropical plants are raised under                  These facts also con-                                                                                                 have slightly different
artificial conditions of heat and humidity.       vinced Arjen Peerdeman,
                                                                                      Single-glazed                          Greenhouse glazed with                           requirements and therefore
That makes them real energy fiends. Good          an orchid grower from               greenhouse                             PLEXIGLAS® double-skin sheets                    depend on PLEXIGLAS
heat insulation and energy conservation           Zaagdijk-Oost. This cost-                                                                          Up to 55%                ALLTOP® SDP. These sheets
have long been particularly important in          conscious and environment-                                                                         energy savings           transmit UV light and let
this branch of industry, and call for efficient   minded operation chose                                                                                                      the entire solar spectrum
glazing. Double glazing with U-values of          PLEXIGLAS ALLTOP® SDP                                                                                                       into the greenhouse.
less than 3W/m²K should be the rule.              as the economical solution                                                                                                        Kees Schoone has
       Many growers rely on PLEXIGLAS® to         to energy consumption in                                                                                                    60,000 square metres of
keep heating costs down to an acceptable          greenhouses. “Not only do                                                                                                   ultramodern production
level. “It transmits more light than other        plants flower better thanks                                                                                                 space at his disposal at
materials, insulates better than conventional     to the UV transmission of                                                                                                   Floricultura in the Dutch
single glazing and therefore saves energy.        PLEXIGLAS ALLTOP® SDP,                U-value = 5.8 W/m²K                       U-value = 2.5 W/m²K                         town of Heemskerk. Energy
It's also highly resistant,” explains Michael     the air cushions in the                                                                                                     conservation was what
Haussmann, responsible for the greenhouse         double-skin sheets help us                                                                                                  prompted him to choose
market in Degussa's Acrylic Sheet Business        save energy. That means                                                                                                     P L E X I G L A S A L LT O P ®
                                                                                                                 Energy supply
Line.                                             I can do my bit for the                                                                                                     double-skin sheets. “I save
                                                  environment and get better                                                                                                  about 40 per cent in energy
                                                  results at the same time.                        watts        The lower the U-value (heat transfer coefficient),            costs as compared with
Double-skin sheets for pot plants                                                             U= 2              the better the insulation offered by the material.
                                                  PLEXIGLAS ALLTOP® SDP                          m • kelvins    That means less energy loss.                                  traditional single-glazed
Growers of pot plants in particular opt           has convinced us, and that                                                                                                  greenhouses,” he reckons.
for energy-saving, light-transmitting             is why we are presently                                                                                                     This figure is confirmed by



                                 02 Plant grower Teun                                                 03 Michael Haussmann                                                  04 PLEXIGLAS® offers
                                    Van der Eijk built his                                               on environmental                                                      more than most:
                                    first greenhouse with                                                consciousness in the                                                  Materials for green-
                                    PLEXIGLAS® in 1977                                                   greenhouse market                                                     house construction
                                                                                                                           2

                                                                                                                               Continued from page 1



                                                                                                                               the Institute of Agricultural and Environ-                               America's largest grower of potted
                                                                                                                               mental Engineering (IMAG-DLO), which                               orchids is presently expanding again.
                                                                                                                               established that energy savings of 24 to 55                        The Matsui Nursery is glazing a further
                                                                                                                               per cent can be achieved using PLEXIGLAS                           15,000 square metres of greenhouse with
                                                                                                                               ALLTOP®. “The UV transmission also has                             PLEXIGLAS RESIST® SDP 8, bringing the
                                                                                                                               a positive effect on seedling growth. So                           total area glazed with PLEXIGLAS ® to
                                                                                                                               we are investing in vigorous growth and                            50,000 square metres. Matsui also began
                                                                                                                               energy saving,” says Kees Schoone, whose                           several years ago to refit his older green-
                                                                                                                               business grows some 30 million orchids per                         houses successively with the long-lasting
                                                                                                                               year.                                                              eight-millimetre-thick double-skin sheets.
                                                                                                                                     The same applies to the Phalaenopsis                         His total greenhouse capacity is an impres-
                                                                                                                               orchid “nursery” of specialist Ed Meeu-                            sive 30 hectares. “The 21st century belongs
                                                                                                                               wissen at Orchids4ALL in Aalsmeer near                             to the orchid,” Matsui says. He expects the
                                                                                                                               Amsterdam. The greenhouses built there                             demand for orchids to grow steadily.
                                                                                                                               in 2001 by greenhouse specialist Bosman
                                                                                                                               using PLEXIGLAS ALLTOP® SDP have now                               The greenhouse of the future
                                                                                                                               been extended to 25,000 square metres.
                                                                                                                                                                                                  Orchids are not the only pot plants and
                                                                                                                                                                                                  ornamental varieties to thrive under
                                                                                                                               Scandinavia and North America                                      PLEXIGLAS ®, which is often chosen to
                                                                                                                                                                                                  cut energy costs. “There is clearly a trend
                                                                                                                               are catching up
                                                                                                                                                                                                  towards the low-energy greenhouse, and
                                                                                                                               “PLEXIGLAS® is not just the trend in the                           the Netherlands plays a pioneering role,
                                                                                                                               Netherlands – Scandinavian countries and                           with plans for greenhouses that can be
                                                                                                                               North America are catching up,” Haussmann                          heated completely without fossil fuels,”
                                                                                                                               says. But there are climatic differences that                      Michael Haussmann tells us. (See also
                                                                                                                               influence the choice of material. Andy                             interview on page 3). sew
                                                                                                                               Matsui in Salinas Valley, California, chose
                                                                                                                               PLEXIGLAS RESIST® SDP in 8mm thickness.
                                                                                                                               That is important because California is very
                                                                                                                               hot in the daytime, but cool at night, so the
                                                                                                                               temperature deficit has to be balanced and
                                                                                                                               the heat level kept constant.                                      www.plexiglas.de
The face of climate protection: Phalaenopsis seedlings in one of Europe's most modern PLEXIGLAS RESIST® greenhouses
in De Lier, Netherlands




30 years of value for money
Plant grower Teun Van der Eijk built his first greenhouse with PLEXIGLAS® in 1977

[Users] — Thirtieth birthdays are usually                      house plants and flowering pot plants
celebrated in style, and Teun Van der Eijk                     spread out as far as the eye can see over
in the Dutch town of Woubrugge has every                       an area of 8 hectares, under 100,000 square
reason to follow suit.                                         meters of PLEXIGLAS® multi-skin sheets.
      Thirty years on, his greenhouse made                     These have by far exceeded the expecta-
of PLEXIGLAS® double-skin sheet still looks                    tions placed in the material.
just like it did in 1977, when it was built.                         Part of the 100,000 square meters
The double-skin sheets have withstood                          were glazed with highly heat-insulating,
almost 11,000 days of sun, rain, wind,                         32mm thick triple-skin PLEXIGLAS® sheets.
storms and hail. Van der Eijk reckons they                     These provide energy savings of up to 60 per
have long paid off: “I save 40 per cent on                     cent. “We use triple-skin sheets particularly
energy as compared with single-glazed                          for growing non-flowering plants, because
greenhouses.” The 10,000 square meters of                      they require less light, but are cost-critical”.
PLEXIGLAS® installed in 1977 are still fully                   PLEXIGLAS ALLTOP® double-skin sheets
functional and just as light-transmitting as                   were also used to glaze the eight-hectare
on day one. “We opted for PLEXIGLAS®                           greenhouse.
back then because the double-skin sheets                             Teun Van der Eijk employs environ-
keep heat levels constant, so we can save                      mentally friendly growing methods, not just
energy. And we were also convinced by                          by saving energy thanks to PLEXIGLAS®.
the material's strength and loadbearing                        “We do our best not to pollute the environ-
capacity. Here in the Netherlands, we have                     ment. So we water most of our plants with
lots of storms, and ordinary glass wouldn't                    an 'ebb and flood' system. The water that
stand up to them for very long,” says Van                      is not absorbed by the plants is collected
der Eijk.                                                      in a special reservoir and used again,” he
                                                               reports. “That also collects the fertiliser
Turning back time                                              that doesn't stay in the soil.” In 1998, Van
                                                               der Eijk won the National Horticultural
When Teun Van der Eijk glazed his first                        Prize for his exemplary methods. “So it's
greenhouse with PLEXIGLAS®, he had no                          worthwhile saving energy, and by choosing
idea that, 30 years later, he would own not                    the right glazing, we can go a long way
only the world's largest PLEXIGLAS® green-                     towards reducing environmentally harmful
house, but also one of the oldest. Today,                      CO2 emissions as well.” sew                                     Durability as a success factor: Teun Van der Eijk in his "anniversary greenhouse"




A walk down memory lane with Teun van der Eijk, Woubrugge, Netherlands


1977                          1978                          1981                           1984                           1985/1986                       1989/1991                        1998                      2006
the first 10,000 m²           area increased                the first 9,000 m²             area increased                 area increased with             area increased with              V.d.e. plant won          area increased
of PleXiGlaS®                 with 4,000 m² of              of PleXiGlaS®                  with 7,000 m²                  30,000 m² PleXiGlaS®            23,000 m² PleXiGlaS®             the “nationale            with 16,000 m²
double-skin sheets            PleXiGlaS® double-            triple-skin sheets             of PleXiGlaS®                  triple-skin sheets              no dRoP double-skin              tuinbouw onder-           PleXiGlaS alltoP®
were installed.               skin sheets                   were installed.                triple-skin sheets                                             sheets                           nemersprijs 1998“         double-skin sheets
energy saving of                                            energy saving of                                                                                                               (nto, national
some 40%.                                                   some 60%.                                                                                                                      horticultural Prize)


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                             "The first greenhouse with PLEXIGLAS® double-skin
                             sheet was built in 1969. After the first energy crisis in
                             the 1970s, more and more gardeners built PLEXIGLAS®
                             SDP greenhouses. "




Greenhouse specialist Michael Haussmann at the Hortifair exhibition in Amsterdam




“It will become increasingly important
to save energy”
Michael Haussmann on environmental consciousness in the greenhouse market


[Interview] —      Michael Haussmann is                       Greenhouse Forum in the presence of                  without gas) are meeting with lively             Hollandia in California cultivate their plants
the greenhouse construction specialist                        many international horticulturalists and             interest, as was recently shown by the           under energy-saving PLEXIGLAS® double-
at Degussa. He has been in charge of                          spelled the breakthrough for PLEXIGLAS®              visit of Dutch Prime Minister Jan Peter          skin sheets.
this segment for over 20 years, and the                       double-skin sheet in the gardening sector.           Balkenende to orchid specialist Maurice                In Asia, Japan presently holds first
extensive knowledge of the market he                          For the first time, it was possible to combine       Van der Hoorn. At his premises, a high-          place, with many small family businesses
has acquired makes him a highly qualified                     high energy savings with excellent light             tech greenhouse was built last year with a       that cultivate orchids, pot plants and cut
contact for customers. Within the company                     transmission. That is extremely important            roof containing 15,000 m² of PLEXIGLAS®          flowers, but also fruit and vegetables, in
too, Haussmann's experience has driven                        for plants, which are, after all, what               ALLTOP that make a major contribution to         greenhouses glazed with PLEXIGLAS®.
further developments to meet market                           greenhouses are all about.                           energy savings.                                        In Europe, we have the largest number
requirements. In past years, there has been                         Further optimisation led to the                                                                 of PLEXIGLAS ® greenhouses in the cool
a lively demand for PLEXIGLAS® in the                         ALLTOP sheet, with improved properties.              Where do you see the main market in              North, in Scandinavian countries. But on
greenhouse construction market. In our                        It now offers a light transmission of 91 per                                                          average, the greenhouses here are a good
                                                                                                                   greenhouse construction?
interview with Michael Haussmann, he                          cent, which puts it in the same league as                                                             deal smaller than in the Netherlands.
looks back in time and into the future.                       single glazing. Low-energy greenhouses               Michael Haussmann: The Netherlands clearly             Throughout the world, 700 hectares
                                                              with ALLTOP double-skin sheets and heat              remains the major market. The highly             of greenhouse area are covered with
How does the greenhouse market of 20                          shielding save over 50 per cent of heating           specialised businesses there secure a global     PLEXIGLAS®.
                                                              costs. The double glazing of greenhouses             edge for the Netherlands in the field of
years ago compare with today's market?
                                                              with highly transparent PLEXIGLAS ®                  horticulture. The country is also home           What will be the trend in years to come,
Michael Haussmann: Single glazing was                         ALLTOP SDP is therefore a very successful            to the leading international horticultural
                                                                                                                                                                    and how will it influence the greenhouse
widespread throughout Europe, and                             and extremely effective measure to save              exhibition “Hortifair” in Amsterdam.
remains so today. In southern Europe,                         heating costs, as well as being the perfect                The Netherlands has the world's most       market?
especially in Mediterranean countries,                        solution in terms of ease of installation and        modern greenhouses, which can grow               Michael Haussmann: The need to save energy
single film glazing is the dominant form. The                 plant growth.                                        everything from pot plants and cut flowers       is growing, and awareness of that need is
world's largest film-covered greenhouses                                                                           to vegetables. Five per cent of all ornamental   also becoming keener. Everyone is talking
are found in Asia, due to the low price.                                                                           plants grown in Dutch greenhouses grow           about how to reduce CO2 emissions at the
But film-covered greenhouses have to be                       What will the greenhouse of the future               under PLEXIGLAS® double-skin sheet. That         moment. Single glazing is simply no longer
renovated at regular intervals.                                                                                    corresponds to some 200 hectares.                state-of-the-art, and the trend is towards
                                                              look like, and how will it evolve?
      The first greenhouse with PLEXIGLAS®                                                                                                                          low-energy greenhouses. The solutions
double-skin sheet was built in 1969. After                    Michael Haussmann: Attempts will be made             What are the national differences in the         offered by PLEXIGLAS® are a step in the
the first energy crisis in the 1970s, more                    to shake off the dependence on conventional                                                           right direction. sew
                                                                                                                   choice of material?
and more gardeners built PLEXIGLAS® SDP                       fuels such as natural gas and oil. Obviously,
greenhouses. The first greenhouse with                        the aim is to cut consumption drastically.           Michael Haussmann: Obviously, differences
PLEXIGLAS® SDP measuring one hectare                          Horticultural research is also looking into          do exist. Demand is growing sharply
in size has stood on Teun Van der Eijk's                      this issue.                                          in all U.S. states. Even in the Sunshine         www.plexiglas.de
premises in the Netherlands for 30 years.                           The Netherlands has made the most              State (California), we detect a clear trend
He is so satisfied with the material that he                  progress in this direction. Research compe-          towards energy-saving and therefore
has now expanded his capacity to eight                        titions like “Kas 2020” (Greenhouse 2020)            environmentally friendly cultivation. Andy
hectares.                                                     and “Kas als Energiebron” (The greenhouse            Matsui in Salinas, for example, the major
      Röhm shook up the greenhouse                            as a source of energy) are in full sway.             producer of orchids in the USA, has been
market 20 years ago with the improved NO                      Greenhouse builders and operators have set           using energy-saving PLEXIGLAS® RESIST
DROP sheet. This prevents dripping and                        themselves the aim of building only zero-            double-skin sheets for his greenhouses for
condensation for better light transmission.                   energy greenhouses by 2020. Pilot projects           several years. Toni Barcelo, a big producer
The idea was born at the Darmstadt                            entitled “Kas zonder Gas” (Greenhouse                of pot plants, and vegetable producers like


                                                                                                        greenhouse
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                                                                                                         4                                                                                      Credits

                                                                                                                                                                                                This is a publication of the
                                                                                                                                                                                                Acrylic Sheet Business Line of

                                                                                                                                                                                                Degussa

PLEXIGLAS® – cream of the crop                                                                                                                                                                  Greenhouse Journal
                                                                                                                                                                                                is published three times a year by:

                                                                                                                                                                                                Röhm GmbH
Materials for greenhouse construction                                                                                                                                                           Acrylic Sheet Business Line
                                                                                                                                                                                                Kirschenallee
                                                                                                                                                                                                64293 Darmstadt
                                                                                                                                                                                                Germany
                                                                                       [Material] — Depending on the variety,              and colourful blossoms in many varieties             Phone +49-6151-18-3646
                                                                                                                                                                                                Fax +49-6151-18-3114
                                                                                       plants require different conditions in order        of plant. Growers of seedlings appreciate            www.plexiglas-greenhouse.com
                                                                                       to flourish. Whereas bedding and balcony            the level of UV light in greenhouses glazed
                                                                                       plants thrive at relatively low temperatures,       with PLEXIGLAS ® ALLTOP because they                 Please send notice of changes in
                                                                                                                                                                                                address to:
                                                                                       tropical plants and orchids prefer a very           promote vigorous and compact growth of               info@plexiglas.com
                                                                                       warm climate with high, stable atmospheric          plants that are highly suitable for further
                                                                                       humidity. And the greenhouse has to take            cultivation.
                                                                                                                                                                                                Edited by: Profilwerkstatt,
                                                                                       these conditions into account. So the choice              PLEXIGLAS RESIST ® double-skin                 64295 Darmstadt, Germany
                                                                                       of glazing determines what the greenhouse           sheets have other strengths, too. They               Phone +49-6151-599020
                                                                                       can be used for.                                    are extremely tough and hail-resistant. In           www.profilwerkstatt.de

                                                                                                                                           comparison with PLEXIGLAS ® ALLTOP                   Editors in Chief: Jürgen Jourdan,
                                                                                                                                                                                                Communication Services
                                                                                       Glass – plenty of light,                            sheets, they only have the NO DROP                   (responsible under Journalists’ Law)
                                                                                                                                           coating on one side. Installed with the              Susanne Diehl, Acrylic Sheet
                                                                                       little heat insulation                                                                                   Martina Keller, Profilwerkstatt
                                                                                                                                           coated side facing the plants, this also
                                                                                       Although conventional single glazing                prevents dripping and provides high levels           English Translation: Mitzi Morgan
                                                                                       transmits plenty of light, it cannot offer          of light transmission.                               Art Direction: Holger Giebeler
                                                                                       adequate insulation and is liable to                                                                     Typesetting/Layout: Profilwerkstatt
                                                                                       breakage.                                           The pros and cons of                                 Managing Editor: Martina Keller
                                                                                             PLEXIGLAS® double-skin sheets share
                                                                                                                                           PLEXIGLAS®                                           Printed by: Zarbock GmbH & Co. KG,
                                                                                       the high light transmission of glass, but                                                                Frankfurt
                                                                                       also have many other properties that are            PLEXIGLAS® double-skin sheets cost more              Printed on paper bleached without
                                                                                       particularly beneficial for greenhouses. With       than other materials, but the difference in          chlorine.
                                                                                       their very good heat insulation, superior light     price is made up for within only a few years         Photos:
                                                                                       transmission, excellent weather resistance,         by their durability, energy savings and              Degussa: Page 2 (top), 3, 4 and cover
                                                                                                                                                                                                Profilwerkstatt: Chart Cover
                                                                                       stability and impact strength, they combine         improved plant growth. In keeping with this          Van der Eijk: Page 2
Visible quality: on the left, conventional polycarbonate double-skin sheets show-      the crucial attributes required for growing         superior quality, the guarantee against loss
ing pronounced signs of weathering that let in less sunlight. Right: clear view with   plants. These double-skin sheets come in            of light transmission and against yellowing
PLEXIGLAS ALLTOP®double-skin sheets.                                                                                                                                                            Degussa’s Methacrylates Business
                                                                                       two variants: PLEXIGLAS ALLTOP ® SDP                has recently been extended to 30 years.              Unit is a worldwide supplier of
                                                                                       and PLEXIGLAS RESIST® SDP. PLEXIGLAS                Added to this is the ten-year hail resistance        PMMA semi-finished products sold
                                                                                       ALLTOP® double-skin sheets have the NO              guarantee for PLEXIGLAS RESIST® multi-               under the PLEXIGLAS® trademark
                                                                                                                                                                                                on the European, Asian, African and
                                                                                       DROP coating on both surfaces and inside            skin sheets.                                         Australian Continents and under the
                                                                                       the cavities. This coating causes water drops       PLEXIGLAS® quadruple-skin sheets offer               trademarks ACRYLITE® and DEGLAS®
                                                                                       to form a continuous thin film of water.            even greater energy savings because the              in the Americas.
                                                                                       Thanks to this water-dispersing effect,             added layers and air cushions result in bet-         ®
                                                                                                                                                                                                    = registered trademark
                                                                                       there are no reflections, and no water drops        ter heat insulation. But since they also
                                                                                                                                                                                                PLEXIGLAS® is a registered trademark
                                                                                       that can act as magnifying glasses. This            reduce the light transmission, they are only         of Röhm GmbH, Darmstadt, Germany.
                                                                                       special coating prevents dripping, makes            used where this property is not so impor-
                                                                                       condensation all but invisible and lets in          tant – say, for tropical plants that require a
                                                                                                                                                                                                This information and all further
                                                                                       plenty of light, including UV light. Plants         lot of heat but less light. sew                      technical advice is based on our
                                                                                       can therefore grow under natural lighting                                                                present knowledge and experience.
                                                                                                                                                                                                However, it implies no liability or
                                                                                       conditions. That is a decisive factor for many
                                                                                                                                                                                                other legal responsibility on our part,
                                                                                       gardening businesses, because UV light is                                                                also with regard to existing third party
                                                                                       particularly important for dark green leaves        www.plexiglas.de                                     intellectual property rights, especially
                                                                                                                                                                                                patent rights. In particular, no
                                                                                                                                                                                                warranty, whether express or implied,
                                                                                                                                                                                                or guarantee of product properties in
                                                                                                                                                                                                the legal sense is intended or implied.
                                                                                                                                                                                                We reserve the right to make any
                                                                                                                                                                                                changes according to technological
                                                                                                                                                                                                progress or further developments.
Right: The NO DROP coating applied on both sides and inside the cavities of
                                                                                                                                                                                                The customer is not released from
PLEXIGLAS ALLTOP® double-skin sheets causes water drops to form a continuous
                                                                                                                                                                                                the obligation to conduct careful
thin film. The sheets thus retain their high light transmission.
                                                                                                                                                                                                inspection and testing of incoming
Left: Double-skin sheets without NO DROP coating. Condensation obscures the
                                                                                                                                                                                                goods. Performance of the product
view and blocks out sunlight.
                                                                                                                                                                                                described herein should be verified
                                                                                                                                                                                                by testing, which should be carried
                                                                                                                                                                                                out only by qualified experts in the
                                                                                                                                                                                                sole responsibility of a customer.
                                                                                                                                                                                                Reference to trade names used
Overview of PLEXIGLAS® multi-skin sheets for horticulture                                                                                                                                       by other companies is neither a
                                                                                                                                                                                                recommendation, nor does it imply
                                                                                                                                                                                                that similar products could not be
                                                                   PLEXIGLAS ALLTOP®                  PLEXIGLAS RESIST®            PLEXIGLAS RESIST®               PLEXIGLAS RESIST®            used. (Status: May 2003)
                                                                   SDP 16                             SDP 8                        SDP16                           S4P 32
                                                                   Clear                              Clear                        Clear                           Clear
                                                                                                      NO DROP                      NO DROP                         NO DROP
  light transmission (%)                                                                   ca. 91                         ca. 84                        ca. 86                         ca. 76
  uV transmission                                                                            yes                             no                            no                             no
  Sheet thickness (mm)                                                                        16                              8                               16                          32
  cavity width (mm)                                                                           64                             16                               32                          32
  Sheet width (mm)                                                                          980                                                           980
                                                                                           1053
                                                                                           1200                            1200                          1200                           1230
  u-value (w/m²K)                                                                            2.5                            3.4                            2.5                            1.6
  energy savings as compared with                                                        40 – 50                          ca. 30                       40 – 50                         ca. 60
  single glazing (%)
  no dRoP coating                                                             on both sides and                    on one side                  on one side                     on one side
                                                                                  inside cavities
  alltoP grade                                                                               yes                             no                            no                             no
  hail guarantee                                                                              no                            yes                           yes                            yes
  Max. service temperature (°c)                                                               70                             70                               70                          70
  fire rating to din 4102                                                                     b2                             b2                            b2                             b2
  Gable-roof greenhouses                                                                     yes                            yes                           yes                            yes
  Venlo and wide-bay systems
  tunnel greenhouses                                                                          no                            yes                           yes                             no




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