Membranes and Waterbars

Technology  Characteristics  Applications  References  Innovations

Technology

Sika's product technology membranes and waterbars is used against rainwater for buildings and against leakage water in civil engineering. This technology offers a wide spectrum of special sealing solutions for technical applications, such as swimming pools, ponds, liquid-manure cisterns, drinking water reservoirs, oil and gasoline tanks, etc.

Since the material must be, primarily, compatible with hot-air welding, only thermoplastic plastics can be used. With respect to long life and durability, we mainly use plastified PVC and polyolefins (polyethylene PE, polypropylene PP and ethylene vinyl acetate copolymer EVA as well as alloys).

In manufacturing our plastic waterproofing sheets, we use the processes of calendering and extrusion/coextrusion. The first step of either process involves the homogenization of the ingredients into a plastic mass. This is achieved by means of a hot or cool mixer, followed by kneading through a BUSS kneader or a planetary roller extruder. Or the mass may also be precompounded. The pieces are then molded in the 2nd step by means of a calender bowl (calendering) or a sheet die (extrusion).

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Characteristics

Different characteristics and requirements are necessary for different applications. In general, when developing roofing sheets, we pay special attention to the following:

• Easy hot-air welding, broader welding windows and no effects on welding behavior as a result of UV radiation and heat during installation.
• Reliable mechanical properties in the temperature range from -40°C to +70°C. The same is true of cold-temperature stability, cold-folding, perforation, resistance to tearing and elongation at tear.
• The sheets are characterized by good weathering resistance, both in terms of exposure to artificial and natural atmospheric conditions, which ensures the longevity of these sheets.
• High degree of flexibility, i.e., low elastic modulus.
• Low vapor resistance. The roof membrane must be able to "breathe".
• High degree of fireproofing against flying sparks and radiating heat.

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Applications

Building construction:

Whenever flat roofs, low-pitched roofs, special designs, roof gardens or utility roofs need to be constructed, renovated or rehabilitated, our range of roofing sheets will prove to be a convincing solution - and best of all, architects or designers will not be restricted in their creativity. Sika-Trocal offers the following systems:

Civil engineering:
We develop plastic waterproofing sheets to be used in tunnel construction (both for drift and strip mining), which help prevent the infiltration of leakage and groundwater, which can be quite aggressive at times. This application requires such sheeting to have a long life of up to 100 years - a tremendous challenge in terms of the material.

Technical membranes:
Using brand names such as "Trocal" or "Mipoplast", Sika-Trocal offers a series of technical membranes, which can be adapted and customized accurately for individ-ual uses. The range of possible uses includes membranes for ponds, sheeting for swimming pools, applications in construction, drinking-water reservoirs, liquid-manure cisterns and lining for gasoline or oil tanks.

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References

Airport of Göteborg (Sweden), Administrative building for Philips in Eindhoven (Netherlands), Airport buildings in Munich and Cologne/Bonn (Germany), mailorder warehouse facility for Quelle Leipzig, Leipziger Messe GmbH (Germany), VW Seat Martorell (Spain), Synchroton in Grenoble, Cité de l'Europe in Calais, Piscine in Castres (France), FIAT Autopiste SASN Nardo in Lecce (Italy), General Motors in Vienna, Eurostar-Puch in Graz, "Airport Center" in Salzburg (Austria).

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Innovations

Our innovations of the past few years include:

• The development and marketing of the polyolefin-based roofing sheet "Futura".
• The development and marketing of the polyolefin-based sheeting "PECO" used in tunnels for drift and strip mining - highly praised by our customers for its flexibility and weldability.
• The development and marketing of a membrane used for lining drinking water reservoirs, based on a pure polyolefin alloy, which stands out for its excellent welding properties and meets the strict drinking water standards of Germany: the KTW recommendations for application of plastics in drinking water pipes and the DVGW W270 Recommended Practice (German Association of Gas and Water).
• The development and marketing of a TPU-based membrane used as lining for gasoline tanks.