SOLAR SOLUTIONSHIGH PERFORMANCE BONDING TECHNOLOGIES FOR CSP

GLOBAL BUT LOCAL PARTNERSHIP

SECURED MIRROR SYSTEMS WITHHIGH PERFORMANCE ADHESIVES

IT SEEMS THAT ADHESIVES are a minor part in the overall CSP system but in reality play a major role for the performance and durability of the mirror and CSP solution. As the adhesive technology bonds the mirrors to the fixation elements they secure the mirrors in the right place for service life of the system. If the adhesive system fails the mirrors may fall, break or the focus is out of target. Therefore the right adhesive selection, joint dimension and application process is crucial to secure the long term performance of the mirror and overall CSP system.

Next to the secured durability Sika provides adhesive solu-tions to optimize the production processes of bonding the fixation devices to the mirror systems. With different curing speeds and thixotropic behaviors of the adhesive technology Sika is able to offer solutions for every existing production process and process improvements.

The newest innovation Sikasil® AS-780 enables an immediate handling and packaging of the bonded mirror systems without the need for complex buffer zones, thanks to the exceptional initial green-strength. This simplifies the production process and eliminates large buffer zones which cause cost and poten-tial glass breakage.

BEST RECOMMENDED SIKA PRODUCTS FOR BONDING FIXATION SYSTEMS TO MIRRORSSikasil® AS-790 2-component ultra-fast curing Silicone adhesive

Sikasil® AS-785 2-component fast curing structural Silicone adhesive, meets EOTA ETAG 002

Sikasil® AS-780 2-component Silicone adhesive with high initial green-strength

Sikaflex®-552 1-component Polyurethane Hybrid with high initial strength

SECURED MIRROR SYSTEMS WITHHIGH PERFORMANCE ADHESIVES

CHOOSING THE RIGHT TECHNOLOGY

THE OUTSTANDING PERFORMANCE of Silicone adhesive technologies in regard to long term durability has proven itself over decades in the facade, insulating glass and other highly demanding industries. The major disadvantage of the Silicone technology so far was the initial green strength for fast handling which now belongs to history with the new innovation of Sikasil® AS-780.

Parameter Tapes Organic adhesives (e.g. PU or MS) Silicones (Sikasil® AS-780)

Surface tolerances Limited tolerance com-pensation. Completely leveled, parallel and smooth surface necessary

Good tolerance compensation

Good tolerance compensation

Pretreatment of surface Cleaning and often priming needed

Cleaning, possibly grinding and priming necessary

Mostly only cleaning or activating necessary

Automated application Comparatively difficult and high investment costs

Easily possible Easily possible

Contact pressure Defined high and well distributed joining pressure necessary

Low demand on joining pressure and pressure distribution

Low demand on joining pressure and pressure distribution

Correction on positioning Not possible Possible during processing time. Except when pre-fixation tapes are used

Possible during processing time

Curing (strength build-up) Immediate tack(100 % adhesion build- up after several hours)

Very fast curing sys- tems available. For in- line processing pre- fixation tapes needed

Immediate tack.No pre-fixation means needed

UV resistance Limited – good Limited – moderate Excellent

Temperature influence on properties

High influence. Decrease in mechanical properties under high temperatures

High influence. Decrease in mechanical properties under high temperatures

Marginal influence.Only minimal impact of temperatures (service temperature -40°C to 150°C)

Weathering resistance Limited Limited Excellent

CHOOSING THE RIGHT TECHNOLOGY KEY CHARACTERISTICS OF Sikasil® AS-780

Sikasil® AS-780 IS SPECIFICALLY DESIGNED to fit into the common production processes and cycle times of a CSP mirror system production. The high initial green strength of Sikasil® AS-780 allows the assembled mirrors to be handled within the cycle time for packaging without any need for complex buffer zones. To ensure a durable and structural bond under harsh environmental impacts, Sikasil® AS-780 has been tested under most severe conditions.

Sikasil® AS-780 shows an exceptional initial green-strength for short handling times compared to common fast curing two component silicones and this with longer mixer open time and pot life for increased freedom in process.

After different test conditions and cycles Sikasil® AS-780 remains at a high level of strength preservation. The failure pattern results in a 100% cohesion failure.

KEY PRODUCT BENEFITS Exceptional initial green strength and fast curing product Prompt handling and packaging within standard cycle times feasible

Elimination of any pre-fixation or complex buffer zones Simplified automation for in-line processes Highly durable and structural yet flexible bonding

SMOOTH INTEGRATIONTo facilitate the integration of this technology Sika supports you with comprehensive project support. Our technical en-gineering, test laboratories and system engineering teams assist you from construction consultancy to implementation and beyond. This might mean reviewing and advising on the most suitable systems for bonding, adhesive joint calcula-tions, material and system tests, consulting on best suitable application systems and equipment as well as training your staff with professional working instructions. All these wher-ever you are.

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Before ageing 1000 h 85°C

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Cycling -40°C to 85°C

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Salt spray(480 h)

Immersion 55°Cwater and UV

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Standard Fast 2CSilicone Adhesive

TECHNICAL PRODUCT DATA OF Sikasil® AS-780Base 2-component Silicone

Color Black

Snap time (CQP 554-1) 10 min approx.

Shore A-hardness (CQP 023-1/ISO 868) 50 approx.

Tensile strength (CQP 036-1/ISO 37) 2.4 N/mm² approx.

Elongation at break (CQP 036-1/ISO 37) 185% approx.

Initial green-strength 6 –7 g/cm² approx.

SIKA SERVICES AGTueffenwies 168048 ZurichSwitzerland

ContactPhone: +41 58 436 52 87Fax: +41 58 436 54 07www.sika.com/solar

SOLAR SOLUTIONSHIGH PERFORMANCE BONDING TECHNOLOGIES FOR CSP

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WHO WE ARESika AG, Switzerland, is a globally active specialty chemicals company. Sika supplies the building and construction industry as well as manufac-turing industries (automotive, bus, truck, rail, solar, wind power plants and facades). Sika is a leader in processing materials used in sealing, bonding, damping, reinforcing and protecting loadbearing structures. Sika’s product lines feature highquality concrete admixtures, specialty mortars, sealants and adhesives, damping and reinforcing materials, structural strengthening systems, industrial flooring as well as roofing and waterproofing systems.

GLOBAL BUT LOCAL PARTNERSHIP

FOR MORE SOLAR SOLUTION INFORMATION:

Our most current General Sales Conditions shall apply. Please consult the most current local Product Data Sheet prior to any use.

www.sika.com/csp