Sikaflex PRO-3 Purform is a 1-part, moisture curing, elastic polyurethane sealant. It seals many kinds of joint configurations in floors and civil engineering structures. The elasticity is maintained over a wide temperature range and high mechanical and chemical resistance provides good durability.

Sikaflex PRO-3 Purform can be used for the following horizontal and vertical interior and exterior joint sealing applications:

• Food industry
• Clean rooms
• Warehouse and production floor areas
• Sewage treatment plants
• Tunnels
• Car park decks
• Pedestrian and traffic areas
• Saw-cut joints

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• Features & Benefits
• Surface Preparation
• Application Notes

Features & Benefits

   
• 1-part, moisture curing, elastic polyurethane sealant
• High movement capability: ±25 % (ISO 9047), ±50 % (ASTM C719)
• Fast development of mechanical properties - High mechanical resistance
• Extended application range to lower temperatures
• High chemical and fuel resistance
• High resistance to weathering
• Non-staining to a wide range of substrates Monomeric diisocyanate content <0.1 %: no user safety training needed (REACH restriction 2023, Annex XVII entry 74)
• Bubble-free curing Good adhesion to many construction materials

Surface Preparation

Important Notes:

• Bituminous, natural rubber or EPDM rubber substrates
  • Do not use the Product on any building materials which might leach oils, plasticisers or solvents that could degrade the sealant
• Primers are adhesion promoters and not an alternative to improve poor preparation / cleaning of the joint surface
  • Note: Primers also improve the long term adhesion performance of the sealed joint

Substrate Testing:

Note: Adhesion tests on project specific substrates must be performed and procedures agreed with all parties before full project application. For more detailed advice and instructions please contact our Technical Department on 0113 2455450 (option 2) or send a message to [email protected].

• The substrate must be sound, clean, dry and free of all contaminants such as dirt, oil, grease, cement laitance, old sealants and poorly bonded coatings which could affect adhesion of the sealant
• The substrate should be of sufficient strength to cope with the stresses induced by the sealant during movement
• Removal techniques such as wire brushing, grinding, grit blasting or other suitable mechanical tools must be used
• Repair all damaged joint edges with suitable Sika repair products
• All dust, loose and friable material must be completely removed from all surfaces before application of any activators, primers or sealant. Where joints in the substrate are saw cut
• After sawing, all slurry material must be flushed away and joint surfaces allowed to dry

For optimum adhesion, joint durability and critical, high performance applications such as joints on multistorey buildings, highly stressed joints, extreme weather exposure the following priming and/or pre-treatment procedures must be followed:

Non-Porous Substrates

Aluminium, anodised aluminium, stainless steel, galvanised steel, powder coated metals, or glazed tiles:

• Lightly roughen the surface with a fine abrasive pad
• Clean and pre-treat using Sika® Aktivator-205 applied with a clean cloth

Other metals, such as copper, brass and titanium-zinc:

• Lightly roughen the surface with a fine abrasive pad
• Clean and pre-treat using Sika Aktivator-205 with a clean cloth
• Wait until the flash off time has been achieved
• Apply Sika Primer-3 N by brush

PVC Substrates:

• Clean and pre-treat using Sika Primer-215 applied with a brush

Porous Substrates:

• Prime surface using Sika Primer-3 N applied by brush

Concrete, aerated concrete and cement based renders, mortars and bricks:

• Prime surface using Sika Primer-3 N applied by brush

Reconstituted, cast or natural stone:

• Preliminary trials must be carried out to check if the stone experiences plasticiser migration. For a suitable primer to prevent plasticiser migration, contact our Technical Department on 0113 2455450 (option 2) or send a message to [email protected]

Asphalt (ACC. TO EN 13108-1 AND EN 13108-6)

• Fresh cut or existing cut asphalt must have a clean bonding surface with minimum 50% exposed aggregate
• Prime surface using Sika Primer-3 N applied by brush

Note: For more details of the primer or pre-treatment products refer to the individual Product Data Sheet.

Application Notes

IMPORTANT: Strictly follow installation procedures - Strictly follow installation procedures as defined in Method Statements, application manuals and working instructions which must always be adjusted to the actual site conditions.

IMPORTANT: Swimming pools - Do not use to seal joints in and around swimming pools.

IMPORTANT: Exposure to alcohol during curing - Do not expose the product to alcohol containing products during the curing period as this may interfere with the curing reaction.

• Apply masking tape where neat or exact joint lines are required
• Remove the tape within the skinning time of the Product after finishing
• After the required substrate preparation, insert a backing rod to the required depth
• Prime the joint surfaces as recommended in substrate preparation
• Avoid excessive application of primer to avoid causing puddles at the base of the joint
• The Product is supplied ready to use. Prepare the end of the foil pack or cartridge, insert into the sealant gun and fit the nozzle
• Extrude the Product into the joint ensuring that it comes into full contact with the sides of the joint and avoiding any air entrapment
• IMPORTANT - Do not use tooling products containing solvents. As soon as possible after application, tool the sealant firmly against the joint sides to ensure adequate adhesion and a smooth finish. Use a compatible tooling agent such as Sika® Tooling Agent N to smooth the joint surface

Over-painting the sealant

• Note: The product can be over-painted with most conventional paint coating systems. However, paints must first be tested to ensure compatibility by carrying out preliminary trials (according to the ISO technical paper: Paintability and Paint Compatibility of Sealants)
• Optimum results are obtained when the sealant is allowed to fully cure first
• Note: non-flexible paint systems may impair the elasticity of the sealant and lead to cracking of the paint coating
• Depending on type of paint used, plasticiser migration may occur causing the paint to become surface ‘tacky’

Colour variations 

• Note: Colour variations may occur due to the exposure in service to chemicals, high temperatures or UV-radiation (especially with white colour shade)
• This effect is aesthetic and does not adversely influence the technical performance or durability of the product