ST12 Polyurethane Sealant

Description ST12 is a one-component adhesive and sealing compound of permanent elasticity.It is based on a special moisture-cured polyurethane with an accelerated curing time. Uses ST 12 is widely used for sealing all joints for buildings. Moving joints: *Precast concrete *Balcony wall column *Bridge cantilever *Retaining wall *Underground subway Filling joints *Windows and doors *Any curtain wall gap except glass walls *Parapet wall *Wall/floor joints *Shutter House Advantages *Excellent adhesion with former cleaned sealant *Single Component, ready-to-use *Excellent performance,easy to use *High adhesion strengthwith all base materials *Fast cure rate. *Light weight construction material *Good weathering resistance and high durability. *No pollution *Can be painted. Instructions for use Surface preparation Keep surface clean. Clean all dirty, dust, loose particles and paint. Joints can be cleaned by compressed air. The filling material in the joints must be polythene.Priming Use specified primer on concrete and porous surface. Application *Stick protecting adhesive tape on both sides of the joints. *Insert filling materials. *Use the sealant with manual caulking gun or aerodynamic caulking gun. Horizontal seal can be finished by spatula. *Smooth with synthesized cleaner mixed by clean water if necessary. *Tear off the protecting adhesive tape befor the sealant is curing. *Clean all the tools after operating. The curing materials can be only cleaned by machinery methods. Joint design For the successful sealing of joints with ST12, it is essential that the following guidelines on joint configuration are observed: General Use: for joints up to 10mm wide, width to depth ratio=1:1 for joints over 10mm wide, width to depth ratio=2:1 To ensure that the correct width to depth ratio is achieved and to provide a firm backing against which the sealant can be tooled off and also to prevent the sealant from adhering to the bottom of the joint, the space under the ST12 must be filled with a tight fitting,non-rotting,non-absorbent backing material ,such as closed cell PE backer. Expansion joint design criteria: for joints up to 10mm wide, width to depth ratio=1:1 for joints from 10mm to 40mm, width to depth ratio=1:0.5 Note:1. For the corners of the concrete joint are usually very fragile,they must be made bevel or concave. 2The bottom of the joints should allow the deformation of the sealant,or it will cause damage after the joints are put to use. 3The sealed depth of the joints should be altered by inserting suitable backing materials. Technical Data (Typical) ST-12LM ST-12MM ST-12HM Colours Gray,White,Black Density 1.30-1.40kg/L Tack free time 45-120mins, depending on weather Curing Rate ≥2MM/24h Hardness,Shore A 20±5 30±5 40±5 Modulus100% Elongation <0.4MP 0.4-0.6MPa >0.6MPa Tensile Strength ≥1.2 Mpa >1.8 Mpa >2.4 Mpa Elastic Recovery >70% >70% >80% Elongation at break >800% >800% >800% Tearing Strength >8N/mm >11N/mm >11N/mm Application Temperature 5-40 Service Temperature -40-+80(maximum 50 in hot water) Shelf life 9 months stored dry below 30 unopened in original containers Packaging : 400ml or 600ml unipac per carton of 20.