Model Number

ST12

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 strength with 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 ST11, 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 ST11 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.

2、The bottom of the joints should allow the deformation of the sealant,or it will cause damage after the joints are put to use.

3、The 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
Modulus（100% 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.

Important Notes

*ST12 is best stored at temperature between 10℃ and 25℃ in dry areas. The storage temperature should not exceed 30℃ for extended periods.
*Use opened cartridges the same day.
*When applying sealant, avoid air-entrapment.

*When smooth the sealant, avoid liquid immerging into the sealant or the sides of the joints.

*Inadequate ventilation or deficiency of moisture can slower the curing rate.
*Joints in low humidity environments should be sprayed with a mist of water as soon as tooling off is complete to accelerate the curing process and minimise the risk of early movement cracks.
*Avoid water in 3 hours before curing.

*To get it’s best performance, don’t seal the joints totally. Please leave 1mm’s space of each side.

*If the joints must be sealed totally,please test the adhension and campatility.

*It’s not suitable for the concrete base smoothed by transparent paints.

*Silicone materials may do harm to the curing and adhension of the sealant.

*The color of the sealant will change when exposure.

*Do not apply when moisture-vapor-transmission condition exists from the substrate as this can cause bubbling within the sealant.

Handling Precautions

ST12 sealants are generally harmless provided that certain precautions normally taken when handing chemicals are observed.The uncured materials must not,for instance, be allowed to come into contact with foodstuffs or food utensils, and measures should be taken to prevent the uncured materials from coming into contact with the skin,since people with particulary sensitive skin may be affected. The use of protective clothing, goggles,barrier creams and rubber gloves is recommended. The skin should be thoroughly cleansed at the end of each working period either by washing with soap and warm water or by using a resin removing cream-the use of powerful solvents is to be avoided. Disposable paper towers, not cloth towers should be used to dry the skin. Adequate ventilation of the working area is recommended. In case of accidental eye or mouth contact,flush with water. Consult a doctor immediately.

Note: The above technical data and instructions are based on our current knowledge and experience. Please test before use to get best performance.