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Basics · Quality · Mould · Three-point adhesion · joints requiring regular maintance
Basics
Sealants must adhere sufficiently to the joint edges in order to absorb the movement to be expected without losing their sealing function. We attach particular importance to ageing-, weather-, and chemicals resistance.
Four fundamental issues must be clarified before starting work:
* Compatibility with the material of the adherent surface
* Adhesion to the joint edges (use primer if required)
* The design type of the joint
* Application of the sealant (in accordance with the specifications of the manufacturer and the current state of technology, taking into account the applicable standards).
For more information refer to the literature published by IVD (“Industrieverband Dichtstoffe” - Association of the Sealants Industry)
Quality
Not every sealant is suitable for any application!
Therefore, there are a variety of special products for specifically defined applications. Even in case of identical systems, there are differences from product to product. The manufacturer exerts a decisive influence on the quality of the final product by determining composition and recipe. For you as a user this means that mere specification of the raw material basis does not define the mechanical or chemical properties of the final product.
Descriptions of material properties are available to the user in the form of Data Sheets prepared by the manufacturer. Due to different testing procedures and testing standards, it is hard or even impossible to compare the information provided in these sheets to other product data.
In order to acquire objective information on the quality of a sealant within a short time, we recommend to refer to the applicable standards (e.g. DIN testing standards, DIN-EN standards, ÖNORM, etc.). Comparisons on the basis of these standards are well founded and objective in any case.
Summary: When working with our tested products you buy safety and reliability. In the bottom line this means - no hassle with complaints, satisfied customers, and more profit!
For more information refer to the literature published by IVD (“Industrieverband Dichtstoffe” - Association of the Sealants Industry)
Mould
Mould fungus is a problem that affects all RTV-1 sealants available on the market. Therefore, our products contain fungicidal agents to make them mould-resistant, with the exception of sealants for applications where this is not permitted. However, the effect of the fungicidal equipment of these sealants decreases in the course of time.
In case of primary growth, the mould spores must find a nutrient substrate already in their first stage of development. However, this is not possible in sealants. This means that initially the mould does not affect the sealant itself but a layer of dirt on the surface of the sealant (e.g. textile dust, soap or grease residues). In most cases, mould fungus of a size just visible (black or yellow dots) can be removed from the surface of the sealant. Detergents containing chlorine are particularly effective for this purpose.
In case of secondary growth, the mould fungus has already penetrated the sealant which must be removed completely. Additional disinfection of the immediate surroundings of the adherent surfaces with a disinfectant solution has proven highly effective. In any case, the new seal must be made using a mould-resistant sealant containing fungicidal agents.
However, when taking any such countermeasures, it must be taken into account that they do not remove the root cause of mould formation. If no measures are taken or can be taken to fight the root cause (e.g. keeping a place dry, sufficient ventilation, cleaning with a disinfectant) it is only a matter of time for the first mould spores to develop to such a point that the mould fungus becomes visible.
For more information refer to the literature published by IVD (“Industrieverband Dichtstoffe” - Association of the Sealants Industry)
Three-point adhesion
In order to perform its function as a seal accommodating movement, the sealant must have the possibility to move. This is the case when the sealant section is in a position to yield to the drawing and pressing movements between joint edges. Therefore, it must be connected firmly to the lateral edges only. On the rear side, i. e. in the lower (rear) part of the joint the sealant section must remain freely movable. If this is not the case, the material is subject to excessive stress and cracks may occur in the sealant which may even lead to complete rupture.
Consequently, during sealing work, adhesion must be prevented in the rear part of the joint. In most cases, the depth of the joint is limited by back-filling material. This is a product to which the sealant will not adhere, e. g. section cords of closed-pore polyethylene (PE) or polyurethane foam (PUR). In some cases, the existing joint is not deep enough for this. Then, the substrate must be covered with foils (e.g. PE).
For more information refer to the literature published by IVD (“Industrieverband Dichtstoffe” - Association of the Sealants Industry)
Joints requiring regular maintenance
Definition according to DIN 52460:
A joint requiring regular maintenance is a joint exposed to strong chemical and/or physical effects. Its sealant must be checked at regular intervals and replaced if necessary in order to prevent consequential damage. The resistance of sealants is subject to limits which are not reached or exceeded under normal conditions of use.
The following must be taken into account:
A joint requiring regular maintenance is not subject to the same warranty as normal joint sealing work. Therefore, any such joint must be defined before starting work. It should be determined already in the offer for work which joint is to be considered a joint requiring regular maintenance. Subsequent notification of the customer in the event of damage is not a solution.
For more information refer to the literature published by IVD (“Industrieverband Dichtstoffe” - Association of the Sealants Industry)
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