Presaturated wipes reduce VOC emissions
European regulations require the reduction of VOC emissions, as they contribute to global warming. Presaturated solvent wipes is one solution that can be found in the market. As industrial companies have learned, the concept involves a number of other advantages.
EMILIE CHAMPAGNE TECHNICAL SUPPORT MANAGER, SOCOMORE
(Published on August-September 2010 – JEC Magazine #59)
Socomore has been manufacturing and developing speciality chemicals since 1970. For the past ten years, the company has been combining this knowhow with textiles for surface preparation and protection applications. In Europe, it has now launched presaturated non-woven solvent wipes that are ready for use.
The concept provides a way to comply with the 1999 European directive requiring a reduction in the emission of volatile organic compounds (VOC). A number of industrial sectors which are major consumers of solvents (for surface preparation before painting, bonding or sealing) have been searching for solutions. The use of wipes that are presaturated with solvents or other cleaning products is eco-friendly, safer for operators, and productivity boosting (Figure 1).
A gesture for the environment
The presaturated wipe system was designed to optimize the amount of solvent used for a given application (see Figure 2). The quality of the cleaning operation depends on the interaction between textile, solvent and contaminant. Cotton cloths are often made from recycled materials from various sources, with different fibres, weaves, thicknesses and sizes that lead to less consistent cleaning results. For non-woven wipes, the fibres, binding techniques, thickness and saturation rate are carefully selected to provide just the right quantity of solvent for the application, and the texture of the wipes remains consistently homogeneous.
Some customers have observed a tendency that people have, when not using presaturated wipes, to soak the cotton cloth with much more product than is needed. This can be due to the preconceived idea that the more product used, the more efficient the cleaning operation, or simply to the fact that the cotton absorbs more of the product than it releases. Some of the solvents used, e.g. methyl ethyl ketone (MEK) or acetone, are highly volatile, and because the cloths generally become soiled before all of the solvent is used up, the residual solvent evaporates into the atmosphere when the cloth is discarded.
In some cases (e.g. during customer trials), it was observed that the quantity of textile waste can be reduced by as much as 75% by using presaturated wipes instead of cloth. It is only logical that using the wipes – which not only are less saturated than cloths, but can be used more sparingly – also cuts down on VOC emissions. The use of less-volatile solvents than traditional solvents like MEK or acetone results in up to 80% lower VOC emissions. Diestone DLS is one of the recommended solvents for presaturated wipes. The table below compares acetone or MEK with Diestone DLS in terms of the surface area that can be cleaned with one litre of solvent, when used on cotton cloths or on presaturated wipes (Table 1).
| Tab.1: Cleaned surface by different solvents : comparison between cotton cloth and presaturated wipes performances |
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| Acetone or MEK | Diestone DLS | |
| Cotton cloth | 2-4 m² | 8-12 m² |
| Presaturated wipe | 7-10 m² | 30-40 m² |
| Viscosity at 25°C (Pa.s) |
Thixotropic paste | Thixotropic paste |
Greater safety for operators
VOC emissions are harmful not only for the environment because they contribute to greenhouse gas emissions, but also for the health of operators. The current regulations aim at reducing the user exposure to chemicals as much as possible. Besides contributing to this reduction, the use of presaturated wipes improves the working environment for operators by reducing the need to handle flammable products in workshops and warehouses. The wipes come in easily handled containers, which reduces the risk and associated cost of fire and contamination that can occur when a large drum is knocked over and solvents spill out all over the floor.
A source of productivity
Another advantage of presaturated wipes is the standardization of surface preparation steps. The wipes now constitute a leading product on automotive assembly lines, used to prepare surfaces before bonding things like monograms, windows, or labels.
| More Information | |
| Several solutions are currently available to decrease VOC emissions in surface cleaning and/or preparation: |
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| presaturated wipes, | low-VOC-emission solvents, |
| less volatile solvents, | VOC-free products. |
In a joint study carried out with manufacturers, a breakdown of consumption, cost and waste was established for each workstation, enabling Socomore to clearly define the exact type and size of wipe and quantity of solvent needed for each step. When crucial operations are standardized, the process depends less on the operator and becomes more reliable.
Quality improves and is more consistent. Aerospace manufacturers have clearly understood this and use approved wipe and solvent solutions for their critical cleaning operations. Presaturated wipes are ready for use at workstations, so they require no repetitive steps such as wipe cutting, folding or soaking, thereby saving considerable time on the production line (Fig. 3).
| AN INTERVIEW WITH EMILIE CHAMPAGNE TECHNICAL SUPPORT MANAGER, SOCOMORE |
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JEC Composites Magazine: What is the company’s view on its strategic launch of the presaturated wipes? EMILIE CHAMPAGNE : Our offer meets our customers’ fundamental requi-rements. It has proved to be a real success because it is technically efficient, reduces the consumption rate and the level of VOC emissions, makes the working environment safer, and improves process quality. It also meets the technical requirements for surface preparation before critical operations. As our Research & Development Manager Bernard Le Turdu says, “by endeavouring to be reactive and customizing the wipe cutting and presaturation processes for our individual customers, we reinforced our know-how”.
JCM: What about the future of wipes? E. C..: According to Martin Goibier, the development engineer in charge of wipes at Socomore, “in order to save time and comply with the REACH regulation (Registration, Evaluation and Authorization of Chemicals), the products used to saturate the wipes are becoming increasingly engineered, with integration of new properties into the cleaning and surface preparation steps. This is forcing us to find replacement solutions for a number of substances that are becoming restricted or even prohibited, such as hexavalent chromium. We are working on cleaning solutions that reinforce the adhesion properties of the surface, or VOC-free cleaners that are efficient even on highly contaminated surfaces”. |
Specific know-how
Presaturated-wipe technology draws on knowledge in cleaning products and non-woven textiles, and also on new skills in combining these. To take one example, the company recently launched a water-based wipe to remove uncured sealants.
Socomore concluded that combining a specific wipe with a given cleaning product can maximize efficiency, since the wipe actually contributes to make the cleaning product more efficient ( Fig. 4).
To determine the most appropriate textile, wipe size and cleaning product for any given customer, factors such as the customer’s needs, the specific application, the critical rate of the operation, the expected results, and environmental requirements must be taken into account.
