[No.6/17] What differences are there in actual usability between VCI paper vs. Rust preventive oil? (Part-1)
In the previous column, I referred to the corrosion preventive effect. Let me compare mainly of the usability and usefulness this time and in the next column.
Please refer to Table 4. It indicates and represents desirable that the usability is highly evaluated as far as the black mark is put in the left side of the field of evaluation.
Although it is necessary to be clean the target metal products prior to coat with rust preventive oil and to pack with VCI paper, the extent and necessity are different and depend on both of them.
Both of rust preventive oil and VCI paper cannot be effective if dirt and foreign substance there, especially of such a nature that it easily let metal get rust, are left and stuck on the metal surface.
Although it is important to wash the target thoroughly, the action of removing dirt and foreign substance, which are simply stuck, can be expected by coating the targets with the oil in the case of rust preventive oil.
But, the said action cannot be expected even simply stuck in the case of using VCI paper.
The followings are subject that the dew formation is happened after using rust preventive oil and VCI paper.
When the dew formation was happened on the metal surface coated with the rust preventive oil, the effectiveness of using rust preventive oil would have been impaired as the condensed water would be sunk under the oil.
However, as far as VCI paper is used for packing, the corrosion preventive effect is continuously performed, which the VCI will solve out from, prevent the rusting and the paper itself will suck up the extra moisture against the condensed water.
As the third item, let me think about the time of using the protected metal products after finishing the role of rust preventive oil and VCI paper.
Although it may be different respectively how to use them, it is enough to simply remove the VCI paper used, prior to coating and plating.
But, it is necessary to degrease if rust preventive oil was used. It is often to wash for removing the contamination like trash etc. if the products were directly used in the assembly lines without painting. Even in that case, the burden on the cleaning solution is large if rust preventive oil was used, while such burden is small in the case of VCI paper.
As the last agenda, please imagine the burden when processing of the rust preventive oil and VCI paper after use.
The processing method is different depending on the nature of degreasing solution, as the rust preventive oil is solved into the degreasing agent during the degreasing work.
It is necessary to process under the effluent regulations in the case of alkaline degrease.
In the case of solvent degreasing, the measure for VOC (volatile organic compounds) and processing of solvent cannot be avoided.
On the other hands, you can simply discard as combustible waste when VCI paper is used.