Consumption of Additives

The preceding discussion concerning the consumption of coumarin in a Watts-type solution can serve as a model in a general discussion on the consumption of additives in electrodeposition. 

To measure the increase or the decrease of a certain type of ion, which corresponds to contamination, wear or thinning (consumption of additives), it is necessary to determine even slight variations of concentration with high precision [125]. The efficiency and precision of the AAS method is... 

In the first instance we see that the efficiency is greater the fewer the irreversible processes involved in the cycle, for we have shown that these can only be reversed by the expenditure of additional work or heat e.g. by the consumption of additional fuel). A machine in which the loss by friction or by radiation or conduction of heat is excluded, that is to say, a machine which makes use only of reversible processes (see p. 88), will therefore have maximum efficiency. Although it is impossible in practice to exclude completely such losses of energy, we may regard the maximum efficiency of a reversible engine as an upper limit, which may be approached more or less nearly according to the skill of the engineer, but which can never be exceeded. The maximum efficiency is a quantity which is characteristic of each type of machine. 

The consumption of additives by incorporation in the deposit, removal with the plated object, or electrochemical reaction during the electroplating process requires careful monitoring and correction. 

Table 6.4 Various analysts estimates for annual consumption of additives ...

Several thousand different additives exist which can be added to plastic polymers in order to create compoimds to be used for specific plastic products. The use of additives is not evenly distributed among the different types of plastic PVC production alone accounts for 73% of the global consumption of additives by volume followed by 10% in PE and PP, and 5% in styrenics [37]. 

During the period of induction the polymer is not subject to significant changes in its properties. After the consumption of additives in combination with chemical and physical effects to the polymer, it comes to an accelerated aging of the plastic and may result in a dramatic loss in properties. 

The efficiency of the colloidal additives is due to the composite structure of the tribo-film (Figure 4.23). The friction reduction is associated with additive adsorbed layer. The antiwear action works via substitution wear of the tribochemical film, which is continuously regenerated from the additive adsorbed layer. The consumption of additive (apart from the initial adsorption on the whole surface) is selectively located in the sliding contact. 

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