Plastic Plating-Water And Electroplating

Plastic plating-Water and Electroplating.
Huizhou Boluo Tenglong Technology Co., Ltd. serves you wholeheartedly! Mainly engaged in plastic hydroelectroplating processing, with plastic injection molding processing, mold processing and so on!
1 understand the significance of water.
Water is the main component of electroplating solution, and electroplating is almost always carried out in aqueous solution. Although there are reports of non-aqueous solution electroplating (such as aluminum plating in glycerol, nano-semiconductor wire plating in dimethyl sulfoxide, semiconductor nano-alloy plating in acetamide-urea-potassium bromide melt), they are limited to laboratory research and have no industrial application. The solution consists of a solute and a solvent. Electroplating bath is a kind of aqueous solution, that is, water is used as solvent, and solute is other water-soluble components in the bath. There is no electroplating solution without water.
Water is closely related to pH, an important process condition of electroplating. If we do not understand the ionization characteristics of water, we do not know the origin of pH, and we cannot understand why it is necessary to control this important process condition and the essence of the important fault of coating coke.

2 the characteristics of water molecules.
Inorganic compounds can be divided into oxides, acids, bases, salts and other categories. Matter is made up of molecules, and molecules are made up of atoms, which are connected by "bonds". Water is actually an oxide of hydrogen. There are two kinds of hydrogen oxides: one is ordinary water molecule H2O, which is composed of one oxygen atom and two hydrogen atoms, and the other is hydrogen peroxide H2O2 (hydrogen peroxide), which is commonly used in electroplating, which is composed of two hydrogen atoms and two oxygen atoms. Hydrogen peroxide is unstable, easy to decompose into oxygen and water, and is oxidizing. It is often used to oxidize inorganic or organic impurities in electroplating. Its biggest advantage is that the generated water is a component of the plating bath and has no side effects.
The three atoms in the water molecule are not arranged in a straight line, and there is an angle of 104 °40 'between the two hydrogen-oxygen bonds. Due to the existence of this angle, the "center of gravity" of positive and negative charges in the molecule does not coincide: the end near the oxygen atom in the water molecule is negatively charged, and the end close to the hydrogen atom is positively charged, which makes the water molecule a "polar molecule". Electroplating books and periodicals often talk about "electrode potential", and the polarity of water molecules is an important reason for the generation of potential.
3 Ion product of water and pH.
In solution, substances in which molecules can be ionized into positive and negative ions are called electrolytes. Almost 100% ionized are called strong electrolytes, such as most acids, bases and salts added to the bath; only partially ionized and some in molecular form are called weak electrolytes, such as boric acid and acetic acid; almost non-electrolytes are called non-electrolytes that are almost non-ionized and exist mainly in molecular form.
The acidity and basicity of the solution has a great influence on the electroplating effect, and anyone engaged in electroplating must have a very clear understanding of the origin and meaning of pH.
4 electrolysis of water.
Since there must be more or less hydrogen ion H + and hydroxide ion OH-, in aqueous solution in any case, the positively charged hydrogen ion H + may also obtain an electron on the cathode surface and be reduced (chemically, the reaction in which electrons are obtained and the valence is reduced is called reduction reaction) as hydrogen atom (called active hydrogen atom, with strong reduction energy), and the valence is reduced from positive valence to zero valence. Two active hydrogen atoms are then combined to form a hydrogen molecule (escaping in the form of gas). If e-is used to represent electrons, the above reduction reaction can be expressed as:
H + + e-H, 2H "H2"
Similarly, negatively charged OH- may lose an electron on the anode and be oxidized (chemically, the reaction that loses electrons and the valence rises is oxidation). The formula is: OH-- e-OH, 4OH 2H2O + O2 (2).
The combination of (1) and (2) is the electrolytic reaction of water. When electrified, oxygen may be produced on the anode and hydrogen on the cathode. The essence of electrolytic oil removal is the electrolytic reaction of water.
5 the purity of water.
Ready-made water in nature always contains minerals and other impurities. For example, more or less impurities such as calcium and magnesium are dissolved in groundwater; the contaminated water is more impurity and more complex. Water with large amounts of calcium and magnesium is called "hard water". If it is used in zincate zinc plating, it will affect the quality of the coating.