Surface treatment industry

  The surface of plated products must be thoroughly pre-treated before plating. Degreasing and etching are indispensable processes, and some metal surfaces need to be thoroughly cleaned before treatment. APG is widely used in this area.

The application of APG in the cleaning and degreasing before and after metal coating and electroplating. Single-component surfactants have obvious residual after cleaning, which can not meet the requirements of pre-coating degreasing (artificial oil stain cleaning rate ≥98%). Therefore, to improve the performance of metal cleaning agents need to compound with Alkyl Polyglucoside. The clean effect of compounding by APG 0814 and isomeric C13 polyoxyethylene ether is more than that of compounding by AEO-9 and isomeric C13 polyoxyethylene ether. Researchers through a series test of screen and orthogonal experiment. Combined APG0814 with AEO-9, isomeric C13 polyoxyethylene ether, K12, and added inorganic bases, builders, etc. to obtain non-phosphorus degreasing powder of eco-friendly, which be applied in metal surface cleaning treatment. Its comprehensive performance is comparable to BH-11 (a phosphorus degreasing power) in market. Researchers have selected several highly biodegradable surfactants, such as APG, AES, AEO-9 and tea saponin (TS), and compounded them to develop an eco-friendly water-based detergency which used in the pre-process of metal coating. The research shows that APG C12~14/AEO-9 and APG C8~10/AEO-9 have synergistic effects. After the compounding of APGC12~14/AEO-9, its CMC value is reduced to 0.050 g/L, and after compounding of APG C8~10/AEO -9,its CMC value is reduced to 0.025g/L. the equal of mass ratio of AE0-9/APG C8~10 are the best formulation. Per m(APG C8~10): m(AEO-9)=1:1, the concentration is 3g/L, and added Na₂CO₃ as an auxiliary to compound metal cleaning agent, the cleaning rate of artificial oil pollution can reach 98.6%. Researchers also studied the cleaning capability of surface treatment on 45# steel and HT300 gray cast iron, with high clouded point and cleaning rate of APG0814,Peregal 0-10 and polyethylene glycol octyl phenyl ether nonionic surfactants and high cleaning rate of anionic surfactants AOS.

the cleaning rate of single component APG0814 is close to AOS, slightly higher than Peregal 0-10; the CMC of the former two is 5g/L lower than the latter. Compounding with four kinds of surfactants and supplemented with rust inhibitors and other additives to get an efficient and environmentally friendly room-temperature water-based oil stain cleaning agent, with a cleaning efficiency of more than 90%. Through a series of orthogonal experiments and conditional experiments, the researchers studied the effect of several surfactants on the degreasing effect. The significant order is K12>APG>JFC>AE0-9, APG is better than AEO-9, and work out the best formula is K12 6%, AEO-9 2.5%, APG 2.5%, JFC 1%, supplemented with other additives. The oil removal rate of oil stains on metal surfaces is over 99%, eco-friendly and biodegradable. Researchers choose sodium lignosulfonate with strong detergency and good biodegradability to mix with APGC8-10 and AEO-9, and the synergy is good.

  Aluminum alloy cleaning agent. Researchers have developed a neutral cleaning agent for aluminum-zinc alloys, combining APG with ethoxy-propyloxy, C8~C10 fatty alcohol, fatty methyloxylate (CFMEE) and NPE 3%~5% and alcohol, additives, etc. It has the functions of emulsification, dispersion and penetration, degreasing and dewaxing to achieve neutral cleaning, no corrosion or discoloration of aluminum, zinc and alloy. A magnesium aluminum alloy cleaning agent has also been developed. Its research shows that the isomeric alcohol ether and APG have a synergistic effect, forming a mixed monomolecular adsorption layer and forming mixed micelles in the inner of  solution, which improves the binding ability of the surfactant and the oil stain, hereby improving the cleaning ability of the cleaning agent. With the addition of APG, the surface tension of the system gradually decreases. When the addition amount of alkyl glycoside exceeds 5%, the surface tension of the system does not change much, and the addition amount of alkyl glycoside is 5% preferably. The typical formula is: ethanolamine 10 %, Iso-tridecyl alcohol polyoxyethylene ether 8%, APG08105%, potassium pyrophosphate 5%, Tetrasodium hydroxy ethyldiphosphonate 5%, sodium molybdate 3%, propylene glycol methyl ether 7%, water 57 % ,the cleaning agent is weakly alkaline, with good cleaning effect, low corrosiveness to magnesium aluminum alloy, easy biodegradation, and environmental friendly. When the other components remain unchanged, the touch angle of the alloy surface increases from 61° to 91° after the isotridecanol polyoxyethylene ether is replaced by APG0810, indicating that the cleaning effect of APG0810 is better than the former. 

In addition, APG has better corrosion inhibition properties for aluminum alloys. The hydroxyl group in the molecular structure of APG easily reacts with aluminum to cause chemical adsorption. Researchers have studied the corrosion inhibition effects of several commonly used surfactants on aluminum alloys. Under the acidic condition of pH=2, the corrosion inhibition effect of APG (C12~14) and 6501 is better. Its order of corrosion inhibition effect is APG>6501>AEO-9>LAS>AES, among which APG, 6501 is better.

The amount of corrosion of APG on the surface of aluminum alloy is only 0.25 mg, but the others three surfactant solutions 6501, AEO-9 and LAS is about 1~1.3 mg. under the alkaline condition of Ph=9,the corrosion inhibition effect of APG and 6501 is better. Besides under the alkaline condition, the APG presents the feature of concentration effect.

In the NaOH solution of 0.1mol/L, the effect of corrosion inhibition will increase step by step accompany with the increase of concentration of APG until to reach the peak (1.2g/L),then with increase of concentration, the effect of corrosion inhibition will be fall back.

Others, such as stainless steel, foil cleaning. Researchers developed a detergency for stainless steel oxide. It is composed of 30%~50% cyclodextrin, 10%~20% organic acid and 10%~20% composite surfactant. Mentioned composite surfactant are APG, sodium oleate,6501(1:1:1), which has better effect of cleaning oxide. It has the potential to replace the cleaning agent of stainless steel oxide layer which is mainly inorganic acid at present.

A cleaning agent for foil surface cleaning has also been developed, which is composed of APG and K12, sodium oleate, hydrochloric acid, ferric chloride, ethanol and pure water. On the one hand, the addition of APG reduces the surface tension of the foil, which is helpful for the solution to spread better on the surface of the foil and promote the removal of the oxide layer; on the other hand, APG can form foam on the surface of the solution, which greatly reduces the acid mist. To reduce the harm to the operator and the corrosive effect on the equipment, Meanwhile, the intermolecular chemical adsorption can adsorb the organic activity in certain areas of the surface of foil small molecules to create more favorable conditions for subsequent organic adhesive bonding process.