Double zero foil sticky phenomenon solve

2015/4/24 8:25:34

Double zero foil sticky phenomenon now contains two meanings: the mechanical properties of aluminum foil irregularities caused by peeling difficulties in the course requirements and foil surface degreasing adverse effects. Finished annealing process by improving and controlling their physical and chemical properties of oil rolling rolling process, adjusting the tension coil slitting parameters, eliminating the sticky foil defects. There are hard and soft aluminum foil production status by two, double zero foil mostly in soft annealed after use, soft annealed only to control the mechanical properties of aluminum foil, but also to eliminate the residual aluminum foil surface, get smooth and bright surface, and can Freedom started. Aluminum foil for different purposes, different levels of oil requirements, such as a composite with aluminum foil and foil capacitor surface may not have residual oil. But in recent years, requiring the user to raise the quality of double zero foil increasing. Aluminum foil sticky become one of the major defects, soft-state double zero foil sticky phenomenon mainly as follows: double zero foil feel "weak", the user process is not easy to maintain a flat plate; double zero volume layers of foil adhesions between serious form a "compaction" in unwinding process, stripping difficulties caused by aluminum foil is not working. Seriously affected the production and sales of aluminum foil.

Double zero foil sticky problem solving measures:

An annealing process improvement

1.1 pairs of zero principle finished foil annealing system usually double zero foil annealing purposes, first, in order to obtain a certain plasticity; the second is to get bright, clean and free of residual surface quality. In the past to develop double zero foil annealing finished the main consideration is the recrystallization temperature of pure aluminum foil and rolling oil distillation range. Because pure aluminum foil recrystallization temperature of about 240 ~ 260 ℃, aluminum foil rolling oil distillation range generally about 200 ~ 260 ℃, annealing process developed in the past, the annealing temperature is generally 300 ~ 400 ℃, annealing cycle 10 ~ 40h. This annealing system, due to high temperature, oil burning, carbon chain oxidative decomposition occurs film, foil cause pollution, resulting brown oil spots.

1.2 conventional double zero foil finish annealing process insufficient In recent years, a so-called low-temperature phase prolonged annealing process, the annealing temperature which is not lower than 280 ℃, annealing time up to 150h, but the effect of the double zero foil after annealing is not ideal. Whether double zero foil annealing temperature must be higher than the recrystallization temperature of pure aluminum foil? If less than the recrystallization temperature annealing, can meet the requirements of users? At low temperatures, degreasing effect how? How to master the annealing temperature and time, in order to ensure the mechanical properties of the surface quality are in line with the requirements must be answered by the test questions.

1.3 develop new annealing process is based on the main parameters of the annealing process is the annealing time, depending on the installed furnace capacity, width and roll diameter foil volume. Installed furnace capacity, roll diameter, the more wide foil, the longer annealing times. Should ensure degreasing effect under the premise of the annealing temperature as low as possible, without having to consider whether sufficient recrystallization of aluminum foil. Meet user requirements is the basis for the development of new annealing.

1.4 Application of the new effect annealing process for annealing the aluminum foil in the test circulating air oven. Taking into account the volume of aluminum foil to eliminate defects from the edge drum to slow heating, slow cooling, heating system using the ladder. According foil roll diameter and width of the test foil annealing holding time; depending on the annealing temperature to examine the mechanical properties of aluminum foil, aluminum foil degreasing properties and adhesion of the aluminum foil. Annealing test combined industrial production, selection box 10t circulating air oven, heating power 360kW, maximum heating temperature of 535 ℃. Aluminum alloy test state 1235-O, having a thickness of 0.006 ~ 0.007mm, roll diameter 300 ~ 500mm, a width respectively 350,460,520,787,920,1024,1216mm, according to the test specifications of the aluminum foil annealing time (heating + Insulation + cooling) of 30 ~ 150h, the annealing temperature is 180 ~ 300 ℃. Mechanical properties of aluminum foil, adhesion and detection methods of execution skim GB3198-1996 respectively Appendix E. Appendix C ~ Tensile test equipment for ZLD-10 electronic tensile testing machine. The results in Table 1, according to the test data, by analysis, to determine the industrial production of the annealing temperature below 250 ℃, the sticky foil can eliminate defects. Table 1 foil annealing temperature annealing results contrast / ℃ σb / MPa δ /% degreasing properties uncoiling 280 ~ 250 41 ~ 69 0.5 ~ 1.0 A grade easy adhesion 240 73 ~ 89 0.5 ~ 1.0 A grade L≤200mm 230 76 ~ 91 0.5 ~ 1.0 A grade L≤200mm 220 87 ~ 98 1.0 Class B.

2, the rolling process control

Through appropriate annealing process can achieve good degreasing effect, obtain surface clean and free of oil residue, no bonding, no oil spots, smooth and free to expand high-quality aluminum foil. But there is a premise that the performance of the oil and aluminum foil rolling process with rolling oil and additives, types and ratios must be appropriate. If the rolling step with a large amount of oil, then by the subsequent annealing step can not achieve good degreasing effect.

2.1 rolling oil control double zero foil surface residual hard state thickness of about 0.02 ~ 0.2μm. Surface residual capacity, composite aluminum foil will, printing and other refined processing produce difficulties. In actual production, should closely monitor the mill outlet side with aluminum foil surface oil, does not allow white with traces of visible oil, otherwise should be checked and adjusted bearing rollers roll is clear, anti-oil exports and rolled plate clean roller device -line parameters.

2.2 rolling speed control rolling speed is too fast, the film will be thicker foil surface, caused by the rejection splash with oil also increased, darkening the surface gloss foil, which will cause difficulties to the annealing process degreasing. Double zero foil finished finishing speed is not easy to over 500m / min, pass reduction rate is controlled at about 50%.

2.3 rolling oil and additives, physical and chemical properties of aluminum foil rolling oil in addition to cooling and lubrication, but also to ensure the foil surface brightness, volatile during annealing, rolling up to a certain reduction ratio, good oxidation stability, no foul smell. Rolling oil is generally a mineral oil base oil, a viscosity of (1.5 ~ 3.0) × 10-6m2 / s, the additive is a higher fatty acid, higher fat, and higher alcohols. Strong acids polarity of the molecules, the more strongly adsorbed film with an aluminum foil surface, at a higher annealing temperature, the oxidation film is decomposed carbon chain, causing contamination of the aluminum foil, resulting in a tan oil spots. Since oleic acid adsorption minimum concentration of 1%, so a small amount of oleic acid in the oil layer of rolling more firmly chemically adsorbed film can be formed on the surface of the aluminum foil, Moreover, oleic acid belonging to the unsaturated molecular structure, in the course of long-term use , and prone to oxidative deterioration, therefore, do not want to use a lot. Rolling oil temperature control is very important. With the increase of rolling oil, rolling oil thinning may be poor lubrication, the rapid increase in the rolling load, rolling speed, rolling oil severe rejection, sticky aluminum phenomenon increases. When using a fatty acid, fine powder is generated faster than alcohol or fat, based on this, it should be limited to the use of an excess of oleic acid.

3, slitting process control

Surface oil quality aluminum foil, except with the rolling process and quality control of the annealing process, but also with the process of cutting the degree of roll tightly. Since the aluminum foil roll in an annealing furnace is surrounded by hot air, the foil rolling oil between the layers need to escape through a certain gap, volatilized into a gas, such as aluminum foil rolls too tight, rolling oil volatile it becomes difficult. Production, control the double zero foil porosity is very important. Slitting operation, depending on the width of the material, the cut taper tension is between 6% to 32% to be adjusted to obtain a good degreasing effect.