Analysis of bubble failure in glassware production

Abstract: the causes of bubbles and stripes and poor whiteness in the production of glassware with suction feeding mode are analyzed, and the solutions are put forward

key words: glassware; Suction feeding; Defects

Shandong Huapeng Glass Co., Ltd. a production line kiln is an oil fired horseshoe flame tank kiln with a melting area of 11 ㎡. How to maintain the scroll spring fatigue testing machine? However, with the development of new consumption formats such as Internet ordering, the answer is to supply materials by suction and match a goblet production line. The forming process includes blowing, mullion drawing, mouth blasting, polishing and other processes

frequent bubbles and stripes are the main problems in production and the main factors restricting the improvement of product output and quality. Poor whiteness also has an important impact on product quality

1 cause analysis

1.1 formula design

in order to reduce production costs, we use sulfate as clarifier. Sulfate is generally shared with fluoride. Considering the corrosive effect of fluoride on refractory materials and molds, it was not introduced. Designed formula: the company has developed a silicone 3D printing technology, which is reductive, with a redox index of - 10.3, and iron mainly exists in fe2+ valence. Since the coloring ability of fe2+ is about 10 times that of Fe3 +, the amount of decolorizer is increased, resulting in poor transparency and low whiteness of the product

due to the absence of fluoride in the formula, there is no reaction between fluorine and iron to produce fef3 gas, which makes the temperature of some f too high, that is, stretching will not only burn the role of human body e2o3 discharged with exhaust gas, but also the amount of Fe2O3 has not been reduced, and the amount of corresponding decolorizer cannot be reduced, which is also a reason for the low whiteness of the product

1.2 melting rate

due to the low melting rate (generally 1.0T/m2 · d) and the long residence time of the feed liquid in the furnace, Fe2O3 can fully interact with the reducing agent, resulting in a large amount of fe2+

1.3 batching and transportation process

Fe2O3 introduced in batching and transportation process accounts for a large proportion in the finished product. The design Fe2O3 content is 0.028%, and the finished product analysis Fe2O3 content is about 0.05%. The introduction of Fe2O3 during batching and transportation leads to a corresponding increase in the amount of decolorizer and a decrease in whiteness and transparency

1.4 feeding mode

the bubble problem is closely related to the current feeding mode. After sucking and cutting, the material liquid is divided into two parts, one part is involved in forming, and the other part is reheated and returned to the material liquid. The temperature of this part of the material is higher than that of the surrounding material liquid. After sinking, it is re homogenized with the temperature of the lower material liquid

due to the low temperature of the working part (the space temperature of the working part is above 1200 ℃, and the temperature of the material liquid is only 1100 ℃. It is quite difficult to completely homogenize. This part of the material liquid returns to the suction point and mixes with the high-temperature glass liquid from the liquid hole to form the same material tire, resulting in the uneven temperature of the material tire exceeding a certain limit and forming stripes. The stripe distribution on the goblet basically confirms the above speculation.

the analysis results of Japanese experts on the stripes and their surrounding components are also not different, It is concluded that it is not caused by uneven composition

we have also melted products with stripes in muffle furnace at 900 ℃ for 2h, and observed the disappearance of stripes after cooling. Under this temperature condition, if the composition is uneven, it is impossible to eliminate the stripes, which also shows that the stripes on the product are caused by the uneven temperature of the feed liquid

in the above reheating process, the gas previously dissolved in the liquid glass is re precipitated due to the change of temperature, and bubbles are generated. Especially, sulfate is used as clarifier. Because sulfur has a variety of valence, the change of temperature is very easy to cause the change of valence, and also increases the chance of bubble formation

2 solution

2.1 change the formula

the introduction of fluoride in the formula design can reduce the Fe2O3 content in the feed liquid and play the role of melting aid and clarification. Change the clarifier, introduce NaNO3, and decolorize by combining chemical decolorization with physical decolorization. A small amount of Na2SO4 is introduced to further improve whiteness and transparency

2.2 transform the equipment

reduce the introduction of iron in the process of batching and transportation, and transform the manpower from the equipment, including transportation tools (forklift, broken glass trailer, feeding tractor, trolley, etc.), broken glass bin, mixing bin, hopper, shovel, mixer bottom plate, side wall, mixing paddle, feeder, etc. Methods such as adding engineering plastic liner and plating polyurethane on stainless steel are adopted

2.3 working part temperature control

to solve the problem of stripes and bubbles, maintaining the uniformity of working part temperature is the key. Although reference can be made to the feeding method of the chute so that the glass liquid participating in the molding is not recycled, it needs to change the kiln structure

in the current production cycle, in order to solve the problems of stripes and bubbles, we have properly adjusted the properties of the formula, appropriately increased the forming temperature of the working part, and reduced the temperature difference of the residual liquid in the working part, the supplementary liquid in the liquid hole, and the residual liquid in the suction. From time to time, the temperature of the working part is forced to be homogenized, and the hot spots are increased to make the glass melt temperature in the depth direction of the working part and even in the whole working part as consistent as possible

3 implementation effect

after the gradual implementation of the above series of measures, remarkable results have been achieved. The content of Fe2O3 in the finished product decreased to about 0.04%, and the whiteness and transparency of the product improved significantly. The influence of stripes and bubbles on production is greatly reduced

now, the average finished product rate of our company's utensils production line has reached more than 70%, reaching the production level of foreign countries, and the profit of over planned production has increased by 180000 yuan per month on average

(Zhao Shoujian, Zhang Huawu, Xing Yongsheng, Wang Zhengyi)