Reasons for the decompression of 21 inner tube joints The de-sweating of inner tube joints is not sufficient when the joints of Shanhai Hu inner tubes are not enough. It is easy to pull and die when the curing is finished, which may cause the joints to disengage or burst. Butt joint adhesion is affected by both process and equipment factors.
(1) Unstable process dimensions of semi-finished products Due to incorporation of more than 30 times of returned rubber, unqualified rubber compound is used, mixing of rubber compound is not uniform, and the rotational speed of the head or conveyor belt is frequently adjusted during the tube extrusion process; the tire tube is not stored as required The storage time of the inner semi-finished products of the inner tube is not enough, so that the process size is long and stable, and it enters the next process. All of these will cause the size fluctuation of the inner tube process, resulting in uneven thickness of the tire tube and the size of the head and tail, resulting in uneven interface of the joint. Dislocation and internal adhesion make the joint easy to disengage and reduce the degree of joints. This condition is normal and is now partially unclear with the presser foot pattern of the inner tube joint.
The operating environment is not clean enough. There is talcum powder near the joint of the tire. When the electric knife cuts the rubber, the excess talcum powder is sprinkled on the cutting surface by cutting the impurities or talc powder on the glove that he or he operated. Causes the joint not to be dense, and the joint is easy to pull open when it is cured.
Electric knife temperature and speed mismatch Improper electric knife temperature is high and the speed is slow. The cutting surface of the plastic part of the cutting part is scorched and cut. It affects the joints. The speed of the electric knife is fast and the temperature is low. 1 knife. The part is wavy. The sound of the joint adhesive, said (4) improper control of the cutting tool distance from the cutter is too large, the cutting edge of the cutting edge left large, that is, docking, curtain contacts were people. Thickness increases. Causes the glue at the extrusion to turn upside down, and also presses the part that is not the cutting surface, thick, and easily breaks after the restoration is resumed; the cutting blade distance is too small, and the 7-inch joint extrusion thickness increases, which affects the joint strength. .
If the presser foot pressure is too large due to improper press control, the carcass at the joint is deformed and the inner wall of the tire is out of place, causing misalignment and internal adhesion of the joint. When the pressure of the presser foot is too low, the carcass is easy to move when 2 inches is connected, and the joint is not secure. , The connector is easily pulled open. In addition, due to the leakage of the pressure foot cylinder, the pressure on both sides of the presser foot is unbalanced, and misalignment easily occurs during docking, resulting in internal adhesion and affecting the joint strength.
Butt pressure is small and time is short Due to the low butt pressure, the docking time is short, the engineer of the rubber material interface adhesive co., Ltd., bachelor, is mainly engaged in tire process management.
In the state of mutual contact, the molecular gravitational force is reduced, the strength of the joint is not enough, the joint 4 is disengaged, and the rubber jaw is damaged during use. If it is not replaced in time, it will cause the joint machine to pass through the rubber mouth during docking. The extrusion force to the butt joint surface is not enough, so that the joint strength is locally small and the phenomenon of disengagement occurs.
2 Solutions Strict process management. The amount of returned rubber is not more than 30. The unqualified rubber should not be used. The compound must be mixed uniformly, and the extrusion process parameters should be controlled steadily to avoid uneven thickness of the tire due to frequent adjustments. It is forbidden for the operator to store the cylinder. Throw away the tires, keep the tires near the joints and the operator's gloves to a thousand. To avoid contamination and cutting, select a reasonable joint process parameters, specifically the following electric knife current 25 ± 5 low temperature and 80 ± 5 high temperature; electric knife speed 43581; cutting tool distance 1.
Answer time 384,8.
These process parameters can be slightly adjusted according to winter and summer. Summer can take a smaller value and winter can take a larger value. The inner tubes produced according to these process parameters, whose joint strength and tensile strength of the carcass are close to the national standards, have been changed to 87036.997 in time to replace the deformed electric knife damaged rubber jaws and cylinder seals.
National standard of the project autumn and winter joint strength MPa maximum minimum average tensile strength MPa upper mold lower mold average note selection of 88, and glue and use than 7030.
3 Conclusion Through the analysis of the reasons for the disconnection of the inner tube joints, corresponding solutions have been proposed in terms of process and equipment, which effectively prevent the inner tube joints from being uncoupled and improve the product qualification rate. According to statistics, the passing rate of inner tubes in 1999 increased by 1.0 compared with that of 1998, and it can increase profits throughout the year. 20 Received Date 2005 Nine highway construction investment and road network scale Nine highway construction investment has reached the highest level in history, and the scale of road network has expanded.
000 yuan, 5 times the period, is 2.73 times that of the Jiuyuan Investment Plan. In particular, since 1998, the country has made highways an important part of China-U.S. infrastructure. Three years of large-scale financial special funds have been allocated, and bank loans have been increased accordingly, creating favorable conditions for road construction. The investment in highway construction exceeded 200 billion yuan in 19982000 for three consecutive years.
It is estimated that by the end of 2000, the mileage of highways will exceed 1.38 million, and 9 new mileages will reach 220,000. Compared with the original plan, plus 13 national highways built by people in poor areas, the conditions for highway access in the central and western regions have been greatly improved. Basically eliminated the broken road in the national highway. The administrative villages of the country's 90 townships have access to highways, respectively, compared with the end, adding 1.9 and 10 percentage points. During the Ninth National Plan, the State decided to speed up the construction of the national trunk road, which will consist mainly of two important sections of vertical and horizontal lines. By the end of 2000, a total of 120001 coffee had been built on 7 roads, accounting for 72. The remaining 4,000 kilometers will be built in the tenth period. By the end of 2000, the proportion of highways reaching 15,000 highways will have reached 85,000 roads, which has increased from 8.4 in 1995 to 13.4. This has initially formed high-grade highway channels linking major cities and regions. Some of the economic developments in the more developed regions have started against the development of high-grade highway channels and high-grade highway networks.
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