The core technology of steel drum manufacturing--triple seven-layer round curling

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The core technology of steel drum manufacturing--triple seven-layer round curling
Xi'an Machinery Research Institute Jing Zhiping
China's steel drum manufacturing technology has undergone a revolution in the last decade. Its logo is the extensive use of the triple seven-layer round crimping technology, resulting in a significant increase in the sealing strength of the steel drum. Since the "sealing strength" is the first of many technical performances of the steel drum, the triple seven-layer round crimping has to become the core technology of the steel drum manufacturing industry. In the mid-1980s, in the face of the serious threat of serious accidents caused by shipping accidents caused by steel drum packaging leakage, the international IMO standard "International Maritime Dangerous Goods Transportation Rules" made the 20th revision, which improved the sealing performance requirements of steel drums. Germany, the United States and other steel barrel technology advanced countries have eliminated the traditional two-layer five-layer flat-rolled steel barrel production process, and developed a new three-layer seven-layer round crimping manufacturing technology. The advent of this technology has increased the sealing strength of steel drums from the third and fourth levels of the International Maritime Dangerous Goods Transportation Regulations to the first and second levels, effectively reducing maritime safety accidents and affecting different risks. This wave of steel barrel production technology revolution has quickly spread to China's steel barrel manufacturing industry, which has triggered a nationwide change in the production technology of the double-layer five-layer flat-rolled side for the three-seven-story round-edged steel barrel production technology.
The three-layer seven-layer round crimping technology is reflected in the steel drum manufacturing process equipment as shown in the following table:
project
Double five-layer flat seam
Triple seven-layer round curl
Bottom cover pre-roller
The bottom cover has no pre-rolling process, no pre-roller
The bottom cover has a pre-rolling process, and there is a pre-roll (and glue) machine.
Bucket forming machine
The width of the barrel is small
The width of the barrel is large
Bottom cover composite die
The bottom cover blanking size and the hem width are small
The bottom cover blank size and flange width are large
Crimping machine
Crimping wheel groove section is rectangular
The groove curve of the crimping wheel is a circle, an involute or a spiral
Steel drum
The barrel section of the steel barrel is a double five-layer rectangle (Figure 1)
The steel drum has a three-layered and seven-layer circular section (Fig. 2).
The previous revisions of China's national steel drum standards reflect this technological advancement. China's "Steel Barrel" standard has four versions of "GB325-1964", "GB325-1984", "GB325-1991" and "GB/T325-2000". The 1991 edition of "GB325-1991" has been included in the three-layer seven-layer round-edged structural form. The test for the sealing strength of the steel drum includes the values ​​of the airtight test, the hydraulic test, the drop test and the stacking test. Provisions of the International Rules for the Transport of Dangerous Goods by Sea.
The former Soviet Union's national steel drum standards "ГOCT 13950-1991" and "ГOCT 5044-1979" are only included in the structural form of the double five-layer flat crimping and not included in the three-fold seven-layer round crimping structure; The test of seal strength is only included in the drop test, and the maximum drop test height required is 1.2 meters, which is lower than the 1.8 meters of the International Maritime Dangerous Goods Transportation Regulations. Therefore, according to the Chinese steel drum standard "GB325-1991" or "GB/T325-2000" steel drums, the sealing strength will be higher.
The central technology for steel drum manufacturing:

Round seaming with three-fold & seven-layer

XI'AN MACHINERY RESEARCH INSTITUTE Jing zhiping The industrial technology for steel drum manufacturing in China experienced a revolution during recent more than ten years. Its marking is extensive applications of the round seaming with three-fold & seven-layer For the steel period. Because the "sealing intensity" is premier one of many technical function for steel drum, as a result the round seaming with three-fold & seven-layer becomes the central technology for steel drum manufacturing. During the middle period of 80's Of 20 centuries, in the face of serious threaten from leaking of the steel drum-packing causing again and again fearful accidents in sea transportation, international IMO standard "The international maritime conveyance rule for dangerous goods" was made with the 20th time of revises. It increased the request about sealing function of steel drums. Many countries have advanced technology for steel drum manufacturing such as Germany , America etc. eliminated in succession traditional production technology about the flat seaming with two-fold & five-layer, turned step to develop new technique: the round seaming with three-fold & seven-layer. The creation of this technique increased grade of Sealing intensity for steel drums from third or four class to first or second class, prescribed by "The international maritime conveyance rule for dangerous goods", reduced the safe trouble in sea transportation effectively, and affect in the world is not trivial matter. This tidal The drum production spread to steel drum manufacturing spread to Chinese steel drum manufacturing industry very quickly, caused nationally changing from the flat seaming with two-fold & five-layer to the round seaming with three-fold & seven-layer, produced the leaps of Technical quality for steel drums production.

The alteration of crafts and equip for the round seaming with three-fold & seven-layer is shown as watch below:
Item
Flat seaming with
Two-fold & five-layer
Round seaming with
Three-fold & seven-layer
Pre-curling
Machine
No pre-curling working procedure,
No pre-curling machine
Have pre-curling working procedure, have pre-curling(and gum-spraying) machine
Drum-body
Forming machine
Width of flanging for
Drum-body is less
Width of flanging for
Drum-body is big
Pressing die for caps & bottoms
Size of material cutting and width of flanging for caps & bottoms is less
Size of material cutting and width of flanging for caps & bottoms is big
Seaming machine
Section of trough form for seaming wheel is rectangle
Section curve of trough form for seaming wheel is rotundity, involute or spirality
Steel drum
Section of seaming for steel drum is rectangle with two-fold & five-layer
(chart 1)
Section of seaming for steel drum is rotundity with three-fold & seven-layer
(chart 2)
The Chinese national standard for steel drums is revised time after time, incarnating this technique progresses. The Chinese national standard "Steel drums" has four editions: "GB325-1964", "GB325-1984", "GB325-1991" and "GB /T325-2000》. Among them in the "GB325-1991" published in 1991 year, the structure of round seaming with three-fold & seven-layer was already listed in it. And in the "GB325-1991" the avoided numerical Value such as the gas-sealing test, the hydraulic pressure test, the falling test and the piling up test, is equal completely to the prescript of "The international maritime conveyance rule for dangerous goods".
In the national standard for steel drums of former Soviet Union "ГOCT 13950-1991" and "ГOCT 5044-1979" was listed only in the structure of the flat seaming with two-fold & five-layer but no the round seaming with three- Fold & seven-layer, and in it was listed only the falling test for the drums testing of sealing intensity, but the requested falling test max. height is 1.2 m, it is lower than 1.8m that prescribed in "The international maritime conveyance rule For dangerous goods. As a result, if the steel drums produced according to Chinese national steel drum standard "GB325-1991" or "GB/T325-2000", their sealing intensity will be higher.

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