Introduction to the process technology of the American barrel industry

1. Overview of the barrel industry

The common feature of American barrel-making enterprises is that the product varieties are relatively single, the annual output is large, and the factory personnel are few. The typical five companies are shown in Table 1.

Factory name

product

Yield

Production line form

Number of people

Plant area

Van Leer

200 liter barrel

1.4 million / year

Vertical layout

240

29,768 m 2

Medium bucket

600,000/year

Convenient bucket

3 million / year

Triller

200 liter barrel

1.1 million / year

Vertical layout

60

Rusll Standly

200 liter barrel

650,000/year

Horizontal arrangement

100

BW Norton

5 gallon bucket

3000 hours

47

5,500 m 2

Meyers, Richmond

200 liter barrel

4600/hour

140

6048 m 2

Travel Trilla

200 liter barrel

700,000/year

48

7116 m 2

Meyers, Los Angels

5 gallon bucket

200 liter barrel

51

6528 m 2

2, barrel process

(1), steel plate cutting American barrel factory all use cold rolled coil and unwinding equipment. The unwinding unit consists of an uncoiler, a straightener, a measuring and guiding system, and a shearing machine to unwind, level and shear the coil. The precision of the barrel body after cutting requires a diagonal error of ±1 mm.

The unwinding unit of the bottom cover of the bucket is connected in series with the punching machine.

(2) The steel plate after the edging and shearing enters the abrasive machine through the automatic feeder, and the edging efficiency is generally not very good, but since it is a cold-rolled steel plate, the problem is not large. The conveying speed of the latest edging machine steel plate in the United States is stepless speed regulation. In addition, the rotation speed of the grinding wheel is also adjustable (2000~4000 rpm, applying speed regulating motor), and it is also equipped with 300 steel plates per grinding. The grinding wheel feeds a 3 inch (0.076 mm) device.

The grinding wheel is generally 1 inch wide and 2 inches wide when the plate is hot rolled. More specifically, a 4 inch wide grinding wheel with an arc-shaped abrasive cloth is used for the galvanized sheet.

(3) Welds Automatic seam welders have been widely used in steel mills in the United States, and most of them are produced by CARANDO Company of the United States. The automatic seam welding machine is composed of a coiling, a feeding barrel, a welding and a press equalizing mechanism. The winding round is still three rolls, and the rolled sheet is placed on the upper part by the baffle block, and then sent to the welding electric board by the barrel chain. At the wheel, the two parts of the electrode wheel separated by the Z-shaped groove are connected with the two stages of the transformer. After the welding, the weld is still in the red hot state, that is, the flattening roller is used to make the weld be smooth and compact.

The welding machine has two kinds of DC and AC. The DC welding has high power factor and is more energy-saving, but the cooling requirements are higher. The AC welding power factor is lower, it is more expensive, but the cooling requirements are lower. There are two types of welding machine clamping barrels, one is funnel-shaped, and it is positioned by 3~6 large concave wheels. It is suitable for single barrel type production. If the varieties are replaced, the wheels need to be replaced, which is more time-consuming and requires barrels. The size of the body is also stricter. The other type is a pleated type. The barrel body is fixed by two rows of inclined wheels and two pairs of pressing rollers. The characteristic is that the adjustment is convenient when the diameter is changed. The disadvantage is that if the adjustment is not good (the inclined wheel top is not real), it is easy to make Too small to form waste.

CARANDO's seam welder has adopted secondary rectification power supply in the power supply mode, achieving better electrical efficiency and stable welding current. As for the three-phase power supply products, it is reported that the power efficiency of the power frequency power supply is too low, and there is no mature product at present.

The main technical features of the 1424-1 automatic seam welding machine produced by CARANDO are: power supply mode: single-phase AC, power: 200 kVA, productivity: 900 pcs/hour, thickness of welded steel plate: 0.6~1.5 mm. The company's other types of automatic seam welding machines, the welding parameters for reference: secondary current 20,000 amps, secondary voltage exchange 4.97 ~ 8.7 volts, DC 2.93 ~ 5 volts.

In addition, the company also produces 1,200 / hour high-speed welding machine, using single-phase secondary rectification power supply.

(4), the flanging and the rib edging machine adopts the die extrusion method, the burring is uniform and the power is high, and the quality is better than the rolling method. The ribbing machine also uses a tapered structure to increase the ribs, and the two ribs respectively increase the ribs. Both machines are operated by mechanical (eccentric, connecting rod) and easy to maintain.

VANLEER and TRILL of the United States have adopted the CNC vertical forming production unit, which is a new multi-station special combination machine. The outstanding advantage of this unit is its high level of automation and process adaptability. It is controlled by the programmable controller of ALLEN-BRADLEY, USA. Modifications, adjustments to process parameters and some product specifications can be achieved with a few seconds of conversion control.

In addition, the vertical forming unit is designed to get rid of the traditional frame and adopt a more flexible transmission mechanism, such as DC servo motor, ball screw and groove wheel mechanism, which greatly reduces the motion inertia of the device. Low energy consumption, higher operating speed, the average production speed of each station can reach the level of 800 200-liter steel drums per hour. At the same time, the transfer between the stations changed the traditional way of horizontal production line chain transportation. The support type rigid conveyor belt was used to shorten the production line and the positioning accuracy was greatly improved. In combination with the process of crushing and trimming, the whole side was combined. A high quality barrel flange provides a reliable guarantee for quality closures.

(5) Some sealing and sealing machines adopt horizontal double acting, and the winding is still used with two wheels. The materials of the wheels and plates are alloy steel, which are used after heat treatment and grinding. The fillers in the sealing section are rubber-based emulsified fillers, and most of the fillers are sprayed at the time of sealing; they are also pre-sprayed, and then sealed after drying. When sealing, the coolant is often sprayed onto the sealing wheel to extend the service life.

In the United States, the standard 200-liter steel drum used for liquid dangerous goods packaging such as chemical industry generally no longer uses double-hem sealing, but mainly adopts circular curling with stress concentration phenomenon. Due to the superior mechanical structure of this type of crimping, it has strong impact resistance. When we visited TRILL in Chicago, we performed a 45° drop test for us. The height was calibrated to 2.4 meters, and the triple round curled There is no leakage or leakage in the steel drum.

The round bead used in the United States is mainly based on the triple crimping technology patent, and the bottom and cover are pre-rolled. The process of pre-spraying the sealing packing. The process of pre-rolling the bottom and the cover is to first pre-roll a bottom edge of the bottom of the bucket on a device, and then roll it into a barrel on the sealing machine.

Of course, this kind of crimping requires a higher size of the flange of the barrel, and the general width error should be controlled within ±0.25 mm, which is one of the important reasons for the extrusion molding into a form-flanging machine.

(6), the test leak test machine is not much different from the domestic use, but the horizontal ends have thread buckles, which can adjust the length of the test, in order to achieve alignment, which has not been used in China.

(7), surface treatment (degreasing, phosphating) After the barrel and the bottom cover of the barrel are formed, each factory is surface-treated, and both have phosphating parts. The equipment is tunnel type, generally degreasing, washing, phosphating , washing, drying and other parts, degreasing, phosphating, washing are spray-type, the transmission is a single row, chain drive. The barrel body and the lid of the bucket are treated in a centralized manner and are also treated separately.

The drying form is the same as the drying form of the inner and outer surfaces. The general drying length is equivalent to the length of degreasing, phosphating and water washing. The relevant parameters of the surface treatment process are shown in Table 2.

Table 2

Process

temperature

speed

Degreasing

160°F (71°C)

28? (8.53 m) / min

Washed

12? (3.66 meters) / minute

Phosphating

140°F (60°C)

32? (9.75 m) / min

Washed

12? (3.66 meters) / minute

Washed

140°F (60°C)

18? (5.49 meters) / minute

drying

(8), the inner surface spraying all spraying equipment has two types of horizontal and vertical, horizontal and domestic methods are not much different, the vertical type has not been seen in China, it is characterized by reducing the change of barrel position. The method is that the gripper lifts the bucket in place and ends the spray during the round trip. Spraying is done by airless spraying. In addition, two-coat one-baked or two-baked two-baked are more common. Drying mostly uses natural gas and is accompanied by hot air circulation. This method has a good drying effect. There is also a method in which a factory uses gas burning and open flame heating. This method is also used in France. It is estimated that the thermal efficiency is not as high as that of hot air circulation. See the use of air curtains, presumably use the hot air circulation method, it will effectively prevent the heat from dissipating.

The drying oven is generally designed to have a temperature of 350~450°F (176~232°C) and a baking time of 15 minutes.

(9) The outer surface painting adopts airless spraying method, and all the equipments are all horizontal spraying machines. This machine is different from the domestic mechanical spraying machine in that there are many spray guns. The barrel has three spray guns, and each side of the barrel cover There are two, and the number of spray guns can shorten the spraying time.

The outer surface painting drying oven can at least dry two rows of barrels, so that the heat consumption of the barrel can be reduced, the drying method is the same as that of the inner surface spraying, and the drying temperature of the polyester paint is 350 °F ( 176 ° C), time 10 minutes.

(10), India Iron and Steel VANLEER factory has three printing iron lines, respectively, printing large, medium and small barrels, of which 200 liters of barrel printing iron is rare. The iron printing machine is a color printing, so the barrel after the manufacture is very delicate, the printed iron plate is welded, the forming still does not fall off, and the surface treatment has no effect. Of course, the finished barrel also has the external coating process of the welded seam.

3. Material utilization

The American National Standard (ANSI MH2.1-1997) stipulates that different 200-liter steel drum bottom covers and barrels are made of different grades of steel. The bottom cover is 20 (0.823 mm or more) and the barrel is 18 (1.09 mm or more). This is a standard set from the concept of mechanical strength. It has great economic significance in material utilization. Each barrel can be used. Save 6.6% on steel.

In addition, the bottom cover blanking is made of wide-width coils, which are staggered, which greatly reduces the waste of scraps. It can save about 5.4% of the steel sheet by the blanking method of the original single-row row.

4, the coil assembly

For the assembly of the closed steel drum, the domestic factory is generally completed by the following three processes: 1. Punching; 2. Hole stretching; 3. Locking. In the United States, we have seen a special assembly mold supplied by the American Flange Company to the barrel factory, and the assembly of large and small coils is completed in one operation. The actual usage seen at Chicago's Qure and Houston Rasch Streis is very satisfying.

5, the application of filler

There are two main types of fillers:

(1), 740HS foaming type filler, produced by DAREX, molding conditions are 110 ° C, 13 minutes; each bottom cover is used 12.5 grams, using high pressure airless coating, the bottom cover rotation speed is 0.7 seconds / turn.

The filler used by companies such as Wanli and Quler in the United States forms an annular sealing gasket on the edge of the pre-rolling of the bottom cover of the bottom of the barrel to ensure the leakage resistance of the barrel.

(2) Latex filler mainly composed of synthetic rubber, the grade is DA-REX60, produced by WRGRACE, and the gelation condition is normal temperature. According to the results of on-site inspection, the success rate of sealing is above 99.9%, indicating that the above two fillers have mature experience in the United States, and its technical performance can be trusted.