At present, in domestic two-piece and three-piece canning and beverage production and filling processes, the used sealing machines are summarized in two main categories: multiple roll heads and single roll head sealing machines. Some of the frequently occurring defects are briefly described:
First, a multi-roll head sealer. Common multi-head sealing machines include: 4 heads, 6 heads and 8 heads. The production speed varies from 180 to 800 cans per minute. Due to its high speed and smooth operation, it is often combined with high-speed canning production lines and beverage canning production lines. Use, its common defects in production are as follows:
(a) the top of the wear: especially in the closure of the tin lid and lid, the top due to wear, (see Figure 1) will make its surface coating off, after the completion of the filling due to the influence of humidity, soon Corrosion occurs in the worn area. In severe cases, the bottom (or top) cover is damaged, so that a vacuum cannot be formed in the tank, which affects the quality and shelf life of the beverage.
Cause: The main reason is that the distance a between the upper end surface of the rolling head and the upper end surface of the first rolling wheel groove (see Fig. 2) is too large.
Figure 1 Figure 2
Adjustment method: Loosen the fixing bolt of the first roll-enclosing wheel, rotate the roll-sealing wheel to make it in full contact with the rolling head, then rotate the sealing wheel in the opposite direction, so that the value of the clearance a is: 0.1-0.15 mm, Then tighten the fixing bolts.
(2) Sharp and sharp openings appear at the top: In severe cases, the bottom cover or the easy cover can be cracked to make the sealant overflow from the crack. Cause: The side clearance between the second roll and the rolling head is too small. The gap b between the second roll and the nipple must be increased to 1.30 ± 0.1 mm. (See Figure 2)
(3) The phenomenon of crooked tongues appears at the lower edge of the edge: At this time, at the position of the vertical tongue, the body hook and the cover hook are not overlapped, or the overlap amount is very small, and the overlap rate cannot be achieved.
There are two main reasons for this:
1. In the case that the bottom cover is intact: First, the cap feeder is not synchronized with the cover turntable so that the card is deformed when the cover is dropped. At this time, the cap separation device should be adjusted according to the position of the cover cap turntable so that it can be operated synchronously to ensure that the capping cover is intact. The second problem is that the rolling head wears badly and the size becomes smaller, and it cannot fit well with the bottom cover. In this way, the slipping phenomenon occurs during the roll sealing, resulting in the final point and the groove of the roll-sealing wheel being too large toward the gap and cannot be completely overlapped. At this point should be replaced with new standards in the rolling head, re-adjust the gap with the roller with the gap, to achieve the desired sealing effect.
2, in the bottom cover deformation or damage, there will be different degrees of crooked tongue phenomenon.
Second, a single roll head sealing machine. At present, the most commonly used and most commonly used domestic ones are 4B2 type machines. The common problems are the high error on both sides of the cans after sealing, the inconsistent results on both sides of the sealing, the high overlapping rate of the large parts of the cans, or even no overlap, and the cans The high and small parts have a large overlap rate, and there are often piles of shoulders. Causes: Mainly tilting occurs when the bottom tray rises, resulting in uneven force distribution of the can body when it is rolled. At this point, the bottom tray or bearing must be replaced so that it can reciprocate up and down vertically to ensure that the tank body is evenly loaded.
In short, the above listed are just a few common defects and adjustment methods. Because the model, type, manufacturer, and accuracy of the sealing machine are all different, the problems that arise are also very different, so must be based on the actual situation in the production process, Make reasonable judgments and formulate reasonable solutions to the problems so that they can achieve the desired results.