If you are working on a processing or manufacturing industry, you must have come through a can making machine. This machine is designated for making cans have different machines integrated together to form a continuous production line. The production line begins by slitting process where a plate is cut into blanks. These blanks are then used for making the can body. After the body is made, necking and beading are done. Finally, there is a seaming process that is very crucial in can production. Can seaming involve joining the bottom part of the can to the rest of the can and sometimes joining the lid with can body.
The processes of seaming involve different operations, and at every single stage, one should be careful as it affects the general shape of the can. There are single and double seaming; double seaming involves several layers mechanically interlocked together to form a seam. As much as this process is smooth, there several factors that has to be taken into considerations. These are:
- Conformity of the can body with the bottom or lid specification
- The nature of the seaming machine
- The condition of seaming rolls
- Lifter pressure and other components
A problem arises when one of these factors is not kept in check. These will result in seam defects that are very common when using a can making machine. These defects normally cause leaking of cans thus allowing the external contamination or reduce in shelf life. Here are some of the common defects in seaming:
- Cover vee- this is a projection of a seam just below the bottom of a normal seam resembling the v-shape.
- Cover droop- this occurs at the bottom of the seam below the double seam. It is usually a small projection.
- Cut over-this normally happens at the top of the seam that is inside and is sharp
- Dead head-also called spinner, it is caused by chuck spinning making the seam to be incomplete
- Knocked down flange- this is a defect that occurs when the body and cover hook do not interlock due to a bent.
- False seam-this is a portion of the seam that is not hooked.
- Long body hook-this is when the body hook exceeds the required specification.
- Long cover hook- this is when the length of the cover hook exceeds the required specification.
These and many more are some of the defects that are common when using a can making machine during the seaming process. Ensure that you keep the condition of the machine and use the correct material to avoid these common defects.