Frankfurter sausage is a type of sausage that originated in Frankfurt, Germany.  Many people call it " hot dog", For factory manufacturing, its production depend on some professional sausage making machines.

The processing of Frankfurter sausage typically involves the following steps:

1. Preparation of the meat: Grinding meat.  The meat used for Frankfurter sausage is usually a mixture of beef, pork, and sometimes bacon. The meat is trimmed of any excess fat and then ground to a fine texture.

2. Mixing: The ground meat is then mixed with spices, salt, and other ingredients. Common spices used in Frankfurter sausage include pepper, nutmeg, and garlic. 

3. Emulsification: The meat mixture is then emulsified, which means that it is finely chopped and mixed until it becomes a smooth paste. This is typically done using a machine called a bowl cutter or a chopper.

4. Stuffing: The emulsified meat mixture is then stuffed into casings, typically made from natural or synthetic materials. The casings are twisted at regular intervals to create individual sausages. Natural casing and collagen casing are the common casings for producing frankfurter sausage, and an automatic sausage production line combined of sausage stuffer and sausage tying machine can easy to finish the process.

5. Cooking: The sausages are then cooked, typically by poaching them in hot water or steam. This process helps to set the shape of the sausages and also cook them through. 

6. Cooling: After cooking, the sausages are cooled, typically by immersing them in cold water or placing them in a cooler. This helps to firm up the sausages and prevent them from shrinking.

7. Packaging: Once the sausages have been cooled, they are typically packaged for sale. Frankfurter sausages are often sold in vacuum-sealed packages or in cans.