The evaluation of casing quality is a systematic project. The following "14 items of quality evaluation" can be reasonably used as the basis for inferior evaluation.

1. Barrier of casing: refers to its barrier degree to oxygen, water vapor and aroma. Good barrier property can provide sausage with a long shelf life and shelf life, avoid return due to deterioration of sausage within the shelf life, and ensure that the freshness and aroma of sausage are not lost.

2. Rationality of casing structure: the reasonable structure design of casing can provide an ideal packaging for sausage.

3. Casing film strength: good mechanical strength can meet the requirements of various filling and punching machines, so as to reduce the loss of casing film in the process of use.

4. Stability of shrinkage rate: it refers to the consistency of the shrinkage rate of the same volume or batch of casings. If the shrinkage rate fluctuates up and down, it will cause uneven length and thickness of sausages of the same specification, which will bring you a lot of trouble in packing and sales.

5. Color uniformity: for the colored casing, the uniform color can win glory and color for the appearance quality of sausage, make it beautiful and attract the attention of consumers.

6. Casing opening: opening is very important for sausage filling. If the opening is not good, the casing and filling are laborious, which will directly affect the work efficiency of operators.

7. Specification accuracy: it means that the deviation of the folding diameter and thickness of the casing should be controlled within a strict range. On the one hand, inaccurate specification will lead to uneven thickness of the sausage, and excessive thickness deviation will also lead to bending of the sausage and performance degradation.

8. Casing film transparency: for transparent