The quality of casing can be evaluated based on the following key aspects:

1. Casing Film Strength: Good mechanical strength is essential to meet the requirements of various filling and clipping machines, thereby reducing film breakage during operation.

2. Barrier Properties: This refers to the casing's resistance to oxygen, water vapor, and aroma. Superior barrier properties contribute to a longer shelf life, prevent returns due to spoilage before the expiration date, and help maintain the sausage's freshness and flavor.

3. Color Uniformity: For colored casings, even and consistent coloring enhances the visual appeal of the sausage, making it more attractive to consumers.

4. Structural Rationality: A well-designed casing structure provides an ideal package for the sausage.

5. Shrinkage Consistency: This indicates the uniformity of the shrinkage rate within the same roll or batch. Significant variations can lead to sausages of the same specification having inconsistent lengths and diameters, causing issues during packaging and sales.

6. Film Transparency: For transparent casings, high clarity is crucial for premium sausages. It allows consumers to clearly see the texture of the meat, boosting appeal and purchase desire.

7. Openability (Ease of Opening): Good openability is vital for efficient sausage filling. Poor openability makes mounting the casing on the horn and filling difficult, directly impacting operator productivity.

8. Dimensional Accuracy: The deviation in folded diameter and thickness must be strictly controlled. Inaccurate specifications can result in uneven sausage diameters, and excessive thickness variation may cause bending and performance issues.

9. Softness/Hardness Feel: A good hand feel facilitates use. Sausages filled in such casings have a fuller meat appearance. For molded hams, a softer casing helps achieve well-defined, smooth shapes, whereas stiff casings can lead to sharp edges and moisture release.

10. Film Gloss: A glossy appearance makes sausages bright and eye-catching on the shelf, easily attracting customer attention.

11. Meat Adhesion:

    • Refers to the film's adhesion to the meat, which helps reduce moisture purge and prevents deterioration in taste.

    • Also indicates the bonding strength between the different layers of the casing film, ensuring structural integrity and stable performance.

12. Roll Flatness: Reflects the uniformity of the film's thickness and provides an overall assessment of the product's quality.

13. Interlayer Bonding Effect: Refers to the adhesion between the layers of the casing film, which ensures a stable structure and consistent performance.

14. Packaging Seal Integrity: The outer packaging must be tightly sealed to prevent the casings from absorbing moisture. Sturdy boxes are necessary to protect the casings from damage, ensuring they are well-preserved.

While applying the casing might be one of the final steps in sausage production, overlooking its importance can lead to significant issues. Therefore, selecting the right casing requires comprehensive consideration. Choose high-quality casings with a good cost-performance ratio and ensure they are suited to the specific requirements of the sausage you are producing. Paying attention to correct usage methods will allow the casings to perform effectively and contribute to substantial economic benefits.