How does the material selection of cosmetic vacuum bottle affect the sealing performance?

Cosmetic vacuum bottles play a vital role in modern cosmetic packaging. Their core function is to protect the stability and effectiveness of product ingredients. Among many factors, the choice of materials plays a decisive role in the sealing performance of vacuum bottles.

Definition of sealing performance
Sealing performance refers to the ability of packaging containers to prevent the entry of external air, moisture and contaminants. Good sealing performance is essential for cosmetics, which can significantly extend the shelf life of products and prevent oxidation, degradation and microbial contamination of ingredients. Therefore, the selection, design and manufacturing process of materials directly affect the quality of sealing performance.

Analysis of material types and their characteristics
Common materials for cosmetic vacuum bottles include plastics, glass and metals. The physical and chemical properties of various materials directly determine their sealing effects.
Plastic materials: Common plastic bottle materials include polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET). The advantages of plastic bottles are that they are light, easy to shape and low cost. However, the air permeability of plastics is relatively high, especially in high temperature and high humidity environments, which may lead to the penetration of air and moisture, thereby affecting the sealing effect. Therefore, it is crucial to select high-quality plastic materials and reasonably design their thickness to improve their sealing performance.
Glass material: Glass bottles are widely popular for their elegant appearance and good chemical stability. Glass is generally better than plastic in sealing performance, almost airtight, and can effectively prevent the entry of air and moisture. In addition, glass materials have good compatibility with most cosmetic ingredients and can avoid reactions with products, thereby ensuring the purity and stability of products.
Metal materials: Metal bottles (such as aluminum bottles) are often used for aerosols and some pump bottles. Metal materials have excellent sealing performance and can effectively block the entry of air and moisture, and are particularly suitable for storing cosmetics that are easily oxidized. However, metal materials may react with certain cosmetic ingredients, so they usually need to be internally coated when used to improve their chemical stability.

Effect of physical properties on sealing performance
Sealing performance is not only affected by the type of material, but also closely related to its physical properties, including density, thickness, elasticity and temperature resistance.
Density and thickness: The density and thickness of the material directly affect its airtightness. Higher density and appropriate thickness can effectively prevent the penetration of gas and moisture. For example, thick-walled glass bottles generally have superior sealing performance, while thin-walled plastic bottles may fail to seal due to deformation under high temperature conditions. Therefore, in the design process of vacuum bottles, the thickness of the material should be reasonably selected according to the product characteristics.
Elasticity: The elasticity of the material has an important influence on its sealing ability during use. For example, some plastic materials may deform when squeezed by external forces, resulting in sealing failure. Choosing materials with good elasticity can enhance the fit between the bottle cap and the bottle body, thereby improving the sealing performance.