The Delicate Nature of Vitamin C Vitamin C, also known as ascorbic acid, is a powerhouse ingredient in skincare, renowned for its antioxidant properties, ability to brighten the complexion, and stimulate collagen production.However, it's also a highly unstable compound. It's extremely sensitive to light, air, and heat.Once exposed to this substance, vitamin C will be quickly destroyed, lose its efficacy and become useless. Such decline not only prevents you from enjoying all the benefits brought by the essence, but may also cause side effects and skin discomfort.   The Advantages of Dark Glass Bottles Dark glass bottle (usually amber or brown in colour) act as a shield for Vitamin C serum. The dark glass bottle acts as a natural filter, blocking most ultraviolet (UV) and visible light. This helps to slow down the oxidation process that occurs when vitamin C is exposed to light, thus maintaining the stability and potency of the serum longer. In addition, glass is an impermeable mat...

1.Thickness measurement The precise thickness of each layer of a tube is fundamental to its performance. This test uses a micrometer or specialized thickness gauge to measure the actual thickness of each layer (from the inner barrier film to the outer printed layer), typically at five to ten points throughout the tube. The goal is to ensure compliance with design specifications. 2.Sealing performance test Heat Seal Strength (Tube End): Tube ends are sealed using heat during the manufacturing process. This test measures the force required to tear the seal. It ensures that the seal will not crack during extrusion, transportation, and storage. Standards generally require a minimum strength to ensure reliability. Torque Test (Tube End to Cap): This test evaluates the tightness of the connection between the tube end and the cap. A torque meter measures the force required to unscrew or tighten the cap, ensuring it is neither too loose nor too tight. Typical ranges vary de...