Cosmetic plastic tube material

What is the general material of cosmetic plastic tube?

Cosmetic plastic tubes are generally made of vinyl chloride monomers, polymers that are polymerized by peroxides, azo compounds and other initiators or under the action of light and heat according to the free radical polymerization reaction mechanism. Vinyl chloride homopolymer and vinyl chloride copolymer are collectively referred to as vinyl chloride resin. The material is an amorphous material. In actual use, PVC materials often add stabilizers, lubricants, auxiliary processing agents, pigments, impact resistance agents and other additives. It has non-flammability, high strength, weather resistance and excellent geometric stability.

PVC has strong resistance to oxidants, reducing agents and strong acids. However, it can be corroded by concentrated oxidizing acids such as concentrated sulfuric acid and concentrated nitric acid and is not suitable for contact with aromatic hydrocarbons and chlorinated hydrocarbons.

Selection of cosmetic plastic tube pipes:

A. Hygiene of cosmetic plastic tube materials

First of all, the materials used must meet relevant sanitary standards, and harmful substances such as heavy metals and fluorescent agents should be controlled within the specified range. For example, for tubes exported to the United States, the polyethylene (PE) and polypropylene (PP) used must meet the US Food and Drug Administration (FDA) standard 21CFR117.1520.

B. Barrier properties of cosmetic plastic tube materials

If the contents of the packaging of the daily chemical company are products that are particularly sensitive to oxygen (such as some whitening cosmetics) or wtube fragrance is very volatile (such as essential oils or some fats, acids, salts and other corrosive chemicals), then Five-layer co-extruded pipe should be used. Because the oxygen transmission rate of the five-layer co-extruded pipe (polyethylene/bonding resin/EVOH/bonding resin/polyethylene) is 0.2 to 1.2 units.

The oxygen transmission rate of ordinary polyethylene single-layer pipes is 150 to 300 units. In a certain period of time, the weight loss rate test of the co-extruded tube containing ethanol is dozens of times lower than that of the single-layer tube. In addition, EVOH is an ethylene-vinyl alcohol copolymer with excellent barrier properties and fragrance retention (the thickness of 15-20 microns is the most ideal effect). Double-layer pipe: adopts high-density HDPE and LDPE low-density PE materials. The pumping method matched with the ratio of the tube to achieve a uniform mixing effect by high-speed rotation. This method can appropriately adjust the softness and hardness of the tube. Compared with the single-layer tube, the tube body is thicker and has better resistance. Corrosive barrier properties and lower oxygen transmission rate are adopted by the majority of cosmetics manufacturers.


C. Stiffness of cosmetic plastic tube material

Daily chemical companies have different requirements for tube stiffness, so how to obtain the desired stiffness? The polyethylene commonly used in tubes is mainly low-density polyethylene, high-density polyethylene, and linear low-density polyethylene. Among them, the stiffness of high-density polyethylene is better than that of low-density polyethylene, so the desired stiffness can be achieved by adjusting the ratio of high-density polyethylene/low-density polyethylene.

D. Chemical resistance of cosmetic plastic tube materials

High density polyethylene lower density polyethylene has better chemical resistance.

E. Weather resistance of cosmetic plastic tube materials

To control the short-term or long-term performance of the tube, it is necessary to consider factors such as appearance, pressure/drop performance, sealing strength, environmental stress crack resistance (ESCR value), fragrance and active ingredient loss.