Selection of cosmetic hose materials

In the previous article, Yusu Packaging used a large section to focus on what plastic is good for producing cosmetic hoses. It concluded that among the same choices, PET plastic is one of the good materials for producing cosmetic hoses. However, PET is not the only material for producing hoses, nor is it the most common material. So here are some common cosmetic hose material choices:

The material of cosmetic plastic hoses is generally vinyl chloride monomer, a polymer polymerized by free radical polymerization mechanism under the action of initiators such as peroxides and azo compounds or under the action of light and heat. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively referred to as vinyl chloride resins. The material is a non-crystalline material. In actual use, PVC materials are often added with stabilizers, lubricants, auxiliary processing agents, colorants, impact agents and other additives. It has non-flammability, high strength, resistance to climate change 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 hose materials:

A. Hygiene of cosmetic plastic hose materials

First, the materials used must meet the relevant hygiene standards, and harmful substances such as heavy metals and fluorescent agents should be controlled within the specified range. For example, for hoses 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 hose materials

If the contents of the daily chemical enterprise packaging are some products that are particularly sensitive to oxygen (such as some whitening cosmetics) or the fragrance is very easy to evaporate (such as essential oils or some oils, acids, salts and other corrosive chemicals), then a five-layer co-extruded tube should be selected. Because the oxygen permeability of the five-layer co-extruded tube (polyethylene/bonding resin/EVOH/bonding resin/polyethylene) is 0.2~1.2 units.

The oxygen permeability of ordinary polyethylene single-layer tubes is 150~300 units. Within a certain period of time, the weight loss rate 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 and fragrance retention properties (the thickness is ideal at 15-20 microns). Double-layer tube: high-density HDPE and low-density LDPE are used in a certain proportion of the tube drawing method, and the mixing effect is achieved by high-speed rotation. This method can properly adjust the softness and hardness of the hose. Compared with the single-layer tube, the tube body is thicker, has better corrosion resistance and barrier properties, and lower oxygen permeability, and is adopted by many daily chemical cosmetics manufacturers.

C. Stiffness of cosmetic plastic hose materials

Daily chemical companies have different requirements for hose stiffness, so how to obtain the desired stiffness? The polyethylene commonly used in hoses 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 hose materials

High-density polyethylene has better chemical resistance than low-density polyethylene.

E. Weather resistance of cosmetic plastic hose materials

To control the short-term or long-term performance of the hose, factors need to be considered: appearance, pressure resistance/drop performance, sealing strength, environmental stress cracking resistance (ESCR value), fragrance and loss of active ingredients, etc.