difference between glass cosmetic bottles and plastic cosmetic bottles & tubes

Glass cosmetic bottles and plastic bottle & cosmetic tubes can be reused and are inconvenient to carry, but there are phenomena of unclear cross-contamination and unstoppable counterfeiting.

Compared with glass cosmetic bottles, plastic cosmetic bottles and tubes have a larger permeability coefficient to oxygen and carbon monoxide. It will cause a chemical reaction between the packaged object and the packaged product, and the packaged product will also deteriorate due to oxidation. The aging of plastic cosmetic bottle & tubes products also affects the appearance quality, is not beautiful and practical, and pollutes the environment.

With the continuous application of new materials and technologies, PC, PET, PEN, mixed materials of PET and PEN, as well as other new plastics such as PETG, have emerged. What are their advantages and disadvantages?

The advantage of PC is that it can withstand high temperatures above 120°C and has high mechanical strength, but it is expensive and has poor gas barrier properties. It has gradually withdrawn from the field of skin care product packaging. According to reports, there are now improved PCs being re-launched on the market.

PEN has good heat resistance and gas barrier properties, UV resistance, and can withstand pasteurization and high-temperature immersion temperature. Its service life can exceed 6 months. It is light in weight, but high in cost, which limits the scope of PEN's popularization and use. 

So PET appeared, but because it is not resistant to high temperatures, it is suitable for cold sterilization skin care products, because the sterilization skin care products use membrane filtration technology and do not undergo pasteurization or high temperature instantaneous sterilization. But it can't block the penetration of gas well, not only the low carbon dioxide content, but also easy to make skin care products cyanide deterioration, and its application is greatly limited. However, PET is the earliest developed, largest output and most widely used polyester product.

PET can easily be quickly cooled to obtain PET products that are basically amorphous, highly transparent, and easy to stretch. Therefore, when used as a packaging material, PET can be made into two-way stretch packaging film or non-standard cosmetic bottles and tubes. The blank obtains a stretch blow molded cosmetic bottle with high strength and high transparency, which can also be directly extruded or blow molded into a non-stretched hollow container.

PET film has the properties of transparency, oil resistance, fragrance retention, sanitation and reliability, and wide use temperature range (both high-temperature steaming and freezing packaging can be used), especially for stretch plastic cosmetic bottle molding, and the most application is tens of milliliters to 2 liters. There are also large cosmetic bottles and tubes with a capacity of 30 liters.

In cosmetic packaging, the most successful application is that cosmetic bottles and tubes have accounted for 1/3 of the total number of PET cosmetic bottles and tubes. In 1998 alone, PET cosmetic bottles and tubes accounted for 57.4% of China's plastic packaging. As early as 1995, Japan used more than 30,000 tons of plastic packaging bottles and tubes, accounting for 13% of the total consumption of PET cosmetic bottles and tubes. Data show that in 2000, the sales of PET cosmetic bottles and tubes in Japan rose from 220 million to 250 million. In the five years from 1995 to 2000, PET cosmetic bottles and tubes rose from 15% to 36%.

Germany generally adopts PET cosmetic bottle blow molding technology suitable for cosmetics and skin care products, and the instantaneous output can reach 1200 cosmetic bottles and tubes/mold. Moreover, it has good environmental protection and energy saving characteristics. The energy consumption of production is only 41% to 64% of that of glass cosmetic bottles and tubes. If it is further recycled and reused, its energy consumption can be reduced by about 50%. If the output of skin care products exceeds 20 million tons as the base, approximately 25 to 30 billion skin care cosmetic bottles and tubes (including recycling) can be consumed. Even if it is partially replaced, the demand for PET cosmetic bottles and tubes will reach 60 in the next few years. 10,000 to 650,000 tons, unlimited business opportunities.

Due to the poor heat resistance and gas barrier properties of PET, its application in hot cans and where high air tightness is required is limited.

To solve the problem of poor heat resistance, people have developed three types of practical heat-resistant polyester cosmetic bottles and tubes through research; heat-set new cosmetic bottles and tubes, which can meet the filling requirements of 85℃; PET/PEN alloy cosmetic bottles and tubes, PEN heat-resistant It has high performance and can be produced on ordinary injection stretch-blowing equipment that meets the requirements of hot cans above 80℃. If it is heat-set, the hot filling temperature can reach above 90℃; it is made of heat-resistant polyarylate. Multi-layer composite cosmetic bottles and tubes to improve heat resistance.

To solve the problem of poor gas barrier properties, there are currently three main methods by cosmetic packaging manufacturers: one is multilayer composite, mainly PET, adding PEN and other materials with good airtightness to make a three-layer or five-layer cosmetic bottle; the other is to use special Treatment methods, such as coating the inner or outer layer of the PET cosmetic bottle with epoxy barrier layer, or performing plasma treatment; third, molding with other barrier resins, using PEN or copolymers or blends of PEN and PET as raw materials, both Improves the yin and heat resistance of cosmetic bottles and tubes. It can also be alkali washed and disinfected and reused, thereby reducing costs, because the first two methods have poor transparency, difficult recycling and processing, complex processes, and equipment requirements. Special problems, and although the air tightness is improved, but the heat resistance is poor, it can only be adapted to the occasion of aseptic filling.

The cosmetics packaging company introduced the PEN blend material, which is to mix 15% of PEN with 85% of PET, and after special processing, such as obtaining amorphous carbon from high-temperature plasma, and mixing a very small amount of amorphous carbon. Incorporated into the materials for plastic cosmetic tube packaging, its performance indicators are greatly improved, almost reaching the level of glass packaging and metal cosmetic packaging, and its packaging performance-price ratio is also better than that of glass cosmetic bottles and cosmetic plastic tubes. The new technology can increase the oxygen resistance of cosmetic bottles and tubes by 29 times and the barrier performance by 6 times.

At present, cosmetics packaging factories have developed a plastic that can replace glass cosmetic bottles and tubes. It is lightweight, strong, tough, not easy to break, and easy to make into various specifications and shapes.