1. Features of cosmetic plastic hose
At present, the commonly used plastic hoses in cosmetic packaging mainly include aluminum-plastic composite hoses, all-plastic composite hoses and plastic co-extruded hoses, which can meet various requirements of cosmetic packaging, such as hygiene and barrier properties.
1. Aluminum-plastic composite hose
Aluminum-plastic composite hose is a kind of packaging container made of aluminum foil and plastic film through a co-extrusion composite process, and then processed into a tube by a special pipe-making machine. Its typical structure is PE/PE+EAA/AL/PE +EAA/PE. Aluminum-plastic composite hose is mainly used for packaging cosmetics that require high hygiene and barrier properties. The barrier layer is generally aluminum foil, and its barrier property depends on the pinhole of the aluminum foil. With the continuous improvement of technology, the thickness of the aluminum foil barrier layer in the aluminum-plastic composite hose has been reduced from the traditional 40μm to 12μm, or even 9μm, which greatly saves resources.
The aluminum-plastic composite hose has the following advantages during use.
(1) High barrier properties. Aluminum foil has barrier properties such as light barrier, oxygen barrier, and water barrier. On the one hand, it can prevent foreign substances from intruding into the cosmetics, prevent the cosmetics from oxidizing and deteriorating, and at the same time can prevent the moisture or flavors in the cosmetics. The ingredients diffuse to the outside through the hose to ensure the quality of the cosmetics.
(2) Low cost. To achieve the same barrier properties, aluminum-plastic composite hoses use less materials, lower cost, and are more economical than all-plastic composite hoses and plastic co-extruded hoses.
2. All-plastic composite hose
All-plastic composite hoses are made of plastic components, and are divided into two types: all-plastic non-barrier composite hoses and all-plastic barrier composite hoses. The all-plastic non-barrier composite hose is generally used for the packaging of low-grade and fast-consuming cosmetics; the all-plastic barrier composite hose is usually used for the packaging of medium and low-grade cosmetics due to the side seams in the pipe manufacturing. The barrier layer can contain EVOH, PVDC, and oxide coatings. Multi-layer composite materials such as PET. The typical structure of all-plastic barrier composite hose is PE/PE/EVOH/PE/PE.
The advantages of all-plastic composite hose are as follows:
Environmental protection. Compared with aluminum-plastic composite hoses, all-plastic composite hoses use economical and easy-to-recycle all-plastic sheets, which can reduce environmental pollution from packaging waste. The recycled all-plastic composite hoses can be produced after reprocessing. Relatively low-end products.
(2) Diversified colors. According to the characteristics of cosmetics and different consumer needs, the all-plastic composite hose can be made into different colors, such as colorless and transparent, color transparent, color opaque, etc., which brings strong visual enjoyment to consumers. In particular, the transparent all-plastic composite hose can clearly see the color state of the contents, giving a strong visual impact, and greatly promoting consumers' desire to buy.
(3) Good resilience: Compared with aluminum-plastic composite hoses, all-plastic composite hoses have better resilience, which ensures that after squeezing cosmetics, the hose can quickly return to its original shape and always maintain a beautiful, The appearance of the rules. This is very important for cosmetic packaging.
3. Plastic co-extrusion hose
The plastic co-extrusion hose utilizes co-extrusion technology to co-extrude materials of different properties and types together to form one-time molding. Plastic co-extrusion hoses are divided into single-layer extrusion hoses and multi-layer co-extrusion hoses. The former is mainly used for fast-consuming cosmetics (such as hand cream, etc.) that require high appearance and low actual performance requirements. Packaging, the latter is mainly used for the packaging of high-end cosmetics.
The main advantages of plastic co-extrusion hoses are as follows:
(1) Because there is no side seal, the appearance effect is better than that of composite hose, which is necessary for high-end cosmetic hose packaging.
(2) According to the different extrusion dies, various shapes of extruded hoses, such as oval, square, etc., can be produced to meet the needs of different consumers.
4. Analysis of the shortcomings of various plastic hoses
The three plastic hoses for cosmetic packaging mentioned above all have their own shortcomings.
(1) Due to the use of aluminum foil, aluminum-plastic composite hoses have many disadvantages, such as invisible content, poor environmental protection, poor resilience, lower composite strength than all-plastic composite hoses, and easy delamination.
(2) The barrier properties of all-plastic composite hoses mainly depend on the type and thickness of the barrier layer material. Taking the all-plastic composite hose with EVOH as the barrier layer material as an example, to achieve the same barrier properties and stiffness, its cost It is about 20% to 30% higher than aluminum-plastic composite hose. For a long period of time in the future, this will become the main factor restricting the full replacement of aluminum-plastic composite hoses by all-plastic composite hoses.
(3) The production and processing technology of plastic co-extruded hose is generally to make the tube first and then print. For the printing process, the efficiency is low, the process is complicated, and the process is difficult.
Second, the advantages of plastic hoses commonly used in cosmetic packaging
The plastic tube is hygienic and convenient to use, and the surface is bright and beautiful, so it has been widely used in the packaging of cream cosmetics, such as facial cleanser, hair conditioner, hair dye, toothpaste and other products in the cosmetics industry, as well as the pharmaceutical industry Packaging of creams and ointments for external use.
The plastic tube packaging is economical and convenient, easy to carry, even if the high-strength squeezing is carried out, it can still be restored to its original shape and maintain a good appearance. The data shows that 60%~70% of the hoses are used in the cosmetics industry, 10%~15% of the hoses are used in the pharmaceutical industry, and about 5% are used in the food industry. Therefore, how to better realize the design concept of the product through the tube packaging, strengthen the decorative effect of the tube packaging, and attract the attention of consumers more quickly and fit the brand temperament has become an important issue for end users to think about.
3. Product structure of plastic hose packaging
The main part of the plastic hose includes a tube shoulder, a tube (body) and a tube tail. The tube part is often decorated by direct printing or self-adhesive labels to carry text or pattern information and enhance the value of product packaging.
At present, the decoration of the hose is mainly realized through direct printing and self-adhesive labels. Among them, direct printing includes screen printing and offset printing. Compared with direct printing, the advantages of self-adhesive labels include: printing diversity and stability: traditional extruded hoses usually use offset printing and screen printing in the process of tube-making and then printing, while self-adhesive printing can use letterpress , Flexo, offset printing, silk screen, hot stamping and other diversified combined printing processes, the difficult color performance is more stable and excellent.
Fourth, the reasonable choice of plastic hose
In the cosmetics industry, packaging quality is the second life of products. According to the characteristics of cosmetics and sales situation and other factors, choosing suitable plastic hoses as packaging can make cosmetics more attractive under the high-quality packaging.
1. Hygiene and safety
Cosmetics are in direct contact with the human body, which imposes high hygiene and safety requirements on their packaging. For plastic hoses, it should be controlled from the aspects of raw material safety (raw material particles must comply with relevant laws and regulations, such as FDA, SGS certification, etc.), production process, production environment, etc., so as to ensure the hygienic safety of the cosmetics inside.
Packaging materials should have sufficient mechanical strength, a certain degree of barrier properties, chemical resistance, weather resistance, etc., to prevent cosmetics from causing quality problems during filling, storage and transportation.
(1) Mechanical properties. The main function of packaging is to use its mechanical properties to ensure that the contents are not damaged. The mechanical properties of plastic hoses for cosmetic packaging, such as compression resistance, impact resistance, bending strength, etc., are mainly determined according to the nature of the packaged product, packaging machinery, and storage and transportation requirements. Generally speaking, plastic hoses must have a certain degree of stiffness to ensure that the overall shape of the product is intact; at the same time, they also need to have good resilience to ensure that they can return to their original shape after being squeezed. However, under the same material composition and the same thickness, stiffness and resilience are a pair of contradictions. Only when both are taken into consideration can the needs of customers be met.
(2) Barrier performance. Commonly used barrier materials for plastic soft for cosmetic packaging include aluminum foil, EVOH, oxide-coated PET and nylon, etc. The barrier properties vary depending on the selected material and thickness. For example, aluminum foil has high barrier properties. When the thickness of aluminum foil is more than 25μm, its barrier performance can reach 100%; the barrier property of EVOH to oxygen is proportional to its thickness, and the oxygen permeability of 15μm thick EVOH is about 0.3~0.4cc/m2 ·24h (mocon detection method); the oxygen transmission rate of PET with oxide coating is generally 0.2～1.0cc/m2·24h (mocon detection method). Therefore, materials with different barrier properties should be selected according to the requirements of the packaged cosmetics. In addition, the interaction between fragrance and packaging materials should also be considered. For example, polyolefin materials absorb essential oils. At this time, a protective coating can be added between the aluminum foil and the polyolefin materials.
(3) Chemical resistance and weather resistance. The material selected for the plastic hose for cosmetic packaging should have resistance to chemical corrosion of the contents, including oil resistance, grease resistance, acid resistance, etc. The matrix resin can be optimized according to actual conditions and needs to meet the requirements of use, such as HDPE It has better chemical resistance than LDPE.
The weather resistance of the plastic hose is related to the temperature resistance, dimensional stability, environmental stress cracking resistance and other factors of the material used. Only by ensuring the short-term or long-term performance of the plastic hose can the quality and safety of cosmetics be guaranteed. For example, some cosmetics are suitable for use in the cold winter. If the plastic hose uses conventional materials such as PP, a series of problems such as failure in the drop test and tube burst may occur. This is because the glass transition temperature of PP is about -10°C. , It is brittle and fragile at low temperature. At this time, it is necessary to adjust the formula structure of the plastic hose and use toughened materials to improve the impact strength of the plastic hose.
In order to facilitate printing and packaging operations and adapt to mechanized operations, plastic hoses for cosmetic packaging should have good printability, heat sealability, and packaging machine suitability.
(1) Printability. From a printing point of view, aluminum-plastic and all-plastic composite hoses have more advantages than plastic co-extruded hoses. Because the aluminum-plastic and all-plastic composite hoses are made of different materials through the extrusion process, the tube is made after the slitting and printing process, or the film after the inner printing is extruded and slitted. The tube is made later; and the plastic co-extrusion hose is made of the tube first and then printed, which will inevitably lead to the complexity of the printing process.
(2) Heat sealing performance. The heat-seal performance includes two indexes: the initiation temperature and the heat-seal strength. Especially for some temperature-sensitive cosmetics, it is required that the temperature of the tube tail welding and sealing should not be too high. At this time, some low-temperature heat-sealing materials can be used for the heat cover to ensure the welding and sealing under low-temperature conditions that do not affect the quality of the cosmetics. When filling cosmetics, the contents may contaminate the seal. Plastic hoses processed with general materials cannot be sealed well. However, if the thermal cover is made of anti-pollution materials, this problem can be effectively solved.
Among the aluminum-plastic composite hoses, the unit price of aluminum foil is the highest, and controlling the thickness of the aluminum foil can effectively control the cost of the hose. Therefore, under the premise of ensuring good product performance, using thinner aluminum foil, reducing losses in the production process, and using simplified packaging as much as possible can reduce the cost of aluminum-plastic composite hoses.
At present, the cost of all-plastic composite hoses is relatively high. On the premise of not affecting various properties, reducing the thickness is also one of its future development directions. As a result, materials with high stiffness (such as PP, etc.) will be increasingly used in all-plastic composite hoses.
In order to reduce the printing cost of the plastic co-extruded hose and take advantage of its appearance (no edge seal), a new hose structure has been formed. The structure is to cover the transparent plastic co-extruded hose on the outside of the printed composite hose through a special process, so that the printed pattern inside is clearly presented in front of consumers, while maintaining the excellent properties of the plastic co-extruded hose. Feel.
5. Prospects for future development trends
In recent years, more and more cosmetics manufacturers have begun to pay attention to environmental protection issues, and green packaging will become a trend. At present, the aluminum-plastic composite hose is still the main packaging material for high-barrier products, which consumes a lot of resources and is very difficult to recycle. Replacing aluminum foil with barrier materials such as EVOH and SiOx coating films can not only achieve high barrier properties, but also can be recycled, but its high cost limits its wide use. On the other hand, the development and application of biodegradable plastics has alleviated environmental problems to a certain extent. The NatureWorks polymer produced by NatureWorksLLC in the United States is a polylactic acid resin that can be used to process various types of plastics and packaging, and has good biological properties. Degradability.
At the same time, multi-layer composite hoses with protective, functional and decorative properties will seize more markets in the future. Multi-layer co-extrusion hoses will gradually replace single-layer co-extrusion hoses. The protection is further enhanced. In addition, the use of advanced technology to minimize the visibility of plastic hose joints and make the plastic hose look more beautiful will also be one of the development trends in the future.