China is the world's packaging manufacturing and consumption power, plastic packaging in the packaging industry, the proportion of total output value has more than 30%, as the packaging industry in the new force in the food, beverages, daily necessities and industrial and agricultural production in various fields play an irreplaceable role. In recent years, the plastic packaging industry packaging products, packaging materials, steady growth, packaging new materials, new technology, new technologies, new products continue to emerge.

Packaging is one of the main applications of plastic materials, especially for thermoplastic materials, the packaging industry needs and development, directly to change or guide the plastic materials manufacturing and processing technology development. In general, the current plastic packaging materials and products mainly in three aspects of the enormous pressure: First, improve product performance, such as increasing the transparency of materials and products, heat resistance, mechanical strength and barrier, and so on; The second is from the environmental protection of the pressure; third is to reduce the cost of pressure. The three aspects of mutual restraint, the result of interaction is that, in addition to individual occasions, only in these three areas to compromise materials and products have a great market space. However, demand will always lead to technological progress, and technological progress continue to create a quality and cheap miracle, many of the previous high price of materials, and now has been due to large-scale production costs caused by large-scale decline.

Packaging products are the main application areas

At present, China's plastic products to plastic film (including agricultural film), plastic wire and woven products, plastic pipe and daily plastic products. If the application to the division, the packaging supplies is one of the main areas of plastic applications. It is expected that by 2005, China's demand for plastic packaging products will reach 5.5 million tons, accounting for 22.0% of total demand.

From the main plastic varieties, in the field of plastic packaging, high-density polyethylene film consumption will continue to grow steadily; hollow products applications will be more varieties, diversification, specialization direction; multi-layer co-extruded plastic hose, Pharmaceutical bottles and a variety of hollow containers will have a greater growth. Polypropylene in the field of injection molding products will continue to increase the proportion of consumption. Polypropylene used in thin film products will also grow rapidly, but in the field of woven products applications, the proportion of polypropylene consumption will be significantly reduced. PVC products will be mainly concentrated in the field of construction, in the field of packaging applications will be further reduced; film products will be more replaced by polyethylene film. Due to the "white pollution" problem of polystyrene fast food boxes and other foamed materials, the amount of polystyrene foam products in the packaging will gradually shrink.

The development of commonly used plastic packaging materials

PE, PP and PET are commonly used in three kinds of plastic packaging materials. Second, nylon and PC, PVDC and other materials are also more applications in the field of packaging.

PE

Non-polar and polar ethylene copolymer and metallocene ethylene is the two major hotspots in Europe and the United States.

Ethylene copolymer can improve the tensile and coextrusion properties of plastic film, and improve the transparency, enhance stability, improve the molecular weight distribution and extrusion rheological properties. VLDPE (ultra low density polyethylene) is to replace LLDPE, PP, EVA, PVC in the extrusion, injection molding, blow molding process, the occupation of medicine, cosmetics and other flexible packaging market, and the impact of food packaging. The production of PA bags with linear vinylene copolymer and ethylene-vinyl acetate copolymer is also used in food packaging such as ice cream, milk fat and so on.

The metallocene polyolefin is a polymer obtained by the polymerization of olefins with a metallocene complex as a catalyst. Metallocene polyethylene has many advantages, such as good gloss, high melt strength and film stability, etc., for food packaging, has been the industry's general concern. It is generally believed that metallocene plastics will directly impact the plastics market such as PP, MDPE, LLDPE, elastomers.

The current PE in the world market demand for 40 million tons, is expected to increase to 50 million tons in 2005, the increase in most of the metallocene polyethylene.

PP

PP performance is very active, new PP grades and modified PP material after another. As a lot of modified PP has the characteristics of engineering plastics, therefore, has been in a considerable number of areas to replace the engineering plastics.

Transparent PP is the current rapid development of varieties, in the medical products and medical packaging products and cosmetics packaging and other aspects of the application more and more. BOPP bottles because it can withstand more than 100 ℃ high temperature, so in the infusion and functional beverage packaging is widely used. BOPP film is the rapid development of plastic film varieties. Multi-layer co-extruded BOPP film is the current trend of development.

PET

PET is also one of the most active plastic packaging materials.

PET bottles are the main form of beverage packaging. However, due to PET high temperature resistance is poor, therefore, and PET molecular structure similar to the PEN has been the concern of the industry. In addition to heat resistance, PEN PET has more excellent barrier properties, especially gas barrier and UV resistance. In the near future, PEN will enter a large number of food packaging areas, triggering another packaging revolution after PET.

PC

PC can be counted as engineering plastics in the field of packaging used in a great variety. The reason for this is because the development of drinking bucket manufacturing this use. PC is one of the most demanding varieties of engineering plastics. But in addition, the PC has not found more in the field of packaging useless.

PVDC, EVOH and nylon

As a barrier plastic packaging material, PVDC, EVOH and nylon in the field of packaging is mainly based on the role of composite materials. EVOH and nylon film which are mostly used for composite materials, instead of aluminum foil to do the barrier layer, but the scope of use is not very wide. PVDC as a more common barrier material, mainly for coating. In China, the great application is the production of tobacco film, but in the field of food applications are increasingly widespread.

The development trend of the main plastic packaging products

A wide range of plastic packaging products, generally can be divided into film, bags, bottles, large hollow containers, tray and tray, and so on. Each package is divided into many varieties because of the use and the materials used.

Cling film will be functional development

Plastic wrap is a very large use of film packaging. At present, the type of Chinese plastic wrap is still relatively small, resistant to grease, high temperature, suitable for microwave heating and other functions of the type of plastic wrap will be more and more. Materials used in addition to PE, PVC and polyolefin plastic wrap will be more and more. The development of the wound film and the heat shrinkable film is similar.

Shopping bags to the direction of the development of plastic degradation

Vest-style shopping bags are often used plastic packaging, often made of PE material.

As the use of shopping bags, is a one-time use of packaging, therefore, is one of the main components of packaging waste.

Easy to recycling, recycling value is not, is the plastic shopping bag recycling more difficult to deal with the main reasons. Therefore, the use of biodegradable degradable plastics is an ideal way to solve the waste shopping bags to pollute the environment. How rapid degradation is the key technology under composting conditions, and the cost and warranty period of performance is the degradation of plastic can replace the traditional shopping bags of two important factors.

High barrier flexible packaging is the development trend

High-barrier flexible packaging for food and medicine will accelerate development. As the main substrate of the BOPP film, its production will gradually develop to multi-layer co-extrusion, 3 and 5 film will be more common. At the same time PET film will be because of its better barrier in more areas instead of BOPP film.

PVDC, nylon and EVOH barrier film will gradually increase the use. In particular, PVDC composite film will be in the field of food packaging to obtain a wider range of applications.

In addition, a large number of multi-functional composite film will be further refined in function, for example, special treatment for PP can be made of moisture film, anti-condensation film, anti-steam film, adjustable water film and other types; special PE film can be made Corrosion-resistant film, mast film and anti-synovium, etc .; and two-way stretch nylon 66 heat-resistant film can be obtained than the two-way stretch nylon 6 film higher heat-resistant temperature, can withstand 140 ℃ high temperature; non-crystalline nylon membrane transparency Similar to the glass, can keep color, smell, taste, and keep the food nutrition indicators and taste quality stability.

Plastic woven bags will be gradually reduced

Plastic woven bags are plastic film, mainly polypropylene, made of a certain width of the narrow band, or hot drawing method to get high strength, elongation of small plastic flat belt, and then these flat ribbon woven. Plastic woven bags than the plastic film bag strength is much higher, and not easy to deformation, impact resistance Ye Hao, and because the woven bag surface weaving pattern, improve the anti-skid performance, easy to store the stacking. Plastic woven bags are mainly used for food and cement, fertilizer and other products packaging, but due to the existence of pest control, poor moisture resistance, environmental pollution and other shortcomings, therefore, in these areas of the application is gradually reduced.

Water and solvent-free adhesives are huge

In the plastic composite plastic materials, water-based adhesives will be the future direction of development. At present, water-based adhesives account for 50% of the market share of US flexible packaging composite adhesives. In the European market, solvent-free adhesives account for 40% of the market share of composite adhesives. With the increase in environmental awareness and environmental regulations more stringent, in the next decade, environmentally friendly water-based and solvent-free adhesives will replace solvent-based adhesives, as mainstream products.

Beverage containers to low-cost, high-performance development

For carbonated beverages and bottled water PET bottles to reduce the weight of the space has been very small, the future development is mainly high-speed production equipment. With the arrival of drinks cold aseptic filling era, ordinary PET bottles come to a great comeback trend. At the same time, in the production of ordinary PET bottles in the production of recycled materials to do the core layer of multi-layer bottle technology has been quite mature, but because of the technology requirements of the equipment is very high, resulting in the cost of restricting the development of the main factors.

Hot bottling PET bottle bottle crystallization technology is the key, the new technology has been able to make the bottle to withstand the filling temperature of 93 ℃, although from the sterilization point of view, the higher the temperature is not necessarily necessary. The future development of hot filling bottles is mainly focused on reducing the weight and developing more bottles.

The development of plastic beer bottles has experienced the addition of PEN, coating barrier coating and several other processes. At present, it is more feasible to use multi-layer bottle production technology, the middle of the use of EVOH or nylon as a barrier layer, but by the cost and other factors, the market when the start is not clear.

PC is currently making 5 gallons of drinking water barrels of the main material, has been reported PET manufacturing drinking bucket can also meet the quality requirements, but a short period of time, PET is still no alternative PC possible.

BOPP bottles as a newly developed products, the current focus on the need for high-temperature sterilization or pasteurization of the beverage, such as herbal tea.

Its main application areas are currently focused on large infusion products. PE containers in the beverage packaging on the application of small, mainly concentrated in a small amount of large capacity (such as 5 liters) bottled water.

Medicinal and cosmetic plastic bottles

Unlike the PET bottles produced by the injection molding process, the bottles of medicinal and cosmetic products are mostly extruded PE bottles, especially for washing bottles. Transparent bottles are now more and more popular, but most of the shampoo bottles or opaque PE bottles, but individual caps to switch to transparent PP material. The future of high transparency of the PP bottles and PET bottles will be in the shampoo and hair care packaging to get more applications.

Medicinal plastic bottles are mainly made of PE and PP, due to consider the preservation of dark, PET bottles in this area of the application subject to certain restrictions. But the overall trend is to use more and more. Part of the production of low-speed PET equipment manufacturers, has been targeted in drug packaging.

Hollow containers to large-scale, multi-layer development.

100 liters of plastic hollow containers have been very common. Domestic equipment has been able to produce and meet the needs. 200 liters of PE barrels can even meet the requirements of Class II shipping regulations, instead of 200 liters of closed steel drums. More than 1 ton of PE plastic barrels have also been several domestic production enterprises, the promotion of the use of this drum, is expected to make it a petrochemical, chemical and other industries the main form of liquid packaging.

In addition, large hollow containers are moving towards double and multilayer coextrusion.

Plastic plate, yogurt cup and plastic tray.

Plastic tray applications are becoming more and more popular, such as in fast food often used. The vast majority of this type of tray is made of PP and can be used in a microwave oven. In addition, PP sheet is also the main material to manufacture yogurt cup. However, high-quality yogurt cups have a tendency to use PS sheet manufacturing.

Plastic tray light, water, not susceptible to pests, beautiful, clean, can be used repeatedly, is conducive to open-air operations and storage. Compared with the wooden tray, its hardness and turnover can be increased by 3-5 times.

Plastic tray with single-sided and double-sided type two, double-sided type is divided into two kinds of integral and assembly. At present, the domestic plastic tray to injection molding, extrusion - hollow blow molding method followed, extrusion products are not too much use, vacuum plastic molding rarely used.