Bright Prospects for Development and Utilization of EVA Resin in China

By Yan Feng

Ethylene-vinyl acetate polymerized resin (EVA) is the fourth most important ethylene series polymer, after HDPE, LDPE and LLDPE. It is produced through the copolymerization of ethylene and vinyl acetate (VA). The VA content is 5-40%. The melting fraction (MFR) is 0.3-400g/10min. The introduction of VA monomer into the molecular chain of EVA has reduced the crystallization degree of the product and improved its toughness, impact resistance, filler compatibility and thermal sealing. EVA resin features good environmental stress cracking resistance (ESCR), excellent optical properties, low-temperature resistance and no toxicity. EVA resin is extensively used in foam materials, functional greenhouse films, packaging films, injection molded products, blow molded products, injection molded foam products, blenders, adhesives, electric wires/cables, voltaic cell encapsulating films and thermosols. It can also be used as modifying raw material for other resins. The demand for EVA resin in both domestic and overseas markets has increased rapidly in recent years, and the development prospects are extremely bright.

Table 1   Major EVA Resin Producers in China, 2012 (kt/a)

Producer    Capacity    Startup time    Process
Organic Chemical Plant of Beijing Dongfang Petrochemical Co., Ltd.     40    1995    Kettle process from Eni of Italy
Sinopec Shanghai Petrochemical Co., Ltd.    60    1986    tubular process switched production in the LDPE unit
Sinopec Beijing Yanshan Petrochemical Co., Ltd.    200    2006    high-pressure tubular process from Exxon Mobil  switched production in the LDPE unit
Beijing Huamei Polymer Co., Ltd.    60    2010    kettle process from DuPont  switched production in the LDPE unit
BASF-YPC Co., Ltd.    200    2005    high-pressure tubular process from Basell
Total    760


1. Slow capacity expansion and low operating rate

In 2012 China’s EVA resin capacity was 760kt/a. Sinopec operates nearly all of China’s EVA units, except those of PetroChina Daqing Petrochemical Co., Ltd . Organic Chemical Plant of Beijing Dongfang Petrochemical Co., Ltd. is specialized in the production of EVA resin. The EVA-capable units of other producers are all switched production. Although Sinopec Shanghai Petrochemical Co., Ltd. and PetroChina Daqing Petrochemical Co., Ltd., have capacity, almost no EVA resin is actually made. The output of EVA resin in China was 312.2 kt in 2012, an increase of around 18% over the previous year. The overall operating rate of production units was only around 41%. Table 1 shows the major EVA resin producers in China in 2012.

2. Many construction and expansion plans

Quite a few EVA resin units will still be constructed or expanded in China in the next few years. Shenzhen Fude Holdings Group Co., Ltd. plans to construct a 200 kt/a EVA resin unit in Songyuan. Construction was already started in 2012, and it will be completed and put on stream in 2014. Shandong Haoda Chemical Co., Ltd. plans to construct a 100 kt/a EVA resin unit in Tengzhou Lunan High-Tech Chemical Industry Park of Zaozhuang. Formosa Plastic Group plans to adopt the kettle process for a 72 kt/a EVA resin unit to be constructed in Ningbo of Zhejiang. The project will start production in the fourth quarter of 2013. Shenhua Oil to Liquid and Chemical Co., Ltd. will use LyondellBasell’s Lupotech T process in the construction of a 300 kt/a LDPE/EVA resin combined unit in Yulin of Shaanxi. Lenovo Group plans to adopt the tubular process for a 200 kt/a EVA resin unit to be constructed in Tengzhou of Shandong. Shanghai Coking and Chemical Corporation plans to adopt the tubular process for a 200 kt/a EVA resin unit to be constructed in Wuhu of Anhui. Shanghai Petrochemical Co., Ltd. plans to adopt the tubular process for a 100 kt/a EVA resin unit to be constructed in Shanghai. If these projects are all executed according to plans, it is expected that the total capacity of EVA resin in China will reach around 1.2 million t/a in 2017. As most of these units will have combined LDPE production, however, their production will be greatly influenced by the respective market trends of LDPE and EVA resin. The effective capacity of EVA resin is therefore expected to be the same as it is today – only 800-900 kt/a.

3. Supply shortage and high import volume

As the capacity and the output of EVA resin in China cannot meet the needs in actual production, great quantities have to be imported from abroad. According to customs statistics, the amount of EVA resin imported by China was 472.0 kt in 2005, 427.4kt in 2007, and reached 607.5 kt in 2012, hitting the all-time high and increasing around 21.30% over the previous year. The average annual growth was around 7.28% during 2007-2012. Small amounts of EVA resin are also exported. The export volume was 8.0 kt in 2005, 24.1 kt in 2007 and went up to 53.6 kt in 2012, an all-time high and an increase of around 10.06% over the previous year.

4. Numerous consumption sectors and bright development prospect

With the booming development of the functional greenhouse film, packaging film, shoe material and thermosol sectors in China in recent years, domestic demand for EVA resin has increased constantly. The apparent consumption of EVA resin in China was 619.4 kt in 2007, and reached 866.1 kt in 2012, an increase of around 20.88% over the previous year. The average annual growth was around 6.93% during 2007-2012. The self-sufficiency rate of products also increased constantly from 34.89% in 2007 to 36.05% in 2012. Table 2 shows the supply/demand balance of EVA resin in China in recent years.
The consumption structure of EVA resin in China is different from foreign countries. In China EVA resin is mainly used in functional greenhouse films, packaging films, shoe materials, thermosols, electric wires/cables and toys. Injection-molded and foam products were the biggest consumption sector for EVA resin in 2012, accounting for around 65% of the total. The consumption in films came next and accounted for around 17% of the total. The consumption proportion was around 7% for thermosols, around 3% for electric wires/cables and around 8% for others.
Films
The most important application of EVA resin in films is its use in functional greenhouse film for agriculture. Some EVA resin is also used in packaging film, medical film, laminating film and casting film.
China is a big agricultural country with a huge market demand for agricultural films. China also has the largest area of horticulture in the world. The area of greenhouse film coverage has already reached nearly 2 million hectares. Output of greenhouse films is more than 800 kt. Due to the supply shortage and high price of EVA resin and the limited purchasing power of farmers for many years, however, the actual consumption of EVA agricultural films is on the low side. EVA resin is therefore used only in high-grade greenhouse films such as 3-ply or multi-ply co-extruded composite films or special mulches, and only as a functional assistant. The proportion added is usually 10-40%. Only in some products made by Beijing Huadun Plastic Packaging Appliances Co., Ltd., Tianjin Second Plastic Products Co., Ltd. and Shandong Ihlshin Chemical Co., Ltd. does the content of EVA resin reach 70%.
China is vigorously implementing policies for resource-saving agriculture and cyclic economy. EVA agricultural films are heat-preserving and easy to recycle, and therefore conform to policies of the state. The excellent optical property of EVA agricultural films and the good compatibility with other assistants can reduce the probability of diseases and the consumption of pesticides and also create favorable conditions for the production of hazard-free vegetables. EVA non-drop film with high-temperature protection and long service life, EVA daylight greenhouse film, EVA sunlight film and PE/EVA high-optical film, all developed in recent years, will remarkably increase the demand for EVA resin. With the accelerated replacement of conventional greenhouse films by functional varieties, the demand for EVA resin in making agricultural films will increase drastically. Agricultural films will become the most important driver for the growth of EVA resin demand in China.
The use of EVA resin in solar module encapsulating films will also be an important application. China ranks first in the output of voltaic modules. Nevertheless, China depends heavily on importing high-performance EVA encapsulating films. Direct consumers of voltaic modules now reportedly require a service life of over 25 years. The poor aging resistance of China’s EVA encapsulating films has become a bottleneck to the development of the voltaic sector here. High-performance EVA collectively worth over RMB1.0 billion has to be imported each year. The high prices, long order cycles and uncertain supply volumes of encapsulating films have seriously constrained the development of the voltaic sector in China.
It is expected that the consumption of EVA resin in films will increase at an average annual rate of around 10.3% in the next few years and film’s proportion of the total consumption of EVA resin will go up from around 17% today to around 21%. The related EVA resin demand will reach around 240kt in 2017.
Foam products
Foam plastics produced through molding using EVA resin as a major raw material and adding appropriate amounts of modifiers, cross-linking agents and foaming agents as assistants feature thermal insulation, heat preservation, shock resistance and no water absorption. Compared with expanded PE foam, such foam plastics have greater flexibility, higher elasticity, smaller compression deformation, better weather resistance and easier secondary processing. They can be used in the industrial, construction and aquatic product sectors.
It is expected that with increased volumes of shoe materials and toys exported to international markets, the demand for EVA resin in China’s foam plastics sector will reach around 695kt in 2017.
Electric wires/cables
EVA resin used in electric wires/cables usually has a VA content of 12-24%. The use of EVA resin as electric wire/cable material has at least two advantages. One is that great quantities of fillers can be added without brittle fracture and without affecting the mechanical properties. The other is that cross-linking is convenient for applications including thermal-shrink insulators, semiconductor screening materials and flame-retardant insulating materials. The use in electric wires/cables (sleeves, inner/outer screening materials, semiconductor materials and thermal-shrink materials) is a major application of EVA resin composite materials. When EVA resin is used to produce electric wires/cables, antistatic agent carbon black, flame-retarding agents and other fillers and assistants need to be added. EVA resin blended with low-price fillers and additives can be used to produce foam materials or sleeve materials with the function of insulating protection. Cross-linking electric cables with conductors coated with EVA/PE blend feature flexibility, cracking resistance and cutting resistance. They are therefore suitable for use in special operating environments such as under water, in mine shafts and in oil wells. With the rapid development of power projects in China, the demand for EVA resin in the manufacture of electric wires/cables will develop rapidly and reach around 35kt in 2017.
Thermosols
EVA resin can be used together with anchoring resin and wax to produce thermosols. The VA content is 25-40%. Such thermosols have good mechanical properties, good stability, high viscosity and controllable particle size. There is an excellent balance between creep resistance and heat sealing behavior. Curing is fast, wet viscosity is good and bonding to problematic film substrates is unique. Thermosols produced with EVA resin as the main ingredient have no environmental hazards and very low flammability, as no solvents are used. Owing to their quick curing, such thermosols are suitable for use in high-speed automotive production assembly lines. They are used extensively in the wireless binding and packaging of books, the sealing of paper boxes, the banding of furniture, the assembly of automobiles and household electric appliances, the making of shoes, the coating of carpets and the anticorrosive coating of metal products. It is expected that domestic demand for EVA resin in thermosols will reach around 80kt in 2017.
Others
EVA resin can be used as additive of oil products, anti-wax agent and flow modifier of crude oil, low-temperature flow modifier of diesel and substrate of electrical conducting materials. In addition, new application sectors can be added through the production of composite materials such as EVA resin/montmorillonite, EVA resin/laminated sodium silicate and EVA resin/nano TiO2. The consumption of EVA resin in such low volume sectors was around 69 kt in 2012, and the demand is expected to reach around 85 kt in 2017.
The demand for EVA resin in China is therefore expected to reach around 1.15 million tons in 2017. The consumption structure will change. Foam products will remain the biggest consumption sector for EVA resin, but as a great portion of shoes are exported in the mode of processing-by-supplied-materials the demand proportion in foam products will shrink, and the growth of demand will slow down. The proportion of the total demand will be down from around 65.0% today to around 61.7%. The demand proportion in film manufacture will, however, increase to around 21.0%. The demand from manufacturers of thermosols, electric wires/cables etc. will maintain a stable growth.

Table 2   Supply/Demand Balance of EVA Resin in China  (kt)

Year Output  Import volume Export volume  Apparent consumption  Self-sufficiencyrate (%)
2007    216.1    427.4    24.1    619.4    34.89
2008    216.9    363.6    34.5    546.0    39.72
2009    238.0    505.6    39.3    704.3    33.79
2010    227.2    479.0    46.0    660.2    34.41
2011    264.4    500.8    48.7    716.5    36.90
2012    312.2    607.5    53.6    866.1    36.05


5. Measures for protecting development

EVA resin should have a unique structure to ensure its extensive applications in foam materials, functional greenhouse films, packaging films, electric wires/cables, voltaic cell encapsulating films and thermosols. The production of EVA resin in the world today mainly uses the mode of EVA/LDPE switched units. The kettle process and the tubular process have their respective advantages. The major use of EVA resin is in making films. Compared with foreign countries, there is still a considerable lag in the EVA resin sector of China. It is mainly manifested in following aspects:
(1) Low operating rate and small output
Quite a few EVA resin units have been constructed in China in recent years, and the total capacity has reached 760kt/a. Nevertheless, the effective capacity is in fact only 500kt/a. A 260kt/a of capacity produces almost no EVA. In the effective capacity of 500kt/a, only a 40kt/a unit in Organic Chemical Plant of Beijing Dongfang Petrochemical Co., Ltd. is specialized in the production of EVA resin. Other producers also produce LDPE in the same units. When the LDPE market is brisk, most of them will no longer make the full-load production of EVA resin. The operating rate of production units is therefore only 41% and the further expansion of EVA resin applications in China is seriously affected.
(2) Incomplete product varieties
Existing EVA resin units in China could produce over a dozen varieties of products when they were introduced from abroad. Some producers have also developed several new varieties. Due to factors such as production technology, however, the quality of some products is unreliable, the production cost is quite high and consumer requirements cannot be satisfied. Only a few conventional varieties can be produced. There is therefore oversupply of conventional varieties and many new varieties have to be imported at high prices.
(3) Inadequate application development
In China the application of EVA resin is rather homogeneous. It is mainly used in foam products. The consumption proportion in films is quite small – only around 17%. It is not at all matched to China’s status as a big agricultural country with a high demand for EVA multi-ply composite films. (The consumption of EVA resin in various films in foreign countries is over 50% and reaches as high as 64% in the United States. 100% of functional films in foreign countries use EVA resin, but only 20% of functional films in China use it.) The second major application sector in foreign countries is thermosols, but the consumption proportion in China is even lower, falling far behind actual needs in the domestic market.
(4) High production cost
The VA production in China today mostly uses the acetylene process and the production cost is quite high. Among producers using the ethylene process, the production cost is also higher than in foreign countries. The cost of EVA resin is therefore also on the high side and there is no evident advantage in market competition with foreign products.
The EVA resin sector in China should therefore do the following:
(1) The capacity of production units should be expanded. The production of EVA resin in the world today mostly uses EVA/LDPE switched units. EVA resin produced through this process contains no solvents, has simple post-treatment steps and low comprehensive cost and conforms better to environmental protection requirements. To meet requirements on the consumption of EVA resin in the domestic market, enterprises located in places with necessary conditions (especially those with vinyl acetate units) can consider adopting advanced technology when constructing EVA resin units. The scale of production units is preferably more than 200kt/a. They can also renovate and expand existing EVA resin units to gain a wider profit margin.
(2) As the R&D of EVA resin shifts toward high-effect, special-effect, hazard-free and multi-functional varieties, the demand for multi-functional films such as films with high light permeability, preservative films for cold storage and non-drop films will make a rapid increase. The new application of EVA resin in voltaic films for solar panels, in particular, has generated brisk demand in recent years. Measures should therefore be taken to accelerate the application development of EVA resin, increase new product brands and promote the development of EVA resin toward high-performance, multi-functional and diverse varieties. Only in this way can the market share and competitiveness of products be enhanced.
(3) Due to the satisfactory LDPE market in China in recent years, the initiative of EVA resin producers in the EVA resin production is affected to a certain extent. The supply shortage of EVA resin has also affected the development of agriculture toward the high technical level. Relevant departments of the state should therefore formulate policies to support and encourage enterprises to make a vigorous development and a large-scale production of EVA resin to increase its output and meet the domestic demand.
(4) With the constant expansion of EVA resin application sectors, many enterprises have started to consider moving into the EVA resin sector. It is suggested that the advantage in raw material resources and especially the supply of vinyl acetate should be taken into full consideration in constructing new production units. The provision of raw material resources should be integrated to reduce production costs and hold a favorable foothold in the market.