【Deep coating society, popular science knowledge】Adhesive film raw materials: EVA process and market analysis and industrial chain research

01

EVA is made of ethylene monomer copolymerized with vinyl acetate (VA) monomer, and is the fourth largest ethylene copolymer after high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE
).
According to the different VA content, EVA can be divided into three categories, namely EVA resin (VA content less than 40%), EVA elastomer (VA content 40%~70%) and EVA emulsion (VA content 75%~95%)
.

Compared with polyethylene, EVA resin has significantly reduced its crystallinity due to the introduction of VA, and the branching, flexibility and impact resistance of the polymer have been significantly improved.
It is widely used
in foam materials, photovoltaic film, functional shed film, wire and cable, packaging film, injection molding products and blending agents.

EVA elastomer has rubber characteristics, the viscosity is similar to nitrile rubber, mainly produced by the medium pressure solution polymerization process, the product is mainly used for polyvinyl chloride (PVC) modification
.
EVA emulsion is usually produced by emulsion polymerization, and the products are mainly used as adhesives, coatings, etc
.

The main indicators of EVA resin performance include melt flow rate (MFR) and VA content
.
MFR mainly characterizes the fluidity
of thermoplastic materials at a certain temperature and pressure.

EVA resin

The MFR value does not change, the VA content increases, and the elasticity, adhesion, transparency, softness, and compatibility of EVA are better
.

The VA content remains unchanged, the softening point decreases when the MFR value decreases, the surface gloss and processability are improved, and the impact resistance of EVA increases when the MFR value increases
.
Usually products with high VA content are used in hot melt adhesives, photovoltaic adhesives and coatings, and products with low VA content are mainly used in the production of
films and injection molding products due to their large surface hardness and tensile modulus.

Ethylene-vinyl acetate copolymer production process

EVA production process

02 EVA resin production at home and abroad has four processes
: high-pressure continuous bulk polymerization, medium-pressure suspension polymerization, emulsion polymerization and solution polymerization.
At present, EVA resin production basically adopts high-pressure continuous bulk polymerization process (similar to LDPE production process, both are high-pressure reactions), which can be divided into two processes
according to the different forms of reactors.
The tubular process is to use the high-pressure continuous bulk method of the tubular reactor for polymerization, and the pressure gradient in the reactor is large, the reaction time is short, the product has less long branched chains, and the molecular weight distribution is wide
.
The advantage of the tubular method is that it can produce LDPE and EVA resin with less than 30% VA content on a large scale, with good mechanical properties and poor foaming properties, which is mainly used for film material and extrusion coating; In addition, the investment and operating costs of the tubular process are lower
than those of the kettle method.
The main suppliers of tubular processes are ExxonMobil, LyondellBasel, Dupont and SABIC
.
The reaction pressure of the kettle method is lower than that of the tubular method, the reaction temperature and pressure are uniform, the branched chain and molecular weight distribution can be accurately controlled, and EVA resin with VA content of less than 40% can be produced, and the product has high added value and more grades; In addition, the kettle method can also produce special copolymers
such as ethylene-methacrylate, ethylene-ethyl acrylate, ethylene-butyl acrylate, etc.
The main suppliers of the kettle process are Dupont, LyondellBasel, ExxonMobil and Versails (Enichem), among others; The kettle process mainly includes: primary compression, high pressure compression, polymerization, high pressure product separation, low pressure product separation, high and low pressure gas circulation, granulation, finished product transportation and packaging and other units, auxiliary processes include initiators, regulators, auxiliary injection systems and chilled water systems; The process steps of the tubular method and the kettle method are similar, and the biggest difference is the difference
in the reactor.
The comparison of tubular method and kettle method is shown in
Table 2.
From the perspective of technical sources, domestic EVA manufacturers mainly use the production process of LyondellBaseld and ExxonMobil.

In 2021, among the existing EVA production capacity in China, the tubular method production capacity will be 1.
200 million tons/year, accounting for 67.
72% of the production capacity; The production capacity of the kettle method is 572,000 tons/year, accounting for 32.
28% of
the production capacity.
In the tubular process, the Basel-tube process accounts for 83.
33%
of the production capacity.
In addition, the Basel tubular process is large-scale, and can realize the flexible switching of EVA and LDPE, and the proportion of Basel-tube method in the domestic planned new production capacity is also high
.

Photovoltaic film is the highest proportion of EVA consumption at present and in the future, and its mainstream production processes are the LyondellBaseld tubular method and the ExxonMobil kettle method
.


The Lyondell Basel tubular method is equipped with a pulse valve, which can reduce the crystal point formed by the polymer bonding on the inner wall of the reactor, so as to achieve a continuous, stable and high proportion of photovoltaic material output
.
In the production of photovoltaic materials, in order to control the crystal point index, the reactor needs to be cleaned frequently, resulting in a low
proportion of photovoltaic materials.
Ethylene-vinyl acetate copolymer raw material supply and demand analysis EVA raw material supply and demand analysis
03 ethylene and VA are the main raw materials required for the production of EVA
。 In the existing EVA production enterprises, ethylene is usually self-sufficient, and VA relies on outsourcing, so only the supply and demand of VA is analyzed
.

VA is mainly used in the production of polyvinyl alcohol, polyvinyl acetate, EVA emulsion, EVA resin and acrylic, etc.
, its production process includes: calcium carbide acetylene method, ethylene method and natural gas acetylene method; The calcium carbide acetylene process is simple and is the mainstream process in China, but the VA products prepared by this method have a high content of aldehydes, which is not conducive to the VA polymerization reaction, so the production of EVA and EVA emulsion basically uses ethylene VA as raw material
.

From the supply side, in 2021, the domestic VA production capacity will be 2.
6 million tons/year (including 67,143,500 tons/year of ethylene, calcium carbide acetylene and natural gas acetylene respectively), and the output will be 1.
7225 million tons (including 420,000 tons of ethylene).


It is expected that the domestic VA production capacity will increase to 3.
49 million tons / year in 2025, of which the ethylene production capacity will be 890,000 tons / year
.
The existing and forecasted domestic production capacity of VA is shown
in Table 3.
From the demand side, domestic VA consumption in 2021 will be 1.
9122 million tons (of which 250,000 tons are used for EVA production), and imports will be 287,300 tons
.

In the future, with the significant increase in EVA production capacity, the demand for ethylene VA will increase rapidly, and if the existing planned EVA plant is put into operation, the annual demand for ethylene VA will increase by at least 670,000 tons
by 2025.

In addition, from the second half of 2019, the demand for ethylene VA has increased
due to the fact that the production cost of ethylene VA is lower than that of calcium carbide acetylene method.

In general, the existing domestic ethylene VA supply and demand show a tight balance, with the rapid increase in EVA production capacity brought about by the rapid increase in ethylene VA demand, the structural difference between VA supply and demand will become more and more significant
.

If the production of existing and planned ethylene VA plants reaches the design values, their domestic supply and demand will be balanced
.
Analysis of supply and demand status of ethylene-vinyl acetate copolymer products Analysis of supply and demand status of EVA products 04Global supply and demand status of EVA products From the perspective of supply, the global EVA production capacity in 2021 will be 6.
5 million tons/year, of which the three major regions of Northeast Asia, North America and Western Europe will account for 88%; Among the production capacity in Northeast Asia, Chinese mainland production capacity is 1.
77 million tons/year (27% of the global share), South Korea has a production capacity of 1.
18 million tons/year (18% of the world), Japan has a production capacity of 640,000 tons/year (10% of the global share), and Taiwan has a production capacity of 510,000 tons/year (8% of the global share).


Driven by the "dual carbon" policy, the development of the photovoltaic industry has ushered in a new growth period, and EVA, as an important raw material in the photovoltaic industry chain, has also ushered in new development opportunities
.
In 2021, the global new EVA production capacity will reach 1.
1 million tons/year (China and South Korea will add 80.
3 million tons/year respectively), and from 2022 to 2024, the global new EVA production capacity is expected to reach 1.
08 million tons/year (concentrated in China), with an average annual growth rate of 5.
3%.


From the perspective of demand, the development of footwear, packaging and photovoltaic industries in Northeast Asia has driven the growth of global EVA consumption, with global consumption of about 4.
2 million tons
in 2019.
Among them, Northeast Asia is the largest consumption region, accounting for up to 50%; followed by Western Europe and North America, accounting for 14% and 11% respectively; Southeast Asia accounted for only 7% of consumption; Other regions consume less, accounting for less than
5%.

In the future, global EVA demand is expected to maintain an average annual growth rate of about 6%, and emerging economies will be the main force driving the growth of
global EVA demand.

In the global EVA consumption structure, the demand for EVA in photovoltaics, hot melt adhesives, wires and cables will grow faster than other fields, and its proportion in the consumption structure will increase
year by year.
From the perspective of supply, as of April 2022, the total domestic EVA production capacity reached 1.
922 million tons/year (see Table 4), of which 49% was new production capacity

The EVA production capacity under construction and proposed in China is shown in
Table 5.
It is expected that the domestic EVA production capacity will reach 4.
6 million tons per year
in 2025.
Among the new production capacity, the unknown part of the planing process is removed, and the tubular method accounts for 86% of
the remaining production capacity.
From the perspective of demand, from 2017 to 2021, China's EVA consumption grew rapidly, with a compound growth rate of more than 9%.


In 2021, the apparent consumption of EVA reached 2.
183 million tons, a year-on-year increase of more than 10%, and the consumption of three products such as photovoltaic materials, foaming materials, and cable materials accounted for 82.
25%; Among them, photovoltaic materials accounted for the highest proportion of 39.
72%, followed by foaming materials (accounting for 26.
41%) and cable materials (accounting for 16.
12%)
.
Pre-coating film enterprises are concentrated in Kunshan, Taicang, Wuxi and Wenzhou, Zhejiang Province
.

Driven by the "dual carbon" policy, the global photovoltaic industry has entered a new stage of development, EVA has also ushered in new development opportunities, it is expected that in 2025, the domestic EVA demand will increase to 3.
33 million tons, of which photovoltaic materials account for the highest proportion of total demand is 45.
05%.

Import and export analysis of ethylene-vinyl acetate copolymer products Import and export analysis of EVA products 05 From 2017 to 2021, domestic EVA imports were 103.
47, 97.
59, 109.
60, 117.
68 and 1.
1167 million tons, respectively, and the external dependence has always remained at about
50%.
With the rapid launch of domestic EVA production capacity, the external dependence and domestic market share of EVA products will gradually decrease
.
In recent years, the import source structure of EVA products has been basically stable
.
South Korea, Taiwan and Thailand ranked in the top three in terms of import volume, and the total imports of the three places accounted for about
70% of the total domestic imports.
Major manufacturers include Total (Korea), LG, Rakuten Korea, Formosa Plastics, Taiwan, etc
.
China's EVA import concentration is very high in provinces and cities, and the import volume of Zhejiang, Fujian, Jiangsu, Guangdong and Shanghai accounts for about 90% of
the total import volume of the country.
The above areas are the main production areas
of domestic photovoltaic materials, foaming materials, cable materials, hot melt adhesives and other products.
With the rapid increase of EVA production capacity in 2021 and 2022, the capacity gap will be effectively alleviated, but the new plant mainly produces low-VA content EVA products in the early stage of operation, and can gradually produce products
with high VA content in the later stage.
With the rapid growth of demand for photovoltaic film materials, it is expected that the structural contradiction of insufficient supply of domestic EVA high-end materials will still exist in 2022, and it is still necessary to meet market demand
through imports.
In recent years, the domestic EVA product production is insufficient demand, and the export base is small
.
From 2017 to 2021, the export volume of domestic EVA products was 6.
36, 4.
88, 6.
00, 5.
34, and 71,300 tons, respectively, which was mainly due to the reverse flow of traders to exports, and the direct export of petrochemical enterprises was less
.
From the perspective of EVA export pattern, export countries are relatively scattered, mainly in Africa, Central Asia and other regional countries
.
Ethylene-vinyl acetate copolymer industry outlook EVA industry outlook

06With the adjustment of domestic industrial structure, the differentiated development trend of EVA industry has become more and more obvious
.
Foaming materials and films belong to the traditional application fields of EVA, and the demand is gradually saturated, and the proportion of consumption is stable or decreasing
.
At the same time, with the development of the domestic photovoltaic industry, coating technology and halogen-free flame retardant cables, photovoltaic film materials, coating materials, wire and cable materials have become important downstream application fields of EVA resin, and the demand will grow
steadily.
As an important path for energy transformation and development, photovoltaic power generation will continue to develop stably, which in turn will drive the rapid increase in domestic demand for EVA photovoltaic film, and it is expected that photovoltaic film will remain the largest downstream application field of
EVA.
The existing EVA manufacturers in China mainly use the production process
of LyondellBaseld and ExxonMobil.
Among them, the production capacity using the Lyondell Basel tubular process accounted for 56.
4%
of the total domestic production capacity.
In view of the excellent performance of the Leondell Basel Tubular process in the production of photovoltaic materials and the increasingly difficult transfer of ExxonMobil process licenses, the vast majority of future EVA production capacity will be planned using the Lyondell Basel Tubular process
.
With the increase of the demand for ethylene VA in the EVA industry, the proportion of its demand in the total demand for VA will continue to increase, the proportion of calcium carbide acetylene VA demand will gradually decline, and the structural difference between supply and demand will become more and more significant
.
With the planned ethylene VA production capacity, domestic supply and demand will be able to maintain a balance
.









Source: Polypropylene Man
Statement: This number is reprinted , sharing, statements, opinions remain neutral, the purpose is only for industry communication, the copyright belongs to the original author
.
If you are involved in copyright and intellectual property infringement issues, please contact this background to delete the content immediately
.

Gather the ordinary to build greatness together