"这批膜的阻隔数据不对，氧透过率超了一倍，客户要退货。"
"不可能啊，EVOH用的是正牌，每层厚度都按公差做的。"
"正牌是正牌，但你确认过这批EVOH的乙烯含量吗？送检测一下。"
EVOH是什么，为什么食品包装离不开它
EVOH，乙烯-乙烯醇共聚物。它的分子链里有两段：一段是乙烯，提供加工性和耐水性；一段是乙烯醇，提供氧气阻隔性。两段的比例——也就是乙烯含量——直接决定EVOH的脾气：乙烯含量低，阻隔性好但耐水性差；乙烯含量高，耐水性好但阻隔性降。
做食品包装的为什么离不开EVOH？因为它的氧透过率（OTR）能做到0.03 cc/m²·day级别，比大多数塑料都低。装在复合膜中间层——典型结构是PE/EVOH/PE——氧气穿不过去，里面的火腿肠、奶酪、番茄酱就能放半年不氧化。这层膜薄到只有十几微米，但它是整个包装保质期的命根子。
全球格局高度集中。可乐丽（Kuraray）是EVOH的开创者和龙头，EVAL品牌占全球产能的三到四成；日本合成化学（Nippon Gohsei，三菱化学子公司）的Soarnol品牌占两成多；台湾长春化工是第三家规模化供应商。三家加起来占全球EVOH产能的绝大部分。这是一个双寡头加一强的市场，后来者很难挤进来。
副牌从哪来，跟回料怎么分
EVOH副牌，定义不变：同一厂家同一牌号中出厂检验未完全达标的批次。但EVOH有个特殊性——它的关键指标是乙烯含量。乙烯含量差两个百分点，阻隔性能就变一个档次。副牌通常就是乙烯含量在标称值附近小幅飘移，或者熔指略有偏差。
四大来源：装置开停车头尾料、牌号切换过渡料、工艺波动批次、副线尾料。EVOH的副牌主要来源是牌号切换——从低乙烯含量切到高乙烯含量，中间过渡段乙烯含量在飘，但分子链还是EVOH，阻隔性能还在。
跟回料的边界：EVOH副牌是原厂原生聚合粒子。回料是膜边角料重新造粒——EVOH是强极性材料，回收过程中容易吸湿降解，阻隔性能掉得厉害。做食品包装膜的如果用了回料EVOH，保质期承诺直接打折扣，客户的食品氧化变味，赔起来不是一吨料的钱能兜住的。
可乐丽：EVAL，EVOH这个品类的定义者
可乐丽（Kuraray）在1972年全球首个把EVOH商业化，EVAL品牌做了五十年。它在日本、美国、比利时都有装置，全球份额在三成到四成之间（不同口径有差异）。EVAL的牌号按乙烯含量分档——典型的有32mol%、38mol%、44mol%三个主流档，数值越高越耐水、越低越阻隔。
做食品包装膜的厂，最熟的是32mol%那档——阻隔性好，适合干食品包装。需要耐水煮的包装，用38mol%或44mol%那档——耐水性好，高温蒸煮后阻隔不掉。EVAL副牌的来源，主要是日本和比利时装置的牌号切换过渡料，乙烯含量小幅飘移，比如标称32%实测33.5%——这个浮动做普通食品膜完全够用。
挑EVAL副牌，关键就是锁乙烯含量。你的复合膜结构如果是按32%设计的，来了一批实测38%的副牌，阻隔性直接降一档，货架寿命缩短。收货前测乙烯含量，对上你的膜结构设计。包装分大包装和小包装，大包装适合多层共挤生产线连续投料，小包装适合打样。
日本合成化学：Soarnol，可乐丽之外的第二极
日本合成化学（Nippon Gohsei）是三菱化学的子公司，Soarnol品牌是EVOH市场的第二极。它在日本有装置，产品牌号体系跟可乐丽类似，按乙烯含量分档。Soarnol的特点是加工性好——多层共挤时的热稳定性略优于EVAL，不容易在螺杆里停留太久变色。
Soarnol副牌的来源，以日本装置的工艺波动批次为主。做食品包装膜的厂拿Soarnol副牌替代EVAL正牌，成本降一截，阻隔性能在同一乙烯含量档下差距不大。注意一点：Soarnol和EVAL虽然都是EVOH，但分子链的序列分布略有差异——复合膜的层间附着力需要重新验证，别直接按EVAL的工艺参数上Soarnol。
长春化工：台湾力量，第三家规模化供应商
长春化工（Chang Chun Petrochemical）是台湾的石化企业，EVOH是它的产品组合之一。它的EVOH牌号主要面向包装应用，价格比可乐丽和日本合成化学略低，在亚洲市场有一定份额。
长春化工的副牌来源，以亚洲装置的牌号切换过渡料为主。做普通食品包装膜的厂拿它当经济型选择——阻隔性能达到食品包装要求那一档，价格比日本两家低一截。但要注意，长春化工的EVOH在高阻隔需求场合——比如需要长期货架期的肉制品包装——批次稳定性跟可乐丽还有差距，做高要求膜建议还是选EVAL或Soarnol正牌或精选副牌。
三个坑，做阻隔膜的别踩
第一个坑：乙烯含量对不上膜结构。这是EVOH副牌最致命的坑。你的复合膜按32%设计阻隔性，来了一批38%的副牌，阻隔性直接降一档——干食品的保质期从六个月缩到三个月。收货前测乙烯含量，别光看包装标签。
第二个坑：把回料当副牌买。EVOH回收料的吸湿降解问题比其他聚烯烃严重——分子链上的羟基容易吸水，二次造粒后阻隔性能大幅下降。做食品包装膜的厂如果用了回料EVOH，客户的食品两个月就氧化变味，退货索赔不是小数。验样时看粒子外观——回料粒子颜色偏黄、粒度不均；副牌是原厂原生粒子，外观跟正牌基本一致。
第三个坑：忽略层间附着力。EVOH是极性材料，跟PE层之间需要粘合剂层（Adhesive）。不同牌号EVOH的表面张力略有差异，副牌如果飘了分子量，层间附着力可能下降——复合膜分层起翘，阻隔层失效。上机前做剥离强度测试，层间粘力达标了再跑大货。
科隆仓库现货｜EVOH伙伴
主推品牌：可乐丽、日本合成化学、长春化工。
主要牌号：EVAL（32/38/44mol%）、Soarnol、长春化工EVOH。
包装规格：小包副牌与箱装副牌走小包装，大包料/吨包料走吨袋，按车间用量分包装备货。
仓库现货：EVOH仓库现货通常在4000吨上下，其中小包副牌备货600-900吨、箱装副牌备货250-450吨、大包料/吨包料备货2650-3150吨。
供应保障：检测单随货，COA与货同行。
选型口诀和一个嘉兴的案子
锁好乙烯含量、测好熔指、对上你的膜结构设计，EVOH副牌进厂——阻隔数据稳得住，货架寿命不缩水，复合膜量产一次过。
嘉兴有家做休闲食品包装膜的客户，之前一直用可乐丽EVAL的32mol%正牌做中间阻隔层，材料成本居高不下。后来试了一批EVAL 32mol%的副牌，乙烯含量实测33.2%（标称32%），熔指实测3.8（标称3.6），两项都在允许偏差内。上机做PE/EVOH/PE三层共挤膜，氧透过率实测0.05 cc/m²·day，跟正牌膜的0.04差距极小，客户货架期测试六个月数据达标。材料成本每吨降了一千多，一年下来光阻隔膜这一项省了二十来万。
这就是EVOH副牌的用法——不是所有包装都要用正牌做。休闲食品的包装窗口六个月够用，副牌那点乙烯含量浮动在设计余量内就能消化。宁波市科隆新材料有限公司做进口EVOH副牌料多年，可乐丽、日本合成化学、长春化工的货源都在跟，食品阻隔膜的案子每年接不少。
"The barrier data for this batch of membranes is incorrect; the oxygen permeability exceeds double, and the customer wants to return the product." "
" Impossible, EVOH uses genuine EVOH, and each layer thickness is made according to tolerances. "
" The genuine brand is genuine, but have you confirmed the ethylene content in this batch of EVOH? Send it for testing. " What is
EVOH, and why is food packaging inseparable from its
EVOH? Ethylene-vinyl alcohol copolymer. Its molecular chain consists of two segments: one is ethylene, providing processability and water resistance; The other is ethylene alcohol, providing oxygen barrier. The ratio of the two stages—that is, the ethylene content—directly determines the temperament of EVOH: low ethylene content means good barrier properties but poor water resistance; High ethylene content means good water resistance but reduced barrier properties.
Why can't food packaging do without EVOH? Because its oxygen transmittance (OTR) can reach 0.03 cc/m²·day, lower than most plastics. Installed in the intermediate layer of composite film—typical structures are PE/EVOH/PE—oxygen can't penetrate, so the sausages, cheese, and ketchup inside can be stored for half a year without oxidizing. This film is only a dozen microns thick, but it's the lifeblood of the entire packaging shelf life.
The global landscape is highly concentrated. Kuraray is the pioneer and leader in EVOH, with the EVAL brand accounting for 30–40% of global capacity; Japan's Nippon Gohsei (a Mitsubishi Chemical subsidiary) owns Soarnol for over 20%; Taiwan's Changchun Chemical is the third large-scale supplier. Together, these three companies account for the vast majority of global EVOH capacity. This is a market of two oligos plus one strong player, making it very difficult for newcomers to break in.
Where does the sub-brand come from, and how do you
EVOH separate it from recycled materials ? The definition remains unchanged: batches of the same manufacturer and grade that do not fully meet factory inspection standards. But EVOH has a special feature—its key indicator is ethylene content. If the ethylene content differs by two percentage points, the barrier performance changes by a whole level. Sub-brands usually have ethylene content slightly drifting near the nominal value, or slight melting finger deviations.
Four major sources: unit startup/shutdown head and tail materials, grade switching transition materials, process fluctuation batches, auxiliary line tailings. EVOH's secondary brand mainly comes from grade switching—from low ethylene content to high ethylene content, with ethylene content floating in the intermediate transition section, but the molecular chain still EVOH, with barrier properties.
Boundary with recycled materials: EVOH secondary brands are original factory virgin polymer particles. Reuse is membrane edge scraps re-pelletized—EVOH is a highly polar material, easily absorbs moisture and degrades during recycling, causing significant loss in barrier performance. If food packaging films use recycled EVOH, the shelf life commitment is directly discounted, causing food oxidation and flavor deterioration, which is not a ton of material cost to cover the loss.
Kuraray: EVAL, the defining of the EVOH category
Kuraray was the first in the world to commercialize EVOH in 1972, and the EVAL brand has been in the industry for fifty years. It has facilities in Japan, the US, and Belgium, with a global market share between 30% and 40% (varies by caliber). EVAL grades are classified by ethylene content—typically, there are three mainstream levels: 32mol%, 38mol%, and 44mol%. The higher the value, the more water resistance; the lower the value, the more barrier.
is the most familiar with the 32mol% grade for food packaging films—good barrier properties, suitable for dry food packaging. If you need packaging that is boil-resistant, use 38mol% or 44mol% grades—good water resistance, and can't be blocked after high-temperature cooking. The source of EVAL's secondary brand mainly comes from switching grades between Japanese and Belgian units, with slight fluctuations in ethylene content—for example, the nominal 32% and the actual measured 33.5%—this floating is more than enough for regular food films.
The key to choosing EVAL secondary brands is the ethylene content in the binding. If your composite film structure is designed for 32%, and you get a batch of sub-brands with a measured 38% yield, the barrier resistance drops by a notch and shelf life is shortened. Test the ethylene content before receiving and match it with your film structure design. Packaging comes in large and small packages. Large packages are suitable for continuous feeding on multi-layer co-extrusion production lines, while small packages are suitable for sampling.
Japan Synthetic Chemical: Soarnol, the second pole after Kuraray
Nippon Gohsei, a subsidiary of Mitsubishi Chemical, is the second pole in the EVOH market. It has facilities in Japan, with a product grade system similar to Kuraray's, classified by ethylene content. Soarnol is characterized by good processability—its thermal stability during multi-layer co-extrusion is slightly better than EVAL, and it doesn't easily change color after staying in screws for too long.
Soarnol sub-brand mainly comes from Japanese equipment with fluctuating batches. Factories making food packaging films use Soarnol sub-brands to replace genuine EVAL brands, reducing costs and providing barrier performance with similar ethylene content. Note: Although both Soarnol and EVAL are EVOH, their molecular chain sequence distribution differs slightly—the interlayer adhesion of composite films needs to be re-verified, so don't directly apply Soarnol based on EVAL's process parameters.
Changchun Chemical: Taiwan Power, the third large-scale supplier
Changchun Petrochemical is a Taiwanese petrochemical company, and EVOH is part of its product portfolio. Its EVOH grade is mainly for packaging applications, priced slightly lower than Kuraray and Japan's Synthetic Chemical, and holds a certain market share in Asia.
Changchun Chemical's sub-brand mainly comes from grade switching transition materials for Asian devices. Manufacturers making ordinary food packaging films consider it an economical choice—the barrier performance meets food packaging requirements, and the price is lower than the two Japanese companies. But note that Changchun Chemical's EVOH is still less stable than Clara-Li in high-barrier demand scenarios—such as meat products requiring long shelf life. For high-demand films, it's best to choose EVAL or Soarnol genuine or carefully selected secondary brands.
Three pitfalls, don't bet on barrier film makers
First pitfall: Ethylene content doesn't match the membrane structure. This is the most fatal pitfall of EVOH secondary brands. Your composite film is designed with 32% barrier properties, but a batch of 38% secondary brands lowers barrier performance by one level—the shelf life of dry food shrinks from six months to three months. Test ethylene content before receipt; don't just look at packaging labels.
Second pitfall: Treat recycled material as a secondary brand. EVOH recycled material has more serious moisture absorption and degradation issues than other polyolefins—hydroxyl groups on the molecular chain easily absorb water, and after secondary granulation, their barrier performance drops significantly. If a factory making food packaging films uses recycled EVOH, customers' food oxidizes and loses flavor within two months, and return claims are significant. During sample inspection, check the appearance of the particles—the recycled pellets are yellowish and uneven in size; The secondary brand is original original particles, which look basically identical to the genuine brand.
Third pitfall: ignoring interlayer adhesion. EVOH is a polar material and requires an adhesive layer between the layers and the PE layer. Different grades of EVOH have slightly different surface tensions; if the secondary brand has a floating molecular weight, interlayer adhesion may decrease—composite film peeling and barrier layer failure. Before installation, perform peel strength tests; only after meeting interlayer viscosity standards can be used for bulk delivery.
Cologne warehouse in-stock | EVOH partners
Main recommended brands: Kuraray, Japan Synthetic Chemical, Changchun Chemical.
Main grades: EVAL (32/38/44mol%), Soarnol, Changchun Chemical EVOH.
Packaging specifications: Small sub-brand and boxed sub-brand use small packaging; large packages/ton packaging are sold in ton bags, sorted by workshop usage.
Warehouse in-stock: EVOH warehouse stock is usually around 4000 tons, with small sub-brand stocks at 600-900 tons, boxed sub-brands at 250-450 tons, and large packages/ton at 2650-3150 tons.
Supply Assurance: Test orders come with goods, COA accompanies the goods.
Selection Tips and a Case from Jiaxing
Lock in ethylene content, measure melting index, match your membrane structure design, EVOH sub-brand arrives at the factory—data is securely blocked, shelf life does not shrink, composite film mass production is completed in one go
There is a client in Jiaxing who produces packaging films for snack foods. They have been using Kuraray EVAL 32mol% genuine product as the intermediate barrier layer, which led to high material costs. Later, they tried a batch of 32mol% EVAL from a secondary brand, with measured ethylene content at 33.2% (nominal 32%) and measured melt index at 3.8 (nominal 3.6), both within allowable deviations. They ran it on the machine for PE/EVOH/PE three-layer co-extrusion film, and the measured oxygen transmission rate was 0.05 cc/m²·day, very close to the 0.04 of the genuine film, and the client’s six-month shelf life test passed. Material costs dropped by more than a thousand per ton, saving around 200,000 in one year just on the barrier film.
This is how secondary-brand EVOH is used—not all packaging needs to use the genuine product. For snack food packaging, a six-month window is sufficient, and the slight ethylene content fluctuation in the secondary brand can be absorbed within the design margin. Ningbo Kelong New Materials Co., Ltd. has been producing imported secondary-brand EVOH for many years, sourcing from Kuraray, Japan Synthetic Chemicals, and Changchun Chemicals, handling many food barrier film projects each year.
