做棚膜、做缠绕膜、做电线电缆绝缘层的老板，对ULDPE这个料又爱又怕。爱的是它软而韧、低温抗冲好、和PE基料相容极佳；怕的是国产ULDPE"听说不稳"，换了三家供应商都翻车——熔指不对、粘连严重、开口性差。今天这篇文章，把国产ULDPE的国内格局给你捋清楚。
ULDPE是什么 国产突破到哪一步了
ULDPE（超低密度聚乙烯）密度通常在0.880-0.905g/cm³之间，介于弹性体和聚乙烯之间，核心特性是柔软、高伸长率、低温抗冲、和PE类材料相容好。它大量用于农膜、包装膜、电缆绝缘层、软管、增韧改性等领域。过去ULDPE市场被陶氏、埃克森美孚、三井等外资企业主导，国产料长期空白。
近三年国产ULDPE取得实质突破。中石化天津石化牵头研发的持液颗粒流化床乙烯聚合技术获2025年度国家科学技术进步奖二等奖，该技术开发出超低密度聚乙烯产品并在天津石化稳定运行十余年。中石化燕山分公司依托茂金属催化剂自主技术平台，ULDPE专用树脂年产能达8.6万吨。中石油大庆石化2025年ULDPE树脂产能为5.2万吨。万华化学2024年第四季度投产首套自主知识产权ULDPE生产线，设计年产能5万吨。
三家头部企业基本覆盖了国产ULDPE的主力供应。外资方面，陶氏ENGAGE系列、埃克森Exact系列仍占据高端膜料市场，但国产料在中低端包装膜和改性增韧领域替代速度很快。
ULDPE副牌和正牌差在哪
ULDPE副牌是原厂聚合线下来的原生粒子，个别指标小幅偏离正牌标准。ULDPE最容易出偏差的指标是密度和熔指——密度差0.005-0.01g/cm³、熔指偏差0.5-2个点，都会影响薄膜的开口性和力学性能。
副牌来源仍是四大类：开停车头尾料、牌号切换过渡料、工艺波动导致密度或熔指小幅偏离的批次、副线尾料。对于做农膜内衬、非直接接触包装膜、电缆填充绳等对密度精度要求不高的场景，副牌ULDPE完全够用。
和回料的区别特别要说：ULDPE回料经过再次挤出后，分子量分布变宽、结晶度变化，薄膜性能明显下降。副牌ULDPE是原生粒子，未经过二次热历史，力学性能和正牌差距很小。
中石化系 燕山和天津两条线各有侧重
中石化系在国产ULDPE领域布局最早。燕山分公司依托茂金属催化剂自主技术平台，ULDPE专用树脂年产能达8.6万吨，产品偏薄膜级，主要服务农膜和包装膜客户。天津石化则依托持液颗粒流化床乙烯聚合原创技术，开发超低密度聚乙烯产品，该技术获国家科技进步奖二等奖，产品在电缆料和改性增韧领域有一定口碑。
中石化系ULDPE副牌的特点是批次稳定性相对好——毕竟是大企业大装置，工艺控制成熟。副牌主要来源于牌号切换和工艺微调批次，密度偏差可控。对于要求薄膜开口性稳定、批次一致性高的客户，中石化系副牌是稳妥选择。包装以大包装为主。
中石油大庆石化 北方ULDPE主力
中石油大庆石化2025年ULDPE树脂产能5.2万吨，是北方地区主力供应基地。大庆石化的ULDPE产品偏通用级，主要服务东北和华北地区的膜厂和改性厂。中石油体系在2024年开发了6个超低密度聚乙烯产品（密度0.884g/cm³），性能对标陶氏POE，实现了气相法技术突破。
大庆ULDPE副牌的特点是性价比高——大庆石化地处东北，原料成本有优势，副牌价格在国产ULDPE中属于偏低梯队。对于对成本敏感、产品附加值不高的农膜和一般包装膜客户，大庆副牌值得关注。包装大小包均有。
万华化学 新入局者技术后发
万华化学2024年第四季度投产首套自主知识产权ULDPE生产线，设计年产能5万吨，依托其C4/C5共聚技术平台。万华的后发优势在于催化剂技术和一体化成本——万华在聚烯烃领域的技术积累深厚，ULDPE装置从投产初期就对标国际水平。
万华ULDPE副牌目前处于装置爬坡期，开停车料和过渡料相对较多，正是副牌货源的窗口期。万华副牌的特点是产品定位偏中高端，早期副牌的外观和基础物性不错，适合做改性增韧和中高端膜材。第二梯队方面，浙江石化2025年二季度实现ULDPE专用牌号规模化稳定出货，可作为备选关注。
ULDPE副牌进厂 密度熔指双检
第一，密度和熔指必须双检。ULDPE副牌最容易出偏差的就是这两个指标。进货前要求供应商提供同批次密度和熔指检测数据，到货后用密度梯度柱和熔指仪复测。密度差0.01就可能导致薄膜开口性异常，别嫌麻烦。
第二，先小批量试机。国产ULDPE副牌首次上机，建议先投50-100公斤试机，观察薄膜的开口性、拉伸强度、撕裂强度是否正常，确认没问题再批量投料。不要一上来就整批上，翻车了损失大。
第三，按用途选厂家。做农膜、内衬袋选中石化燕山副牌，批次稳；做低成本包装膜选大庆副牌，价格好；做改性增韧、中高端膜选万华副牌，性能有潜力。别拿大庆副牌去做高端膜，也别拿万华副牌去做最便宜的内衬袋。
科隆仓库现货 国产ULDPE副牌直供
科隆仓库现货ULDPE副牌，主推中石化燕山分公司、中石油大庆石化、万华化学三家国产ULDPE树脂，主要牌号覆盖薄膜级和通用级，大包装和小包装均有备货。仓库现货通常在5000吨左右，其中小包副牌备货800-1000吨、箱装副牌备货300-500吨、大包料/吨包料备货3500-3900吨。供应保障走先测后签通道——先送检合格再签合同，检测单随货同行。
Bosses who make greenhouse films, stretch films, and wire and cable insulation both love and fear ULDPE material. What I love is that it is soft yet tough, has good low-temperature impact resistance, and excellent compatibility with PE substrates; What worries me is that domestic ULDPE is "rumored to be unstable," and after switching suppliers, all failed—incorrect fusion fingers, severe adhesion, poor opening performance. Today's article will clearly outline the domestic landscape of domestic ULDPE. What is
ULDPE? How far has domestic breakthroughs come
ULDPE (ultra-low density polyethylene) usually has a density between 0.880-0.905g/cm³, between elastomer and polyethylene. Its core characteristics are softness, high elongation, low-temperature impact resistance, and compatibility with PE materials. It is widely used in agricultural films, packaging films, cable insulation layers, hoses, toughening modification, and other fields. In the past, the ULDPE market was dominated by foreign companies such as Dow, ExxonMobil, and Mitsui, with domestic materials remaining unavailable.
In the past three years, domestic ULDPE has achieved substantial breakthroughs. Sinopec Tianjin Petrochemical led the development of liquid holding particle fluidized bed ethylene polymerization technology, which won the second prize of the 2025 National Science and Technology Progress Award. This technology developed ultra-low-density polyethylene products and has been operating stably at Tianjin Petrochemical for over ten years. Sinopec Yanshan Branch, relying on its own metallocene catalyst technology platform, has an annual ULDPE resin production capacity of 86,000 tons. PetroChina Daqing Petrochemical's ULDPE resin production capacity is expected to reach 52,000 tons by 2025. Wanhua Chemical will begin production of its first independently owned ULDPE production line in Q4 2024, with a designed annual capacity of 50,000 tons. The three leading
companies basically cover the main supply of domestic ULDPE. On the foreign side, Dow ENGAGE series and Exxon Execute series still dominate the high-end film material market, but domestic materials are rapidly replacing in mid- to low-end packaging films and modified toughening fields.
ULDPE What is the difference between sub-brand and genuine brand
ULDPE Sub-brand refers to original particles produced from the original polymerization line, with some indicators slightly deviating from genuine standards. The most common indicators for ULDPE deviation are density and melting index—a density difference of 0.005-0.01g/cm³ and melting index deviation of 0.5-2 points can affect the film's opening and mechanical properties.
The secondary brand still comes from four main categories: start-stop tail material, grade switching transition material, batch of batch with slight deviation in density or melting index due to process fluctuations, and auxiliary line tailing. For agricultural film linings, non-direct contact packaging films, cable filling ropes, and other scenarios where density precision is not high, the secondary brand ULDPE is fully sufficient. The difference between
and recycled material is especially noteworthy: after ULDPE return material is extruded again, the molecular weight distribution widens and crystallinity changes, and the film performance significantly declines. The secondary brand ULDPE is a primary particle that has not undergone secondary thermal aging, so its mechanical properties differ very little from genuine grade.
Sinopec Group Yanshan and Tianjin lines each have their own focus .
Sinopec Group was the earliest to establish itself in the domestic ULDPE field. Yanshan Branch relies on its own metallocene catalyst technology platform, with an annual ULDPE resin production capacity of 86,000 tons, focusing on film-grade products mainly serving agricultural film and packaging film customers. Tianjin Petrochemical, relying on original fluidized bed ethylene polymerization technology for holding particles, has developed ultra-low density polyethylene products, which won the second prize of the National Science and Technology Progress Award. The products have a certain reputation in cable materials and modified toughening fields. The characteristic of
Sinopec ULDPE sub-brands is relatively good batch stability—after all, they are large enterprises and large units with mature process control. Sub-brands mainly come from grade switching and process fine-tuning batches, with controllable density deviations. For customers requiring stable film opening and high batch consistency, Sinopec's sub-brands are a reliable choice. Packaging mainly consists of large packages.
PetroChina Daqing Petrochemical Northern ULDPE Main Supplier
PetroChina Daqing Petrochemical has a ULDPE resin production capacity of 52,000 tons by 2025, making it the main supply base in northern China. Daqing Petrochemical's ULDPE products are more general-grade, mainly serving membrane and modification plants in Northeast and North China. In 2024, PetroChina developed six ultra-low density polyethylene products (density 0.884g/cm³), benchmarking Dow POE performance and achieving breakthroughs in gas phase technology.
Daqing ULDPE sub-brand is characterized by high cost-performance — Daqing Petrochemical is located in Northeast China, with advantageous raw material costs, and sub-brand prices are relatively low among domestic ULDPE. For customers sensitive to cost and low product added value for agricultural films and general packaging films, the Daqing sub-brand is worth considering. Available in both large and small packages.
Wanhua Chemical New entrant latecomer
Wanhua Chemical will put into operation its first independently owned ULDPE production line in Q4 2024, designed with an annual capacity of 50,000 tons, relying on its C4/C5 copolymerization technology platform. Wanhua's latecomer advantage lies in catalyst technology and integrated costs—Wanhua has deep technical accumulation in the polyolefin field, and ULDPE units have benchmarked international standards since their initial production.
Wanhua ULDPE sub-brand is currently in the ramp-up phase, with relatively large amounts of start-up and shutdown materials and transition materials, making it a window for sub-brand supply. Wanhua's sub-brand is characterized by a mid-to-high-end product positioning. Early sub-brands had good appearance and basic physical properties, suitable for modified toughening and mid-to-high-end film materials. In the second tier, Zhejiang Petrochemical will achieve large-scale and stable shipments of ULDPE dedicated grades in Q2 2025, which can be considered as a backup option.
ULDPE sub-brand entering the factory: Double inspection of density melt index
First, density and melt index must be double-tested. These two indicators are most prone to deviation from ULDPE secondary brands. Before purchase, suppliers are required to provide density and melt index test data for the same batch, and after arrival, re-measure with density gradient columns and melt finger meters. A density difference of 0.01 may cause abnormal film opening, so don't mind the hassle.
Second, test the machine in small batches first. For domestic ULDPE sub-brands on the machine for the first time, it is recommended to test the film with 50-100 kg of knit and observe whether the opening, tensile strength, and tear strength are normal. Only batch feed after confirming there are no issues. Don't rush to buy the whole batch right away—if it backfires, the losses will be huge.
Third, choose manufacturers based on usage. For agricultural film and lining bags, choose the Sinopec Yanshan sub-brand—stable batch sales; For low-cost packaging films, choose Daqing sub-brand—the price is good; For modified toughened and mid-to-high-end films, choose the Wanhua sub-brand—it has performance potential. Don't use Daqing sub-brand for high-end film, and don't use Wanhua sub-brand for the cheapest lining bags.
Cologne warehouse in-stock, domestic ULDPE sub-brand direct supply
Cologne warehouse in-stock ULDPE sub-brand, mainly recommending three domestic ULDPE resins: Sinopec Yanshan Branch, PetroChina Daqing Petrochemical, and Wanhua Chemical. The main grades cover film and general grades, with both large and small packages available. Warehouse stock is usually around 5,000 tons, with 800-1,000 tons of sub-brand stockpiled for small parcels, 300-500 tons for sub-label containers, and 3,500-3,900 tons for large packages/ton packages. Supply assurance follows the 'test first, sign later' channel—first send for inspection before signing contracts, and test forms travel with the goods
