反常识：便宜的LLDPE副牌，往往比贵的更稳
很多人一听LLDPE副牌，头一个反应是"便宜没好货"。可泉州一家做农膜的厂，账算得不一样：他们用国产LLDPE副牌做了三年农膜，膜的拉伸强度和耐候性，居然和用正牌做的没差多少，单吨成本却降了一截。反常识的地方在——不是便宜没好货，是便宜的料你得会验。
LLDPE（线性低密度聚乙烯）韧性好、耐穿刺、延伸率高，做农膜、包装膜、地膜都靠它。国产LLDPE副牌能不能用住？中石化、中石油、宝丰能源，这三家是主流货源，这篇实测对比给你答案。
国产LLDPE格局：两桶油主导，宝丰煤化工抢位
LLDPE是低压气相法生产的线性聚乙烯，分子链支链短而规整，韧性和耐穿刺优于LDPE。国内LLDPE产能约1600万至1800万吨/年，是聚烯烃里产能大的品类。
中石化系统LLDPE产量约310万至490万吨/年，茂名、镇海、燕山、齐鲁等基地都有装置，农膜和包装膜专用料积累深；中石油系统LLDPE产量约210万至370万吨/年，依托大庆、独山子等基地；宝丰能源是煤制烯烃路线的代表，宁夏基地LLDPE产量约80万至115万吨/年，成本有优势。这三家，构成了国产LLDPE的主流货源。
LLDPE副牌：韧性料最怕熔指和密度跑偏
LLDPE副牌的概念和其他聚烯烃一致：同一装置同一牌号，出厂检验个别指标——熔指、密度、拉伸强度——小幅偏离正牌标准。来源是开停车头尾料、牌号切换过渡料、工艺波动批次。仍是原生聚合粒子。
LLDPE副牌有个特殊性：它是做膜的料，韧性和耐穿刺是核心指标。副牌容易波动的就是熔指和密度，熔指偏了，膜的厚薄均匀度和拉伸性能就受影响。分清四层：正牌全指标达标；副牌基材一致、个别指标略偏；回料受过一次热历史；再生料性能波动大。LLDPE副牌价格通常低于正牌，适合农膜、一般包装膜、内衬袋这类对韧性要求高但对透明度不苛求的场景。
中石化LLDPE：农膜包装膜的老牌户
中石化是国内LLDPE产量规模领先的企业，茂名、镇海、燕山、齐鲁等基地都有装置。代表牌号如7042是经典薄膜料，LL0209AA、DFDA7042也是常用牌号。
中石化LLDPE副牌的特点，是装置多、牌号熟，副牌主要来自过渡料和波动批次。做农膜和包装膜的厂对7042这些牌号都熟，副牌的熔指和密度波动相对可预期。适合做农膜、一般包装膜、内衬袋。要注意的是，做超薄地膜和高端包装膜，副牌的熔指和厚度均匀度风险大，得谨慎。
中石油LLDPE：西北成本底子，农膜有积累
中石油LLDPE依托大庆、独山子等基地，西北原料和能源成本有底子。代表牌号如7042、DFDA7042、LL0220KJ等。
中石油LLDPE副牌的特点，是西北装置开车率稳，副牌货源以农膜和包装膜过渡批次为主。适合农膜、一般包装膜、内衬袋这类对成本敏感的场景。因为成本结构有优势，它的副牌价格带往往有竞争力。
宝丰能源LLDPE：煤制烯烃，成本路子不同
宝丰能源是煤制烯烃路线的代表，宁夏宁东基地用煤制甲醇、再制烯烃、聚合出LLDPE。产量约80万至115万吨/年。代表牌号如7042薄膜料、DNDA8320等。
宝丰LLDPE副牌的特点，是煤化工路线成本低，副牌集中在薄膜料过渡批次。因为原料路线和油制不同，它的副牌在灰分和水分上要单独测。对做农膜、一般包装膜的下游，宝丰副牌在成本上有自己的位置。要注意的是，煤化工料做膜，进厂先测灰分和水分。
国产LLDPE副牌怎么验，检测单随货才踏实
一是先测熔指和密度。LLDPE副牌容易波动的就是熔指和密度，做膜对这两个指标敏感，进厂先打。二是，先测灰分和水分。宝丰这类煤化工料，灰分水分要单独测。三是，要检测单随货。小样上机试膜，过了再签。农膜厂都知道，膜的拉伸强度和耐穿刺是硬指标，副牌能不能用住，测了才知道。
科隆仓库现货｜国产LLDPE备货充足
做国产LLDPE副牌，备货足、检测全才敢上膜机。科隆仓库常备国产LLDPE现货，主推中石化、中石油、宝丰能源三家品牌。
• 主推品牌：中石化、中石油、宝丰能源
• 主要牌号：7042、DFDA7042、LL0209AA、DNDA8320等常用牌号
• 包装规格：大包装、小包装都有
• 仓库现货：通常在4000吨上下
• 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
大包料、吨包料适合连续生产的膜厂，小包副牌和箱装副牌适合中小厂试机和补单，按需调度。
选型口诀加一个真实案例
国产LLDPE副牌选型，记住三句话：先测熔指密度、灰分水分单测、检测单随货。别光听"便宜"两个字，把指标测全了，省下来的才是真钱。
说泉州那个农膜厂。他们用宝丰7042副牌做地膜，进厂先测熔指和密度，偏差在农膜工艺窗口内；单独测灰分和水分，也在可接受范围。上机试膜，拉伸强度和耐穿刺测试和正牌做的膜对比，数值没明显差距。正式投产后，单吨成本比正牌降了约450元，做了三年没出过大问题。差别不在料多神，而在测全了指标。
Counterintuitive: Cheap LLDPE sub-brand is often more stable than expensive
Many people's first reaction when hearing LLDPE sub-brand is, "Cheap makes no good product." But a factory in Quanzhou that makes agricultural film has a different story: they used domestic LLDPE sub-brand for three years to make agricultural film, and the tensile strength and weather resistance of the film were almost the same as those made with genuine brand, but the cost per ton dropped significantly. The counterintuitive part is—it's not that cheap goods are good, but that you have to test cheap materials.
LLDPE (linear low-density polyethylene) has good toughness, puncture resistance, and high elongation, making agricultural film, packaging film, and mulch film all rely on it. Can domestic LLDPE sub-brand be used? Sinopec, PetroChina, and Baofeng Energy are the mainstream suppliers. This real-world comparison will give you the answer.
Domestic LLDPE Landscape: Two major oil giants dominate, Baofeng Coal Chemical competes for the position
LLDPE producing linear polyethylene by low-pressure vapor phase method, with short and regular molecular and branch chains, better toughness and puncture resistance than LDPE. Domestic LLDPE capacity is about 16 to 18 million tons/year, making it the category with the largest capacity in polyolefins.
Sinopec System LLDPE output is about 3.1 million to 4.9 million tons/year, with facilities in Maoming, Zhenhai, Yanshan, Qilu, and other bases, with deep accumulation of specialized materials for agricultural and packaging films; PetroChina Systems LLDPE output is about 2.1 million to 3.7 million tons per year, relying on bases such as Daqing and Dushanzi; Baofeng Energy represents the coal-to-olefin route, with Ningxia base LLDPE output about 800,000 to 1.15 million tons per year, offering cost advantages. These three companies form the mainstream supply sources for domestic LLDPE.
LLDPE sub-brand: The tough material is most vulnerable to melt index and density deviation
LLDPE The concept of sub-brands is the same as other polyolefins: same device and grade, but individual factory inspection indicators—melt index, density, tensile strength—slightly deviate from genuine brand standards. Sources include start-and-stop starting and parking end materials, grade switching transition materials, and process fluctuation batches. Still primary polymer particles.
LLDPE sub-brand has a special feature: it is the material used for the film, with toughness and puncture resistance as core indicators. The sub-brand is prone to fluctuation in melt index and density; if the melt finger is off, the film's thickness uniformity and tensile properties are affected. Four layers are clearly divided: genuine brand meets all standards; Sub-brand base material is consistent, with some indicators slightly off; Reclaimed material has undergone one heat history; Recycled material performance fluctuates greatly. LLDPE sub-brand prices are usually lower than genuine brands, suitable for agricultural films, general packaging films, lining bags, and other scenarios where toughness is high but transparency is not demanding.
Sinopec LLDPE: A long-established manufacturer of agricultural film packaging films .
Sinopec is a leading domestic LLDPE production company, with facilities in Maoming, Zhenhai, Yanshan, Qilu, and other bases. Representative grades include 7042, which is a classic film material, while LL0209AA and DFDA7042 are also commonly used grades. The characteristics of the
Sinopec LLDPE sub-brand are its many units and familiar grades, with sub-brands mainly coming from transition materials and fluctuating batches. Factories producing agricultural film and packaging film are familiar with 7042 grades, so the melting index and density fluctuations of the sub-brand are relatively predictable. It is suitable for making agricultural film, general packaging film, and lining bags. It should be noted that for ultra-thin mulch film and high-end packaging film, the sub-brand's melting index and thickness uniformity carry significant risks, so caution is needed.
PetroChina LLDPE: Cost base in the northwest, agricultural film accumulation
PetroChina LLDPE relies on bases like Daqing and Dushanzi, with a solid foundation in raw material and energy costs in the northwest. Representative grades include 7042, DFDA7042, LL0220KJ, etc. The characteristic of
PetroChina LLDPE sub-brand is its stable operating rate at the Northwest plant, with sub-brand supply mainly being transitional batches of agricultural film and packaging film. It is suitable for cost-sensitive scenarios such as agricultural film, general packaging film, and lining bags. Due to its cost structure advantage, its sub-brand price range is often competitive.
Baofeng Energy LLDPE: Coal-to-olefin, different cost paths
Baofeng Energy represents the coal-to-olefin route, using coal-to-methanol and reprocessed olefins at the Ningxia Ningdong base to produce LLDPE. Output is about 800,000 to 1.15 million tons per year. Representative grades include 7042 film material, DNDA8320, etc.
Baofeng LLDPE sub-brand features low cost in the coal chemical route, with sub-brands concentrated in the film material transition batch. Because the raw material route and oil production differ, its sub-brand must be measured separately for ash content and moisture. For downstream products like agricultural film and general packaging films, Baofeng's sub-brand has its own position in cost. It should be noted that when making films from coal chemical materials, ash content and moisture content must be measured before entering the factory.
How to test domestic LLDPE sub-brand? Test forms are reliable with the goods
First, first measure melting index and density. The weak parts prone to fluctuation in LLDPE secondary brands are melting index and density; membrane processing is sensitive to these two indicators, so test before entering the factory. Second, first measure ash and moisture content. For coal chemical materials like Baofeng, ash and moisture must be measured separately. Third, test the order with the goods. Small samples are tested on the machine for film testing, and only after passing can they be signed. Agricultural film factories know that tensile strength and puncture resistance are hard metrics; whether the secondary brand can be used depends on testing.
Cologne warehouse stock | Domestic LLDPE stock is sufficient
Do domestic LLDPE secondary brand; only with sufficient stock and full testing can the film machine be installed. The Cologne warehouse always stocks domestic LLDPE stock, mainly promoting Sinopec, PetroChina, and Baofeng Energy brands.
• Main Brands: Sinopec, PetroChina, Baofeng Energy
• Main Grades: 7042, DFDA7042, LL0209AA, DNDA8320 and other commonly used grades
• Packaging Specifications: Both large and small packages available
• Warehouse Stock: Usually around 4000 tons
• Small sub-brand stock: 600-900 tons, Containerized sub-brand stock 250-450 tons, large package material/ton package material stock stock 2650-3150 tons
• Supply guarantee: test orders with goods
Large package materials and ton package materials are suitable for continuous production film factories; small package sub-brands and boxed sub-brands are suitable for small and medium factories to test machines and supplement orders, with on-demand scheduling.
Selection Mnemonic plus a real case
Domestic LLDPE sub-brand selection, remember these three points: first test melting finger density, ash content and moisture separately, test the order with the goods. Don't just listen to the word "cheap"; measure all the indicators and you'll save real money.
Talking about that agricultural film factory in Quanzhou. They use Baofeng 7042 sub-brand to make mulch film, first testing melting fingers and density upon arrival, with deviations within the agricultural film process window; Measuring ash content and moisture separately is also within acceptable ranges. Testing the film on the machine, tensile strength and puncture resistance tests, compared to genuine films, show no significant difference. After official production, the cost per ton dropped by about 450 yuan compared to the genuine brand, and after three years of work, there were no major problems. The difference isn't in overthinking, but in measuring all the metrics
