再生PE聚乙烯:吹膜、管材、托盘,再生HDPE省下的不止料价

塑料知识科普 发布时间: 2026-09-16 1042 阅读

New material sells for seven thousand, recycled material sells for five thousand, yet the experienced workers in the film-blowing workshop just shake their heads at the cheap stuff—the moment the material goes into the machine, the film bubbles, there are many crystal points, and the rolls come out brittle. The same ton of material, taken by the neighboring factory, works perfectly for making pallets, but in his hands, it turns into a pile of scrap. The difference isn't in the material; it's that he simply hasn't figured out which types in the recycled PE family are equivalent to each other.

Let's spend two minutes getting to know the main character. Ningbo Kolon New Materials Co., Ltd. is a plastic raw material supplier integrating both industry and trade. Recycled PE (polyethylene) is a common category, with multiple grades of HDPE, LDPE, and LLDPE available. Polyethylene is one of the most widely produced types among general-purpose plastics. The cling film, vest bags, plastic buckets, water pipes, and turnover pallets you see in daily life are all made from it. The sources of recycled PE are divided into two routes: one comes from industrial packaging film scraps and sprues from pelletizing plants, which are clean and easy to process; the other route comes from recycled agricultural films, chemical barrels, engine oil bottles, daily chemical bottles, and pipes, which need to be washed, crushed, and pelletized. The technical basis is GB/T 40006.2-2021 "Plastics – Recycled Plastics – Part 2: Polyethylene (PE) Materials," which classifies recycled PE by density into low-density, high-density (HDPE), and filled mixed categories, and has clear requirements for ash content, moisture, density deviation, and MFR variation coefficient. This article will explain in one go the distinctions between high and low pressure recycled PE, how to choose films, pipes, and pallets, and how the accounting works.

Hearing 'recycled material' makes people shake their heads; it's mostly because they were scared by the previous generation of recycled materials.

Many people's bad impression of recycled PE comes from the early type of pellets that were black, mixed with calcium carbonate, and would break easily when pulled. Such material did exist, but it was 'homemade recycled material' without sorting or cleaning, which is not the same as today’s compliant recycled PE managed according to GB/T 40006.2. The standard classifies recycled PE according to density: those with a density not exceeding 0.940 are classified as low-density types (LDPE, LLDPE, MDPE); those exceeding 0.940 are classified as high-density HDPE types. Additionally, there is a type that allows for filled, higher-ash mixed material.

Many bosses frown when they hear 'recycled material,' and what they fear is basically a few things: impurities, inconsistency between batches, and failing customer factory inspections. These concerns are exactly what standards and legitimate suppliers are designed to address. Standards list out things like ash content, moisture, density, and MFR variation coefficients so that you have something to check; legitimate suppliers provide testing data for each batch so that you can present it during factory inspections. These worries won't disappear depending on whether you use recycled material; they only vary depending on whether you choose the right supply channel. If the channel is chosen correctly, recycled material can also be used as the main component.

The hard indicators in the standard are obvious to outsiders at a glance: under the 600°C ash test, ordinary recycled PE must not exceed 2%, and mixed types with fillers are allowed up to 5%; moisture must not exceed 0.2%; MFR should report the measured value, and the coefficient of variation must be controlled. For key properties like tensile strength, recycled PE is allowed to be slightly lower than virgin material, but it must be stable. In other words: the state allows recycled PE to have discounted performance, but it does not allow each batch to have a different discount.

This is why some people make money using recycled PE, while others end up failing. The one who failed used low-grade HDPE meant for pallets to blow film, which is like asking a truck driver to drive a race car—the material itself wasn't bad, it was just put on the wrong track. Film manufacturers need materials with good flow, easy opening, and few crystallization points, while pallet manufacturers need rigid, impact-resistant, and cheap structural materials; the requirements for the materials are completely different paths.

Recycled PE is not shameful; being on the wrong track is shameful — a film is not a tray, and a tray cannot replace a film.

Adding another layer of context: why are the film, pipe, and pallet industries all rushing to use recycled PE? Because they have low requirements for appearance, large usage volume, and stable recycling channels. The liner films used by film factories are packaging consumables that are discarded after use, so making them into recycled material and returning them to the production line creates a short closed loop. Pipes and pallets rely on structural performance, so being a bit darker in color or rougher on the surface doesn't affect their use. Hollow daily chemical bottles are even larger in volume and widespread; motor oil bottles and laundry detergent bottles pile up in recycling stations, and once sorted, they become good raw materials. With strong demand and supply on both ends, recycled PE naturally becomes one of the main varieties of recycled plastics in terms of volume.

Figure 1 Regenerated PE Blown Film and Hopper Feeding Scene (Schematic)

In the world of PE, there are high and low pressures; HDPE and LDPE are two temperaments.

Before talking about recycled PE, let's first translate the jargon of high and low pressure. In the industry, 'high-pressure material' refers to LDPE, low-density polyethylene, which has low crystallinity, a soft feel, good film gloss, and excellent heat-sealing properties. It is indispensable for making T-shirt bags and packaging films. 'Low-pressure material' refers to HDPE, high-density polyethylene, with well-ordered molecular arrangement, strong rigidity, high tensile strength, and puncture resistance, making it more suitable for pipes, hollow containers, and pallets. LLDPE linear material falls in between, has good toughness, and is often mixed with LDPE when blowing films, with common ratios adjusted according to the weight of the packaging.

Recycled PE turns from waste into pellets and follows the same process of sorting, crushing, washing, and pelletizing. However, PE has its own challenges: film material is thin, carries sand or dirt, and may have printing ink; agricultural film is also prone to carrying soil, making the cleaning cost much higher than for rigid products. Hard materials such as chemical drums and motor oil bottles have high density, are easy to clean, and have good rigidity. After being made into recycled HDPE, they become the main material for pallets and hollow products; clean industrial packaging films provide recycled material for blown film grades. According to origin and use, common recycled PE grades on the market are roughly as follows (the indicators are summarized from general industry standards, specific standards refer to GB/T 40006.2 and manufacturer TDS):

Level NameTypical sourceKey indicatorsTypical uses
Blown Film Grade Recycled LDPE/LLDPEIndustrial packaging film, film scrapsLow MFR, few crystal points, good opennessLiner bags, light packaging films, shrink films
Injection molding grade recycled HDPEChemical drums, turnover boxes, turnover palletsModerate MFR, relatively good rigidityTrays, tray covers, daily necessities
Pipe-grade recycled HDPEOld water pipes, corrugated pipesLow melt index, resistant to environmental stress crackingCorrugated pipes, non-pressure drainage pipes
Hollow blow molding grade recycled HDPEEngine oil container, daily chemical bottlesLow MFR, drop-resistantNon-food daily chemical bottles and barrels
Natural Light-Colored Recycled PEClean film, packaging scrapsFew impurities, can be color-matchedColor film, modified base material
Black filled recycled PEMixed-color film, mixed recyclingHigh ash content, low pricePallets, cable conduits, spacers

Market Reference: Recently, the mainstream quotations for white, first-grade transparent recycled LDPE film-grade pellets in the market are around over 6,000 yuan per ton. White, first-grade recycled HDPE for injection molding and film-grade are in a similar range. Black or filled grades are cheaper, generally over 5,000 yuan per ton. When Ningbo Kolon New Materials Co., Ltd. quotes for PE materials, they usually first ask whether the downstream application is film, pipe, hollow, or injection molding, and then adjust the grade according to the use — because in the PE business, knowing the correct process is essential for accurately negotiating the material price.

One more point about PE recycling: PE molecular chains degrade after multiple heating cycles, the MFR tends to rise, and the material becomes brittle. Therefore, when recycling film-grade materials, the extrusion process usually needs to be readjusted, and if necessary, a bit of processing aid is added to stabilize flow. This is also why recycled film-grade material is expensive — it needs to be cleaned thoroughly and the degradation must be controlled. On the other hand, items like trays and pads are not sensitive to slight changes in MFR and can tolerate mechanical property decline, so using cheap black filled material is quite suitable. In short: the closer the material is to the process it was originally designed for, the better it is to use after recycling; for cross-purpose applications, it needs to be reconditioned.

What is saved is not just the cost of materials, but also the stability of the entire production line.

The accounts for recycled PE are easier to miscalculate than for recycled PP because its process variations are so large: for blown film, you check if the bubbles are stable and if there are many crystal spots; for extrusion tubing, you see if the surface is smooth and if the thickness is uniform; for hollow molding, you check if there will be bubbles during blow molding or cracks when dropped. If the wrong material is chosen, the small savings on material costs are entirely offset by machine adjustments and waste. Laying it out:

Cost itemBrand new PE materialRecycled PEDifference Explanation
Raw material purchase priceBenchmark priceAround a few thousand yuan per tonThe price difference at the film level is narrow, while the price difference for black filling is wide.
Process yieldStableDepends on level matchingFilm-level crystal points and tube-level surfaces are key
Appearance ColorconsistentThe natural color may need to be matchedFor light-colored films, choose white transparent material
Mechanical propertiesStableHDPE is rigid, LDPE is softMixing high and low pressure requires a set ratio
Scrap reworkfewConcentrated outbreak due to choosing the wrong levelFirst try a small test to determine the mixing ratio
Annual Comprehensivesuperficially expensiveBuying large quantities of big items is more cost-effectiveFood contact films are also subject to compliance restrictions

Boundary List — When to Keep in Mind, When to Hold Back:

Use with confidence: trays, shims, cable conduits, non-pressure drainage pipes, black or color-matching hollow parts.

Use with caution: For packaging blown film, first select high-grade white transparent film material, check the specks and openness, and increase the quantity only after a small trial.

First verify: hollow chemical drums and containers, test for drop resistance and dimensional stability; for high and low pressure blends, test with film bubbles first.

Do not touch: food directly contacting the packaging film without compliance basis; high-transparency, high-end packaging film; blown film from mixed, unknown sources.

Procurement actions: For film-grade materials, look at the crystallization point and ash content; for pipe-grade materials, look at the melt index and ash content. Don’t just ask, 'How much per ton?'

By the way, let's thoroughly explain the high- and low-pressure blending experience in film blowing: using only LDPE makes the film soft but it can't hold up or stand; using only HDPE makes the film hard but brittle, prone to cracking. So conventional vest bags and light packaging films usually blend LDPE with LLDPE according to a certain ratio, while heavy-duty industrial films increase the HDPE proportion. When recycled material comes to you, don't expect to directly replace a particular type of virgin material. Instead, use the same blending ratio you originally had and find corresponding grades of recycled material to substitute—for example, if your original mix was LDPE to LLDPE at seven to three, then find the corresponding two grades of recycled material, keep the blending ratio unchanged initially, and only adjust slightly once the film begins to stabilize. This way, cost reduction is minimal and risks are controllable.

Cologne New Materials' film material debugging: only when the blending ratio is correct will the film not curl.

To make the explanation clearer, a typical scenario that has been adapted will be demonstrated below; it is not a real order record. A small factory in Ningbo that produces industrial lining films wanted to reduce costs, so it directly purchased a batch of cheap black recycled PE. Problems arose as soon as it was put into production: the film bubbles were unstable, wrinkles appeared during rolling, and crystalline spots were scattered, resulting in a high defective rate. The owner almost gave up on using recycled materials.

Later, they got in touch with Ningbo Kolon New Materials Co., Ltd. After looking at the film specifications, Kolon New Materials first rejected the black material — the liner film needs to be light-colored and have few crystal points, and black filler is inherently unsuitable for film blowing. Their suggestion was: use white transparent primary recycled LDPE as the main material, add a small portion of LLDPE recycled material to adjust toughness, with the blending ratio tested according to film thickness and packaging weight; first do small-scale lab tests by blowing a few rolls, and once the film bubbles are stable and the crystal points pass inspection, proceed to batch production. Once the process ran smoothly, the material supply was secured, the defect rate fell from double digits at its peak to normal levels, and the rolled films came out flat without curling.

The lesson illustrated by this scenario is very simple: reducing costs with recycled PE is not about 'finding the cheapest material,' but about 'finding material that can run stably on your production line.' Ningbo Kolon New Materials Co., Ltd. supplies PE by putting effort into the preliminary work—first asking about the process, then determining the grade, and finally discussing the price. The order is exactly the same as when selecting PP.

Reviewing this case, Kolon New Material summed it up in one sentence: for film blowing using recycled material, the clarity of the material matters more than the color, and the presence of spots matters more than the price. The reason why premium white transparent material is expensive is that it is thoroughly washed, finely screened, and has few black spots, so the blown film is clear; going for a cheaper black material mixed with calcium powder will result in defective film, no matter how cheap it is. Later, this factory applied the same method to thick liners, steadily increasing the proportion of recycled material used, and even during peak season, production never stopped due to material issues.

You think you are saving on material costs, but in fact, you are leaving the crystal defects, blisters, and rework for yourself—the wrong grade means every penny saved has to be paid back double.

For selecting recycled PE, first consider the density, then look at the application.

Condense common applications into a quick reference table and check them before placing an order:

Application scenarioRecommendation LevelPrecautionsWhen to stop using
Liner film, lightweight packaging filmWhite Transparent Recycled LDPE/LLDPE Film GradeObserve crystal points and opennessFood direct contact films must pass compliance first
Pallets, padsRecycled HDPE Injection Molding Grade / Black Filled GradeCheck rigidity and ash contentHigh-load outdoor parts are first tested for impact
corrugated pipe, drainage pipePipe-grade recycled HDPEObserve the molten tip and surfaceDo not use for pressurized drinking water pipes
Daily chemical bottles and barrelsHollow blow molding grade recycled HDPEDrop resistance testFood-grade containers to be discussed separately
Modified base materialNatural Light-Colored Recycled PEDetermine color matching and blending ratioDo not mix with high-transparency optical components

Three sentences to wrap up: First, clearly identify whether the material in your hands is HDPE or LDPE. Next, figure out whether your process is film blowing, pipe extrusion, or hollow molding. Only then should you discuss the price. If the order is reversed, the film bubbles, the pipes bend, and the barrels crack—the money saved on materials wouldn't even cover machine repairs. The industry is moving towards a circular economy, and policies are promoting graded applications of recycled materials. Factories that know how to use recycled PE have been quietly reducing costs in recent years; those that don't are still being blocked by the prejudice that 'recycled material = inferior product.' This calculation will become clear sooner or later, and those who start early will save money early.

Here’s a practical tip for you when purchasing: for the first cooperation, don’t go straight for a ton. Start with a few kilograms of sample material, run it for half a day, check the melting point, black spots, and moisture, and then discuss bulk orders. The trick with recycled PE often isn’t in the indicators of a single batch, but between two batches—this batch is clean, the next might be mixed with impurities. Include the acceptance criteria in the contract and attach test data with each batch; it’s more reliable than any verbal guarantee. This step may seem slow, but it can help you eliminate six months of potential headaches in one go.

Recycled PE has never been a 'synonym for cheap'; it is a craft of putting the right material into the right process. When the craft is mastered, both cost and yield will be on your side.

Using recycled PE in the right places saves more than just the material cost.

Disclaimer: The brands and trademarks mentioned in this article belong to their respective original manufacturers. This article is a third-party material selection knowledge sharing. The specific grades, parameters, prices, certifications, and other information involved in the text are subject to the latest official data from each manufacturer. This article does not constitute any procurement or investment advice.

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