LyondellBasell HDPE H4837
- Product Name: LyondellBasell HDPE H4837
- Factroy Site: Yudu County, Ganzhou, Jiangxi, China
- Price Inquiry: admin@ascent-chem.com
- Manufacturer: Ascent Petrochem Holdings Co., Limited
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- LyondellBasell HDPE H4837 is typically used in formulations when melt flow rate and density and processing temperature and pressure must be controlled within specific ranges.
| HS Code | 559955 |
| Density | 0.948 g/cm³ |
| Melt Flow Rate 190 C 2 16 Kg | 3.5 g/10 min |
| Tensile Strength At Yield | 28 MPa |
| Tensile Strength At Break | 30 MPa |
| Elongation At Break | 600% |
| Flexural Modulus | 1200 MPa |
| Charpy Notched Impact Strength At 23 C | 15 kJ/m² |
| Vicat Softening Temperature | 75°C |
| Heat Deflection Temperature At 0 46 Mpa | 70°C |
| Hardness Shore D | 62 |
| Melting Temperature | 130°C |
| Water Absorption | 0.01% |
| Brittleness Temperature | -70°C |
| Thermal Conductivity | 0.4 W/m·K |
| Coefficient Of Linear Thermal Expansion | 1.5E-4 /°C |
| Specific Heat | 1.9 kJ/kg·K |
As an accredited LyondellBasell HDPE H4837 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | LyondellBasell HDPE H4837 is packaged in 25 kg (55 lb) polyethylene bags, palletized and stretch-wrapped for transport. |
| Container Loading (20′ FCL) | 20′ FCL: LyondellBasell HDPE H4837 in 25 kg bags; approximately 18–20 MT per container, depending on palletized or floor-loaded stowage. |
| Shipping | LyondellBasell HDPE H4837 is shipped as non-hazardous high-density polyethylene pellets in 25 kg bags, octabins, bulk bags, or bulk trucks/railcars. It is not DOT/IMDG/IATA regulated. Protect from moisture, contaminants, and excessive heat. Store in a cool, dry, well-ventilated area away from ignition sources. Keep containers closed and avoid prolonged direct sunlight. |
| Storage | Store LyondellBasell HDPE H4837 indoors in a cool, dry, well-ventilated area, away from direct sunlight, heat, sparks, flames, and strong oxidizers. Keep original packaging closed, clean, and palletized off the floor. Prevent moisture, dust, and contamination. Use first-in, first-out stock rotation. Avoid prolonged UV exposure, extreme temperatures, and incompatible materials. Always follow the supplier’s SDS and applicable local regulations. |
| Shelf Life | LyondellBasell HDPE H4837 shelf life is typically two years when stored unopened in cool, dry conditions away from direct sunlight. |
At a nominal density of 0.948 g/cm³ (ISO 1183-1) and with a high-molecular-weight bimodal structure, LyondellBasell HDPE H4837 is processed on accumulator-head shuttle blow moulding machines to produce UN 1H1 drums and UN 3H1 jerricans in the 15–60 L class. The barrel temperature profile is set from 170°C at the grooved feed bush to 215°C at the die head, with a melt temperature of 205–225°C measured at the accumulator inlet. Shot weights of 1.2–3.8 kg remain stable without parison draw-down when the die gap is held between 1.5 mm and 2.8 mm, and blow air is introduced through a calibrated needle at 0.6–0.9 MPa. Mould cooling water is controlled at 8–15°C so that the pinch-off zones develop compression welds rather than brittle quenched seams. Clean post-industrial trimmings from the same production line are gravimetrically metered into the recycle feed at 20–30 wt%, with melt filtration at 80–120 mesh upstream of the accumulator to remove crosslinked gel particles generated during repeated heat histories. The handle bridge and bottom pinch weld are the controlling defect sites: compacting the weld to less than 1.5 times the nominal wall thickness creates a stress concentration that fails leakproofness at 30 kPa internal air pressure after low-temperature impact. Acceptance for hazardous liquid transport is based on the UN Manual of Tests and Criteria, Part III, section 6.1.5: drop impact from 1.2 m at −18°C onto the most vulnerable seam, hydraulic pressure at 100 kPa for packaging group II liquids, and stack load at 40°C for 24 h. Production audits under ASTM D1693 condition A at 50°C with 10 wt% Igepal record F50 values above 300 h, but flame treatment for label adhesion above 45 dyn/cm has been observed to reduce pinch-line ESCR by promoting surface oxidation microcracks.
| UN test | Condition | Acceptance | Standard reference |
|---|---|---|---|
| Drop impact | 1.2 m, −18°C, PG II | No leakage | UN 6.1.5.3.5 |
| Leakproofness | 30 kPa internal air | No leakage | UN 6.1.5.4 |
| Hydraulic pressure | 100 kPa, 30 min, PG II | No leakage | UN 6.1.5.5 |
| Stack | 40°C, 24 h, stack mass | No deformation causing leakage | UN 6.1.5.6 |
If EVOH Layer Sheath Stability Collapses at the Die Gap in Six-Layer Fuel Tank Blow Moulding
Fuel tanks are coextruded with H4837 as the outer and inner HDPE skins because the grade’s melt strength permits heavy parisons up to 10 kg without sag. The layer arrangement is: H4837 outer skin, regrind layer, maleic anhydride grafted polyethylene tie layer, ethylene-vinyl alcohol copolymer barrier layer, second tie layer, and H4837 inner skin. The HDPE extruders are set at 190–230°C, the regrind stream at 180–220°C, and the EVOH line at 190–210°C; the six-layer accumulator head is held within a ±3°C band to prevent viscosity mismatch at the spiral mandrel exits. EVOH is targeted at 1.5–3.0 vol% of the parison wall, and each tie layer is maintained at 5–10 µm to prevent post-impact delamination. Blow air is introduced at 0.5–0.8 MPa, mould water at 10–16°C, and the parison drop is profiled to avoid thin spots at the filler neck pinch. The primary process conflict is layer sheath instability at the die gap: when the draw-down ratio exceeds 4:1 or when the EVOH melt temperature falls below 188°C, the barrier layer fractures into lens-shaped defects that fail hydrocarbon permeation testing. Published data for this exact six-layer H4837 configuration is limited; however, industrial fuel-tank lines control the die gap at 1.5–2.2 mm and keep the shear rate at the die land below 300 s⁻¹ to maintain layer continuity. Compliance testing follows ECE R34 Annex 5 for fire resistance and the vehicle-level SHED procedure for hydrocarbon losses; tanks exceeding 2.0 g/day at 40°C in a 48 h SHED cycle are rejected.
| Layer position | Typical thickness | Polymer/function |
|---|---|---|
| Outer skin | 1.0–1.5 mm | H4837, carbon black/UV, impact shell |
| Regrind | 0.4–1.0 mm | Recovered HDPE trim, stiffness |
| Tie layer 1 | 5–10 µm | MAH-g-PE, adhesion |
| Barrier | 0.03–0.10 mm | EVOH, hydrocarbon permeation barrier |
| Tie layer 2 | 5–10 µm | MAH-g-PE, adhesion |
| Inner skin | 0.3–0.8 mm | H4837, fuel contact |
What Breaks Agrochemical Bottle Handle Bridges Under Polar Solvent Contact?
Blow-moulded bottles for emulsifiable concentrates and solvent-based agricultural formulations are produced with H4837 as the structural layer in three-layer constructions: H4837 outer layer, maleic anhydride grafted polyethylene tie layer, and polyamide or EVOH internal barrier. On intermittent extrusion blow moulding machines with 1+1 or 2+2 cavity moulds, melt temperatures are set from 200°C to 215°C, with the die gap at 1.2–1.8 mm and main blow pressure at 0.5–0.7 MPa. The handle bridge is a compression weld formed when the parison is pressed by the mould parting line; its residual stress state is determined by the pre-blow delay and the calibration air pressure. Environmental stress cracking in the handle bridge is the dominant failure mode when the bottle contains xylene, cyclohexanone, or chlorinated amide formulations: quenched welds with cooling rates above 15 K/min exhibit low tie-chain density, and crack propagation follows the weld line under hoop stress. Process correction requires raising the melt temperature within a narrow 10°C window and reducing calibration air pressure to 0.45 MPa to permit stress relaxation before the part leaves the mould. UV-stabilized black formulations for outdoor storage use 2.0–3.5 wt% of a 40 wt% carbon black masterbatch in LDPE; dispersion is checked by a 50× microscope on microtomed sections, because agglomerates above 20 µm initiate pinholes in the barrier layer. UN 3H1 certification for these bottles follows the same drop and leakproofness sequence as larger containers, but the handle bridge is subjected to an additional 1.2 m drop at −18°C with the bottle oriented to strike the handle.
Marine blow-moulded floats for aquaculture cage collars and dredge-line buoyancy use H4837 at wall thicknesses of 4–8 mm on shuttle machines with 20–40 kg shots; mould cooling at 10–15°C is standard, and each float is pressure-tested at 20–40 kPa with soap solution to detect pinch-line voids.
Coolant Expansion Tank Pinch-Off Folds in Constant-Pressure Mould Cooling at 12°C
Coolant surge tanks and selective catalytic reduction urea tanks are blow-moulded from H4837 for sustained exposure to glycol-water mixtures and 32.5% aqueous urea solution. In production, the tank neck and bracket bosses are formed at mould temperatures below 15°C; when the cooling water is held at 12°C, the outer skin freezes before the pinch-off lands fully compress, leaving a V-notch that fails thermal pressure cycling from 0 kPa to 180 kPa at 90°C in OEM reservoir validation. The corrective action is to increase the pinch-off land length to 3–4 times the nominal wall thickness and to stage pre-blow at 0.3 MPa followed by main blow at 0.7 MPa. For urea tanks, material compatibility with 32.5 wt% urea solution is assessed under ISO 22241-3; production audits show no surface cracking after 1000 h immersion at 60°C, but published data for this specific H4837 tank configuration is limited. Melt temperatures above 240°C are avoided because chain scission at the HDPE chain ends generates carbonyl species that reduce weld toughness.
Large IBC inner bottles of 1,000 L nominal capacity are blow-moulded from H4837 on single-station accumulator machines with shot capacities above 15 kg. The parison is pre-inflated at 0.1–0.2 MPa during mould closing to prevent double-wall folding, then blown at 0.5–0.7 MPa; wall-thickness distribution is controlled by die-gap profiling synchronized with accumulator stroke, and the top and bottom corners require a measured minimum wall thickness of 2.8 mm for drop resistance. Because H4837 absorbs less than 0.02% water at 23°C and 50% relative humidity, pre-drying is unnecessary unless the regrind content exceeds 40 wt%. Leak testing is performed at 10–20 kPa, followed by assembly into steel cages for UN 31H composite IBC qualification.
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- LyondellBasell HDPE H4837 is manufactured under an ISO 9001 quality system and complies with relevant regulatory requirements.
- COA, SDS/MSDS, and related certificates are available upon request. For certificate requests or inquiries, contact: admin@ascent-chem.com.
LyondellBasell HDPE H4837 is a high-density polyethylene grade supplied as a pelletized reactor product for rigid packaging and industrial container applications. The grade identifier appears in the LyondellBasell HDPE portfolio as a blow-molding and sheet-extrusion candidate; however, open-source lot-specific physical property data for H4837 are limited. Accordingly, this document restricts numerical values to the grade-family envelope and to standardized test methods that should appear on a valid certificate of analysis. The polymer is not classified as a universal drop-in for all HDPE applications; substitution into a validated line requires review of lot density, melt flow rate, environmental stress-cracking resistance, and additive package.
What Differentiates HDPE H4837 from High-Flow Injection Molding and Film Grades?
HDPE H4837 is differentiated by its melt rheology under low-shear blow-molding conditions rather than by the single-point melt flow index alone. High-flow injection-molding grades typically report a melt flow rate of 15–40 g/10 min at 190 °C and 2.16 kg, yielding a low melt viscosity that fills thin-wall tools rapidly but cannot sustain a stable parison. Film grades often operate at 0.5–2.0 g/10 min and are designed for high draw-down and tear resistance; their molecular orientation during film blowing differs from the biaxial orientation generated in blow molding. HDPE H4837 is evaluated for an intermediate melt flow regime, commonly below 1.0 g/10 min, where melt strength and shear thinning are sufficient for accumulator or shuttle blow molding. The direct comparison is made with capillary rheometry according to ISO 11443; a high-flow injection grade can exhibit apparent shear viscosity at 1000 s⁻¹ below 50 Pa·s, while blow-molding grades under the same shear rate can remain above 150–300 Pa·s, depending on temperature. This viscosity gap is process-limiting: the same tool cannot be converted from an injection-molding grade to H4837 by changing temperature alone.
On a single-cavity accumulator blow molder with a 60 mm barrier screw and 24:1 L/D, HDPE H4837 typically requires a feed-zone setting of 170–180 °C and a head/die zone of 200–215 °C. The extruder is commonly operated at 40–70 rpm, producing a melt pressure at the head of 220–300 bar. At the lower limit, melt-pressure fluctuations above ±5 bar can produce visible weld-line thinning and wall-thickness variation greater than ±0.6 mm on a 20 L container. Parison sag becomes the controlling variable when hang time exceeds 8–12 s; reducing die gap from 2.0 mm to 1.4 mm may improve wall distribution, but a gap below 1.2 mm can lower die swell and create a rough inner parison surface. The accumulator drop speed should be set so that parison length at contact does not exceed 1.2 times the mold cavity length. These are process limits derived from industrial blow-molding practice, not fixed H4837 datasheet values; lot-specific verification remains necessary.
Melt Flow, Density, and ESCR Test Methods for Incoming Resin
Receiving inspection should verify three properties: melt flow rate by ISO 1133-1:2022 method A at 190 °C and 2.16 kg, density by ISO 1183-1:2019 method A, and environmental stress-cracking resistance by ASTM D1693-15 condition A or B. The melt flow specimen should be conditioned at 23 °C ± 2 °C and 50 % ± 10 % relative humidity for at least 3 h, and the density specimen should be pressed to a void-free plaque according to ISO 293 and conditioned for 24 h. For blow-molding HDPE, the typical density envelope is 0.945–0.957 g/cm³; a lot above 0.960 g/cm³ should be quarantined because the crystallinity increase can reduce environmental stress-cracking resistance and notched impact even if stiffness improves. Melt flow rate below 0.20 g/10 min can increase screw torque and reduce output; melt flow rate above 1.0 g/10 min can increase sag and reduce top-load consistency. The grade-specific nominal value for H4837 must be read from the lot-specific certificate of analysis, not from generic HDPE tables.
| Property | Standard | Specimen preparation | Typical blow-molding HDPE envelope |
|---|---|---|---|
| Melt flow rate | ISO 1133-1:2022 | Method A, 190 °C, 2.16 kg | 0.20–1.0 g/10 min |
| Density | ISO 1183-1:2019 | Method A, compression-molded plaque | 0.945–0.957 g/cm³ |
| Tensile yield stress | ASTM D638-14 | Type IV specimen, 50 mm/min | 22–30 MPa |
| Flexural modulus | ASTM D790-17 | 1.3 mm/min, 23 °C | 800–1400 MPa |
| Charpy notched impact | ISO 179-1:2010 | 23 °C, notched | 4–15 kJ/m² |
| Environmental stress-cracking resistance | ASTM D1693-15 | 10 % Igepal CO-630, 50 °C | 10–100 h |
When HDPE H4837 is run as a sheet core or monolayer sheet on a 90 mm, 30:1 L/D extruder with a gear pump, melt temperature at the die entry is controlled between 200 °C and 220 °C. The gear pump inlet pressure is held at 80–120 bar, and the discharge pressure is maintained at 150–220 bar. Pressure fluctuation above ±5 bar can directly produce thickness variance greater than ±1.5 % on a 1.0 mm sheet. Chill-roll temperatures of 60–90 °C are typical; lower roll temperatures below 45 °C can quench the surface and generate warpage after trimming, while higher roll temperatures above 105 °C can cause sticking and gloss loss. On a three-roll stack, the nip gap should be set to the sheet thickness minus 0.02–0.10 mm to avoid excessive calendering that can create transverse orientation and unequal shrinkage.
When Accumulator Head Pressure Falls Below the Melt Homogeneity Threshold
In HDPE blow molding, a drop in head pressure below 180 bar on a 60 mm extruder usually indicates low melt viscosity, low screw speed, or high melt temperature. If the pressure falls below 160 bar, unmelted resin can pass through the die, causing parison surface roughness and variable swell. Increasing screw speed to restore pressure can entrain air and generate micro-voids; therefore, the first corrective action is to check feed-throat temperature and screw cooling. A feed-throat temperature above 70 °C can cause resin bridging and intermittent feeding, while a temperature below 30 °C can bring condensation and hydrolytic additive loss. The barrel profile should be verified with a contact thermocouple against the setpoint; deviations of more than ±5 °C on the transition zone can shift melt compression and reduce mixing.
Screen-pack and breaker-plate design also affect head-pressure stability. A common configuration for HDPE blow molding is a 20/40/60 mesh screen pack; however, if the pack is too fine, 80 mesh or higher, pressure drop can exceed 50 bar and lower output. If the pack is too coarse, 20 mesh or lower, carbonized particles and gel can reach the die. A continuous screen changer with 600–800 µm filtration is often installed for H4837 when the product is used for critical industrial containers with visible surface quality requirements. Pressure-before-screen and pressure-after-screen should be monitored; a differential pressure above 40 bar usually signals screen blockage and requires a screen change.
Why Environmental Stress-Cracking Resistance Is a More Decisive Metric than Density?
Density and environmental stress-cracking resistance are both governed by crystallinity and comonomer distribution, but ESCR is the more sensitive gate for H4837 in rigid packaging because it responds to tie-molecule concentration, comonomer length, and molded-in orientation. In general, increasing density from 0.950 g/cm³ to 0.960 g/cm³ may increase tensile yield stress by 1–3 MPa, but the same shift can reduce ESCR by 50 % or more if the density increase is obtained by reduced comonomer content. ASTM D1693-15 condition A tests at 50 °C in 10 % Igepal CO-630 are widely used; a pass threshold of 50 h is common for detergent bottle applications, while industrial chemical containers may require 100 h or a full-notch creep test according to ISO 16770. For H4837, users should not infer ESCR from melt flow rate or density alone; a lot-specific ESCR value must be obtained before changing suppliers or blending with recycled HDPE.
Adding post-consumer recycled HDPE to H4837 at 10–30 wt% can shift viscosity and ESCR unpredictably. On a shuttle blow molder, a 20 wt% recycled HDPE addition often lowers ESCR by 20–50 % and increases melt flow rate by 0.1–0.4 g/10 min, depending on the source. The recycled fraction should be dried and melt-filtered to 400 µm or finer; if silica-gel desiccant drying is used at 80 °C for 4 h, absorbed surface moisture can be reduced below 0.01 %. Uncontrolled regrind particle size above 8 mm can cause screw bridging and output variation. These are operational constraints for any blow-molding HDPE; the specific H4837 compatibility with recycled content must be validated on a pilot line before production.
Thermal Stability, Purging, and Residence-Time Limits
HDPE H4837 should be processed within a bounded temperature and time envelope. At melt temperatures above 230 °C, thermal degradation begins to generate volatile decomposition products, and residence times above 10–15 min at 220 °C can produce crosslinked gels that appear as surface specks or die lines. In an accumulator head, stagnant melt zones can retain polymer at high temperature even when the screw is stopped; purging with a commercial HDPE purge grade or medium-viscosity polyolefin can reduce the residence-time load. A typical purge procedure uses 5–10 kg of purge material at 220 °C, with the screw running at 20–30 rpm until the melt is clear. The presence of black specks after purging indicates degraded carbonized material in the head or die, which requires tool disassembly rather than increased purge volume.
Mold temperature influences shrinkage and drop-impact resistance. For H4837 in a 20 L industrial container, mold cooling water at 10–20 °C is common, but surface temperature below the dew point can cause condensation and pitting on the cavity. A mold chiller setpoint of 12 °C can be used if the plant air is dehumidified to 40 % RH or below. Ejection of the part before the interior wall reaches 70 °C can produce post-mold shrinkage and ovality. In-cycle cooling time is usually controlled so that the part average temperature at ejection is below 80 °C; thermal imaging can verify distribution. Excessive mold cooling can reduce cycle time but can also increase residual stress and lower ESCR, especially near the pinch-off and handle regions.
| Characteristic | HDPE H4837 blow-molding envelope | High-flow injection HDPE | Film HDPE |
|---|---|---|---|
| Melt flow rate at 190 °C, 2.16 kg | 0.20–1.0 g/10 min | 15–40 g/10 min | 0.5–2.0 g/10 min |
| Density range | 0.945–0.957 g/cm³ | 0.950–0.965 g/cm³ | 0.930–0.958 g/cm³ |
| Melt strength and parison stability | High | Low | Medium |
| Environmental stress-cracking resistance | Higher than injection grades | Lower | Variable with draw orientation |
| Typical conversion process | Accumulator or shuttle blow molding, sheet extrusion | Injection molding | Blown film, cast film |
For intended food-contact use, H4837 is evaluated against FDA 21 CFR 177.1520 for olefin polymers and EU Regulation (EU) No 10/2011 on plastic materials in contact with food. However, such compliance is article-specific and depends on migration testing under the actual surface-to-volume ratio, temperature, and simulant. A resin datasheet may state resin-level compliance; it does not cover colorants, masterbatches, or recycled content. Therefore, the converter must obtain a declaration of compliance from the finished-article testing program rather than relying solely on the grade datasheet.
In direct substitution assessments, HDPE H4837 should not be dropped into a high-flow injection-molding tool without re-evaluating melt cushion, gate freeze time, and pressure drop. It should also not replace a film-grade HDPE in a blown-film line unless die geometry and air-ring cooling are recalibrated for the higher melt viscosity. The governing qualification method for a specific part is a process capability study on the actual blow-molding or sheet line, supported by the lot-specific certificate of analysis.
