| HS Code | 153670 |
| Density | 0.955 g/cm³ |
| Melt Flow Rate 190 C 2 16 Kg | 0.35 g/10 min |
| Melt Flow Rate 190 C 21 6 Kg | 35 g/10 min |
| Tensile Strength At Yield | 26 MPa |
| Tensile Strength At Break | 30 MPa |
| Elongation At Break | 600% |
| Flexural Modulus | 1100 MPa |
| Notched Izod Impact | 200 J/m |
| Vicat Softening Point | 125°C |
| Melting Point | 131°C |
| Environmental Stress Crack Resistance | >1000 h |
| Shore D Hardness | 65 |
| Brittleness Temperature | < -70°C |
| Thermal Deflection Temperature At 0 45 Mpa | 70°C |
| Water Absorption | <0.01% |
As an accredited Braskem HDPE HDB8550 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Braskem HDPE HDB8550 is packaged in 25 kg polyethylene bags, supplied on 1,000 kg pallets for convenient handling and storage. |
| Container Loading (20′ FCL) | 20′ FCL stuffed with palletized Braskem HDPE HDB8550 resin bags, shrink-wrapped and braced for ocean transit; approx. 25 MT net. |
| Shipping | Braskem HDPE HDB8550 is shipped as non-hazardous solid polyethylene pellets, typically in 25 kg moisture-barrier bags or 1,000 kg octabins on pallets, stretch-wrapped. Transport in clean, dry trucks or containers at ambient temperature. Avoid moisture, contamination, direct sunlight, and excessive heat. Follow SDS and local regulations. |
| Storage | Store Braskem HDPE HDB8550 in a cool, dry, well-ventilated warehouse, away from direct sunlight, heat, flames, and strong oxidizing agents. Keep original bags or containers sealed and off the floor to prevent moisture, dust, and contamination. Use first-in, first-out stock rotation. Avoid prolonged UV exposure, extreme temperatures, and physical damage. Follow the manufacturer’s SDS and local regulations. |
| Shelf Life | Typically 24 months when stored in original unopened packaging, in a cool, dry, well-ventilated area away from direct sunlight. |
On accumulator-head extrusion blow moulding lines producing UN-certified 3H1 jerricans from HDB8550, the extrusion temperature profile is segmented from 175 °C in the feed zone to 195–210 °C at the die head, with clamp tonnage between 150 kN and 350 kN for 5 L to 30 L containers. HDB8550 operates in the high-molecular-weight HDPE range, with a melt flow rate below 0.50 g/10 min when measured under ISO 1133-1:2022 at 190 °C/5 kg and density of 0.953–0.957 g/cm³ under ISO 1183-1:2019, which provides the parison hang strength needed for wall-thickness uniformity in tall rectangular jerrican geometries. Compliance is established through design type testing under the UN Recommendations on the Transport of Dangerous Goods, 23rd rev., Part 6.3.5 for 3H1 plastics jerricans, including drop impact at 1.2 m after conditioning at −18 °C, stacking load for 28 days at 40 °C, and leakproofness under 30 kPa internal air pressure per ADR 6.1.5.2.6. The production formulation uses 100 parts HDB8550, 20–25 wt% clean in-house regrind from the same lot family, 1.0–2.0 wt% of a 40% carbon-black masterbatch in LDPE carrier, and 0.05–0.10 wt% of a hindered-phenolic process stabilizer concentrate; regrind above 25 wt% is not recommended because environmental stress cracking resistance in ASTM D1693 condition B declines non-linearly once mixed-crystalline tie-molecule density is diluted by repeated extrusion histories. Blow moulding uses a diverging die gap of 1.0–1.6 mm, blow air pressure of 0.6–0.8 MPa, and parison programming with 80–100 points to redistribute the parison wall between chimb, handle pinch-off, and base corners. Finished articles are 5 L to 30 L UN-certified jerricans for liquid hydrocarbons, agrochemical concentrates, lubricant additives, and corrosive acids at concentrations approved by the chemical resistance data set under ASTM D543.
In six-layer automotive fuel tank coextrusion, HDB8550 serves as the outermost and innermost structural layers, while a central EVOH barrier layer is tied through maleic-anhydride-functionalized tie resins; the melt temperature of the HDB8550 layers is held between 210 °C and 230 °C, whereas the EVOH is processed at 190–210 °C to avoid thermal degradation. The six-layer weight distribution on production lines typically falls at 55–70 wt% HDB8550, 25–35 wt% regrind, 2.0–3.0 wt% EVOH, and 1.5–2.5 wt% total tie resin; the regrind is generated from post-industrial fuel tank flash and is fed into a dedicated regrind layer to maintain barrier continuity. Compliance is governed by UN ECE R34 mechanical strength and fire resistance tests, 40 CFR Part 86 evaporative emission limits for complete vehicles, and ASTM D471 immersion testing in fuels and oxygenated fuel blends. A critical process limit in continuous coextrusion blow moulding is the die gap, maintained at 1.2–2.0 mm depending on parison length and swell; HDB8550’s melt strength permits parison lengths up to 2.0 m without excessive drawdown, but die lip deposits increase below 190 °C and oxidative chain scission is measurable above 240 °C. The addition ratio for process aids remains below 300 ppm fluoropolymer-based polymer processing aid in the outer and inner HDB8550 layers, because excess migration to the tie-layer interface reduces peel adhesion between polyolefin and EVOH in 90° peel tests conducted according to ASTM F904. Downstream, the coextruded part is cooled in a forming mold at 10–15 °C mold temperature, then trimmed, drilled, and assembled with fittings; terminal products include 40 L to 90 L gasoline and diesel fuel tanks for passenger vehicles, agricultural machinery, and off-highway equipment where multilayer barrier performance is required for evaporative emission control.
Because agricultural chemical formulations increasingly contain dimethylamine salts, chloroacetamide actives, and high-electrolyte microemulsions, container resin selection in agrochemical packaging focuses on environmental stress cracking resistance, top-load strength, and UV stability rather than short-term burst pressure alone. HDB8550 is processed on single-station shuttle blow moulding machines with clamp forces from 120 kN to 250 kN, extruder sizes 65–90 mm, and L/D ratios 24:1–30:1; melt temperatures are set at 185–205 °C, with die temperatures 195–210 °C and blow pressure 0.5–0.7 MPa. The formulation on typical high-speed agrochemical bottle lines is 100 parts HDB8550, 15–20 wt% closed-loop regrind, 1.5–2.5 wt% of a HALS-based UV stabilizer masterbatch, and 0.8–1.2 wt% of a carbon black masterbatch; if carbon black is specified only for light opacity, the UV-stabilizer addition must remain in the upper half of the range because carbon black alone does not protect polyethylene from surface nitrosative oxidation. Relevant compliance standards include UN 3H1 design type testing for dangerous goods packaging, ASTM D1693 condition B for stress crack resistance, ASTM D2659-16 for top-load strength, and ASTM D638-14 for tensile yield. The blow moulding process relies on 30–50 point parison programming to create a chimb and label panel without excessive thinning at the shoulder; containers are then flame-treated to 38–42 mN/m surface energy for adhesive label application. Terminal products include 1 L to 20 L high-density polyethylene containers for herbicide, insecticide, fungicide, and plant growth regulator formulations, where the bottle must resist permeation, gasket contact, and prolonged outdoor storage under rural ambient conditions.
| Application segment | HDB8550 loading | Regrind blend | Functional additive | Addition ratio |
|---|---|---|---|---|
| UN-rated jerricans | 100 parts | 20–25 wt% | 40% carbon-black masterbatch | 1.0–2.0 wt% |
| Six-layer fuel tanks | 100 parts structural layers | 25–35 wt% of total structure | Maleated tie resin | 1.5–2.5 wt% total |
| Agrochemical containers | 100 parts | 15–20 wt% | HALS UV stabilizer masterbatch | 1.5–2.5 wt% |
| IBC inner bottles | 100 parts | 10–15 wt% | Oleamide slip agent | 0.02–0.05 phr |
| Lubricant containers | 100 parts | 20–30 wt% | Fluoropolymer processing aid | 0.3–0.8 wt% |
| Chemical dosing tanks | 100 parts | 10–20 wt% | Antistatic masterbatch | 0.5–1.5 wt% |
Accumulator-head machines with 120 mm extruder diameter, 30:1 L/D screw, and 300–600 kN clamp force are used for 1 000 L rigid intermediate bulk container inner bottles, where the parison shot mass can exceed 25 kg and the part height and parting-line pinch-off create severe wall-thickness control requirements. HDB8550 in this conversion process is processed at a melt temperature of 195–215 °C, with the accumulator head temperature held within ±3 °C across the die circumference to avoid parison curling; blow pressure is set at 0.7–0.9 MPa and the mold is circulated with chilled water at 8–12 °C to stabilize the large flat sidewalls. The addition ratio in industrial practice is 100 parts HDB8550, 10–15 wt% clean regrind, 0.02–0.05 phr of an external oleamide-based slip agent for demoulding, and 0.05–0.08 phr of a processing stabilizer; higher slip-agent loadings are avoided because they reduce static load-bearing capacity at the top and bottom seams and can contaminate filled chemicals through surface migration. Under the UN Recommendations on the Transport of Dangerous Goods, Part 6.5.2 design type qualifications for composite IBCs, the inner bottle is tested after filling and stacking, with hydraulic pressure at 100 kPa for 10 min, drop impact at 1.2 m after conditioning at −18 °C, and stacking for 28 days at 40 °C; resin-specific short-term mechanical properties are verified by ISO 527-2:2012 tensile yield, ISO 178:2019 flexural modulus, and ASTM D2463-15 falling dart impact. This process is not suitable for strong oxidizing acids above 45 °C, aromatic hydrocarbons above 40 °C, or prolonged outdoor exposure unless an additional UV-stabilized outer packaging layer is present; published data for this specific configuration is limited for highly permeating low-boiling solvents, and users should conduct chemical resistance trials under ASTM D543 before specifying the grade. Terminal products include 600 L to 1 250 L composite IBC inner bottles for non-oxidizing industrial chemicals, latex emulsions, water treatment polymers, and food-grade syrups when processed under appropriate hygiene conditions.
At 1 L to 4 L lubricant container output rates up to 1 200 containers/h per mould, continuous shuttle blow moulding lines running HDB8550 reach steady-state melt homogeneity only after 20–30 min of screw recovery stabilization; grip-to-grip cycle times on 4-cavity shuttle machines are typically 8–12 s, with blow pressure 0.55–0.75 MPa and mold cooling at 10–15 °C. The grade’s high-molecular-weight distribution provides drop impact and top-load margins needed for motor oil bottles, but the narrower die gap of 0.8–1.2 mm and high shear in the die lips can produce melt fracture if melt temperature is below 185 °C. Formulation additions in this fast-cycle environment consist of 100 parts HDB8550, 0.3–0.8 wt% of a fluoropolymer processing aid masterbatch on grooved-feed extruders where pressure fluctuations are observed, 20–30 wt% post-industrial regrind, and 0.03–0.06 wt% total antioxidant supplementation after regrind incorporation. Industry compliance for motor oil containers focuses on ASTM D543 immersion testing in paraffinic and synthetic base oil blends at 50 °C for 7 days, ISO 1133-1:2022 for melt-flow quality control, and ASTM D256 notched Izod impact for cap and handle robustness; food-contact status is not implied for this industrial packaging unless the specific bottle construction is qualified under 21 CFR 177.1520 by the packer. The downstream conversion process uses continuous extrusion with single or dual station shuttle blow moulders, in-mold labeling, and automated leak testing at 20–30 kPa internal pressure. Terminal products are 1 L, 4 L, 5 L motor oil bottles, gear oil containers, hydraulic transmission fluid packs, and heavy-duty diesel lubricant jugs, where the container must resist swelling, top-load cracking, and occasional exposure to hydrocarbon vapours in warehouse storage.
| Application segment | Compliance framework | Test standard | Threshold or condition |
|---|---|---|---|
| UN-rated jerricans | UN 3H1, ADR 6.1.5.2.6 | ASTM D1693 | F50 > 300 h condition B |
| Six-layer fuel tanks | UN ECE R34, 40 CFR Part 86 | ASTM D471, ASTM F904 | 210–230 °C HDB8550 melt |
| Agrochemical containers | UN 3H1 | ASTM D2659-16, ASTM D638-14 | 1.5–2.5 wt% HALS masterbatch |
| IBC inner bottles | UN Part 6.5.2 | ISO 527-2:2012, ASTM D2463-15 | 100 kPa hydraulic pressure for 10 min |
| Lubricant containers | ASTM D543, 21 CFR 177.1520 when qualified | ISO 1133-1:2022, ASTM D256 | 50 °C oil immersion for 7 days |
| Chemical dosing tanks | ISO 16101:2004, NSF/ANSI/CAN 61 when qualified | ASTM D1998-15, ASTM D543 | 0.6–0.8 MPa blow pressure |
Large-part chemical dosing tanks moulded from HDB8550 are produced on single-station accumulator blow moulding machines with extruder diameter 90–120 mm, L/D 24:1–30:1, and clamp force 250–600 kN. Melt temperature is maintained at 190–210 °C, die head temperature at 200–215 °C, and blow pressure at 0.6–0.8 MPa; die gap is adjusted from 1.5 mm at the top to 2.5 mm at the bottom by means of a 100-point parison programmer to compensate for the tapered geometry. The formulation for this application is typically 100 parts HDB8550, 10–20 wt% closed-loop regrind, 0.5–1.5 wt% of an antistatic masterbatch when the tank is used for solvent-based or low-conductivity chemical dosing, and 1.0–2.0 wt% of a UV stabilizer concentrate for outdoor exposure. Relevant compliance frameworks are ISO 16101:2004 for transport packaging for dangerous goods, ASTM D1998-15 for polyethylene upright storage tanks, and ASTM D543 for chemical resistance; when the tank is used for drinking water treatment chemicals, the finished tank itself must be evaluated under NSF/ANSI/CAN 61 by the tank fabricator, and no claim of potable-water certification applies automatically to the resin alone. The manufacturing process includes sequential coextrusion of the neck, blow moulding of the body, post-mould cooling in 20–25 °C conditioned air for 60–120 s, and fusion welding of fittings by hot-plate welding at 200–220 °C plate temperature. Terminal products are 50 L to 200 L cylindrical and rectangular dosing tanks for water treatment chemicals, cleaning-in-place concentrates, and industrial metering pumps, where the HDB8550 wall provides a balance of tensile stiffness, impact toughness, and stress-crack resistance under intermittent hydrostatic loading.
Competitive Braskem HDPE HDB8550 prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618136850665 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8618136850665
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Braskem HDPE HDB8550 is a high-density polyethylene extrusion blow molding resin supplied in pellet form for rigid hollow packaging in which melt strength, chemical contact, stress crack resistance, and drop-impact survival interact simultaneously. The grade is a medium-melt-index HDPE with a manufacturer-published nominal density of 0.955 g/cm³ measured according to ASTM D792-20 and a melt flow rate of 0.55 g/10 min at 190 °C under a 2.16 kg load per ASTM D1238-20. Its CAS registry number is 9002-88-4. The resin is most often converted on accumulator-head or continuous shuttle machines for containers in the 1 L to 20 L range, including household cleaners, agrochemical containers, and light industrial drums. The following table lists typical property data from laboratory specimens; these values are not specification limits and do not replace finished-container certification.
| Property | Test Method | Nominal Value |
|---|---|---|
| Density | ASTM D792-20 | 0.955 g/cm³ |
| Melt flow rate | ASTM D1238-20 | 0.55 g/10 min |
| Tensile stress at yield | ASTM D638-14, Type IV, 50 mm/min | 29 MPa |
| Elongation at break | ASTM D638-14 | >800 % |
| Flexural modulus | ASTM D790-17, 1 % secant | 1,310 MPa |
| Notched Izod impact | ASTM D256-10, Method A | 4.0 kJ/m² |
| Environmental stress crack resistance | ASTM D1693-15, Condition B, 100 % Igepal | >100 h F50 |
| Vicat softening temperature | ASTM D1525-17, Rate A | 128 °C |
| Shore D hardness | ASTM D2240-15 | 64 |
The tabulated values are typical data from compression-moulded or injection-moulded laboratory specimens and should not be interpreted as specification limits for finished containers. Actual container properties depend on processing history, wall thickness distribution, cooling rate, and regrind content. Users validating containers under UN Dangerous Goods packaging requirements should measure top load, drop impact at -18 °C, hydraulic pressure, and environmental stress crack resistance on production-scale bottles, because laboratory plaque data do not capture weld-line performance or pinch-off tail impact. Compression-moulded plaques for mechanical testing are generally prepared according to ASTM D4703-16, conditioned at 23 ± 2 °C and 50 ± 10 % relative humidity for 40 h per ASTM D618-21, and then machined into test specimens.
Density and melt flow rate are inversely related to molecular design in HDPE. The 0.955 g/cm³ density indicates low short-chain branching, which raises crystalline fraction, modulus, and chemical resistance. The 0.55 g/10 min melt flow rate indicates a higher average molecular weight than high-flow blow molding grades; high molecular weight improves environmental stress crack resistance and parison strength but increases extruder torque. The combination of these two values is narrower than general-purpose HDPE and is intended to balance container top load with processability. Because the resin is a commercial formulation, the full molecular weight distribution is not disclosed in public datasheets; however, the processing behavior indicates sufficient melt elasticity for accumulator discharge without excessive swell.
The resin’s utility in extrusion blow molding derives from a combination of moderately low melt flow rate and melt elasticity sufficient to limit parison sag between die exit and mould closure. Medium-molecular-weight HDPE grades with melt flow rates between 0.4 g/10 min and 0.8 g/10 min generally exhibit higher low-shear viscosity than injection molding HDPE, which stabilizes the parison under gravity, but their shear-thinning response permits acceptable output through narrow die gaps. HDB8550 follows this trend; however, published capillary rheometry data for the exact commercial formulation are limited. Processors often evaluate sag by measuring parison length after fixed hang time on a shuttle machine; for this grade, stable parison lengths at melt temperatures below 220 °C are observed on typical continuous shuttle lines running 5 L to 20 L containers.
At low shear rates, the higher apparent viscosity relative to general-purpose HDPE reduces necking; at die shear rates above 100 s⁻¹, the viscosity decreases sufficiently for stable extrusion. The grade’s density of 0.955 g/cm³ also contributes to a higher modulus than lower-density polyethylene grades, reducing deflection in container walls under hydrostatic head and stack load. The laboratory flexural modulus of 1,310 MPa is a 1 % secant value rather than a tangent modulus; direct comparison with tangent-modulus data from other resins can be misleading. The notched Izod value of 4.0 kJ/m² is obtained at 23 °C on specimens notched according to ASTM D256-10, Method A.
Processing of HDB8550 is performed on general-purpose extrusion blow molding extruders with length-to-diameter ratios from 24:1 to 30:1. The preferred screw has a barrier profile or a Maddock mixing section to ensure melt homogeneity before the die head. Melt temperature at the adapter should be held between 190 °C and 220 °C; die-head temperature is normally set 10 °C to 20 °C lower than the melt to increase viscosity at the die and stabilize the parison. Blow mold temperatures in the range of 10 °C to 25 °C provide adequate cycle time and surface quality. Shuttle presses, reciprocating screw machines, and accumulator-head systems can process the grade, but the die gap, die land length, and mandrel temperature must be profiled for the desired parison diameter and wall-thickness program.
| Processing Variable | Reference Range |
|---|---|
| Melt temperature | 190–220 °C |
| Die-head temperature | 190–210 °C |
| Blow mold temperature | 10–25 °C |
| Extruder L/D | 24:1–30:1 |
| Compression ratio | 2.5:1–3.5:1 |
| Regrind maximum for industrial use | 30 wt% |
Pre-drying is not normally required because HDPE is nonhygroscopic. Condensation on pellets stored in cold areas and transferred to a warm processing floor can introduce surface moisture; if visible free moisture is present or the ambient relative humidity exceeds 60 %, hot-air drying at 65 °C for 2 h is a handling correction rather than a melt-defect requirement. High melt temperatures above 220 °C combined with long hold times in the accumulator or die head can initiate chain scission and off-taste generation; therefore, head volumes should be minimized and screened adapters should be inspected for dead spots. Regrind addition up to 30 wt% can be acceptable in non-regulated industrial containers when regrind is clean, dry, and free of incompatible polymer contamination; however, food-contact and UN-certified containers require validation of regrind ratios against migration and performance requirements.
Specified uses for HDB8550 include rigid containers exposed to surfactant formulations, agricultural emulsifiable concentrates, mild hydrocarbon-based cleaners, and other liquids that cause slow crack growth in lower-ESCR HDPE grades. The resin’s stress crack resistance is commonly screened by ASTM D1693-15, Condition B, with 100 % Igepal at 50 °C; the typical F50 value is reported to exceed 100 h. Finished-container ESCR is influenced by pinch-off weld quality, frozen-in orientation, wall thickness distribution, and neck and handle stresses. Multilayer structures with ethylene vinyl alcohol or polyamide barrier layers can be used where oxygen or solvent permeation is rate-limiting, provided the HDB8550 exterior layers retain sufficient thickness to carry the pinch-off and top load.
Environmental stress crack resistance is a critical differentiator rather than a single-point property. In HDPE, ESCR is strongly affected by comonomer type and placement, molecular weight, and thermal history. Lower-density HDPE grades with reduced crystallinity often show high ESCR but lower stiffness and chemical resistance. HDB8550 is formulated to preserve ESCR at 0.955 g/cm³, which is closer to the high-density end of the density range. For containers holding surfactant-based cleaners, oils, or agricultural concentrates, the relevant failure mode is usually slow crack growth at the base pinch-off or handle weld rather than burst. Screening tests such as ASTM D1693-15 use a bent, notched specimen under constant strain in a heated surfactant; the F50 value is a comparative ranking, not a guaranteed service life. Finished-part tests under actual fill liquid and load are therefore required for specification.
If a converter reduces wall thickness to lower part weight, the hoop stress in the container sidewall under internal pressure increases for a given fill volume and drainage load. This shifts failure mode toward slow crack growth and creep rupture rather than short-term burst. HDB8550 is positioned for this condition because it maintains a high density of 0.955 g/cm³ and high flexural modulus while retaining sufficient stress crack resistance for aggressive fluids. The usual inverse relationship between density and ESCR in polyethylene means that simply raising density to increase stiffness would normally reduce ESCR; the grade’s molecular architecture is intended to offset this penalty. However, published data for specific wall thickness reductions and chemical mixtures are limited, so each container format must be tested with the actual fill fluid under top load, drop impact at -18 °C, and internal pressure per the relevant UN or regional packaging code.
Compared with injection molding HDPE grades having melt flow rates above 5 g/10 min, HDB8550 has a much lower melt flow rate and far greater melt strength, making it suitable for parison extrusion but too viscous for thin-wall injection molding. Compared with fractional-melt blow molding grades around 0.30 g/10 min, HDB8550 has a slightly higher MFR and therefore reduced head pressure and better flow distribution in smaller extruders, but may exhibit somewhat higher sag on very large parisons above 30 L. The choice between HDB8550 and a fractional-melt HDPE for a given drum application should be made on the basis of accumulator capacity, parison weight, die gap, and required ESCR rather than on melt flow rate alone.
The grade’s melt viscosity also differs from HDPE grades used in pipe or film. Pipe grades often have lower melt flow rates and additional long-term hydrostatic strength requirements, while film grades have higher melt strength and different stabilization packages. HDB8550 should not be substituted into injection molding or film processes without pilot trials, because the processing window and stabilizer system are not optimized for those shear histories. In blow molding plants running multiple HDPE grades, purging between products is required because differences in melt flow rate and additive packages can produce gels, streaks, or reduced weld strength if the grades are mixed. Published purging protocols for this specific grade are limited; processors typically purge with a compatible fractional-melt HDPE or a commercial purge compound and continue until melt pressure and extruder torque stabilize.
For food-contact end uses, the finished article must meet FDA 21 CFR 177.1520 or European Commission Regulation (EU) No 10/2011 as applicable, including migration limits and organoleptic suitability. The resin’s additive package is addressed in the manufacturer’s food-contact documentation, but the converter bears responsibility for migration testing on the final package because processing temperatures, regrind content, and barrier layers affect the composition of the contact surface. Dangerous-goods containers made from HDB8550 are qualified under the UN Model Regulations and modal frameworks such as ADR/RID and IMDG by package performance testing, not by resin property data alone.
Vicat softening temperature is reported as 128 °C under ASTM D1525-17 Rate A, and Shore D hardness is typically 64 under ASTM D2240-15. These values indicate adequate stiffness at ambient and mildly elevated temperatures, but they do not imply continuous service at that temperature. Long-term exposure to hot filling above 60 °C may require downgauging or additional heat-stabilization review because oxidative induction time and creep resistance, not Vicat softening, govern service life. The resin is not recommended for continuous contact with strong oxidizing acids, aromatic solvents, or chlorinated hydrocarbons at elevated temperature; published compatibility data for aggressive fluids should be generated before specification.
On production-scale shuttle and accumulator-head lines, the defects most often associated with HDB8550 are pinch-off weld weakness, parison curl from mandrel-bushing temperature mismatch, and surface melt fracture at excessive shear rates. These conditions are corrected by die centering, separate control of mandrel and bushing zones, and adjustment of die gap or extrusion rate. Quantitative defect thresholds for this grade are not fully published; therefore, machine-specific qualification runs are required to define acceptance windows for a given container design.
