LyondellBasell HDPE 50-1052 is a high-density polyethylene resin identified within the supplier’s injection-moulding grade range. The designation is typically parsed by density and melt-flow indicators: the first segment corresponds to a nominal density of 0.950 g/cm³ when tested under ASTM D1505 or ISO 1183-1, and the middle segment corresponds to a nominal melt mass-flow rate of 10.5 g/10 min at 190 °C and 2.16 kg load when tested under ASTM D1238 or ISO 1133-1:2022. The grade is supplied as pelletized resin for high-shear injection-moulding operations; it is not intended for large-part blow moulding or for stretched-tape extrusion where high melt strength and strain-hardening behaviour control dimensional stability. The material’s polymer architecture—molecular weight distribution, short-chain branching and comonomer placement—is reactor-controlled, and the 0.950 g/cm³ density places it in the medium-range crystallinity segment of the HDPE family. Typical uses include thin-wall containers, closures, housewares and general-purpose moulded articles in which short filling time and fast cycle time are critical production variables.

What Processing Boundaries Appear When HDPE 50-1052 Is Run in High-Speed Injection Moulding?

On production-scale reciprocating-screw injection machines with screw L/D ratios between 20:1 and 24:1 and compression ratios from 2.0:1 to 3.0:1, the material is normally processed at barrel temperatures escalating from 180 °C in the rear zone to 220 °C at the nozzle. Melt temperatures above 240 °C may accelerate oxidative degradation and increase purge frequency, while temperatures below 190 °C can increase screw recovery torque and promote gate freeze-off in thin sections. Mould temperatures are typically held between 10 °C and 40 °C; higher mould temperatures reduce orientation-induced shrinkage anisotropy but extend cycle time. Published data for the specific interaction of HDPE 50-1052 with high-speed hot-runner valve gates in multi-cavity tools is limited; however, injection velocities above 120 mm/s and hold pressures between 30 MPa and 50 MPa are conventional starting conditions for comparable 0.950 g/cm³ HDPE grades. A mould-flow simulation should be considered for wall sections below 0.6 mm because the short packing window and rapid gate freeze-off create a process conflict: higher melt temperature delays gate freeze but increases oxidative risk; higher hold pressure extends packing but increases internal stress and mould flash.

In multi-cavity hot-runner systems, the high melt-flow rate of HDPE 50-1052 can produce balanced fill only if runner diameters are not undersized relative to the gate lay-out. A recurrent failure mode on 24-cavity and 32-cavity valve-gated tools is end-cavity fill order reversal when the manifold temperature is below 200 °C: the first cavities to fill show excessive sink, while end cavities show weak weld lines. Reducing manifold temperature below 190 °C is not recommended, because the resultant melt-pressure increase can exceed the machine’s available first-stage injection pressure and create screw-recovery variability of more than 0.5 s.

Moisture uptake in HDPE is generally low, and drying is not normally required for surface-quality-critical moulded parts when pellet storage is below 60 % relative humidity. If pellet surfaces exhibit condensation after cold warehouse movement, a 4 h desiccant-dryer residence time at 70 °C with a dew point of −30 °C may be applied; higher temperatures or prolonged residence can initiate pellet sintering in hopper dryers. Regrind addition up to 30 wt% is common, but the effect of repeated high-temperature moulding on the 10.5 g/10 min melt-flow rate must be monitored because chain scission can shift the apparent MFR upward and reduce part impact performance.

Mechanical and Thermal Benchmarks for Quality Assurance

Quality assurance for injection-moulded HDPE 50-1052 articles typically includes density confirmation by ASTM D1505 or ISO 1183-1:2019, melt-flow verification by ASTM D1238 or ISO 1133-1:2022, and tensile testing at 50 mm/min according to ASTM D638-14 or ISO 527-2:2012. Because the grade has a nominal density of 0.950 g/cm³, its crystallinity is intermediate within the HDPE range; tensile yield stress is generally higher than that of a 0.940 g/cm³ density HDPE and lower than that of a 0.965 g/cm³ homopolymer. The notched Izod impact resistance is governed by molecular weight and may be assessed under ASTM D256-23; however, published numerical Izod data for this specific grade should be obtained from the lot certificate rather than inferred from density alone. Environmental stress crack resistance under ASTM D1693 should be specified for detergent or surfactant-containing applications, where high-flow HDPE grades can show shorter failure times than lower-melt-index grades.

Differential scanning calorimetry according to ISO 11357-3:2018 shows a broad HDPE melt endotherm with peak temperature around 130 °C; for high-speed injection moulding, this peak does not eliminate the need for feed-zone stability below the hopper melting point. If the rear barrel temperature is maintained above 180 °C, bridge formation at the feed throat is generally avoided, but pellet surface tack can occur in hopper dryers above 70 °C.

Comparative processing suitability of HDPE 50-1052 and adjacent HDPE classes

Parameter	HDPE 50-1052	Blow moulding HDPE	Extrusion HDPE
Nominal density	0.950 g/cm³	0.950–0.955 g/cm³	0.940–0.955 g/cm³
Melt mass-flow rate at 190 °C/2.16 kg	10.5 g/10 min	0.2–1.0 g/10 min	0.15–0.8 g/10 min
Primary process	Injection moulding	Extrusion blow moulding	Sheet/profile extrusion
Melt strength	Low-moderate	High	High
Representative part examples	Thin-wall packaging, closures	Bottles, large containers	Geomembrane, thick sheet

When HDPE 50-1052 Is Evaluated as a Replacement for Lower-Flow HDPE in Existing Tools

If the grade is dropped into a tool originally qualified for a 0.30 g/10 min or 0.50 g/10 min HDPE, the lower melt viscosity alters shear heating, pressure transmission and gate seal behaviour. Shot mass and cushion become more sensitive to screw recovery settings because the higher MFR reduces melt pressure at a given injection velocity. Cushion positions below 4 mm may lead to inconsistent packing and sink marks; a cushion of 6–10 mm is typical for screw machines in the 250–1,000 kN clamp-force class. Short shots in long flow-length parts may be addressed by increasing injection velocity, but too high a velocity can generate shear heating above 5 °C across the runner and cause uncontrolled viscosity loss. When compared with HDPE blow-moulding grades, HDPE 50-1052 exhibits lower melt tension and is not a drop-in substitute for continuous-extrusion blow moulding.

For cap and closure applications, the higher flow path length-to-thickness ratio achievable with HDPE 50-1052 allows multi-cavity moulds with lower injection pressure than a 5.0 g/10 min HDPE; however, lower molecular weight can reduce strip torque and long-term stress-crack resistance. Performance tests should include ASTM D2063 for closure retention or ASTM D2659 for column crush where the closure is stacked.

Starting process window for HDPE 50-1052 on a 20:1–24:1 L/D reciprocating screw

Parameter	Lower set-point	Upper set-point	Observation point
Rear barrel temperature	180 °C	200 °C	Feed zone stability
Middle barrel temperature	190 °C	220 °C	Melt homogeneity
Front barrel/nozzle temperature	200 °C	230 °C	Part weight consistency
Mould temperature	10 °C	40 °C	Shrinkage and warp
Injection velocity	120 mm/s	250 mm/s	Short-shot boundary
Hold pressure	30 MPa	50 MPa	Sink marks
Back pressure	0.5 MPa	1.5 MPa	Screw recovery time

Storage, Food-Contact and Regulatory Review

Polyethylene grades in this density and melt-flow class are commonly covered by FDA 21 CFR 177.1520 for use in contact with food, subject to end-use limitations and migration testing; the specific regulatory datasheet from LyondellBasell should be consulted for the version and conditions of use. European food-contact evaluations follow Regulation (EU) No 10/2011, with overall migration limit of 10 mg/dm² for general food-contact plastics. REACH compliance is assessed under Regulation (EC) No 1907/2006; RoHS 2011/65/EU restrictions do not typically apply to unmodified HDPE but electrical and electronic equipment applications may require supplier declaration. Storage at temperatures above 40 °C or under ultraviolet exposure can reduce stabilizer performance and raise carbonyl index; therefore pellets should be stored in closed containers and protected from direct sunlight.

Regrind from HDPE 50-1052 moulded parts can be reintroduced into the same process at levels up to 30 wt% if the regrind is dust-free and not degraded. Repeated regrind cycles shift melt-flow rate upward; a 10.5 g/10 min virgin resin may exhibit MFR increases above 12 g/10 min after three cycles on a reciprocating screw with barrel residence times above 3 min. Therefore, lot verification of melt-flow and density is mandatory for regrind blends. Avoid combination with amine-based additives unless compatibility is confirmed, because certain hindered amine light stabilizer packages may alter acid scavenger distribution and surface migration. Purging with PVC or acetal should be avoided without a full melt-displacement protocol because thermal decomposition products can corrode mould surfaces and create part defects.

For profile or sheet extrusion, HDPE 50-1052 is not the primary choice: the 10.5 g/10 min MFR reduces melt strength, and draw resonance or edge tear can occur at haul-off ratios above 5:1. A lower-flow HDPE with MFR below 1.0 g/10 min provides more stable melt curtain formation in sheet lines with 300–1,000 mm die widths.

Chemical exposure data for HDPE with 0.950 g/cm³ density generally shows resistance to dilute acids, bases and aqueous salt solutions at temperatures below 60 °C; resistance to strong oxidizers, chlorinated solvents and aromatic hydrocarbons is limited. Swelling in non-polar hydrocarbons can exceed 1 % mass uptake and reduce density-based quality-control readings. For packaging of surfactants or essential oils, ESCR testing under ASTM D1693 with 10 % Igepal CO-630 at 50 °C may be more relevant than tensile or Izod data. Published data for HDPE 50-1052 in these specific chemical environments is limited; material substitution should be validated by full immersion testing rather than by density or MFR alone.

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LyondellBasell HDPE 50-1052 is a high-density polyethylene resin identified within the supplier’s injection-moulding grade range. The designation is typically parsed by density and melt-flow indicators: the first segment corresponds to a nominal density of 0.950 g/cm³ when tested under ASTM D1505 or ISO 1183-1, and the middle segment corresponds to a nominal melt mass-flow rate of 10.5 g/10 min at 190 °C and 2.16 kg load when tested under ASTM D1238 or ISO 1133-1:2022. The grade is supplied as pelletized resin for high-shear injection-moulding operations; it is not intended for large-part blow moulding or for stretched-tape extrusion where high melt strength and strain-hardening behaviour control dimensional stability. The material’s polymer architecture—molecular weight distribution, short-chain branching and comonomer placement—is reactor-controlled, and the 0.950 g/cm³ density places it in the medium-range crystallinity segment of the HDPE family. Typical uses include thin-wall containers, closures, housewares and general-purpose moulded articles in which short filling time and fast cycle time are critical production variables.

What Processing Boundaries Appear When HDPE 50-1052 Is Run in High-Speed Injection Moulding?

On production-scale reciprocating-screw injection machines with screw L/D ratios between 20:1 and 24:1 and compression ratios from 2.0:1 to 3.0:1, the material is normally processed at barrel temperatures escalating from 180 °C in the rear zone to 220 °C at the nozzle. Melt temperatures above 240 °C may accelerate oxidative degradation and increase purge frequency, while temperatures below 190 °C can increase screw recovery torque and promote gate freeze-off in thin sections. Mould temperatures are typically held between 10 °C and 40 °C; higher mould temperatures reduce orientation-induced shrinkage anisotropy but extend cycle time. Published data for the specific interaction of HDPE 50-1052 with high-speed hot-runner valve gates in multi-cavity tools is limited; however, injection velocities above 120 mm/s and hold pressures between 30 MPa and 50 MPa are conventional starting conditions for comparable 0.950 g/cm³ HDPE grades. A mould-flow simulation should be considered for wall sections below 0.6 mm because the short packing window and rapid gate freeze-off create a process conflict: higher melt temperature delays gate freeze but increases oxidative risk; higher hold pressure extends packing but increases internal stress and mould flash.

In multi-cavity hot-runner systems, the high melt-flow rate of HDPE 50-1052 can produce balanced fill only if runner diameters are not undersized relative to the gate lay-out. A recurrent failure mode on 24-cavity and 32-cavity valve-gated tools is end-cavity fill order reversal when the manifold temperature is below 200 °C: the first cavities to fill show excessive sink, while end cavities show weak weld lines. Reducing manifold temperature below 190 °C is not recommended, because the resultant melt-pressure increase can exceed the machine’s available first-stage injection pressure and create screw-recovery variability of more than 0.5 s.

Moisture uptake in HDPE is generally low, and drying is not normally required for surface-quality-critical moulded parts when pellet storage is below 60 % relative humidity. If pellet surfaces exhibit condensation after cold warehouse movement, a 4 h desiccant-dryer residence time at 70 °C with a dew point of −30 °C may be applied; higher temperatures or prolonged residence can initiate pellet sintering in hopper dryers. Regrind addition up to 30 wt% is common, but the effect of repeated high-temperature moulding on the 10.5 g/10 min melt-flow rate must be monitored because chain scission can shift the apparent MFR upward and reduce part impact performance.

Mechanical and Thermal Benchmarks for Quality Assurance

Quality assurance for injection-moulded HDPE 50-1052 articles typically includes density confirmation by ASTM D1505 or ISO 1183-1:2019, melt-flow verification by ASTM D1238 or ISO 1133-1:2022, and tensile testing at 50 mm/min according to ASTM D638-14 or ISO 527-2:2012. Because the grade has a nominal density of 0.950 g/cm³, its crystallinity is intermediate within the HDPE range; tensile yield stress is generally higher than that of a 0.940 g/cm³ density HDPE and lower than that of a 0.965 g/cm³ homopolymer. The notched Izod impact resistance is governed by molecular weight and may be assessed under ASTM D256-23; however, published numerical Izod data for this specific grade should be obtained from the lot certificate rather than inferred from density alone. Environmental stress crack resistance under ASTM D1693 should be specified for detergent or surfactant-containing applications, where high-flow HDPE grades can show shorter failure times than lower-melt-index grades.

Differential scanning calorimetry according to ISO 11357-3:2018 shows a broad HDPE melt endotherm with peak temperature around 130 °C; for high-speed injection moulding, this peak does not eliminate the need for feed-zone stability below the hopper melting point. If the rear barrel temperature is maintained above 180 °C, bridge formation at the feed throat is generally avoided, but pellet surface tack can occur in hopper dryers above 70 °C.

Comparative processing suitability of HDPE 50-1052 and adjacent HDPE classes

Parameter	HDPE 50-1052	Blow moulding HDPE	Extrusion HDPE
Nominal density	0.950 g/cm³	0.950–0.955 g/cm³	0.940–0.955 g/cm³
Melt mass-flow rate at 190 °C/2.16 kg	10.5 g/10 min	0.2–1.0 g/10 min	0.15–0.8 g/10 min
Primary process	Injection moulding	Extrusion blow moulding	Sheet/profile extrusion
Melt strength	Low-moderate	High	High
Representative part examples	Thin-wall packaging, closures	Bottles, large containers	Geomembrane, thick sheet

When HDPE 50-1052 Is Evaluated as a Replacement for Lower-Flow HDPE in Existing Tools

If the grade is dropped into a tool originally qualified for a 0.30 g/10 min or 0.50 g/10 min HDPE, the lower melt viscosity alters shear heating, pressure transmission and gate seal behaviour. Shot mass and cushion become more sensitive to screw recovery settings because the higher MFR reduces melt pressure at a given injection velocity. Cushion positions below 4 mm may lead to inconsistent packing and sink marks; a cushion of 6–10 mm is typical for screw machines in the 250–1,000 kN clamp-force class. Short shots in long flow-length parts may be addressed by increasing injection velocity, but too high a velocity can generate shear heating above 5 °C across the runner and cause uncontrolled viscosity loss. When compared with HDPE blow-moulding grades, HDPE 50-1052 exhibits lower melt tension and is not a drop-in substitute for continuous-extrusion blow moulding.

For cap and closure applications, the higher flow path length-to-thickness ratio achievable with HDPE 50-1052 allows multi-cavity moulds with lower injection pressure than a 5.0 g/10 min HDPE; however, lower molecular weight can reduce strip torque and long-term stress-crack resistance. Performance tests should include ASTM D2063 for closure retention or ASTM D2659 for column crush where the closure is stacked.

Starting process window for HDPE 50-1052 on a 20:1–24:1 L/D reciprocating screw

Parameter	Lower set-point	Upper set-point	Observation point
Rear barrel temperature	180 °C	200 °C	Feed zone stability
Middle barrel temperature	190 °C	220 °C	Melt homogeneity
Front barrel/nozzle temperature	200 °C	230 °C	Part weight consistency
Mould temperature	10 °C	40 °C	Shrinkage and warp
Injection velocity	120 mm/s	250 mm/s	Short-shot boundary
Hold pressure	30 MPa	50 MPa	Sink marks
Back pressure	0.5 MPa	1.5 MPa	Screw recovery time

Storage, Food-Contact and Regulatory Review

Polyethylene grades in this density and melt-flow class are commonly covered by FDA 21 CFR 177.1520 for use in contact with food, subject to end-use limitations and migration testing; the specific regulatory datasheet from LyondellBasell should be consulted for the version and conditions of use. European food-contact evaluations follow Regulation (EU) No 10/2011, with overall migration limit of 10 mg/dm² for general food-contact plastics. REACH compliance is assessed under Regulation (EC) No 1907/2006; RoHS 2011/65/EU restrictions do not typically apply to unmodified HDPE but electrical and electronic equipment applications may require supplier declaration. Storage at temperatures above 40 °C or under ultraviolet exposure can reduce stabilizer performance and raise carbonyl index; therefore pellets should be stored in closed containers and protected from direct sunlight.

Regrind from HDPE 50-1052 moulded parts can be reintroduced into the same process at levels up to 30 wt% if the regrind is dust-free and not degraded. Repeated regrind cycles shift melt-flow rate upward; a 10.5 g/10 min virgin resin may exhibit MFR increases above 12 g/10 min after three cycles on a reciprocating screw with barrel residence times above 3 min. Therefore, lot verification of melt-flow and density is mandatory for regrind blends. Avoid combination with amine-based additives unless compatibility is confirmed, because certain hindered amine light stabilizer packages may alter acid scavenger distribution and surface migration. Purging with PVC or acetal should be avoided without a full melt-displacement protocol because thermal decomposition products can corrode mould surfaces and create part defects.

For profile or sheet extrusion, HDPE 50-1052 is not the primary choice: the 10.5 g/10 min MFR reduces melt strength, and draw resonance or edge tear can occur at haul-off ratios above 5:1. A lower-flow HDPE with MFR below 1.0 g/10 min provides more stable melt curtain formation in sheet lines with 300–1,000 mm die widths.

Chemical exposure data for HDPE with 0.950 g/cm³ density generally shows resistance to dilute acids, bases and aqueous salt solutions at temperatures below 60 °C; resistance to strong oxidizers, chlorinated solvents and aromatic hydrocarbons is limited. Swelling in non-polar hydrocarbons can exceed 1 % mass uptake and reduce density-based quality-control readings. For packaging of surfactants or essential oils, ESCR testing under ASTM D1693 with 10 % Igepal CO-630 at 50 °C may be more relevant than tensile or Izod data. Published data for HDPE 50-1052 in these specific chemical environments is limited; material substitution should be validated by full immersion testing rather than by density or MFR alone.