| HS Code | 982761 |
| Product Name | MARPOL COPP 18.3 PP Copolymer |
| Polymer Type | Polypropylene Copolymer |
| Melt Flow Rate | 18.3 g/10 min (230°C, 2.16 kg) |
| Density | 0.90 g/cm³ |
| Tensile Strength At Yield | 24 MPa |
| Elongation At Break | 12% |
| Flexural Modulus | 1150 MPa |
| Izod Impact Strength Notched 23 C | 7.5 kJ/m² |
| Rockwell Hardness | R 85 |
| Vicat Softening Temperature | 140°C |
| Heat Deflection Temperature 0 45 Mpa | 95°C |
| Melting Temperature | 165°C |
| Water Absorption | 0.01% |
As an accredited MARPOL COPP 18.3 PP Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | MARPOL COPP 18.3 PP Copolymer is supplied in sealed 25 kg polyethylene-lined paper bags, palletized and shrink-wrapped for safe transport. |
| Container Loading (20′ FCL) | 20' FCL container loading for MARPOL COPP 18.3 PP Copolymer: palletized, shrink-wrapped bags, secure bracing, ventilation as required. |
| Shipping | MARPOL COPP 18.3 PP Copolymer is a non-hazardous polypropylene-based material, typically supplied as pellets. Ship in clean, dry, lined containers to prevent contamination and moisture pickup. Keep away from heat, direct sunlight, and ignition sources. Avoid creating dust; ensure adequate ventilation. No IMDG marine pollutant designation applies under normal transport conditions. |
| Storage | Store MARPOL COPP 18.3 PP Copolymer in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and open flames. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid contact with oxidizing agents, acids, and alkalis. Ensure storage area is clean, spill-proof, and compliant with local regulations. Handle with care to prevent physical damage. |
| Shelf Life | Shelf life is approximately 2 years when stored in original sealed containers in a cool, dry, well-ventilated area. |
When talc-filled polypropylene compounds replace ABS in door panel lower sections, the material evaluation matrix shifts from painted-gloss surface retention to unpainted substrate aesthetics under scuff loading, cold impact survival at service temperatures approaching -30°C, and long-term dimensional stability inside a passenger cabin thermal envelope that fluctuates between -40°C and 95°C. The impact copolymer designated MARPOL COPP 18.3, characterized by nominal melt flow rate of 18 g/10min (ISO 1133-1:2022, 230°C, 2.16 kg) and ethylene comonomer content in the range of 8-12 wt% (FTIR internal method), is compounded on twin-screw extrusion lines with L/D 40:1 and screw diameter of 92 mm at throughput rates of 350-550 kg/h. The formulation comprises 72-80 wt% MARPOL COPP 18.3, 12-16 wt% ultra-fine talc with median particle diameter d50 of 1.5-2.0 μm (laser diffraction per ISO 13320-1:2020), 5-8 wt% metallocene POE elastomer with octene comonomer content of 25-30 mol% and melt mass-flow rate of 1.0-3.0 g/10min (190°C, 2.16 kg), and 1.5-2.5 wt% additive package comprising 0.25-0.35 wt% pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] hindered phenolic antioxidant, 0.15-0.25 wt% tris(2,4-di-tert-butylphenyl) phosphite secondary stabilizer, 0.3-0.5 wt% bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate HALS light stabilizer, and 0.1-0.2 wt% calcium stearate acid scavenger. Barrel temperature profile during compounding is maintained at 190/200/210/220/225/230/230/230/225/220°C across ten zones with side-feeding of talc at zone 6; screw speed is set at 420-520 rpm. The compounded pellet exhibits flexural modulus of 1900-2500 MPa (ISO 178:2019, 2 mm/min, 23°C), notched Izod impact strength of 18-25 kJ/m² at 23°C and 5.5-8.0 kJ/m² at -30°C (ISO 180/A), tensile yield strength of 26-30 MPa (ISO 527-2:2021), and heat deflection temperature under 1.8 MPa load of 58-64°C (ASTM D648-18, Method B).
Injection molding of door panel lower sections is performed on electric-hydraulic hybrid presses with clamp force of 1000-1600 kN and 24:1 L/D barrier screws of 40-50 mm diameter. Barrel zone temperatures are programmed as 190/205/215/225/235°C from feed throat to nozzle, with the feed throat cooled to 40-50°C to prevent premature pellet bridging. Mold temperature is controlled at 30-45°C by chilled water thermolator; for grained surfaces, mold texture depth of 25-35 μm (VDI 12-15 equivalent) requires mold temperature of 50-60°C to replicate texture fidelity. Injection velocity is set at 80-120 mm/s corresponding to fill time of 3.5-6.0 s; fill pressure reaches 85-110 MPa at the transfer point. Holding pressure of 55-75 MPa is applied for 6-10 s, followed by cooling time of 18-28 s; total cycle time falls within 38-55 s depending on part mass (450-950 g). Pre-drying with desiccant dryer at 80°C for 2-4 h is mandatory when ambient relative humidity exceeds 60%, targeting residual moisture below 0.02 wt% (Karl Fischer titration, ISO 15512:2019). Weld line performance at gate junctions of map pocket reinforcements is evaluated by tensile testing at 50 mm/min crosshead speed on specimens cut perpendicular to the weld line; specimens achieving ≥85% of parent material tensile strength with strain at break >250% pass production validation. Published data for MARPOL COPP 18.3 in this specific configuration is limited; the above values represent typical ranges for equivalent MFR 18 impact copolymer compounds.
Regulatory compliance for automotive interior applications requires flammability rating per FMVSS 302 (equivalently ISO 3795) with burning rate not exceeding 100 mm/min for parts thicker than 13 mm; fogging resistance per DIN 75201 Method B with condensate mass not exceeding 2 mg at 100°C over 3 h; VOC and FOG emissions per VDA 278 with VOC ≤ 100 μg/g (30 min at 90°C) and FOG ≤ 250 μg/g (60 min at 120°C); and SVHC declaration under REACH Regulation (EC) No 1907/2006. End product types produced from this compound include door panel lower sections, map pocket liners, scuff plate substrates, speaker grille mounting brackets, load floor support frames, and A/B/C-pillar lower covers.
The outer tub assembly in horizontal-axis front-loading washing machines is subjected to combined static loading from drum mass of 8-14 kg dry expanding to 22-38 kg wet load with saturated textiles, dynamic eccentric forces reaching 450-600 N at spin speeds of 1200-1400 rpm, and hydrolytic-alkaline exposure from residual detergent solutions with pH 9.5-11.0 at thermal cycling envelopes from 15°C to 95°C. Glass fiber reinforced compounds formulated with MARPOL COPP 18.3 at 68-75 wt% incorporate 20-30 wt% E-glass chopped strand fiber (4.5 mm length, amino-silane sized, filament diameter 10-14 μm) to raise heat deflection temperature under 1.8 MPa load from baseline 54°C to 138-145°C (ASTM D648-18, Method B) and flexural modulus from 1250 MPa to 3200-4200 MPa (ISO 178:2019, 2 mm/min). Maleic anhydride grafted polypropylene (MAH-g-PP, graft degree 0.8-1.2 wt%, MFR 100-150 g/10min at 190°C, 2.16 kg) functions as the interfacial coupling agent at 1.5-3.0 wt%; when MAH-g-PP loading drops below 1.0 wt%, notched Izod impact strength at -20°C (ISO 180/A) degrades from 9.5 kJ/m² to below 4.0 kJ/m² and tensile strength (ISO 527-2:2021, 5 mm/min) falls from 68-72 MPa to 55-60 MPa, confirming insufficient fiber-matrix adhesion. An additional 2-4 wt% POE elastomer may be incorporated in formulations targeting low-temperature impact; however, this reduces flexural modulus by 8-12% per 1 wt% elastomer addition. Stabilizer package at 0.4-0.8 wt% includes hindered phenolic primary antioxidant and phosphite co-stabilizer at 2:1 ratio; copper-containing heat stabilizer at 0.05-0.1 wt% may be required for continuous service above 85°C. Incompatibility note: amine-based antistatic additives and amine-cured epoxy adhesive residues from bearing housing inserts accelerate polypropylene chain scission at elevated temperatures and must be excluded from all contact surfaces.
Production of washing machine outer tubs requires injection molding machines with clamp force of 500-700 tonnes, screw diameter of 40-60 mm with L/D 22:1, and hot runner manifold with sequential valve gate control. The sequential valve gate actuation sequence is configured to position weld lines away from bearing housing attachment points—typically offset by 25-40° from the main load-bearing axis. Melt temperature at the nozzle is controlled to 235-245°C (verified by infrared pyrometer reading of the melt stream, not barrel setpoint); barrel zone temperatures are 200/215/225/235/240°C. Mold temperature is held at 45-60°C by oil-heated thermolator to minimize fiber orientation anisotropy between skin and core layers; skin-core fiber orientation ratio exceeding 5:1 as measured by X-ray micro-CT leads to differential shrinkage and ovality of the tub bore. Back pressure is set at 3-6 bar, decompression at 3-5 mm, screw speed at 40-70 rpm, injection velocity at 60-90 mm/s corresponding to fill time of 4-8 s, holding pressure at 60-80 MPa applied for 12-20 s, and cooling time of 25-40 s; total cycle time is 55-75 s for part masses of 3.5-6.5 kg. Pre-drying in desiccant dryer at 80°C for 3-4 h achieving residual moisture below 0.02% (ISO 15512:2019) is mandatory; moisture above 0.05% during processing causes hydrolysis of the silane coupling agent on the glass fiber surface, reducing tensile strength by 10-15% and producing splay defects on the tub exterior.
Compliance verification covers IEC 60335-2-7 clause 11 (heating), clause 19 (abnormal operation), clause 22 (stability and mechanical hazards), and clause 15 (moisture resistance); GB/T 4288-2018 washing machine safety requirements; and UL 2157 section 12. Dark gray masterbatch at 1-2 wt% (carbon black in PP carrier, 40% pigment loading) provides UV opacity for visible exterior sections. End products include front-loader outer tubs, agitator hub liners, lint filter housings, detergent dispenser drawer chassis, and pump mounting brackets.
Within enclosed lithium-ion battery compartments of electric vehicles and stationary energy storage systems, impact copolymer polypropylene is evaluated against parametric requirements for dimensional stability during thermal cycling from -40°C to 85°C, flame propagation resistance at wall thickness ≤3.0 mm, electrical insulating performance with comparative tracking index (CTI) ≥ 400 V, and long-term thermal-oxidative resistance at continuous use temperatures of 65-85°C with peak excursions to 105°C. Flame-retardant compounds formulated with MARPOL COPP 18.3 at 78-85 wt% incorporate intumescent ammonium polyphosphate (APP, CAS 68333-79-9, phosphorus content 31-32%, degree of polymerization >1000) at 10-15 wt% combined with melamine cyanurate synergist at 3-5 wt% and zinc borate at 1-2 wt%; a 0.3-0.5 wt% primary antioxidant package (hindered phenolic + phosphite at 2:1 ratio) completes the formulation. The critical processing constraint arises from APP thermal degradation initiating at approximately 215°C with release of ammonia and polyphosphoric acid species that corrode chrome-plated tool steel, generate surface splay defects, and deplete flame retardant efficacy. Barrel temperature profile must therefore be strictly maintained at 170/180/190/200/205°C from feed to nozzle with melt temperature verified at 195-202°C by manual thermocouple immersion; residence time exceeding 60 s at temperatures above 210°C initiates measurable FR degradation, indicated by UL 94 vertical burn after-flame time increasing from <5 s to >10 s at identical 3.0 mm thickness. Processing window of ±5°C around the optimal 200°C melt temperature classifies this compound as a narrow-window material requiring high-precision temperature control (±2°C band) on all barrel zones.
Injection molding is performed on machines with 1200-2000 kN clamp force and chrome-plated screws hardened to 50-52 HRC with L/D of 18:1 to 20:1 to minimize shear heating; the low-compression screw design (compression ratio 1.8:1) avoids excessive viscous dissipation that would elevate melt temperature above the APP stability threshold. Mold temperature is controlled at 30-50°C; lower temperatures reduce cycle time but produce higher frozen-in stress and warpage in carrier tray geometries exceeding 300 mm length. Injection velocity of 40-70 mm/s is maintained with fill pressure of 70-95 MPa; fill time is 5-10 s. Holding pressure of 45-65 MPa is applied for 8-12 s; cooling time is 20-35 s; total cycle time ranges 40-60 s for part masses of 200-600 g. Venting along parting lines at depth of 0.02-0.03 mm (vent land width 1.5 mm) is critical for evacuation of decomposition gases; inadequate venting produces gas traps at the last-filled regions with brown discoloration. Hot runner systems should use external heating with maximum manifold temperature 205°C; internally heated hot runners exhibit greater temperature heterogeneity and are not recommended for APP-based systems.
| APP Loading (wt%) | UL 94 Rating at 3.0 mm | Tensile Strength (MPa, ISO 527-2:2021) | Notched Izod at 23°C (kJ/m², ISO 180/A) | CTI (V, IEC 60112) |
|---|---|---|---|---|
| 8 | V-2 | 24 | 12 | 550 |
| 10 | V-1 | 22.5 | 10 | 525 |
| 12 | V-0 | 21 | 8.5 | 500 |
| 15 | V-0 | 19 | 7 | 475 |
Data in the table above represent typical ranges for equivalent MFR 18 impact copolymer compounds with APP-MC-ZB flame retardant systems; published data for MARPOL COPP 18.3 in this specific configuration is limited. Compliance verification covers UL 94 V-0 at 3.0 mm minimum thickness; IEC 62660-2 clause 6.3 mechanical shock; GB 38031-2020 clause 5.2.1.2 thermal runaway propagation resistance; UN ECE R100 Rev.3 Annex 8D; REACH Regulation (EC) No 1907/2006 Annex XVII entry 50 (PAH restrictions); RoHS Directive 2011/65/EU Annex II. Comparative tracking index is determined per IEC 60112 Method A using solution A. Incompatibility note: avoid combination with chlorendic anhydride-based additives, which interact with melamine cyanurate and compromise UL 94 performance; also avoid acid-functionalized processing aids below pH 4.5 that catalyze APP hydrolysis and reduce char formation efficiency. End products include lithium-ion battery module carrier trays, busbar insulation frames, terminal covers, cooling plate spacer frames, and junction box housings.
Injection molded logistics crates and collapsible pallet systems produced from MARPOL COPP 18.3 at 90-95 wt% with 5-8 wt% calcium carbonate filler (precipitated, d50 = 1.0-1.5 μm, stearic acid surface treated) and 1-2 wt% carbon black masterbatch (40% pigment loading in LLDPE carrier, melt index 20 g/10min at 190°C, 2.16 kg) are used where stacking load capacity under 40°C warehouse conditions and dimensional stability across 1000+ return cycles determine container service life. ASTM D2990 creep testing at 23°C with static load at 20% of ultimate compressive strength contributes design data; ISO 8611-1 flat pallet rating of 1000 kg equivalent uniform load requires rib geometry validation by finite element simulation prior to tool commissioning. Production employs injection molding machines of 350-600 tonnes clamp force with 22:1 L/D screws, melt temperature 200-230°C, mold temperature 10-30°C (chilled water), injection velocity 30-60 mm/s, holding pressure 35-50 MPa for 10-18 s, and total cycle time of 40-75 s for part masses of 1.8-8.0 kg. Structural foam variants incorporate 0.3-0.5 wt% azodicarbonamide chemical blowing agent achieving 15-20% density reduction while maintaining wall thickness of 4-6 mm; gas counter-pressure of 0.2-0.6 MPa minimizes surface swirl marks. UV stabilization for outdoor use requires 0.3-0.5 wt% HALS addition; without HALS, carbonyl index increases by factor of 12 after 5000 h of xenon arc exposure (ISO 4892-2:2013, cycle 1). End products: ventilated vegetable crates, foldable pallet boxes, dairy distribution crates, automotive parts dunnage trays, and pharmaceutical logistics containers.
Thin-wall injection molding of opaque dairy packaging from MARPOL COPP 18.3 at 97-99 wt% with 0.15-0.25 wt% sorbitol-derived nucleating agent and 0.1-0.15 wt% erucamide slip agent exploits the intermediate melt flow rate of 18 g/10min (ISO 1133-1:2022, 230°C, 2.16 kg) to achieve flow length-to-wall thickness ratios of 180:1 to 220:1 at injection velocities of 180-280 mm/s without short shots in wall sections of 0.5-0.8 mm. Melt temperature at the nozzle is controlled to 235-250°C to lower apparent viscosity into the range of 120-180 Pa·s at apparent shear rate of 10³ s⁻¹; barrel zones are set at 200/215/230/245/250°C. Injection is performed on high-speed accumulator-driven machines with clamp force of 250-400 tonnes, L/D 22:1, and electrically driven injection units capable of 250 mm/s maximum velocity; the accumulator permits instantaneous velocity response preventing hesitation marks at the gate transition. Mold temperature is maintained at 10-20°C by chilled water at 8-12°C through conformal cooling channels; cooling time is 2.5-4.5 s for 0.6 mm wall thickness; total cycle time is 5.5-7.5 s. Hot runner systems with valve gate diameter of 0.6-1.2 mm and gate land length of 0.3-0.5 mm provide gate freeze-off within 0.8-1.5 s. Stack molds with 2×4 cavity configuration are standard; 2×8 cavity configurations require doubling clamp force to 600-800 tonnes.
| Standard Designation | Test Method Designation | Limit Value | Test Condition |
|---|---|---|---|
| FDA 21 CFR 177.1520 paragraph (c) | Extraction per 21 CFR 177.1520 | Soluble fraction limits in xylene and hexane | Reflux 2 h |
| (EU) No 10/2011 Annex I | EN 1186-1 | 10 mg/dm² overall migration | Food simulant D1, 40°C, 10 days |
| (EU) No 10/2011 Annex II | EN 13130-1 | Specific migration per substance listed | As specified per substance |
| GB 4806.6-2016 | GB 31604.1 | 10 mg/dm² total migration | 4% acetic acid, 20% ethanol, 50% ethanol |
The material is compliant without additional testing only if no post-production surface treatments or printing inks containing non-listed substances are applied. Pre-drying at 80°C for 2 h in desiccant dryer is standard when ambient relative humidity exceeds 60%; residual moisture target is below 0.02 wt% (ISO 15512:2019). End products: margarine tubs, dairy spread containers, deli containers, whipped cream tubs, opaque lid systems, and frozen food containers with wall thickness 0.6-1.0 mm.
Among seating system structural components, the five-star office chair base manufactured from MARPOL COPP 18.3 compounded with 15-20 wt% E-glass chopped strand fiber (4.5 mm, silane sized) and 2-4 wt% POE impact modifier is evaluated against BIFMA X5.1-2017 cyclic seat-base test loading (100,000 cycles at 75 kg) and EN 1728:2012 seating durability tests. The gas-assist injection molding process injects melt at 220-245°C into a mold at 30-50°C with nitrogen gas pressure of 12-20 MPa following 65-80% volumetric fill; gas channels of 6-12 mm diameter are positioned along the radial arms to eliminate sink marks while achieving 20-35% mass reduction versus solid molding. Gas delay time of 1.0-2.0 s and gas hold time of 10-18 s govern internal cavity formation; premature gas breakthrough at the castor mounting bosses causes structural collapse and is detected by ultrasonic thickness mapping with 15 MHz transducer at resolution ±0.1 mm. ASTM D256-23 notched Izod values of 8-12 kJ/m² at 23°C (conditioning per ASTM D618-21, 50% RH, 40 h) are required; flexural modulus of 1800-2500 MPa (ISO 178:2019) provides the stiffness-to-weight relationship. Incompatibility note: do not dry above 90°C as this causes fiber sizing degradation and reduces coupling efficiency by 20-30%. End products: five-star office chair bases, armrest support brackets, stadium seating shells, and auditorium bench supports.
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Designated in supplier documentation as MARPOL COPP 18.3 PP Copolymer, this resin is a heterophasic polypropylene impact copolymer supplied in pellet form for injection moulding and selected extrusion operations. The numerical suffix 18.3 is interpreted in material logistics as the nominal melt mass-flow rate of 18.3 g/10 min determined under ISO 1133-1:2022 condition M at 230 °C and 2.16 kg. The grade is not a controlled rheology homopolymer; the high MFR is obtained through reactor molecular weight control and copolymer phase design, placing the material in the medium-flow segment used for thin-wall packaging, closures, appliance housings, battery cases, and interior automotive trims. Published property values for this specific configuration are limited, and the ranges cited in this document should be read as representative envelopes for medium-flow polypropylene impact copolymers of equivalent melt flow rate. A lot-specific certificate of analysis is required to convert these ranges into product acceptance limits.
The material is typically converted in high-speed injection moulding lines where dimensional stability and impact resistance at low temperatures are prioritized. The main substitution choice is a nucleated homopolymer injection grade with equivalent MFR; the selecting engineer accepts a lower flexural modulus in exchange for a measurable improvement in notched impact and crack propagation resistance. The COPP designation identifies a copolymer grade; it does not indicate copper content.
On production-scale hydraulic injection moulding machines, the recommended barrel temperature corridor for MARPOL COPP 18.3 PP Copolymer feed is set rear to nozzle at 200 °C, 210 °C, 220 °C, 230 °C, and 230 °C. Melt temperatures above 250 °C are permissible only when residence time is held below 10 min; longer exposure can raise the melt flow rate by thermo-oxidative chain scission and increase gate blush in thin-wall parts. Mould temperature is held between 30 °C and 60 °C. The lower interval is used for fast-cycling packaging, while the upper interval improves surface gloss, knit-line impact, and dimensional stability in structural parts. At wall thicknesses below 1.0 mm, mould temperatures above 40 °C can extend cycle time without improving properties and are typically avoided.
The resin is supplied below 0.05 wt% moisture; pre-drying is not normally required unless saturated storage or high regrind ratios are used. When pre-drying is specified, desiccant drying at 80 °C for 2–4 h with a dew point of −20 °C to −30 °C prevents splay on visible surfaces. A general-purpose polyolefin screw with L/D 20:1 to 24:1 and compression ratio 2.5:1 to 3:1 is suitable; high-shear barrier screws are not required for this flow class. Back pressure is typically 5–15 bar hydraulic, and screw recovery speed is set at 50–150 rpm. Injection velocity ranges from 100 mm/s to 250 mm/s depending on flow length. Hold pressure is developed from 400 bar to 700 bar hydraulic; pack time for a 2 mm wall is 4–8 s. The gate seal point should be confirmed by weighing parts, not by visual appearance alone.
In a 40-mm reciprocating screw, recovery time should remain below 12 s at 150 rpm. Longer recovery indicates excessive back pressure or rear-zone temperature and shifts the melt temperature beyond the set point. Practical testing of similar grades has shown gloss variation on a 4-cavity hot runner cap mould when recovery time exceeds 12 s; published data for this specific configuration is limited, but the mechanism is well documented for polypropylene copolymers. Hot runner systems should use open-pipe nozzles or valve gates with no dead spots; full-open gate temperatures are set 10–20 °C above the nozzle set point. Gate diameter for a 1.0-mm wall is typically 0.6–1.0 mm. Cold runner sprue and runner diameters should not fall below 4.0 mm for main sprue pull, and cold slug wells should be included. Vent depth should remain 0.02–0.03 mm; deeper vents produce flash while shallower vents create burn marks at flow-front collision points.
The mechanical values obtained on 4 mm ISO injection moulded specimens do not transfer directly to sections below 1.5 mm. Rapid cooling increases the skin-layer fraction and freezes molecular orientation, which can reduce notched impact by 10–20 % relative to the data sheet value, even at constant mould temperature. The effect is measured according to ISO 180/A on specimens cut from injection moulded plaques. Copolymer phase morphology also matters. The ethylene-propylene rubber particle size in medium-flow impact copolymers is typically in the submicron range; rapid cooling from the melt and high shear through thin gates can orient the rubber phase and reduce impact. This explains why impact values on gate-near specimens can be lower than values on specimens taken from the opposite side of the tool.
| Property | Typical range | Test method |
|---|---|---|
| Melt mass-flow rate | 18.3 g/10 min | ISO 1133-1:2022 |
| Density | 0.900–0.910 g/cm³ | ISO 1183-1:2019 |
| Tensile stress at yield | 24–28 MPa | ISO 527-2:2012 |
| Tensile modulus | 1,100–1,500 MPa | ISO 527-2:2012 |
| Flexural modulus | 1,200–1,600 MPa | ISO 178:2019 |
| Notched Izod impact at 23 °C | 8–20 kJ/m² | ISO 180/A |
| Notched Izod impact at −20 °C | 3.5–6.0 kJ/m² | ISO 180/A |
| Heat deflection temperature 0.45 MPa | 90–105 °C | ISO 75-2:2013 |
| Vicat softening temperature A50 | 150–156 °C | ISO 306:2013 |
| Mould shrinkage parallel/normal | 1.0–1.8 % | ISO 294-4:2018 |
The impact values are influenced by ethylene content in the rubber phase; a shift within the range does not indicate a change in polymer species but may reflect batch-to-batch variation or test specimen preparation under ISO 294-1:2017. For applications requiring low-temperature ductility, validation should include −20 °C notched impact on specimens cut from production parts, not from standard plaques alone. Optical microscopy and scanning electron microscopy after ruthenium tetroxide staining are used to evaluate rubber particle distribution in failure investigations.
The operational boundary for unpredried regrind addition is 15 wt%. Above this level, the combined effect of additional heat history, fines, and absorbed moisture can shift melt flow rate upward and reduce impact. In three-pass reprocessing of an equivalent medium-flow impact copolymer at 230 °C, the melt flow rate can rise from 18.3 g/10 min to 22–26 g/10 min when measured under ISO 1133-1:2022. The shift is accompanied by a decline in notched Charpy impact at −20 °C of 10–20 % under ISO 179-1:2023, depending on the previous heat history and the level of processing stabilizer remaining.
On a 250-ton toggle clamping machine running a 4-cavity hot runner closure mould, increasing regrind from 10 wt% to 25 wt% may increase peak injection pressure by 50–100 bar because fines alter melt compressibility. This is observed as a reduction in shot-to-shot consistency and more frequent screw slip alarms. Cushion position on a 40-mm screw may require adjustment by 2–3 mm when lot melt flow rate varies by ±0.5 g/10 min. The regrind ratio is controlled by gravimetric blender; spike loads above 25 wt% are avoided because the fines fraction can segregate and cause flow fluctuations at the feed throat. If regrind is not dried, moisture in the melt can reduce molecular weight at high temperature and produce surface splay; the effect is more evident in hot runner drops with long residence time.
Pre-drying of regrind at 80 °C for 2–4 h in a desiccant dryer, followed by blending with virgin resin by metering conveyor, is used when surface splay or gas marks appear. Transition-metal contamination should be avoided; despite the COPP prefix, the grade does not contain copper as a functional additive, but copper-based contact surfaces in hot runner tips can accelerate oxidative degradation during extended production campaigns.
At equivalent melt flow rate, a PP homopolymer injection grade provides higher tensile modulus and heat deflection temperature but lower notched impact, particularly below 0 °C. A PP random copolymer provides clarity and lower modulus but cannot match the low-temperature impact resistance of a heterophasic copolymer. The MARPOL COPP 18.3 PP Copolymer grade is positioned between these alternatives: the rubber phase reduces stiffness by roughly 10–20 % compared with a nucleated homopolymer at the same MFR, while the notched Izod impact at 23 °C can be 2–4 times higher. The material is opaque in natural form; applications requiring contact clarity should use random copolymer instead.
| Attribute | MARPOL COPP 18.3 PP Copolymer | PP homopolymer 18 g/10 min | PP random copolymer 18 g/10 min | Low-flow impact copolymer 3 g/10 min |
|---|---|---|---|---|
| Melt flow rate ISO 1133-1:2022 | 18.3 g/10 min | 18 g/10 min | 18 g/10 min | 3 g/10 min |
| Tensile modulus ISO 527-2:2012 | 1,100–1,500 MPa | 1,500–1,800 MPa | 850–1,100 MPa | 1,100–1,500 MPa |
| Notched Izod ISO 180/A at 23 °C | 8–20 kJ/m² | 2.5–4.0 kJ/m² | 4–7 kJ/m² | 20–40 kJ/m² |
| Heat deflection temperature 0.45 MPa ISO 75-2:2013 | 90–105 °C | 100–110 °C | 80–95 °C | 90–105 °C |
| Mould shrinkage ISO 294-4:2018 | 1.0–1.8 % | 1.2–2.0 % | 0.8–1.5 % | 1.3–1.8 % |
The low-flow impact copolymer offers higher impact at the cost of higher injection pressure, longer cycle time, and greater clamp force on the same tool. The 18.3 MFR grade is therefore specified where thin-wall fill and impact resistance must be balanced without moving to a higher melt-flow grade that sacrifices molecular weight and environmental stress crack resistance. In contrast, a homopolymer grade is selected for stiff, simple geometries with short flow paths; a random copolymer is selected for transparency or low-temperature sealing performance. The density of the heterophasic copolymer remains close to that of homopolymer, so part mass is not significantly different; the change is in mechanical performance. For living hinge applications, homopolymer is preferred due to repeated flexural fatigue resistance; for deep freeze containers, impact copolymer at −20 °C provides fewer brittle failures in drop tests.
In thin-wall packaging and closure tooling, the grade is used with high-speed injection moulding machines with part mass 4–8 g and wall thickness 0.8–1.2 mm. Fill times below 0.8 s are typical when gate velocity is set at 250–350 mm/s. Tool design uses a shrinkage factor of 1.2–1.6 % in the flow direction and 1.4–1.8 % perpendicular, with higher values near hot gates. Mould temperatures below 30 °C reduce cycle time but may produce dull surfaces and lower drop-impact resistance. At wall thickness 2.0 mm for appliance housings, gas injection or 0.5–1.0 wt% chemical foaming agent reduces sink marks but can lower flexural modulus by 5–10 % measured by ISO 178:2019. Flammability classification for natural resin is typically UL 94 HB at 1.5 mm; pigmented formulations require separate testing.
Dimensional control in multi-cavity tools is affected by gate freeze time and packing pressure. Cavities should be balanced within 5 % of fill time; unbalanced filling shifts shrinkage and warpage. In on-machine trials of similar materials, balancing fill time to within 0.05 s across an 8-cavity tool reduced part weight variance from 0.25 g to 0.08 g, measured with a laboratory balance. This level of control is required when the material is used for tamper-evident closures with sealing surface flatness below 0.2 mm. For food-contact applications, lot-specific certification under FDA 21 CFR 177.1520(c) and EU Regulation (EU) No 10/2011 is required; the statement “food grade” is not accepted without production campaign documentation. For automotive interior trim, odour and fogging tests under VDA 270 and SAE J1756 are performed on production-representative parts because stabilizer packages influence volatile emission levels. The resin should not be exposed continuously to hot water above 80 °C under mechanical load unless long-term hydrostatic testing under ISO 9080 demonstrates otherwise.
