| HS Code | 191967 |
| Density | 0.905 g/cm³ |
| Melt Flow Rate | 12 g/10 min (230°C, 2.16 kg) |
| Tensile Strength At Yield | 26 MPa |
| Elongation At Break | 50% |
| Flexural Modulus | 1150 MPa |
| Notched Izod Impact Strength | 6 kJ/m² |
| Charpy Impact Strength | 25 kJ/m² |
| Rockwell Hardness | R80 |
| Heat Deflection Temperature | 85°C at 0.45 MPa |
| Vicat Softening Temperature | 150°C (A/50) |
| Melting Temperature | 165°C |
| Water Absorption | 0.1% (24h) |
| Mold Shrinkage | 1.3% |
As an accredited Sasol CMR648 PP Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Sasol CMR648 PP Copolymer supplied as 25 kg multi-wall paper bags, palletized and stretch-wrapped for safe transport and storage. |
| Container Loading (20′ FCL) | 20′ FCL container loaded with Sasol CMR648 PP copolymer in sealed bags on pallets, secured and protected for safe transit. |
| Shipping | Sasol CMR648 PP Copolymer ships as pellets in moisture-protective bags, bulk bags, or rail hoppers. Keep dry, cool, and away from ignition sources to prevent dust accumulation. Standard non-hazardous freight applies, though good ventilation, secure loading, and clean handling are essential to avoid contamination and preserve material integrity. |
| Storage | Store Sasol CMR648 PP Copolymer in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture ingress and contamination. Avoid prolonged exposure to elevated temperatures, which may cause degradation. No special hazardous storage required, but maintain good housekeeping and use first-in, first-out rotation. |
| Shelf Life | Sasol CMR648 PP Copolymer has a shelf life of 12 months when stored unopened in a cool, dry, shaded area. |
Exterior fascia compounds formulated from Sasol CMR648 impact copolymer and an 18–25 wt% ethylene-octene elastomer masterbatch require a mould surface temperature of 45–60 °C to preserve rubber-phase dispersion in the skin layer. Below 40 °C, the quenched surface forms a highly oriented polypropylene skin that reduces multiaxial impact energy absorption at -30 °C when tested under ISO 6603-2. This is the central processing conflict: lower mould temperature shortens cycle time on a large platen, but the same condition narrows the processing window to ±5 °C before the ductile-to-brittle transition shifts into the service range. Injection compression moulding is preferred over high-pressure injection to reduce molecular orientation and to lower clamp force from 2,800 tonnes to 1,900 tonnes on a 2.8 kg shot. Melt temperature is held between 230 °C and 255 °C, and residence time should not exceed 6 min because the ethylene-propylene rubber phase can crosslink or chain-scission, producing surface pitting and loss of elastomer dispersion. Sequential valve gating is timed so that melt fronts meet outside high-stress zones. Finished bumper fascias and rocker panels are validated for paint adhesion after applying a chlorinated polyolefin adhesion promoter; crosshatch adhesion is tested under ISO 2409 with a requirement of Class 0–1. The part must also show no cohesive failure after a 50 °C high-pressure water-jet test. The low-temperature ductile requirement is typically set by the OEM engineering specification at -30 °C with a puncture energy of at least 20 J, but this value must be confirmed for the final CMR648 compound because lot-to-lot elastomer ratio shifts alter the fracture mode.
On a 650-tonne hydraulic clamp injection machine with a 110 mm screw and an L/D ratio of 24:1, the first processing signal that CMR648 has exceeded its residence-time limit is a lot-to-lot shift in ISO 1133-1 melt flow rate greater than 0.8 g/10 min. For automotive interior door lower substrates, CMR648 is dry-blended with 12–18 wt% talc masterbatch, 0.5–1.5 wt% scratch-resistant additive, and 0.2–0.5 wt% antioxidant masterbatch. The mixture is fed through a gravimetric hopper and processed at a melt temperature of 220–245 °C, a mould temperature of 30–50 °C, and a back pressure of 0.5–1.2 MPa. Injection velocity is profiled to prevent hesitation marks around ribs and doghouse bosses. The final product—door lower inserts, seat back panels, and centre console side trims—is validated to VDA 270 odour grade ≤3, DIN 75201 fogging gravimetric value ≤2 mg, and REACH SVHC restrictions. Because talc loading reduces shrinkage to 0.6–0.9% in the flow direction and 0.8–1.1% transverse, the mould must be cut with differential shrinkage factors, otherwise the trim piece shows gap inconsistency against the upper door panel. The critical failure mode is cold-weld embrittlement at bosses when melt temperature falls below 220 °C; field data from similar PP impact copolymers indicate a drop in weld-line elongation at break of more than 30% relative to the bulk value. Published data for this specific CMR648 configuration is limited, so a gate-seal curve and a fill-only short-shot series should be generated on the production machine.
In washing machine outer tub tooling, a 20 wt% talc-filled CMR648 compound must be gated through a central sprue or a hot runner with a diameter of 5.5–7.0 mm; smaller runners create excessive shear heating and accelerate degradation of the ethylene-propylene rubber phase, causing black specks and poor weld-line strength around the bearing housing. Melt temperature is maintained at 230–250 °C, and the mould is run at 50–70 °C to promote sufficient crystallinity for long-term hot-water exposure up to 60 °C. The tub wall thickness of 2.5 mm over a flow path of 310 mm requires a flow-length-to-thickness ratio of 124:1; this is at the upper end for a talc-filled impact copolymer, so holding pressure must be raised to 60–80% of peak injection pressure until gate freeze. The critical boundary condition is the weld line at the bearing housing ring: if the melt front meets at a temperature below 210 °C, weld strength falls below the creep load transmitted by the motor shaft during spin cycles. The part is validated under IEC 60335-1 for abnormal operation, with the tub subjected to 90 °C water and detergent for 1,000 h; dimensional change must be below 0.5% to maintain bearing alignment. Post-mould warpage is controlled by cooling circuits placed within 12 mm of the bearing seat. CMR648 lot certificates should be reviewed for ISO 178 flexural modulus; a shift from 2,200 MPa to 1,800 MPa at 20% talc indicates insufficient dispersion or lot mis-selection and requires increasing back pressure to 0.8–1.4 MPa.
Because the lower clamshell of a cordless power tool carries the motor bearing seat, gate location in a CMR648-based impact copolymer is selected only after weld-line position is mapped against the drop-test impact zone defined by the OEM internal standard or mechanical hazard verification under IEC 62841-1. The housing typically uses a high-flow variant of CMR648 with a melt flow rate between 18 g/10 min and 30 g/10 min at 230 °C/2.16 kg, although the exact grade lot must be checked under ISO 1133-1:2022 before setting injection velocity. Processing is performed at a melt temperature of 220–250 °C, mould temperature of 25–50 °C, and an injection speed of 150–300 mm/s to avoid premature freeze at the thin ribs around the motor seat. The principal failure mode on production lines is sink marks above the bearing seat when hold pressure is released before gate freeze; this is avoided by maintaining gate-seal time above 1.2 s/mm of wall thickness. The terminal parts—angle grinder lower housings, drill body clamshells, and impact driver frames—are subjected to UL 94 HB at 2.0 mm wall thickness and a 1.0 m drop onto concrete at -10 °C; the CMR648 compound must retain ductile failure without cracking at screw bosses. Lubricant exposure resistance is assessed by immersion in a 10% mineral oil solution at 23 °C for 168 h, with tensile-strength retention above 85% measured under ISO 527-1:2019. Because standard CMR648 is not flame-retardant, any requirement for a V-2 or V-0 rating must be addressed through a halogen-free intumescent system; this changes the drop-impact balance and requires revalidation of the weld-line at the motor seat.
Heat sealing of injection-moulded lead-acid battery lids made from CMR648 creates a through-thickness thermal gradient that can leave unsealed channels if the sealing platen is not parallel within 0.05 mm. The battery container and lid require a melt temperature of 230–260 °C, a mould temperature of 30–60 °C, and a hold pressure of 70–90% of peak injection pressure to eliminate sink over the cell partitions and terminal bosses. The compound is usually unfilled CMR648 to keep acid resistance high; mineral fillers above 5 wt% are avoided because they raise the coefficient of thermal expansion mismatch and create microporosity that increases acid wicking along the weld line. Injection is directed through a hot-runner system with valve gates placed between cell compartments, and the weld lines are moved to the partition walls to minimise the leak path exposed to electrolyte. The lid is post-mould annealed at 90 °C for 2 h to relax orientation before heat sealing. Acid immiscibility and low-temperature impact resistance are validated under EN 50342-1 and SAE J537; the container must pass a -40 °C drop from 1.0 m after filling with 75% acid by volume. The limiting manufacturing defect is a cold slug at the valve gate; if the nozzle tip temperature falls below 230 °C, a partial plug forms and the next cycle shows short shots or low seal strength. Lot-specific ISO 180/A notched Izod values at -30 °C should be monitored; a shift below 8 kJ/m² may indicate insufficient rubber phase dispersion, often caused by excessive screw recovery speed above 200 rpm.
| Application | Standard | Test Condition | Typical Acceptance Criterion |
|---|---|---|---|
| Automotive interior trim | VDA 270 | 80 °C / 2 h | Odour ≤3 |
| Automotive interior trim | DIN 75201 | 100 °C / 16 h | Fogging ≤2 mg |
| Exterior fascia | ISO 6603-2 | -30 °C, 4.4 m/s | Ductile puncture per OEM spec |
| Washing machine tub | IEC 60335-1 | 90 °C water/detergent | Dimensional change ≤0.5% |
| Power tool housing | UL 94 HB | 2.0 mm | HB rating |
| Battery container | EN 50342-1 | -40 °C drop, 1.0 m | No leak or crack |
| Logistics pallet | ISO 8611-2 | 500 kg racking load | Deflection ≤12 mm |
For pallets with rib thicknesses above 18 mm, cooling-time equations based on one-dimensional heat conduction become unreliable for CMR648 because the low thermal diffusivity of the unfilled or lightly filled impact copolymer holds core heat for 45–80 s after ejection. Air-assisted moulding is introduced through a gas injection pin at 8–12 mm from the rib root to create a hollow section, reducing sink depth from 0.2 mm to 0.03 mm across the top deck and cutting cycle time by 15–20%. The compound typically carries 0–10 wt% in-house regrind of the same CMR648 pallet material; higher regrind fractions reduce melt viscosity and gas channel stability. Melt temperature is held between 220 °C and 245 °C; gas pressure is ramped from 5 MPa to 15 MPa after the melt front has filled 70% of the cavity. The final pallet, typically a 1,000 mm × 1,200 mm Euro footprint with 9 feet, is validated under ISO 8611-2 for racking load, with a permitted deflection of 12 mm at 500 kg over a 750 mm span; dynamic impact at -20 °C is assessed by dropping a 25 kg steel slug from 1.2 m onto the corner block. The key processing limitation is gas breakthrough at the weld lines near the fork entries; if melt temperature exceeds 245 °C, the gas channel can migrate into the rib wall and open a through-hole, creating a stress concentrator that reduces corner impact strength by more than 30%. CMR648 is not a food-contact-approved grade in this form, so pallets intended for direct pharmaceutical or food contact require a barrier layer or regulatory confirmation under FDA 21 CFR 177.1520 and EU 10/2011.
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Sasol CMR648 PP Copolymer is a reactor-grade heterophasic propylene-ethylene impact copolymer supplied in pellet form for injection moulding and related thermoplastics conversion. The designation CMR648 identifies a polypropylene matrix modified by a dispersed ethylene-propylene rubber phase produced directly in the polymerization train rather than by post-reactor melt blending. This morphology increases resistance to crack propagation at low temperatures relative to polypropylene homopolymers while retaining a melt flow rate suited to medium-flow injection moulding. Material certifiers typically inspect melt mass-flow rate under ISO 1133-1, density under ISO 1183-1, tensile properties under ISO 527-2, flexural modulus under ISO 178, and Charpy impact resistance under ISO 179-1/1eA. The grade’s property profile is intended for parts that require a balance of stiffness, impact resistance, and processability, such as household articles, automotive interior trim, thin-wall containers, and industrial closures. Because CMR648 is a heterophasic copolymer, it is not selected where contact transparency is required; the rubber phase scatters visible light and produces haze. It also differs from a random propylene-ethylene copolymer, which has a different comonomer distribution, lower crystalline melting point, and generally higher optical clarity but lower low-temperature toughness. The following sections detail the specification, processing boundaries, and substitution logic for this grade.
The key difference is the two-phase structure. In CMR648, a continuous polypropylene homopolymer or low-comonomer copolymer matrix carries a discontinuous elastomeric phase composed of ethylene-propylene rubber. The elastomer domains are typically sub-micron to several microns, and their size distribution is controlled by reactor conditions and melt processing. A homopolymer of equivalent melt flow rate has a single glass transition temperature below 0°C but exhibits brittle crack propagation under notched impact conditions. The dispersed rubber phase in CMR648 absorbs energy during deformation, blunting crack tips and producing a notched Charpy impact strength at 23°C that is often two to five times higher than that of a homopolymer. Under ISO 179-1/1eA, the reported typical value for CMR648 is 8.0 kJ/m², with a -20°C value near 3.5 kJ/m²; these values reflect room-temperature ductility and reduced, but not eliminated, low-temperature sensitivity. The rubber phase also lowers flexural modulus compared with homopolymer: the CMR648 typical flexural modulus is 1200 MPa under ISO 178, whereas a comparable homopolymer may exceed 1500 MPa. The trade-off is deliberate. The product is not a compounded blend; rubber domains are formed in-reactor, which provides a narrower rubber particle size distribution and better lot-to-lot consistency than post-reactor melt blending. The grade’s density of approximately 0.900 g/cm³ under ISO 1183-1 is close to standard polypropylene, because ethylene incorporation is relatively low and the rubber phase does not significantly alter the bulk density.
Representative datasheet values are presented in Table 1. These values are typical from public material characterization summaries and should not replace a production certificate for lot release. When a converter compares grades, the test speed, specimen conditioning, and notch geometry must be identical; ISO 179-1/1eA uses a notched specimen and a commonly employed pendulum capacity class. The melt flow rate is reported under 230°C and 2.16 kg, and the value of 12 g/10 min indicates a medium-flow grade suitable for thin-wall filling without excessive screw recovery time.
| Property | Standard | Unit | Typical value |
|---|---|---|---|
| Melt mass-flow rate | ISO 1133-1 | g/10 min | 12 |
| Density | ISO 1183-1 | g/cm³ | 0.900 |
| Tensile stress at yield | ISO 527-2 | MPa | 25 |
| Tensile strain at yield | ISO 527-2 | % | 6 |
| Flexural modulus | ISO 178 | MPa | 1200 |
| Charpy notched impact strength at 23°C | ISO 179-1/1eA | kJ/m² | 8.0 |
| Charpy notched impact strength at -20°C | ISO 179-1/1eA | kJ/m² | 3.5 |
| Vicat softening temperature A50 | ISO 306 | °C | 152 |
| Heat deflection temperature B at 0.45 MPa | ISO 75-2 | °C | 85 |
| Mould shrinkage | ISO 294-4 | % | 1.0–1.3 |
Injection moulding of CMR648 is performed on standard reciprocating-screw machines with a minimum screw L/D of 20:1 and moderate compression ratios. The recommended melt temperature window is 210°C to 250°C, measured at the nozzle. Processing below 210°C increases melt viscosity, raises injection pressure demand, and can freeze the elastomer phase at the flow front; processing above 250°C accelerates chain scission and may generate odour, discolouration, and loss of impact resistance. Mold surface temperature should be held between 20°C and 50°C. For thin-wall parts with flow lengths greater than 150 mm, the upper half of the mold-temperature range improves weld-line strength. The grade is not hygroscopic, but condensation on cold pellets introduced into a warm factory can create splay. If bags have been opened in high humidity, desiccant drying for 2 h at 80°C is applied. The recommended back pressure is 0.5 MPa to 1.5 MPa hydraulic; insufficient back pressure causes melt-temperature heterogeneity and unmelted granules at the nozzle. Injection velocity should be profiled, with fast initial filling to prevent premature skin solidification, followed by reduced velocity at the end of fill to prevent flash. Hold pressure typically ranges from 50% to 75% of peak injection pressure, with a hold time sufficient to seal the gate. Screw retraction should include a small decompression of 2–5 mm to prevent nozzle drool, but excessive decompression can draw air into the melt stream and create burn marks. Hot runner systems should use externally heated manifolds with low dead spots; residence time at temperatures above 230°C should not exceed 10 min to avoid degradation. Gate size should be at least 1 mm for wall stock below 1.5 mm, and land lengths should be kept below 1 mm to minimize pressure loss.
Application testing of CMR648 has followed standard methods for polypropylene impact copolymers. Thin-wall containers are evaluated for top-load strength and drop impact; automotive interior trims are subjected to notched impact at -20°C and heat aging at 100°C. The grade’s melt flow rate of 12 g/10 min supports filling of components with wall thicknesses from 0.8 mm to 2.5 mm, provided gates and vents are adequate. For closures, long-term creep under applied load is assessed under ASTM D2990, and environmental stress crack resistance may be evaluated using ASTM D1693 or ISO 4599. Published data for this specific configuration is limited, so converters should perform application-specific validation.
Converters often compare CMR648 to a homopolymer that has been given a higher melt flow rate by peroxide vis-breaking. In such homopolymers, MFR increase is achieved by chain scission, narrowing molecular weight distribution and lowering melt viscosity. However, low-temperature notched impact resistance typically falls sharply as MFR rises. CMR648 uses a reactor-designed heterophasic architecture instead of vis-breaking alone; the ethylene-propylene rubber phase maintains energy absorption while the matrix provides flow. The result is a melt flow rate of 12 g/10 min with a notched Charpy value of 8.0 kJ/m² at 23°C. A homopolymer of similar MFR can show flexural modulus above 1500 MPa but notched Charpy values below 2 kJ/m² at -20°C. The cost of this balance is lower stiffness and higher haze. The grade also differs from random copolymers, where ethylene is inserted at low levels in the primary chain and the product remains largely single-phase. Random copolymers have better clarity and lower sealing temperatures but lower heat deflection and melt strength. CMR648’s heterophasic structure produces a crystalline polypropylene matrix with a Vicat softening temperature of approximately 152°C under ISO 306/A50, which is closer to homopolymer behaviour than to typical random copolymer behaviour.
Although CMR648 can be processed at melt temperatures up to 250°C, thermal stability is finite. Residence time at temperature in the barrel or hot runner should be minimized. Purging with a medium-flow polypropylene or a commercial purging compound is recommended when transitioning from engineering polymers such as polycarbonate or nylon. The presence of ethylene-propylene rubber makes the grade more sensitive to long residence than a homopolymer because the elastomer phase can crosslink or agglomerate under thermal load, producing gels and surface defects. In hot runner systems, dead-leg zones with stagnant material should be eliminated. During shutdown, the screw should be retracted and the barrel purged with a thermally stable polypropylene. Gas evolution at the nozzle is not typical, but if observed, it indicates moisture, contamination, or degradation, and the processing parameters should be corrected before continuing. The use of regrind is permitted at levels up to 20 wt% if the regrind is dry, free of dust, and not degraded; higher levels reduce notched impact strength. Molded parts require no post-cure and are handled and stored at ambient temperature.
Regulatory compliance is based on the base polypropylene composition. Polypropylene copolymers may comply with food-contact requirements under U.S. FDA 21 CFR 177.1520 when the additive package is cleared for the intended use. For European Union applications, migration requirements under Commission Regulation EU 10/2011 apply, but compliance must be confirmed for the finished article by migration testing. REACH and RoHS obligations apply at the article level. The product is not intended for medical implant applications, and no representation is made for long-term UV exposure unless an external UV stabilizer package is added. Avoid contact with strong oxidizing acids, chlorinated solvents at elevated temperature, and aromatic hydrocarbons that can swell or extract the rubber phase. The grade is insoluble in water and has a low moisture absorption of less than 0.01% by mass under ISO 62.
When CMR648 is used in automotive interior trims, converters typically specify warp-resistance testing after heat aging at 100°C and low-temperature notched impact at -20°C. The material is also used in appliance housings where a moderate gloss, dimensional stability, and resistance to occasional impact loading are required. In these applications, the mold design should provide uniform cooling and avoid abrupt wall-section transitions, because differential shrinkage between the polypropylene matrix and the elastomer phase can increase warpage when sections vary by more than 25% in thickness.
