Dongguan Pusen ABS PA-747(2) is an acrylonitrile-butadiene-styrene terpolymer distributed in pellet form for injection molding applications in which a measured balance of rigidity, surface hardness, and notched impact resistance is required. The commercial model PA-747(2) belongs to the PA-747 family, but the suffix (2) should not be interpreted generically. The precise technical meaning of the suffix—whether it denotes a version code, a lot-controlled adjustment, or a distributor-specific packaging classification—must be obtained from the Dongguan Pusen certificate of analysis or sales specification. Published data for this specific configuration is limited; therefore mold-filling simulation and tool design should use supplier-confirmed melt viscosity, pressure-volume-temperature data, and mechanical properties rather than nominal literature values for a PA-747 base grade. In terms of chemical structure, the material consists of a styrene-acrylonitrile copolymer matrix with grafted polybutadiene rubber particles and is designated by ISO 11469 as ABS; the PA prefix is a trade-code element and does not indicate polyamide. The grade is used in indoor electrical and electronic housings, appliance facias, domestic articles, and industrial covers where crack propagation resistance is evaluated by notched Izod impact per ISO 180 and dimensional stability is assessed by mold shrinkage measurements per ISO 294-4. Relative to high-gloss, high-flow ABS grades, differences are typically reflected in a lower melt volume-flow rate when tested per ISO 1133-1:2022 and a higher notched Izod impact when tested per ISO 180; relative to polycarbonate/ABS blends, PA-747(2) is processed at lower melt and mold temperatures but does not provide the higher heat resistance of PC/ABS.

Material handling data for PA-747(2) should include warehouse storage conditions and transport moisture exposure before drying. Bags should be stored indoors at a temperature below 50 °C and away from direct sunlight because ultraviolet exposure can pre-oxidize the styrene-acrylonitrile matrix, as monitored by yellowing index under ASTM D1925. If bags are opened in a high-humidity environment above 60 % RH, the resin should be transferred to a desiccant hopper within 30 min to 60 min; otherwise surface moisture adsorption can raise the moisture content above the safe molding threshold measured by ISO 15512. These limits are ordinary ABS handling practice, not supplier-specific test results. The hopper volume should be matched to the shot weight and cycle time so that the resin residence time in the drying hopper is no more than 3 h to 4 h at 80 °C; longer residence does not normally improve drying but may cause pellet discoloration or dust generation. In central drying systems, the conveying air should be dried to a dew point of at least −29 °C and the purge air should be free of oil carry-over from the compressor. Batch-to-batch variance in melt flow and color should be logged against the certificate of analysis; a shift of more than ±10 % in melt volume-flow rate may require adjustment of the barrel temperature or the injection speed, but the affected process parameter must be verified on the molding floor rather than assumed.

What Does the PA-747(2) Designation Cover in Supplier Documentation?

Supplier lot documentation for Dongguan Pusen ABS PA-747(2) should identify the base resin, the production date, the lot number, and the reference test methods used for release. Incoming resin acceptance should compare the lot melt volume-flow rate to an agreed nominal value; if no nominal is available, the purchaser should request a reference sample and a method statement based on ISO 1133-1:2022 or ASTM D1238. The designation PA-747(2) can create confusion with the established PA-747 grade. In practice, a change from PA-747 to PA-747(2) may require a small processing adjustment if the melt flow and the rubber particle size distribution are not identical. The absence of publicly available structural data for the (2) variant means that incoming inspection should not rely on the base grade datasheet. Instead, the buyer should require a product specification sheet listing density, ash content, melt flow rate, tensile yield stress, flexural modulus, notched Izod impact, and Vicat softening temperature. Each release document should specify the test standard designations: ISO 1183-1:2019 or ASTM D792 for density, ISO 527-2 or ASTM D638-14 for tensile properties, ISO 180 or ASTM D256 for impact, and ISO 306 or ASTM D1525 for Vicat. Without these designations, data are not directly comparable across lots, and a shift in property balance can be missed before the material reaches production. For lot traceability, the shipping label should carry the supplier code, the material grade, the lot number, and the net weight; under ISO 9001:2015 supplier management requirements, missing lot traceability is recorded as a process-risk observation.

Processing and Performance Boundary Conditions for Injection Molding

Typical ABS processing conditions are used as a starting point for PA-747(2); however, the exact melt temperature window must be confirmed from the supplier datasheet or a capillary rheometry curve. Moisture control is the first boundary. ABS resins absorb surface and internal moisture, and molding at moisture above roughly 0.1 % by weight can produce silver streaks, splay, and reduced weld-line strength. A desiccant dryer with a dew point of −29 °C or lower is recommended; if the relative humidity of the production hall exceeds 60 %, drying time should be extended and hopper dryer loads should be monitored with an in-line moisture analyser. Drying at 80 °C for 2 h to 4 h is common for ABS in forced-air desiccant systems, but the supplier lot moisture content and the regrind fraction may shift the upper and lower limits. The melt temperature is typically set between 200 °C and 240 °C, depending on screw geometry and injection speed. Lower melt temperatures help limit yellowing but increase viscosity and may reduce flow into thin ribs. Higher melt temperatures above 240 °C can cause thermal degradation of the polybutadiene phase, leading to brown streaks and reduced impact strength. The barrel temperature profile should show a rear zone between 180 °C and 200 °C, a middle zone between 200 °C and 220 °C, and a nozzle between 200 °C and 230 °C; these are starting points, not a replacement for a supplier-validated window. For mold temperature, 40 °C to 80 °C is a common ABS range. Low mold temperatures near 40 °C may improve cycle time but can reduce surface gloss and increase molded-in stress. Higher mold temperatures near 80 °C may improve weld-line appearance and dimensional stability but can extend cooling time. Injection speed should be set to achieve a short fill time without causing jetting, gate blush, or excessive shear heating. In thin-wall parts, the gate shear rate may exceed 10,000 s⁻¹; ABS is shear-thinning, so apparent viscosity decreases under high shear, but excessive shear can overheat the melt and create local oxidation. Holding pressure and holding time must be optimised by gate seal studies; a common method is to weigh the molded part as holding time is increased stepwise and to identify the point at which part weight no longer changes. Parts molded with insufficient holding time show sinks and high shrinkage variation, while excessive holding pressure can produce overpacking and ejection damage.

In production-scale molding, PA-747(2) is generally evaluated in electrical enclosures, appliance housings, power tool shells, and cosmetic side walls. The material is not a flame-retardant ABS unless a specific UL 94 classification is declared on the lot certificate; general-purpose ABS typically achieves only HB or no rating. Components intended for proximity to current-carrying parts should therefore be specified only after a V-0, V-1, or 5VA classification is formally documented by the supplier. Mold shrinkage in ABS is direction-dependent; mold designers should use a gate-to-flow shrinkage value and a cross-flow shrinkage value rather than a single global percentage. The common ABS linear mold shrinkage falls between 0.004 mm/mm and 0.007 mm/mm, but these figures depend on wall thickness, gate type, mold temperature, and whether regrind is used. For PA-747(2), if no supplier-specific shrinkage curve exists, a prototype cavity with cavity pressure sensors is required before producing steel for high-tolerance parts. Compared with high-flow ABS grades, PA-747(2) is expected to display a lower melt volume-flow rate and a higher notched Izod impact; this trade-off is typical for ABS resin families where increased flow is achieved through molecular weight reduction or lubricant addition, which can lower toughness. Compared with PA-747 base stock, the (2) designation may or may not imply a shift in rubber content; without thermogravimetric analysis or dynamic mechanical analysis, no difference can be claimed. The grade is not recommended for outdoor load-bearing applications unless an appropriate UV stabilizer package and accelerated weathering data such as ISO 4892-2 are provided. Contact with strongly polar solvents, aromatic hydrocarbons, ketones, and esters can cause environmental stress cracking or surface attack; compatibility should be tested according to ISO 22088 or ASTM D543 for the specific chemical environment.

Secondary operations such as painting, electroplating, and solvent bonding impose additional requirements on ABS grade selection. PA-747(2) may be suitable for electroplating only if the supplier has qualified the lot for adhesion of an electroless copper/nickel layer under a defined etch process; general-purpose ABS is often plateable, but the exact etch time and chromic acid concentration must be validated by adhesion testing according to ASTM B533 or cross-cut ISO 2409. If the grade contains an external lubricant package, plating adhesion may be lower than a dedicated plating ABS because the lubricant can migrate to the surface. The (2) suffix does not by itself indicate a plating-rated product. Painting and solvent welding should be tested with the process-solvent blend used in production; aromatic hydrocarbons and ketones can attack ABS, and a stress-cracking panel test under constant strain is recommended. The heat deflection temperature of general-purpose ABS is typically in the range of 80 °C to 100 °C at 1.82 MPa, but the exact value for PA-747(2) must be taken from ASTM D648 or ISO 75 data on the supplier certificate. Applications requiring continuous service above this range should be switched to a heat-resistant ABS or PC/ABS only after part testing confirms that the thermal load is within the installed product limit.

When PA-747(2) Is Substituted for High-Flow ABS in Thin-Wall Molding

If PA-747(2) replaces a high-flow ABS grade in an existing thin-wall mold, the process window may narrow because the lower melt flow of a general-purpose ABS requires higher melt temperature or injection pressure to fill the same geometry. The molder should first map a short-shot series on an injection molding machine with a known screw diameter, typically 30 mm to 60 mm, and record the fill volume at increments of 5 % to 10 % of the shot size. From this short-shot progression, the minimum fill pressure and the gate seal time can be compared with the previous grade. A pressure drop increase greater than 15 % at the same melt temperature may require moving the switch-over point or increasing the nozzle temperature; however, this is a diagnostic threshold, not a universal limit. Mold-filling simulations should use supplier-confirmed pvT data for PA-747(2); when these data are unavailable, published data for this specific configuration is limited, and simulation should be treated as comparative rather than absolute. Weld-line strength in thin-wall parts is often the limiting property. When two melt fronts meet, the polybutadiene rubber phase may not re-entangle across the interface, and the weld-line efficiency of ABS can drop below 60 % of the base impact strength. For PA-747(2), weld-line evaluation should be performed with a notched Izod or unnotched Charpy impact test on molded plaques cut perpendicular to the weld line, and the results should be compared with the original grade under the same molding conditions. In high-speed injection, shear heating in the gate can exceed the nominal melt temperature by 20 °C to 40 °C. This transient temperature rise may permit filling with a lower barrel set-point but can reduce the molecular weight of the polybutadiene phase if residence time is prolonged. The recommended melt residence time should not exceed five to six barrel capacities; the screw recovery time, barrel volume, and shot weight should be recorded from the production machine to calculate the residence time. If the replacement material is processed on the same machine without reducing the barrel temperature, thermal degradation may be observed as black specks or a drop in notched Izod impact. On a production line with a 40:1 L/D twin-screw extruder used for masterbatch dilution, the torque and melt pressure should be monitored because PA-747(2) may have a higher viscosity than a high-flow ABS; the extruder should not be run beyond 80 % of the maximum torque for extended periods. The exact limit depends on gearbox rating and screw design.