Tianjin Dagu MABS DG-T515N is an unfilled methyl methacrylate-acrylonitrile-butadiene-styrene injection moulding grade supplied by Tianjin Dagu Chemical Co., Ltd. The model code DG-T515N identifies a transparent MABS product positioned for injection moulded components that require a balance of optical clarity, impact resistance, and processability in thin-wall or high-gloss tooling. Because producer-specific datasheet values for DG-T515N are not fully replicated in public material databases, the following sections separate class-typical MABS data from published test methods and processing literature from values that must be verified with a producer-issued certificate of analysis before purchase specification.

In material substitution and procurement workflows, DG-T515N is best evaluated as a transparent styrenic copolymer rather than as a conventional opaque ABS. The presence of methyl methacrylate is the structural feature that distinguishes MABS from standard ABS and enables optical clarity after melt processing. Where suppliers report properties under Chinese national standards, the grade may be specified using GB/T test designations; where international comparisons are required, the corresponding ISO or ASTM method should be stated explicitly.

What Material Class and Designation Scope Apply to DG-T515N?

MABS belongs to the four-monomer styrenic copolymer family covered by ISO 19066-1:2014. In an unfilled transparent MABS, methyl methacrylate is incorporated into the styrene-acrylonitrile matrix to modify its refractive index. This refractive index shift reduces light scattering at the interface between the continuous phase and the dispersed polybutadiene-based rubber phase. Transparent MABS grades therefore exhibit total luminous transmittance in the class-typical range of 88% to 90% at 3 mm plaque thickness when measured according to ISO 13468-1, with haze values from 1.5% to 4.0% under ASTM D1003-21. These values are class-typical for unfilled transparent MABS, not producer-confirmed DG-T515N data.

The producer code DG-T515N is an internal commercial designation rather than an ISO designation string. It does not by itself provide the complete specification block, such as melt volume-flow rate, Vicat softening temperature, or notched impact strength. A proper material specification for DG-T515N should therefore include the producer datasheet, the test method designators, and any agreed lot-to-lot control limits.

The grade is usually supplied as natural transparent pellets. Lot acceptance commonly includes melt flow rate, moisture content, yellowness index, tensile yield stress, notched impact strength, Vicat softening temperature, and optical transmission or haze. For Chinese domestic supply chains, methods may include GB/T 3682.1 for melt flow rate, GB/T 1040.1 and GB/T 1040.2 for tensile properties, GB/T 1043.1 for impact strength, GB/T 1633 for Vicat softening temperature, and GB/T 2410 for light transmission and haze. International comparisons should be method-aligned because specimen geometry, thermal conditioning, and test speed can shift reported values.

Specification-oriented evaluation of DG-T515N should begin with the measurement methods used for unfilled transparent MABS. Table 1 compiles class-typical ranges from public transparent MABS datasheets and technical literature; these ranges are not a substitute for a producer-issued databook for DG-T515N.

Table 1. Class-typical property envelope for unfilled transparent MABS.

The property envelope for DG-T515N may be narrower than the class-typical range shown above because producer lot-to-lot control is commonly tighter than the broad published grade range. When comparing alternative transparent MABS grades, the same test method and specimen thickness should be specified; optical values are particularly sensitive to plaque thickness and surface finish.

Drying and Melt Temperature Limits for Injection Moulding

Dagu MABS DG-T515N pellets are hygroscopic enough to require closed-loop desiccant drying before melt processing. Residual moisture should be reduced below 0.05% by weight. Drying at 80 °C for 4 h is the commonly cited starting point for transparent MABS; when plant relative humidity exceeds 60%, drying time should be extended to 6 h or the dryer dew point should be held at -30 °C or lower. Moisture-related failure on production lines appears as splay, silver streaking, gate blush, and a measurable loss of notched impact. On hot-runner tools, moisture steam pockets in the manifold can produce intermittent clear-to-opaque transition bands that are not visible until the part is inspected under controlled lighting.

For injection moulding, general-purpose screws with an L/D ratio between 20:1 and 24:1 and compression ratios of 2.2:1 to 2.6:1 are suitable for MABS. The melt temperature measured at the nozzle should be maintained between 230 °C and 250 °C. Barrel settings typically run from 210 °C to 230 °C in the feed zone to 240 °C to 250 °C in the metering zone. Mould surface temperature should be controlled between 40 °C and 70 °C; the upper half of this range improves surface replication and reduces flow lines in high-gloss transparent parts but increases cooling time. Packing pressure between 50% and 70% of peak injection pressure is typical, with back pressure from 0.5 MPa to 1.0 MPa.

Clamp force requirement is commonly estimated at 3 kN/cm² to 5 kN/cm² of projected cavity area for transparent MABS, though long-flow or thick-wall parts may require additional margin. Gate geometry should promote uniform flow-front advancement; direct gates in visible areas often require local cooling or post-mould trimming to avoid optical distortion. Valve-gated hot-runner systems are preferred over open hot tips when surface appearance is critical because the valve pin can reduce drool and gate blush.

Residence time at melt temperature should be kept below 5 min to 8 min. On production-scale machines with long cycle times or heated manifolds, this means shot size should occupy at least 40% of barrel capacity and the melt cushion should remain constant. If the material is purged, SAN or PMMA carrier purging compounds are preferred; polystyrene alone may not fully remove MABS from boundary layers and hot runner channels. Regrind addition above 20% tends to increase yellowness index and lower Charpy impact after repeated heat histories, so closed-loop regrind ratios should be controlled by weight, not by volume.

Comparing DG-T515N with Polycarbonate, Polystyrene and PMMA

Thermoplastic selection often compares DG-T515N with polycarbonate, general-purpose polystyrene, SAN, or PMMA. In transparent housings where polycarbonate is selected for high-temperature resistance, MABS of the DG-T515N class has a lower Vicat softening temperature, generally 90 °C to 105 °C under ISO 306 method A50, whereas many unfilled polycarbonate grades fall between 140 °C and 150 °C. The MABS trade-off is lower melt viscosity and lower processing temperature, which can permit thinner-wall filling and reduced energy input. Density also favours MABS: unfilled transparent MABS is typically 1.07 g/cm³ to 1.10 g/cm³, while unfilled polycarbonate is approximately 1.20 g/cm³. Typical applications include transparent appliance windows, cosmetic packaging, houseware containers, toys, and display covers where a 3 mm plaque transmittance near 90% is acceptable.

Compared with general-purpose polystyrene or SAN, the MABS advantage is primarily impact resistance. Typical notched impact values for transparent MABS range from 8 kJ/m² to 18 kJ/m² at 23 °C, while general-purpose polystyrene is often below 2 kJ/m². SAN provides higher stiffness but remains relatively brittle; MABS is chosen when a transparent part must survive drop testing or repeated handling without cracking. In contrast, PMMA provides better surface hardness and scratch resistance, while MABS offers better toughness and flow in thin-wall tools. PMMA may show lower haze and better outdoor weathering in some transparent grades, but published data for the specific optical gap between DG-T515N and a particular PMMA grade in a given tool is limited.

Compared with standard transparent ABS, the distinction is chemical rather than merely visual. Some products described as transparent ABS are MABS-type materials, because methyl methacrylate is required to match the refractive index of the rubber phase and the matrix. However, not all MABS grades have identical impact or optical balance; butadiene content, rubber particle size distribution, and MMA content vary between producers. DG-T515N should therefore be compared using the same specimen thickness, surface polish, and test method rather than on supplier trade-name alone.

When DG-T515N Replaces Opaque ABS Grades in Transparent Components

In opaque ABS, higher butadiene rubber content contributes high impact resistance but scatters light, producing a milky or opaque natural appearance. Transparent MABS reduces rubber content and uses refractive index matching through methyl methacrylate to maintain clarity. The consequence is that transparent MABS has lower notched impact than high-impact opaque ABS. A high-impact opaque ABS may show Charpy notched values from 20 kJ/m² to 35 kJ/m², while transparent MABS is commonly 8 kJ/m² to 18 kJ/m². Direct substitution of an opaque ABS rib design into DG-T515N without wall-thickness or rib-radius adjustments may therefore create brittle failure at gates, bosses, or snap-fit features.

Low-temperature performance is another boundary. At temperatures below -20 °C, the impact resistance of general MABS grades decreases, and the material is not recommended for high-impact load-bearing structures in freezer or outdoor service unless the part is validated under the actual use temperature and impact energy. Transparent parts may also develop stress whitening near gates, ejector pins, or snap-fit deflections if the tool does not provide adequate radii and ejection area.

Chemical compatibility follows the general limitations of styrenic copolymers. MABS is attacked or stress-cracked by ketones, esters, chlorinated solvents, and some essential oils. Aromatic hydrocarbons and certain plasticisers can migrate into the surface and cause haze or microcracking. DG-T515N should not be combined with PVC regrind or PVC-contaminated material because thermal degradation of PVC can release corrosive hydrogen chloride and damage mould surfaces. Contact with amine-based additives or certain flame-retardant systems without producer validation may also destabilise the material during long residence at melt temperature.

When replacing opaque ABS with DG-T515N, the part design should compensate for lower notched impact by increasing wall thickness in high-stress regions, using larger corner radii, and avoiding sharp transitions at snap arms. The mould should be polished to a high-gloss finish if the transparent part is expected to maintain low haze. Venting is also more critical than in opaque ABS because gas traps can appear as local burn marks that are highly visible in transparent material.

For procurement, DG-T515N should be specified by model, colour, melt flow-range, impact requirement, optical transmittance at the agreed plaque thickness, and any applicable regulatory certificates. REACH Regulation (EC) 1907/2006 and RoHS Directive 2011/65/EU as amended by (EU) 2015/863 are commonly requested for consumer goods, but compliance must be confirmed on the producer-issued declaration for each batch or formulation. Published data for DG-T515N-specific long-term ultraviolet ageing and food-contact status is limited; applications requiring such certifications should obtain the relevant producer letter or third-party test report before production release.

Incoming inspection should include melt flow rate, moisture content, and yellowness index on dried pellets, because these three measurements often detect regrind variability or drying faults before production starts. If the material has been stored in humid conditions, a desiccant dryer audit should be performed before processing. The material is amorphous, so melt viscosity, Vicat softening temperature, and optical plaque checks are more useful than crystallinity-based thermal methods. Process trials should determine whether the grade meets optical and mechanical requirements under full-scale clamp force, cycle time, and regrind load before transfer to production.