LATI LATILUB 82-01M is a polyamide 12 (PA12) compound modified with a nominal 1% by weight molybdenum disulfide (MoS₂) to provide self-lubricating sliding behavior without external grease or oil. The base resin is a high-viscosity nylon 12, and the filler is incorporated as a solid lamellar lubricant distributed primarily in the polymer matrix; the product is supplied in pellet form for injection molding and profile extrusion. Published supplier data identify the material as a general-purpose self-lubricating PA12 grade intended for dry-running motion-control components such as gears, bushings, cams, sliding blocks, and wear strips. The selection of PA12 rather than PA6 or PA66 is significant because the lower amide-group density of PA12 reduces equilibrium moisture absorption and provides more stable dimensional behavior in humid or condensed-water service. In comparison with unfilled PA12, the addition of 1% MoS₂ does not function as a reinforcing filler; the tribological modification occurs at the sliding surface through shear-induced orientation of lamellar particles, while the bulk tensile and flexural response remains close to that of the base polymer. The product designation 82-01M encodes both the polymer family and the lubricant modification, although the exact suffix logic is supplier-specific and does not represent a standard ISO nomenclature.

How Does the 1% MoS₂ Dispersion Alter Sliding Wear Response?

The lubrication mechanism of LATILUB 82-01M is derived from the solid lamellar structure of molybdenum disulfide. Under sliding shear, the basal planes of MoS₂ slide over one another at low resistance, and fractured particles can transfer to the steel counterface, creating a semi-stable tribolayer that reduces metal-to-polymer adhesion. In dry-running bushings, this mechanism shifts the failure mode from adhesive stick-slip to mild abrasive or transfer-film wear. Comparative pin-on-disk tests performed according to ASTM G99-17 on PA12 compounds have shown that a nominal 1% MoS₂ addition reduces the dynamic coefficient of friction from the 0.35–0.45 range typical of unfilled PA12 against hardened steel to approximately 0.18–0.25 at 0.50 m/s and 0.50 MPa contact pressure. Static coefficient of friction measurements performed according to ASTM D1894-14 generally fall in the 0.20–0.30 range under dry conditions. Wear factor data under ASTM D3702 thrust-washer conditions are more scattered; published values for LATILUB 82-01M are often in the 10⁻⁵ mm³/(N·m) range, but end users should validate the specific counterface hardness and surface finish combination because the transfer film is sensitive to Ra values below 0.20 µm and above 0.80 µm.

In sliding systems, the reduction in coefficient of friction has a secondary effect on noise and stick-slip. Unfilled PA12 under low-speed high-normal-load conditions can exhibit audible stick-slip and frictional vibration. The lamellar MoS₂ at the interface reduces the static-to-dynamic friction ratio, which in turn suppresses stick-slip oscillation. Measurements on tribological test rigs show that PA12 with 1% MoS₂ can maintain a static-to-dynamic friction ratio below 1.2, whereas unfilled PA12 can exceed 1.5 under dry conditions. This is why the material is selected for office equipment motion sequences where acoustic noise is a rejection criterion.

Counterface material compatibility must be considered. Hardened carbon steel with hardness HRC 50–60 and surface roughness Ra 0.20–0.40 µm is a common reference surface for tests and for bushings. Aluminum and zinc die-cast countersurfaces are less desirable because the transfer film can be disrupted by oxide regeneration; brass and bronze can be used if the sliding partner is polished, but the debris generated may be darker. Stainless steel is acceptable but may require a longer run-in period. The use of grease or mineral oil is not required, but if external lubrication is present, the coefficient of friction may drop below the dry value; however, the MoS₂ transfer film may be washed out in fully flooded oil systems, so the design should not rely on both mechanisms simultaneously unless verified by component testing. The product is not a solid metal replacement; the MoS₂ additive reduces friction and adhesive wear rather than eliminating the pressure-velocity limits of the polymer matrix. In high-relative-humidity environments above 60% RH, the lubricating efficiency of MoS₂ can be partially suppressed by moisture and oxidation products, so dry conditions or periodic aeration are operationally preferable.

Processing Precision Hinges on Moisture and Melt Residence Time

For injection molding of LATILUB 82-01M, the critical processing boundary is residual moisture control. As with all PA12 grades, a moisture content above 0.10% by weight as determined by Karl Fischer titration will hydrolyze the melt and produce surface splay, porosity, and viscosity loss during barrel residence. The product should be dried at 80°C for 4–6 hours in a desiccant dryer with a dew point of −30°C or lower; when the molding environment exceeds 60% relative humidity, drying time should be extended to 8 hours and the hopper should be blanketed with dried air. Melt temperature should be maintained between 220°C and 250°C, with the nozzle temperature held near 230°C. Barrel residence time should not exceed 8 minutes at maximum temperature, because PA12 with dispersed MoS₂ undergoes progressive yellowing and thermal degradation that can release sulfur-containing volatiles and reduce molecular weight. In reciprocating-screw machines with screw L/D ratios from 18:1 to 25:1 and a compression ratio between 2.0:1 and 2.5:1, a low-to-medium shear profile is preferred. Back pressure in the 2–5 MPa range is sufficient to homogenize the MoS₂ dispersion; high back pressure does not improve dispersion and may increase shear heating. Screw speed in the 80–150 rpm range is typical for medium-sized machines, but the actual setpoint should be adjusted to avoid screw recovery times shorter than the cooling timer. Mold temperatures between 40°C and 80°C are acceptable; the higher end of this range promotes better packing and surface finish but increases cycle time. Linear mold shrinkage according to ISO 294-4:2018 measurements on 60 mm × 60 mm × 2 mm plaques is anisotropic and typically falls in the 0.8–1.2% range in the flow direction and 1.0–1.4% transverse to flow depending on wall thickness and gate geometry. Production-scale molding has shown that under-packed parts exhibit excessive post-mold dimensional change, especially in gear hubs and thin-walled bushings with asymmetric gating.

Melt volume-flow rate (MVR) according to ISO 1133-1:2022 at 235°C with a 2.16 kg load is commonly reported in the 8–20 cm³/10 min range for 82-01M, placing it in the medium-flow region suitable for multi-cavity injection molding; however, the exact release value should be read from the current LATI technical datasheet. In production-scale equipment, the main batch-to-batch processing defect observed with MoS₂-filled PA12 is the appearance of dark agglomerates when the screw has inadequate mixing capability or is run with low melt temperature. These agglomerates are not uniformly dispersed filler but locally aggregated MoS₂ domains that can initiate surface defects in thin ribs and gear teeth. A general-purpose two-stage screw may be adequate for unfilled PA12 but can leave visible streaks in 82-01M; a screw with intensive mixing elements and a longer feed section is preferable. Because molybdenum disulfide is mildly abrasive relative to unfilled polymer, screw and barrel wear rates may be higher over long campaigns; bimetallic barrels, nitrided screws, or hard-coated check rings are recommended for high-volume production. Purging should be performed with a high-viscosity polyolefin or a dedicated PA12 purge compound after each run, particularly when switching to light-colored or transparent materials.

Mold design for 82-01M should follow PA12 practice: gates of 0.5–1.0 times wall thickness, generous radii in cold runners, and vent depths of 0.01–0.02 mm are used to prevent short shots and burn marks. Hot-runner systems should use externally heated manifolds without dead spots; internally heated torpedo designs can degrade PA12 if long residence times occur. Clean regrind from sprues and runners can be incorporated at up to 20% by weight without serious loss of mechanical properties in non-safety components, but the dust fraction may contain MoS₂-rich fines; higher regrind levels can increase wear inconsistency and dark speck frequency. For gear and bushing molds, gate location should be arranged away from the sliding surface where possible, because gate vestige on a tooth flank can create a local stress concentration and disturb the transfer film.

Comparative Data From Supplier and Laboratory Sources

The following table compares typical reported values for LATILUB 82-01M with unfilled PA12 and a 30% glass-fiber-reinforced PA12. Values are representative ranges from supplier datasheets and are not intended as production release limits; the current LATI certificate for the 82-01M grade should be consulted for lot-specific release data.

The comparative data show why 82-01M is not interchangeable with glass-filled PA12. Glass-filled PA12 grades provide higher modulus and heat deflection temperature but are generally unsuitable for dry-running slide pairs against soft aluminum or steel because exposed glass fibers score the counterface. The 1% MoS₂ grade does not raise the HDT beyond the unfilled PA12 range; therefore, the product is limited to low-speed or intermittent motion where heat build-up from friction remains low. For applications requiring both self-lubrication and higher load capacity, a reinforced grade with internal lubricant or a PA12 blend with PTFE may be required, but the wear mechanism and counterface compatibility must be re-evaluated. Compared with PA6 or PA66 self-lubricating grades containing MoS₂, 82-01M offers lower saturated water absorption—PA12 typically absorbs 0.60–0.80% at 23°C saturation per ISO 62:2008, whereas PA6 and PA66 absorb 1.5–2.8% in similar conditions—but the PA12 matrix has a lower continuous-use temperature and lower tensile strength at elevated temperature. In cold or dry environments, the PA12 grade demonstrates better dimensional stability and lower moisture-induced expansion, which is particularly relevant for precision gear centers and bushing press-fit assemblies.

The thermal behavior of 82-01M follows the PA12 matrix. Differential scanning calorimetry according to ISO 11357-3:2018 places the melting peak near 176–180°C, and the glass transition is observed near 45°C. This glass transition is significant for sliding components because the frictional interface must remain below this temperature under continuous load. If the interfacial temperature approaches the glass transition, the storage modulus falls and the wear rate increases rapidly. Thus the practical operating envelope is defined partly by the thermal diffusivity of the mating part and the ability of the mold design to conduct heat away from the contact zone.

Compared with PTFE-filled PA12, the MoS₂ grade tends to produce a less sticky transfer film and is less likely to generate fluoropolymer volatiles during processing at PA12 melt temperatures, but PTFE offers lower initial breakaway friction in some systems. Compared with silicone-based additive systems, MoS₂ is non-migrating and does not rely on replenishment from the bulk; after a wear-in phase, the sliding coefficient can remain relatively stable. The principal aesthetic limitation of 82-01M is its dark gray to black appearance, which excludes it from light-colored or color-matched components unless secondary pigmentation is acceptable. Electrical or food-contact compliance is not automatically conferred by the MoS₂ filler; suitability must be confirmed for the finished part under the relevant end-use regulation.

For dry-running gear pairs in office automation and light mechanism applications, the material is commonly used where the nominal PV remains below 0.05 MPa·m/s continuous and interfacial temperature stays below the PA12 glass transition of approximately 45°C. In intermittent motion, higher peak PV values may be tolerated, but published data for this specific configuration is limited; therefore, end-use validation should include instrumented wear testing under actual load, velocity, and duty cycle. When molded gears are run against an acetal or steel gear, flank temperatures can be monitored with embedded thermocouples to ensure that the MoS₂ transfer film remains stable. Failure in over-loaded dry-running systems typically appears as surface melting, transfer film disruption, and increased coefficient of friction.