PCISO is a polycarbonate-based monofilament sold in spooled canisters as a fused deposition modeling feedstock within the 3D Systems material portfolio. The model designation PCISO identifies an unfilled amorphous polycarbonate formulation that has been screened under ISO 10993-1:2018 biological evaluation principles for limited-contact medical device prototyping and short-term patient-contact components. Supplier technical bulletins list a heated build chamber range of 100–115 °C and extrusion tip temperatures of 330–355 °C; these setpoints vary with machine model, layer thickness, and raster fill speed. The material is supplied in a limited number of spooled canister formats, and regional availability can constrain transfer to certain fused deposition modeling platforms. Because the polycarbonate backbone is amorphous, the feedstock exhibits no crystallisation exotherm during cooling, which reduces warpage relative to semi-crystalline filaments but increases sensitivity to chamber thermal uniformity and moisture-mediated hydrolysis.

What distinguishes PCISO from generic FDM polycarbonate under ISO 10993-1 screening?

Generic FDM polycarbonate can be manufactured from recycled resin streams and additive packages that are not lot-traced for biomedical use. PCISO is controlled under a medical-grade change-control programme, with batch-level certificates of analysis for melt flow rate, moisture content, and tensile response. The biological evaluation package cited in supplier literature includes cytotoxicity per ISO 10993-5:2009, intracutaneous reactivity per ISO 10993-10:2010, and acute systemic toxicity per ISO 10993-11:2017. Formulation controls restrict processing aids and colourants to compounds that satisfy USP Class VI extraction limits. In consequence, PCISO exhibits a narrower additive slate than general-purpose polycarbonate. Mechanical performance is broadly similar to unfilled polycarbonate; however, the restricted additive system can yield a notched Izod impact value of approximately 53 J/m when tested per ASTM D256-10 in flat orientation, compared with 70–85 J/m for general-purpose FDM polycarbonate produced at similar layer thickness and raster air gap. Tensile strength values in supplier documentation are reported between 50 MPa and 57 MPa depending on raster angle, air gap, and conditioning at 23 °C and 50% RH.

On production fused deposition modeling platforms equipped with actively heated build chambers, PCISO is typically deposited at chamber setpoints of 100–115 °C and extrusion head temperatures of 330–355 °C. The amorphous polycarbonate solidifies by vitrification rather than crystallisation; residual stress therefore scales with the thermal gradient between the build tray and the upper layers. Field data from industrial runs using a 0.010 in (0.254 mm) layer thickness show corner lift exceeding 0.3 mm when the chamber temperature deviates more than ±5 °C from the qualified setpoint for parts larger than 120 mm in the X/Y plane. For Z-height builds above 150 mm, operators report interlayer delamination when the extrusion tip temperature decays below 330 °C during high-speed raster fills. Polycarbonate-compatible breakaway support reduces stress concentration at the support interface but does not replace active chamber heating. Sharp inside corners should be radiused to at least 1.0 mm to limit crack initiation during chamber cooldown. Incompatibility with strong alkalis, chlorinated solvents, and methyl ethyl ketone is documented for polycarbonate grades; PCISO should not be cleaned with these solvent classes because solvent-induced crazing can reduce impact strength before visible cracking occurs.

When ethylene oxide exposure replaces gamma irradiation in PCISO components

PCISO is referenced as compatible with ethylene oxide gas sterilisation and with gamma irradiation at a committed dose commonly stated as 50 kGy when the facility follows ISO 11135:2014 validation requirements. EtO preconditioning of PCISO components should be limited to temperatures no higher than 55 °C and relative humidity between 45% and 70%. Polycarbonate retains EtO monomer more strongly than amorphous polyethylene terephthalate; residual outgassing times can be extended by 24–48 h when wall thickness exceeds 4 mm. Gamma irradiation above 50 kGy produces a measurable loss in tensile modulus and an amber colour shift. This degradation is generally acceptable for non-load-bearing prototypes but can fail visual acceptance criteria in clinical lots. Steam autoclave exposure is not recommended for PCISO because repeated 121 °C saturated steam cycles hydrolyse the polycarbonate backbone and lower interlayer adhesion before bulk tensile failure is observed. When dry-heat sterilisation above 160 °C is required, the part geometry should be unsupported because the approach to the glass transition temperature can cause creep under self-load.

Comparative Mechanical Data for PCISO, Standard FDM Polycarbonate, and ABS-M30i

Representative data from supplier technical bulletins are shown in the table below for flat orientation. Current revision documents govern lot acceptance; values may shift with layer height, air gap, and conditioning history.

Standard FDM polycarbonate and PCISO share a specific gravity of 1.20, but PCISO notched Izod impact is lower by roughly 30–35%. This difference is consistent with the removal of impact-modifying additives that are not listed as USP Class VI-compatible. ABS-M30i has a lower heat deflection temperature and lower flexural strength, which makes PCISO preferable when a part must withstand dry-heat exposure or maintain dimensional stability in a 100 °C hospital washer-disinfector cycle for non-sterile reprocessing. However, ABS-M30i has higher impact resistance and is less sensitive to moisture during storage; porous absorber fixtures that will be aggressively handled may fail earlier in PCISO if not redesigned with thicker walls.

PCISO is used in fused deposition modeling for surgical template prototypes, medical device enclosures, and short-term tissue-contact moulds. Published case studies frequently cite use in anatomical models that require gamma or EtO sterilisation after finishing. The material is not intended for permanent implantation because the biological evaluation package does not include long-term implantation per ISO 10993-6 for all configurations; projects requiring permanent tissue contact must obtain additional testing. In clinical settings, repeated exposure to lipid emulsions and alcohol-based disinfectants should be tested because polycarbonate can develop microcrazes after cyclic alcohol contact. Parts built with fused deposition have anisotropic mechanical behaviour; Z-direction tensile strength is generally 45–70% of XY values depending on raster settings and chamber temperature. Published data for this specific configuration is limited for dynamic fatigue and creep; engineering decisions should not extrapolate from injection-molded polycarbonate tables without physical validation.

Processing PCISO on fused deposition platforms requires control of filament moisture below 0.02% by weight prior to extrusion. Polycarbonate absorbs approximately 0.15–0.35% moisture at 50% RH over 24 h; trapped moisture vaporises in the melt stream and forms voids that can reduce interlayer tensile strength by up to 20%. Drying is commonly performed in desiccant dryers at 80 °C for 4–8 h, or in vacuum ovens at 75 °C for 8 h under a minimum vacuum of 10 kPa. Production extrusion heads with 0.4 mm diameter nozzles exhibit pressure spikes when spool humidity exceeds 0.03%; operators may observe nozzle popping and random surface blisters. These defects are not visible in the toolpath file but are measurable as an increase in in-process filament diameter variability from ±0.02 mm to ±0.05 mm on multi-axis laser micrometers. Storage at relative humidity above 60% therefore requires pre-drying before loading; unsealed spools should not be left in an open build environment for more than 8 h.

Support removal from PCISO using breakaway support generates sharp fracture surfaces at the interface. Solvent-based smoothing with methylene chloride is not compatible because it attacks polycarbonate; vapour smoothing is not recommended for medical parts because solvent residues may alter the leachable profile. Sanding and abrasive media blasting with polycarbonate-compatible media are acceptable. Surface roughness after 0.010 in layer deposition typically ranges from Ra 8–15 µm on sidewall surfaces before finishing, depending on raster width and chordal deviation; this range is higher than injection-molded polycarbonate and should be accounted for in mating assembly clearances of at least 0.25 mm on printed bosses.

Observing batch-to-batch viscosity deviations in production extrusion heads

Production extrusion heads operating at a 0.010 in (0.254 mm) layer thickness display melt pressure drops of 0.3–0.7 MPa when the PCISO melt mass-flow rate varies across the supplier-specified range of 5–12 g/10 min at 300 °C under a 1.2 kg load per ISO 1133-1:2022. Batches near the upper melt-flow boundary extrude with lower shear heating and can produce wider toolpaths by 0.05–0.10 mm if volumetric flow is not closed-loop corrected. Batches at the lower melt-flow boundary require higher drive torque and may trigger filament stripping in extruders that are not equipped with hardened drive wheels. Manufacturing lines using heated build chambers at 110 °C report that layer-to-layer adhesion is more sensitive to melt-flow variation than to chamber temperature within the qualified band; a shift of 1 g/10 min in melt flow rate changes tensile Z-strength by approximately 5–8% in square-edge tensile coupons tested per ASTM D638-14 after conditioning at 23 °C and 50% RH for 40 h. Acceptance criteria for medical-device prototyping should therefore specify both melt flow rate and notched Izod impact on the same build orientation, and should reject any spool lot with moisture above 0.03% at the time of loading.