Material Profile: Uniontech Fix C4 Tough Resin for Industrial SLA 3D
Uniontech SLA Resin Technical Report Series
Compiled from Uniontech, Stratasys / Covestro official datasheets, SDS documents, and third-party technical reviews
Abstract—Uniontech Fix C4 is a tough 355 nm SLA photopolymer in Uniontech's tough-resin catalogue tier. Marketed alongside UTR 6180-90R as the recommended tough-engineering pair, Fix C4 emphasises fixturing applications — workholding jigs, assembly templates, and verification fixtures that must survive shop-floor handling and repeated workpiece insertion / removal cycles.
Index Terms—additive manufacturing, SLA, photopolymer, tough, fixtures, jigs, Uniontech, 355 nm laser.
I. MATERIAL IDENTIFICATION
This section establishes the canonical names and commercial designations under which the resin is supplied.
A. Designation
Trade name: Uniontech Fix C4 (often capitalised 'FIX C4'). Manufacturer: Shanghai Union Technology Corporation (Uniontech).
B. Resin Family
Tough acrylate / urethane-acrylate photopolymer with rubber-toughened oligomer modifiers; 355 nm UV laser cure.
C. Aliases and Alternative Designations
|
Alias |
Origin / Usage |
|
Fix C4 |
Standard product designation |
|
FIX C4 |
Capitalised marketing variant |
|
Uniontech Fix C4 |
Full marketing name |
II. COMPOSITION AND PHOTOPOLYMER CHEMISTRY
A. General Resin Family
Generic photo-polymerisation: monomers (multi-functional acrylates / urethane-acrylates) + photoinitiator + 355 nm UV laser → crosslinked thermoset network. Exact formulation is proprietary. Toughness-engineered formulation for fixturing service.
Fig. 1. Photopolymer crosslinking schematic for the resin family.
Fig. 2. Industrial SLA print → wash → post-cure process flow.
B. Composition Breakdown
TABLE I COMPOSITIONAL BREAKDOWN OF UNIONTECH FIX C4 RESIN (TYPICAL / PER SUPPLIER DATASHEET)
|
Constituent |
Mass fraction |
Function |
|
Multi-functional acrylate + tough urethane-acrylate oligomers (fixturing-tier tough) |
≈ 70–85 wt% |
Form the backbone of the cured network |
|
Reactive diluents (low-viscosity acrylates) |
≈ 10–20 wt% |
Reduce viscosity for laser scanning; increase crosslink density |
|
Photoinitiator (laser-tuned, e.g., Irgacure / TPO blend) |
≈ 1–3 wt% |
Absorbs 355 nm UV; initiates radical polymerisation |
|
Pigments, stabilisers, additives |
≈ 1–3 wt% |
Color, UV blocker for shelf life, surface flow |
|
Total |
100 wt% |
— |
III. MECHANICAL PROPERTIES
Fix C4 sits in Uniontech's tough-resin tier alongside UTR 6180-90R. Mechanical envelope is similar to general tough SLA resins; specific datasheet values should be confirmed with Uniontech for any application-critical decision.
TABLE II MECHANICAL PROPERTIES OF UNIONTECH FIX C4 RESIN (POST-CURE, ISO 527 / ASTM D638)
|
Property |
Value |
Test method / source |
|
Density |
≈ 1.10–1.15 g/cm³ (estimate) |
ASTM D792 |
|
Viscosity (uncured liquid) |
≈ 350–500 cP @ 30 °C (estimate) |
Brookfield viscometer |
|
Surface hardness |
≈ Shore D 80–84 (estimate) |
ASTM D2240 |
|
Tensile strength, ultimate (UTS) |
≈ 45–55 MPa (estimate) |
ASTM D638 |
|
Tensile (Young's) modulus |
≈ 1,800–2,300 MPa (estimate) |
ASTM D638 |
|
Elongation at break |
≈ 10–18 % (estimate, tough-tier) |
ASTM D638 |
|
Flexural strength |
≈ 60–75 MPa (estimate) |
ASTM D790 |
|
Izod impact, notched |
≈ 30–50 J/m (estimate) |
ASTM D256 |
IV. RECOMMENDED PRINT PARAMETERS
Values below are the manufacturer-recommended starting points for compatible Uniontech industrial SLA printers (Lite, Pilot, RSPro series); specific machines may require ±10–20% adjustment based on laser power, build size, and ambient temperature.
TABLE III RECOMMENDED PRINT AND POST-PROCESS PARAMETERS FOR UNIONTECH FIX C4 RESIN
|
Parameter |
Value / range |
Notes |
|
UV wavelength |
355 nm (solid-state UV laser) |
Standard for industrial SLA |
|
Compatible printers |
Uniontech Lite450 / 600 / 800, Pilot250 / 450, RSPro600 / 800 / 1400 / 1800 / 2100 |
Industrial 355 nm laser SLA platforms |
|
Layer thickness |
0.05–0.15 mm (typical 0.10 mm) |
Industrial SLA layering range |
|
Laser scan speed |
≈ 5–15 m/s |
Galvanometer-driven; depends on printer model |
|
Recoating |
Wiper / vacuum recoating with auto liquid level control |
Maintains constant resin level for accuracy |
|
Wash medium |
TPM (tripropylene glycol monomethyl ether) or IPA |
Recommended for industrial cleanliness |
|
Post-cure |
UV oven, 30–90 min @ 405 nm broadband |
Required for full mechanical property development |
|
Optional thermal post-cure |
Not required (or per datasheet) |
Improves HDT / strength on selected resins |
V. GLASS TRANSITION TEMPERATURE (TG)
Reported / typical Tg: ≈ 60–75 °C (estimate, tough-tier photopolymer).
Standard tough-photopolymer Tg range. Confirm with Uniontech datasheet for batch-specific certified values.
VI. HEAT DEFLECTION TEMPERATURE (HDT)
HDT defines the temperature at which a 1.27 mm-thick standardised bar deflects 0.25 mm under the specified flexural load. Two test loads are reported per ASTM D648 / ISO 75.
TABLE IV HEAT DEFLECTION TEMPERATURE OF UNIONTECH FIX C4 RESIN
|
Test load |
HDT |
Test method / source |
|
0.45 MPa |
≈ 60–75 °C (estimate) |
ASTM D648 |
|
1.82 MPa |
≈ 50–65 °C (estimate) |
ASTM D648 |
VII. DISTINGUISHING CHARACTERISTICS AND STANDARDS
A. Engineered for fixturing applications
The 'Fix' designation reflects Uniontech's positioning of this resin for fixture / jig service. Workholding and verification fixtures see unique loading patterns (repeated workpiece insertion, tightening, sliding) — Fix C4 is tuned for these conditions.
B. Tough-tier mechanical envelope
Comparable mechanical envelope to UTR 6180-90R: ABS-like elongation (10–18%), moderate stiffness (1.8–2.3 GPa), and Izod 30–50 J/m. Survives drop-impact and clamping loads typical in shop-floor use.
C. Compatible with full Uniontech industrial line
Lite, Pilot, and RSPro families through RSPro2100. Particularly relevant for the RSPro large-format machines, where single-piece fixture printing avoids assembly seams.
D. Use case guidance: pair with UTR 6180-90R
Uniontech's catalogue lists FIX C4 and UTR 6180-90R together as the tough-resin pair. Choose based on the specific use case: Fix C4 for fixturing / workholding, UTR 6180-90R for prototype housings and vacuum-cast masters with extended indoor service.
VIII. REPRESENTATIVE APPLICATIONS
Uniontech Fix C4 Resin is typically deployed in the following applications:
1) Workholding fixtures and jigs: Custom workpiece holders for machining, inspection, and assembly stations.
2) Assembly templates: Drilling guides, alignment templates, gauging tools.
3) Verification / inspection fixtures: Go / no-go gauges, dimensional check fixtures.
4) Light-duty mechanical prototypes: Snap-fit assemblies, hinged enclosures, mid-stage product validation.
5) Industrial production fixtures (low-volume): Replace machined-aluminium fixtures for short product cycles.
IX. REFERENCES
[1] upcores / Uniontech, “UnionTech RSPro1400 Compatible Resins (includes FIX C4),” 2024. Available: https://upcores.com/products/uniontech-rspro1400
[2] Uniontech, “Uniontech Stereolithography Resin Catalogue,” 2024. Available: https://www.uniontech3d.com/stereolithography-resin/
[3] ASTM D638-14, “Standard Test Method for Tensile Properties of Plastics,” ASTM International.
[4] ASTM D2240-15, “Standard Test Method for Rubber Property — Durometer Hardness,” ASTM International.
[5] ASTM D648-18, “Standard Test Method for Deflection Temperature of Plastics Under Flexural Load,” ASTM International.
[6] ISO 527-2:2012, “Plastics — Determination of tensile properties — Part 2,” ISO.
(Image Resouce : Upcores)