Industry
Medical & Laboratory Technology – Sintering Furnaces and Climatic Chambers
Medical implants, dental restorations and laboratory equipment place the highest demands on purity, precision and documentation. NTH Therm laboratory furnaces and ACS climatic chambers meet the requirements of medical technology.
Thermal Processes for Medical Technology and Laboratory Applications
Medical technology places unique demands on thermal processes: process purity (no contamination), temperature control precision, complete documentation for regulatory requirements (FDA, CE marking, ISO 13485) and reproducibility of every individual batch. A sintering defect in an implant or an incorrect climatic test for a medical device can directly affect patient safety.
NTH Therm supplies laboratory furnaces, high-temperature furnaces and climatic chambers for medical technology and laboratory applications — with the necessary qualification services.
Sintering of Dental Ceramics and Dental Implants
Dental technology is one of the most intensive users of laboratory furnaces. Zirconia (ZrO2) and other high-performance ceramics are sintered at high temperatures after computer-tomography-guided milling.
Zirconia Sintering (Y-TZP) Typical sintering temperatures: 1450–1550 °C. Densified zirconia shrinks by approximately 20–25 % during sintering — this must be accounted for in milling planning. Temperature uniformity and precise temperature control are critical for optical and mechanical properties:
| Parameter | Requirement |
|---|---|
| Max. temperature | up to 1600 °C |
| Temperature uniformity | ±5 °C in sintering zone |
| Heating rate | 1–10 °C/min (material-dependent) |
| Atmosphere | Air (oxidising) or inert gas |
Glass Ceramics and Feldspar Ceramics For pressing and crystallisation annealing of IPS e.max, Vita Mark II and similar materials: 750–950 °C, very precise temperature control, clean atmosphere (no contamination from heating elements).
Heat Treatment of Implant Metals
Surgical instruments from stainless steel (1.4021, 1.4028, 1.4057) Hardening treatment for scalpels, scissors, clamps: austenitising at 1000–1050 °C, oil quenching, tempering at 150–350 °C. High-cleanliness, contamination-free.
Titanium alloys for implants (Ti-6Al-4V ELI) Stress relieving after machining (600–700 °C), solution treating and ageing for specific implant types. Inert gas atmosphere mandatory.
Cobalt-chromium alloys For hip and knee prostheses and dental frameworks: stress relieving and tempering treatments at 700–900 °C.
Analytical Chemistry and Pharmaceutical Processes
IBF laboratory furnaces and TH1 tube furnaces are widely used in analytical laboratories and the pharmaceutical industry:
- Ashing: organic sample destruction for chemical analysis
- Calcination: decomposition of inorganic compounds (carbonate decomposition, hydroxide decomposition)
- Catalyst preparation: support impregnation and activation annealing
- Pharmaceutical powder processes: drying, crystallisation control, bulk conditioning
- Synthesis: solid-state synthesis under inert gas atmosphere (tube furnace with gas)
Climatic Testing for Medical Devices
Medical devices must function safely and reliably under a wide range of environmental conditions — in the operating theatre at +25 °C, in a transport container at −20 °C, in storage at 90 % humidity. ACS climatic chambers support qualification per:
- IEC 60601-1: General requirements for medical electrical equipment
- IEC 60068: Environmental tests for electronic assemblies
- ISO 11135 / ISO 17665: Sterilisation validation (complementary to climatic testing)
On request, we supply chambers with complete IQ/OQ/PQ documentation — meeting ISO 13485 quality management systems and FDA requirements (21 CFR Part 11-compatible data recording on request).
Frequently Asked Questions
What are the requirements for sintering furnaces for dental ceramics?
Dental sintering furnaces for zirconia must reach temperatures up to 1600 °C (fully stabilised ZrO2) with very good temperature uniformity (±5 °C). The heating rate is critical: too fast leads to microstructural stresses and cracks. For Y-TZP zirconia, typical sintering temperatures are 1450–1550 °C. NTH Therm IBF laboratory furnaces and ICF chamber furnaces are configurable for these requirements.
Can NTH Therm supply furnaces for PEEK/PAEK implant processing?
PEEK (polyether ether ketone) is not sintered in the classical sense but processed at 300–400 °C under pressure or compacted as powder at somewhat higher temperatures. For heat treatment of PEEK blanks to relieve stress or for conditioning, our ICO forced-air furnaces at 200–300 °C are suitable.
Which standards apply to climatic testing of medical devices?
IEC 60601-1 (general requirements for medical electrical equipment) with collateral standards IEC 60601-1-2 (EMC) and environment-related requirements. ISO 10993 for biocompatibility supplements the electrical standards. Climatic testing per IEC 60068 for environmental robustness.
Does NTH Therm offer laboratory furnaces with QMS-compliant documentation?
Yes. IBF laboratory furnaces and TH1 tube furnaces can be supplied with complete IQ/OQ/PQ documentation (Installation Qualification, Operational Qualification, Performance Qualification) — meeting the requirements of ISO 13485 quality management systems.