--- title: Thermal Modification - Thermowood Process | Jartek description: Discover Jartek's precision-engineered kilns, designed for efficient thermal wood processing with automated cycles, energy savings, and consistent quality for your production needs. image: https://www.jartek.com/hubfs/website/featured-image.png --- # Thermo­wood Process --- Drying-Heating-Cooling and conditioning, the sustainable thermal wood modification method without chemicals, just heat and steam.  The patented ThermoWood® process involves heating wood material in a kiln to a temperature of 160 – 230 °C (320–446 °F) simultaneously protecting it with clean water steam. Steam protects wood, but it also influences the chemical changes taking place in wood. The treatment involves using only heat and steam. All this in atmospheric pressure with no chemicals. ![ITWA_TMT_ThermoWood_R](https://www.jartek.com/hs-fs/hubfs/ITWA_TMT_ThermoWood_R.jpg?width=945&height=945&name=ITWA_TMT_ThermoWood_R.jpg) Proof of quality. ThermoWood® is a patented production process and a registered trademark, that may only be used by licensed producer members of International ThermoWood Association (ITWA). These producers, their products and operations are monitored annually by a third-party auditor. Premium quality TMW products carry the ThermoWood® trademark. [ Download guide ](https://cta-service-cms2.hubspot.com/web-interactives/public/v1/track/click?encryptedPayload=AVxigLKC1Hqaa4z5OWCx3fKpxyI8cvd8%2FU82TgQcm36iBR2YmDZciqI6iUc4US25iqRgKAw%2FjueApOEfspR8QFIXAU05kNsYXRabRXx4QhL%2FHmMwZPhd88yoVWcmaO%2BCS44O07lduJoek0jsnfoBu5PB8T4Xh7DXnB7tpBMr6ORBdEkeJHWH8QRjEB%2BjFfzw0LqbQxnisJbDfQ39Dbaqadb8n4ptKJP0PVW5D8zwtnEsackUNBr0QQZ7v%2FZDhrZd&portalId=48911540) ![Jartek_Infograph_Process_0526](https://www.jartek.com/hs-fs/hubfs/Jartek_Infograph_Process_0526.png?width=2000&height=345&name=Jartek_Infograph_Process_0526.png "Jartek_Infograph_Process_0526") ## Benefits of Thermowood process --- The process results in a natural wood material with improved properties, suitable for both indoor and outdoor use, in all climates. Invented in Finland 1994. The process permanently changes wood structure and moisture behavior, resulting in reduced EMC, improved dimensional stability, and enhanced resistance to biological degradation.  ![Thermal_Modified_Wood_21](https://www.jartek.com/hs-fs/hubfs/Thermal_Modified_Wood_21.jpg?width=5617&height=3745&name=Thermal_Modified_Wood_21.jpg) - ### Quality guaranteed Thermowood is a patented process ensuring quality. - ### Sustainable Naturally with just heat and steam in atmospheric pressure. - ### Improved TMW properties Wood structure and moisture behavior changed for stability, durability, and biological resistance. - ### Extensive recipe book Recipe library for variation of hardwood and softwood species. - ### Proven process Invented in Finland in 1994 - now in use globally. ## Key features of Thermowood process --- The process results in a natural wood material with improved properties, suitable for both indoor and outdoor use, in all climates. Invented in Finland 1994. The process permanently changes wood structure and moisture behavior, resulting in reduced EMC, improved dimensional stability, and enhanced resistance to biological degradation. ![Thermal_Modification_Chamber](https://www.jartek.com/hs-fs/hubfs/Thermal_Modification_Chamber.jpg?width=3840&height=2160&name=Thermal_Modification_Chamber.jpg) - ### Three phase process Optimized drying-modification-conditioning process for both softwood and hardwood. - ### Open system Thermowood process takes place in atmospheric pressure. - ### Two product classes Heat is set according to end product to get either durable or stable class TMW. - ### Adjustable Settings are easily made according to wood species and dimensions - ### Physical and chemical changes of TMW Process removes resins and other organic compounds and changes wood structure permanently. ### Thermowood process The patented Thermowood process involves heating wood material in a kiln to a temperature of 160 – 230 °C (320–446 °F) simultaneously protecting it with clean water steam. Steam protects wood, but it also influences the chemical changes taking place in wood. The treatment involves using only heat and steam. All this in atmospheric pressure with no chemicals.  ## Jartek Thermowood Technology --- With over 25 years' experience and innovation, and over 100 thermal wood modification kilns delivered Jartek is the world leader of TMW solutions. Jartek technology is fully compatible with Thermowood process. Jartek offering portfolio covers everything from full solutions to individual parts from heat production to kilns, software, and testing. ![Thermal_Modification_kilns](https://www.jartek.com/hs-fs/hubfs/Thermal_Modification_kilns.jpg?width=4032&height=3024&name=Thermal_Modification_kilns.jpg) ### Jartek TMW Kilns Engineered for precision, durability, energy efficiency, and long-lasting performance. They are equipped with advanced digital control, and operating system. Available from small to bulk batches.  [Read More › ](https://www.jartek.com/thermal-modification/kilns?hsLang=en) ![Boiler_Plant](https://www.jartek.com/hs-fs/hubfs/Boiler_Plant.png?width=1589&height=989&name=Boiler_Plant.png) ### TMW Heat Production Fully compatible with Jartek kilns the boiler plant ensures fluent heat production, is energy optimized, removes odors, extractives and other process gases.   [Read More › ](https://www.jartek.com/thermal-modification/heat-production?hsLang=en) ![Thermal_Modification_minikiln](https://www.jartek.com/hs-fs/hubfs/Thermal_Modification_minikiln.jpg?width=3500&height=2695&name=Thermal_Modification_minikiln.jpg) ### TMW Software Specialized operating software for thermal modification kilns. Compatible with both new and existing kiln systems, it controls and optimizes the entire TMW process. The software allows tailoring specific recipes for each wood species.  [Read more › ](https://www.jartek.com/thermal-modification/tmw-software?hsLang=en) ## Real Results. Real Partnerships. [ Read all › ](https://www.jartek.com/references/?hsLang=en) --- Since 1957 hundreds of production solutions for lumber manufacturing and thermal wood modification have been delivered by Jartek. Latest references speak for themselves. Here is a collection of readings for you on thermal modification. By clicking "Read all" you find the same on whole Jartek offering. ![Thermal_Modification_Kiln_Jartek](https://www.jartek.com/hs-fs/hubfs/Thermal_Modification_Kiln_Jartek.jpg?width=7008&height=4672&name=Thermal_Modification_Kiln_Jartek.jpg) ### Arbor Wood Co. - Indiana, USA Arbor Wood Co. strengthens its thermal wood production with Jartek’s energy-efficient kiln solution, designed for high-quality output and long-term growth.  [Read more › ](https://www.jartek.com/references/arbor-wood?hsLang=en) ![Thermal_Modification_Mini_Kiln_Jartek](https://www.jartek.com/hs-fs/hubfs/Thermal_Modification_Mini_Kiln_Jartek.jpeg?width=1536&height=2048&name=Thermal_Modification_Mini_Kiln_Jartek.jpeg) ### ThermalWood Canada Inc. - Bathurst, Canada ThermalWood Canada expands its specialty wood processing capabilities with Jartek’s flexible thermal modification kiln for custom species and small-batch production.  [Read more › ](https://www.jartek.com/fi/referenssit/thermalwood-canada?hsLang=en) ![Thermally Modified Wood-1](https://www.jartek.com/hs-fs/hubfs/Thermally%20Modified%20Wood-1.jpg?width=2101&height=2101&name=Thermally%20Modified%20Wood-1.jpg) ### 5 reasons TMW is the future for North American building projects Thermally modified wood offers superior stability, durability, and sustainability without chemicals. Discover five reasons why TMW is becoming a top...  [Read more › ](https://www.jartek.com/articles/5-reasons-tmw-is-the-future-for-north-american-building-projects?hsLang=en) ![1st_Jartek Charge_2023](https://www.jartek.com/hs-fs/hubfs/1st_Jartek%20Charge_2023.jpg?width=3920&height=2586&name=1st_Jartek%20Charge_2023.jpg) ### Imbue Wood - Kapar, Malaysia Imbue Wood upgrades its thermal modification plant with Jartek automation, achieving significant energy savings and improved process control. [Read more › ](https://www.jartek.com/references/imbue-wood?hsLang=en) ‹ › ## Let's talk about your next project. --- Let's build something that lasts. Whether you're looking for a new production solution, service support or a career that shapes the future of the wood industry – Jartek is ready to connect. [Contact sales › ](https://www.jartek.com/contact/#contact-us) ### STAY AHEAD WITH Jartek Subscribe to our newsletter for fresh insights and the latest industrial innovations. ```json { "@context" : "https://schema.org", "@type" : "VideoObject", "contentUrl" : "https://48911540.fs1.hubspotusercontent-na1.net/hubfs/48911540/video_assets/212339764281/inherited/web_optimized.mp4", "dateModified" : "2026-05-06T05:22:40.816Z", "duration" : "PT3M5.767S", "height" : 1080, "name" : "jartek_thermal_modification_process", "thumbnailUrl" : "https://api-na1.hubspot.com/filemanager/api/v3/files/thumbnail-redirect/212339764281?portalId=48911540&size=medium", "uploadDate" : "2026-05-06T05:22:40.814Z", "width" : 1920 } ```