It’s an understatement to say heat treatment has become a key part of the UK timber kilning sector.

One kiln manufacturer told TTJ that 40% of his turnover was now based on heat treatment business – compared to nothing just three years ago.

The reason for this surge in demand is the international phytosanitary standard ISPM 15 – designed to ensure wood packaging does not carry forest pests and diseases across national borders.

The EU implemented the standard last March, with North America to follow in July. Some 140 nations have signed up to the principle of adopting ISPM 15.

Ron Hodson, who represents Czech kiln manufacturer Katres in the UK, said: “Before very long most packaging and pallets going out of the country will be made out of heat-treated timber.”

Role model

John Commons, director of UK kiln manufacturer Kiln Services Ltd, said other countries were looking at Britain’s successful introduction of ISPM 15, due to the proactive approach of the Forestry Commission (FC) and TIMCON which administer the scheme.

Kiln Services is receiving heat treatment enquiries from as far afield as UAE and recently supplied a heat treatment kiln to Dubai, while new contracts include four large forklift loaded hardwood drying kilns with high pressure humidification at International Timber.

The company has also just won an order from Doncaster-based PTG Treatments for two custom-made kilns, which will be used as part of PTG’s new fire-retardant treatment operation. Unusually, the large fork lift loaded kilns will be designed for drying both sawn timber and sheet materials.

Most sawmillers seem to be factoring in heat treatment as part of a kiln drying process.

Howie Forest Products, which operates nine kilns with a combined annual capacity of 110,000m3, has seen a big improvement in the performance of its packing grade material since deciding to heat treat and kiln dry every piece of timber going through its mill.

Beforehand, material which did not meet the C16 grading process was a problem to shift but heat treatment and kiln drying has transformed its potential, with Howie currently holding a waiting list for the product.

Howie and BSW both report good demand for surface products such as kiln-dried planed all round timber.

Alan Wheat, BSW’s sales and marketing director, said: “Over the past four years we have seen demand for kiln-dried material exert pressure on supply. This growth has been fuelled by demand in the construction industry for kiln-dried, graded and machined timber, plus regulatory requirements from the pallet sector.”

Two rail loaded 150m3 capacity Bes Bollmann kilns will be introduced at its Newbridge on Wye site during February to support value-added timber developments. The efficiency of current kilning activity is also being improved by new control systems.

The rising cost of energy has produced some concern from UK sawmillers with regard to kilning operations – one operator expects a 25% year-on-year rise in energy costs – so Howie’s decision to install wood-fired boilers to serve its kilns is now paying dividends.

Bollmann’s UK and Ireland agent I Woodward & Co Ltd is also to supply three fork lift-entry 180m3 kilns at James Jones & Sons‘ Lockerbie plant for heat treating and kiln drying a range of products.

Bollmann’s developments include an anti-plume device (meeting environmental concerns), a high pressure spray system (which produces a fine mist for humidification) and the Calmatic 10-1 unit for testing to the ISPM 15 standard. Air movement has been speeded up by higher fan speeds, leading to more even drying.

Efficiency

American Wood Dryers is looking to expand its ThermoVent power venting and heat exchanger system to European lumber manufacturers by using a UK-based distributor. The technology is designed to boost kiln efficiency and improve lumber uniformity and quality.

And Kiln Services recently introduced potentiometric control on inlet and exhaust dampers. This makes the kiln work with a slight negative pressure to stop heat loss and steam leakage.

According to Roddy Burgess, the FC’s head of plant health, there doesn’t seem to be a shortage in heat treatment capacity or in ISPM 15 compliant wood packaging.

He said there are now more than 600 participants in FC’s wood marking programme, of which eight are fumigators and 78 are registered heat treatment facilities. The remainder are buying in heat treated wood and marking accordingly.

Mr Burgess said blue stain was an ongoing issue because heat treatment actually makes the wood more susceptible to attack by blue stain. Many treaters are incorporating heat treatment into a kiln drying program to minimise the risk.

Meanwhile, the Timber Packaging and Pallet Confederation (TIMCON) and National Association of Pallet Distributors are advising members to retreat repaired or recycled pallets to ensure they meet ISPM 15.