Scrimber CSIRO Adhesive Process Opens Structural Market for Small Diameter Logs

Last week, Wood Central explored the challenges in meeting the future global demand for forest products. To meet demand, low value logs are being upcycled using a technology that has been around for almost 40 years. Below is a report filed by Wood Central’s senior editor almost 40 years ago. The terminology is different, but the technology is the same!

Tue 11 Apr 23


Originally filed by Jim Bowden (7 July 1985) who was there at the beginning.

SCRIMBER, a new timber product made from pine thinnings and small trees which matches the qualities of the best natural timber, is to be launched on the Australian market.

Invented by CSIRO and developed in collaboration with Repco, Scrimber will be manufactured by the South Australian Timber Corporation (SATCO), the production and marketing arm of the Department of Woods and Forests in South Australia.

The commercial agreement with SATCO is an early major success for CSIRO’s new marketing company Sirotech which was launched in March.

Sirotech also will negotiate licences overseas where the Scrimber process is already attracting interest.

Manufacture of Scrimber comes after eight years of research and development by the CSIRO’s division of chemical and wood technology and Repco Research Pty Ltd, which established a pilot plant at Dandenong near Melbourne.

A still from an original CSIRO promotional video (1985). The video is dated from the time the original article appeared and is still available to view on the CSIRO website.
A still from an original CSIRO promotional video (1985). The video is dated from the time the original article appeared and is still viewable on the CSIRO website. In 1985 the patent was secured by Scrimber International and in 1990 the AFR reported on the expansion of the technology in the North American market.

SATCO, which estimates the first production plant will involve an investment of $12 million, plans to commence construction during the next year.

It will use radiata pine from the extensive forests around Mount Gambier.

The new process makes strong, structural timber out of small-diameter logs which can either be plantation-grown over a seven to 10-year period or obtained as thinnings from normal forestry operations.

It does this by separating the wood into interconnected strands then re-forming it into beams using a water-resistant adhesive.

Current sawmilling techniques only use about 40% of the log. However, Scrimber is able to use more than 85%, making the whole process more efficient.

Scrimber is expected to be priced competitively with conventional large beams which are imported into Australia, and with its strength and attractiveness it should find a significant market both in Australia and overseas.

Scrimber has a wide range of building applications and can be used for structural work in the same way as top-quality wood. In fact, Scrimber could provide an alternative to natural large beams which must now be sawn from increasingly scarce older trees.

It is a unique reconstituted wood product which has full structural properties and can be used in the same way as ordinary structural timber for building exposed beams, etc. It can be machines, sawn, painted, nailed and moulded in the same way as timber using, using conventional tools.

Scrimber can be made from young wood, and can convert small-diameter logs into high-grade building material. This means it can make use of fast-yielding forest plantations.

Today Scrimber technology is used in a variety of forest products including bamboo in Southeast Asia. Footage courtesy of @cemcacol2309

The process has been designed to use radiata pine logs or pine thinnings. In the manufacture of Scrimber, the natural orientation of wood fibres is preserved, and this gives it the strength which is lacking in reconstituted wood products such as particleboard and hardboard.

Knots and other imperfections in the wood are eliminated leading to a uniform, strong product which may be produced in long structural lengths and deep sections.

In the past, attempts to reconstitute wood have been largely limited to the production of sheet materials.

Apart from plywood, this has involved breakdown of the wood into particles or dispersed fibres, which are then re-aligned into the desired form. Processes of this kind have resulted in products such as particleboard and hardboard, ideally suited to sheet applications but lacking in structural strength for engineering purposes.

However, using purpose-built equipment designed by the joint CSIRO-Repco research project team, the Scrimber process breaks down green logs in a way that hasn’t been done before. After removal of the bark, tree stems are crushed in a series of rolls in the ‘scrimming mill’. This forms bundles of interconnected and aligned strands which largely maintain the original orientation of the wood fibres.

For additional reading, please visit Wood Central's special report on future Wood Supply.
For additional reading, please read Wood Central’s special report on the quadrupling of timber demand by 2050 and the challenges facing wood supply.

After drying, the bundles of strands are coated with a conventional water-resistant adhesive. The pilot plant produces 200 mm by 80 mm rectangular Scrimber. But the general manager of Repic Research Dr Jim Stobo said eventually it might be possible to produce huge beams of Scrimber 2 m wide by 500 mm thick.

SATCO, which is the production and marketing arm of the South Australian Department of Woods and Forests, will build a Scrimber plant at Mount Gambier using equipment designed by the CSIRO-Repco project.

It will be constructed next to SATCO’s timber mill, and all pine to produce Scrimber will come from South Australia’s forest resources. The pilot project established by

Repco at Dandenong is likely to be transferred eventually to Mount Gambier.

Scrimber was invented 10 years ago by John Coleman, a principal research scientist at the CSIRO Division of Chemical and Wood Technology (or Chemical Technology as it was then), which has been closely associated with the subsequent development.

In November 2022, the Bern University of Applied Sciences awarded a project using Scrimber technology a 50,000 CHF Innovation prize for upcycling low-value forest products to create reconstituted cross-laminated timber. (Photo credit: Bern University of Applied Science)
In November 2022, the Bern University of Applied Sciences awarded a project using Scrimber technology a 50,000 CHF Innovation prize for upcycling low-value forest products to create reconstituted cross-laminated timber. (Photo credit: Bern University of Applied Science)

Mr Coleman realised that to make true reconstituted wood it was “rather illogical” to destroy the natural alignment of the wood fibres, then devote considerable effort to realigning them. Rather, it would be better to breakdown the structure of wood only so far as necessary to allow the wood to be formed into the desired end product.

So Mr Coleman conceived the idea of ‘scrimming’, which maintains the alignment of the fibres and has allowed the development of a product having the strength of clear timber beams.

In 1976, CSIRO applied for patents covering the product and the process for its manufacture, and these have been granted in Australia and several overseas companies.

Following initial work, CSIRO advertised in 1977 for partners to development the equipment for Scrimber manufacture. Repco was selected largely on the basis of its success in developing equipment for the textile industry with CSIRO. In 1982, Repco research established the Dandenong pilot plant.

By early 1985, development work had demonstrated the technical and economic feasibility of moving into the production phase. A licence has been granted to SATCO giving the corporation sole rights to produce Scrimber in Australia, New Zealand and the ASEAN countries. The future role of CSIRO and Repco will be to assist in the design of the prototype production plant.

CSIRO will also be concerned with developing new products based on the Scrimber concept.

A joint CSIRO-Repco research team has collaborated for the past eight years to bring Scrimber to a commercial level. The project, including Repco Research’s Melbourne pilot plant, has been largely funded by the company, with considerable backing from the Australian Industrial and Development Incentives Board (AIR-DIB), which now falls under the jurisdiction of the Minister for Industry, Technology and Commerce.

The total AIR-DIB investment by December this year will be $1,935,655. AIR-DIB has been active in the project since March 1978 when it allocated $52,800 to Repco Research for evaluations of Scrimber.

SATCO will receiver licences to a series of CSIRO and Repco patents to enable it to build a commercial Scrimber plant during 1986-87. SATCO expects to plough some $12 million into its commercial plant at Mount Gambier to produced 25,000 cub m of Scrimber a year on a single shift.

  • Story appeared in Australian Timberman on July 7, 1985.


  • Jim Bowden

    Jim Bowden, senior editor and co-publisher of Wood Central. Jim brings 50-plus years’ experience in agriculture and timber journalism. Since he founded Australian Timberman in 1977, he has been devoted to the forest industry – with a passion.


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