The first article presented in WBPI about this Malaysian company appeared on page 12 of the October 1996 edition and bore the headline ‘Merbok: Making MDF in a hurry’.

German company GreCon says that often questions like “What is bond quality?” and “Is there a correlation between bond quality and internal bond?” are asked.
While appreciating that a wood based panel manufacturer does not want to sell bond quality as such, but panels of an adequate quality, GreCon claims that its UPU 3000 helps to achieve that goal by monitoring the bond quality in the panels as they are produced.
As a specialist in on-the-line measuring technology for wood based panels, GreCon has already offered earlier generations of the Ultrasonic Camera UPU 3000 and blow detection systems UPU 919 and UPU 2000.
The target of the new UPU 3000 was to reveal hidden optimisation potential and offer more than a simple blow detection system.
Thus the company says that with the new UPU 3000, the range between a simple blister/ no blister, or good/bad, statement is broken down. Now the question it is designed to answer is “how good?” or “how bad?”
However, GreCon suggests that the real question is what these statements actually refer to. It is not the panel quality as such, because, due to physics, some important quality parameters such as internal bond and expansion cannot be determined online – at least not yet.
But GreCon says that the ultrasound measuring method does allow the measurement of other features. The number and size of glue bridges as well as their degree of hardening, for example, have an important effect on both the panel quality and the ultrasound signal.
The higher the number of glue bridges and the bigger their extent, the better the ultrasound signal can penetrate the panel – and vice versa. A similar behaviour applies to the hardening of the glue: the harder the glue, the easier the ultrasound can penetrate the panel.
To describe these correlations, the term ‘bond quality’ was chosen.
This behaviour was already used for blow-detection systems, but their configurations were not able to resolve and display the processes within the panel. The information from these systems may be considered digital – a ‘good/bad’ statement on quality control.
Automatic calibration and dirt accumulation control are used to ensure consistent and reliable measuring results, despite high temperatures and high amounts of dust in the measuring position, says GreCon.
The bond quality is graphically represented by the system, with a true resolution of up to 250 values in their allocated colours.
Due to its varied configuration possibilities, the UPU 3000 can be adapted to different panel parameters and, importantly, tothe customer’s requirements. It has a high a resolution and can display the full range of a ‘too good’ and an ‘extremely bad’ bond quality.
GreCon says a clear and simple representation of the bond quality and its trend is shown by a quality indicator. All measured data is compressed in a graph, which indicates the quality on a scale, similar to a speedometer.
The UPU 3000 can detect blisters and automatically sort out panels, like its predecessor, the UPU 2000 system, but it is also said to be a reliable aid to optimising the production process and increasing productivity.
Changes in the bond quality caused, for example, by changes in the press factor, panel moisture, share of glue, or the glue quality are immediately shown by a change in colour.
The UPU 3000 can be used for changes in the process, such as prolongation of the press or change from wet to dry gluing. Due to the continuous monitoring of the panel bond quality, the time required for start-up is reduced and GreCon says that a pay-off time of only six months is possible.

Founded in 1908 in Finland, Raute has always specialised in the peeling of logs to produce veneer, originally for the plywood industry. Over the years, that business has become more challenging as peeler log resources have become both more scarce and more expensive.
Having a Finnish background has, no doubt, helped Raute as the company has had to grapple with the problems of peeling one of the most difficult species – birch. The often small and irregularly-shaped logs, coupled with their small diameter and therefore whippy nature, has required the development of some very specific technologies.
The company has also supplied all the production lines for producing spruce veneer in Finland – an industry which has grown dramatically in more recent times.
But Raute is not just a Finnish company today. It has subsidiaries in Canada, the US, Germany, Singapore, Indonesia, China, Russia and Chile, so is familiar with a wide variety of raw material, both hardwood and softwood.
In other parts of the world than Finland, Raute has adapted its knowledge of peeling technology to such species as fir and pine in North America, tropical hardwood species in Asia and radiata pine in Australasia.
The company is also no longer just concerned with the production of plywood. The growth of laminated veneer lumber (LVL) as a construction product has also presented opportunities for it to expand its customer base. In fact it supplied the first eight-foot wide line to Finnforest’s Punkharju mill in 2001 and this is also capable of laying up some veneers with the grain at right angles to the main axis to produce a large size, plywood-like, panel with various applications.
The company has always had to concentrate on maximising the recovery of veneer from each log and its latest innovation in block optimisation is the SMART-SCAN XY+ system. This offers features such as 3-D block imaging and auto-calibration and Raute says it can be retrofitted to all existing lathes.
Raute claims the system is unique in that it utilises data from thousands of measuring points to create a true 3-D image of the block. This data is then used to optimise peeling in several ways.
Firstly, it can determine the largest cylinder within the block that will produce the greatest yield and it does this by using its 3-D imagery to undertake virtual peeling of each block, once every revolution of the spindles.
The company claims that recovery improvements of 0.4 to 3.0% have been achieved on a variety of wood species in this way and that the greater the variation from a true cylinder, the greater the benefits of SMART-SCAN XY+.
The second way in which the system operates is by optimising the position of the block relative to the point of contact with the knife. It does this by optimising the path of the knife during peeling, as well as the point at which the knife contacts the block at the start of the peeling cycle, in order to ensure that round-up waste is kept to a minimum. Surface defects on a block, such as knots, can cause spin-out and this is where the third optimisation feature comes in. The new Raute system is claimed to reduce this risk by accurately identifying such surface defects.
Smart Scan takes measurements in 1in (25mm) increments along the entire length of the block, identifying surface defects, such as those protruding knots. The operator only needs to monitor the process, as the carriage can be operated in fully-automatic mode.
As a result, the distance the carriage has to travel between peeling cycles can be reduced, says the company, and the knife carriage can be positioned as close as possible to the surface of the incoming block, taking into consideration protruding knots and butt flare. This means that cycle times can be reduced at the same time as reducing the risk of those spin-outs.
Unlike conventional X-Y systems, the line does not need to be stopped when calibrating SMART-SCAN, says Raute. This optional feature is claimed to reduce down time, save raw material and eliminate calibration errors.
The system has what Raute calls an advanced user interface which enables the block to be viewed as a picture image, grid, or geometric shape. In every case, a true 3-D image of the block is generated and can be stored in the computer’s memory. The system is also network-ready, making it accessible for remote diagnostics, reporting and servicing.
SMART-SCAN can be retrofitted to all existing lathe models and Raute arranges with a mill to have a representative travel to the site to determine the scope of the retro-fit required. Typically, it would involve the relevant controls, touchscreen, mounting hardware, multi-point laser sensors, temposonic probes and spindles.
This new scanning system follows fast on the heels of Raute’s Smart-Peel concept, formally launched at the Ligna exhibition in Hannover, Germany, last May.
Raute says the system was another product that was developed in response to the industry’s need to maximise value from its raw materials, regardless of wood species, block diameter or capacity requirements. It claims that flexibility is the key element here.
It incorporates the latest developments including the new optimal peeling geometry, digital knife carriage feed and what Raute claims is “the most rigid and accurate gap adjustment method yet designed”.
Of course the plywood industry is regarded as being at the ‘mature’ end of its product life cycle and has seen its market attacked first by particleboard, hardboard, then MDF, and in the construction and packaging sector by OSB.
However, there remain many applications where only plywood will do, whether for reasons of stability and thickness swell, strength-to-weight ratio, or pure aesthetics. It is said that the Egyptians invented plywood and it is showing little sign of disappearing from the specifiers’ portfolios.
But it has had to adapt to continually changing demands made on it and not least of these has been competitive pressure – price. Product costs have had to be reduced in the face of rising raw material costs, which means increases in efficiency have become a lot more than a luxury – they are a means of survival. Thus companies like Raute have had to find ways to maximise the returns from logs.
A new lease of life has been given to the technology used in plywood production by the advent of LVL. That product, made in a very similar way to plywood, has been relatively slow to gain market acceptance but that is changing. The quality demands that such a sophisticated engineering product as LVL makes on its manufacturers should help to ensure that veneer production technology remains at the ‘cutting edge’.

Before embarking on its new venture in the production of LVL, Nelson Pine Industries Ltd sent radiata pine peeler logs to Japan for peeling and structural property evaluation to determine the suitability of this species for LVL production.
The company identified three key markets for its LVL. Australasia was the first, but as it is comparatively small and has two other large LVL plants already supplying the market, the larger consumers – Japan and the US – were the next two obvious destinations.
Each market requires different product certification: in the Australasian markets, it is AS/NZS 4357, while in Japan it is JAS 1443 and in the US, ASTM D5456. The testing regimes for each standard differ slightly and separate certification is required for each.
In order to gain certification for the three key LVL markets, Nelson Pine became an associate of the Plywood Association of Australasia (PAA), through which it has so far gained certification for the products sold into the Australasian market.
The PAA has worked closely with the Japanese MAFF during the recent changes to the JAS (Japanese Agricultural Standard) laws.
This has enabled the PAA to certify its members for production to JAS standards once all the required criteria have been met.
The PAA is also working with a US certification agency for the US market, using the testing and auditing systems that PAA already has in place with its members.
Having made the decision to make LVL, machinery suppliers were selected.
Raute of Finland supplied the peeling line, complete with veneer stackers, incorporating moisture grading to complement the log preparation section which includes ring debarker, cut-to-length saw and hot water cooking vats.
The LVL plant itself was contracted to Dieffenbacher of Germany and incorporates veneer scarfing and lay-up by Corvallis Tool Company (CTC) of the US and a 45m continuous press with microwave pre-heating.
LVL billets are produced in 1,250mm widths, thicknesses of 12mm to 120mm, and lengths up to 18m.
The Nelson Pine veneer production line was commissioned in September 2002, five months ahead of the LVL production line, with the stepped start-up providing a more even workload for the construction and installation workforce and early cash flow from veneer sales to local and international markets.
The veneer and LVL lines are on separate parts of the site. The veneer line positioning ties in with pre-existing log handling facilities, while chip from green veneer waste and peeler cores can go to the MDF line.
The LVL line, on the opposite side of the site, is right beside the Dynea resin plant, which makes the majority of the adhesives used in the production of Nelson Pine LVL and GoldenEdge MDF.
Selected logs are debarked using a Nicholson 35in A5 Tandem ring, prior to cross-cutting with a bank of five chain saws. The resultant blocks go to collection bins, from which they are transferred to the conditioning vats by overhead gantry cranes.
The blocks are cooked in water for 16-24 hours at 850C to raise their core temperature to a minimum of 550C to improve veneer peel quality while prolonging knife life.
The lathe is a 9ft Raute with laser-controlled XY charger, three-stage chuck, roller nose bar, and power back-up rolls. It is capable of peeling veneer between 2mm and 4.5mm at up to 365m/minute.
The veneer is clipped to width using a Raute rotary clipper controlled by camera scanner. The clipped sheets are automatically graded and stacked by moisture content, measured by a Raute RMS 3000 meter.
The three moisture grades from the green stackers are accumulated for separate drier runs. Reducing the variability of veneer entering the drier by moisture segregation assists in reducing the variability of the dried veneer.
A steam-heated, 50m, six-deck, three-lane veneer dryer was supplied by Babcock BSH, now Grenzebach BSH. It has automated infeed and pack accumulator. The dryer’s length is divided into three temperature-controlled stages and a six metre cooling section, and incorporates an automatic grading and sorting system.
The veneer is dried to a target moisture content of 6%. Another feature of the dryer is that all exhaust gases are ducted to the 20MW energy plant supplied by Easteel of New Zealand. This technique completely eliminates blue haze exhaust from the dryer in the atmosphere.
An Elliot Bay moisture meter and in-house software is used to monitor drier performance and a running tally keeps the operators aware of the re-dry rate. The feed speed of the drier is adjusted if this rate moves outside operating limits.
Additionally, each veneer sheet can be tracked to its deck and lane position in the drier, and a cross-sectional picture built up on the positions in the drier which are being overor under-dried. This information is used in tuning the drier, through jet box modifications by Grenzebach technicians.
The dry veneer sheets are transferred automatically to an automated grading line consisting of a Metriguard 2800 DME ultrasonic stiffness grader, a Babcock Novascan 4000 line camera scanner and an Elliot Bay Cypress 2000 dry chain moisture meter.
The addition of a Metriguard to the grading line was a first for Babcock, but the three components have been integrated successfully. Veneer is automatically machine-graded by a combination of structural and visual characteristics, plus moisture content.
Six structural classes are defined within the Metriguard 2800 DME, based on any combination of modulus of elasticity, ultrasonic propagation time, specific gravity, moisture and width.
Six visual classes are defined within the Novascan computer. Twelve defect types exist, and a visual grade consists of minimum and maximum limits for width, length, area and number for each of these 12 defect types.
The Elliot Bay moisture meter is set up with four moisture classes.
The Novascan holds an eight-grade matrix containing the simultaneous requirement of structural, visual and moisture classes necessary to meet a veneer grade. Six of the eight grades are the user-defined visual grades, one grade is re-dry and the last grade is ‘everything else’.
Using the ability of the Metriguard to spray-mark defined grades, it is also possible to amalgamate two structural grades that have the same visual requirement onto a single stacker. The resultant pack is then segregated later into marked and unmarked sheets.
The graded veneer is automatically stacked on one of nine Babcock stacking tables for the eight grades, plus one floating spare stacker.
The veneer is transferred to the LVL plant, accumulated by grade, then all LVL veneer is scarfed using a CTC scarfer with skew correction and two-bin stacker.
The appropriate grades of scarfed veneer are then placed onto each of 10 CTC veneer feeder line stations according to the grading and the recipe being run. Half the veneer packs are turned over using a CTC pack rotator so that the finished LVL product has alternate tight and loose veneer orientations to assist product stability.
The veneer passes through an Elliot Bay Cross Tipple moisture meter which gives the opportunity to reject overly wet veneer and feeds moisture trends to the press control room so the operators can make adjustments to press or glue-spread parameters if required.
A Koch 1400mm curtain coater is used to coat the sheets with Ready to Use (RTU) Phenol Formaldehyde (PF) adhesive. The RTU is made at Dynea’s neighbouring plant.
The glue-coated veneer continues down the transport conveyor to the Dieffenbacher/CTC automated dual level lay-up station.
Veneers are arranged with the stiffest structural grade on the outside of the lay-up, and the least stiff veneers in the core. Either two or three structural grades will be placed in a structural LVL lay-up.
The laid up veneer billet is then continuously transferred to the press via a 300kW, 924MHz microwave that pre-heats the veneers prior to entry into the continuous press.
The 46.2m Dieffenbacher CPS 150 press has 30 pressure and three heat zones. At the end of the press, the billet passes through an EWS Ultra-Scan ultrasonic 12-head blow detector.
The LVL billet is edge-trimmed to 1258mm wide, which later cools to 1250mm.
The billets are cut in nominated lengths between 6m and 18m with the flying cutoff saw, identified with a traceable pack number and left to cure for a minimum of 24 hours before running on the billet processing line.
Each pack has at least one laboratory sample cut from it during the production process to check bond quality and structural performance and full records are kept.
The packs have an initial quality inspection in the lay-down area where they are checked for over-lap or related quality issues. Once cured these are de-stacked into single billets and cut to length on a Dieffenbacher saw, when any ‘blown’ sections of billet can be rejected.
During the finishing process billets can be sanded using a Steinemann four-head widebelt sander. They then pass through a Paul rip saw which rips them into widths between 90mm and 1230mm.
From log to finished LVL pack, Nelson Pine has quality control measures to ensure greater process efficiency, reduced waste and a better product. Combining this with the comprehensive automated veneer grading system to select the optimal veneers for each product means that Nelson Pine LVL is fast gaining a marketplace reputation for superior product presentation and quality.