SHS and Egger pioneered frameless lightweight panel production.

The world's first large-scale industrial production plant for lightweight boards has been in operation since 2006 at the Egger plant in St. Johann, Austria.

The plant, provided by Siempelkamp Handling Systems (SHS), has a daily capacity of 1000m³ (35,300 cu. ft.) of 5610x2070 mm (18.4 ft. x 6.79 ft.) boards of its signature brand, Eurolight®.SHS was the groundbreaker in developing the production machinery and technology and, with an investment of 25 million euros, Egger became a pioneer in the market, launching Eurolight at the ZOW 2006 fair.

Lightboard bonuses
Lightweight board, lightboard, honeycomb board - whatever the name, it’s a product that offers the lightest possible weight while keeping the other positive properties of traditional composite panels - dimensional stability, smooth surface and defined finished size. Lightboard allows certain applications such as interior doors or wall and ceiling linings that were out of the question with traditional panels due to their weight.

The breakthrough was the honeycomb panel, consisting of two thin wooden surface layers and a honeycomb core made of cardboard. It provides a compact, stable and light design without compromising the surface finishing.The hexagonal honeycomb structure of the core material is one of nature’s basic design principles. It combines minimal material and energy requirements with the highest possible stability.

Originally, a glued wooden frame around all four edges of the board kept all board components together. This simple, effective board-with-frame principle had one major disadvantage: it was only suitable for specific components with fixed dimensions, such as small series production in the furniture industry or for standard dimensions of interior doors. Other disadvantages were a high organizational work effort and considerable pre-production costs. Industrial mass production with variable finished sizes was not yet possible.

Thinking outside the frame In this scenario, with a view to saving material and costs and an ongoing quest for lighter weight, Siempelkamp engineers rediscovered the honeycomb panel and further developed it with today’s technological capabilities. The result is a frameless lightweight panel and a technical revolution.

Siempelkamp Handling Systems (SHS) in Wolfratshausen, Germany, had always been closely involved in the design of new Siempelkamp lines for the panel products industry, so the weight factor and the optimization of resources were ongoing important issues.

The right recipe
The honeycomb panel is produced without a frame on the Siempelkamp line. The surface layer boards are made of MDF, particleboard, OSB, or other thin materials. The surfaces can be unfinished, sanded, laminated on one or both sides, or coated. Thickness of the surface layer boards can range from 3 to 10 mm (1/8” to 3/8”).

Core materials for the panels include honeycomb structures manufactured out of paper, corrugated core structures of paper, or lattice structures made of cardboard or MDF. The latter two are newer developments available as finished core material but because of a high ratio between volume and weight during transport and storage (the material cannot be compressed), the traditional honeycomb structure made of paper is still the preferred core material.

These honeycomb structures come pre-compressed. Their expansion takes place on honeycomb stretching and drying equipment. One pallet of honeycomb paper can result in a core material area of up to 3,000 m2 (32,300 sq ft). This area is strongly dimension dependable. The honeycomb paper is available in cell widths of 10 mm to 40 mm (3/8” to 3 1/4”) and a 10 mm to 90 mm (3/8” to 3 1/2”) core material height. Finally, its excellent price and stability speak for the traditional honeycomb structure made of paper.

The highlight of the production line for frameless lightweight panels is the double belt press by SHS. At Egger this press is 34 m (112 ft) long. With a feed rate of 13.5 m/min (44 ft/min), it will produce 34,000 m2 (366,000 sq ft) of frameless lightweight panels per day (8 million m2 or 86 million sq ft per year) at full capacity. The SHS scope of supply also includes the handling systems from material infeed, to glue application, to the panel cooling and stacking line.

Making the sandwich
During pass-through, the honeycomb structures are first decompressed and then cut to length. Glue is then applied to the lower surface (spray application) and the cut-to-size honeycomb core layer furnished in-line.After that, glue is applied to the top surface layer before being joined with the bottom and core layers. Directly after joining of the three (3) layers, the glue starts expanding and the assembled boards transfer into the double belt laminator for calibration and curing.

Following calibration and curing, boards are cut to size, cooled and stacked. In general, the double belt press can be shortened to 15 m (49 ft); the working width can range between 1,300 to 2,500 mm. Thus – for instance at Egger – a double occupancy of the belt becomes possible.

For a rigid, stable and non-water based bonding, a high tack, two component adhesive based on Polyurethane is used. The applied adhesive amounts to only 80-150 g/m2; the processing temperature is 20 degrees C (68 F), +/–5 degrees. The excellent foaming abilities of the adhesive and a short curing time of 3.5 min allow for a quick passage of the board through the press as well as an immediate subsequent processing such as sawing and milling.

The Egger production plant allows frames to be inserted into the panels, thereby making traditional furniture designs, hardware attachments and joining solutions possible.

The production line also features a few other SHS specialties. These include a feed for alternative core materials as well as two longitudinal trim saws, one to cut raw boards and one for finished boards.Serving it upThe finished panel thickness ranges from 16 to 100 mm (5/8” to 4”) with the same interior strength as that of solid panels, but with a reduced weight of 20% for 20 mm (3/4”) boards and 80% for 80 mm (3”) boards. The thickness tolerance, as required by the furniture industry, is maintained.

The board length can range from 4.1 m to 5.6 m (13.5 ft to 18.4 ft) and the board width from 1.8 m to 2.2 m (5.9 ft to 7.2 ft). The range of variation for panel decors, materials, and sizes is extensive. Even large, frameless lightweight panels, such as for kitchen countertops, can be handled manually with ease.

The industrial frameless lightweight panel is increasingly influencing the furniture and interior finishing industries. Innovative and proven hardware attachments and joining solutions make industrial use of the panels in the furniture industry an exciting option. The product is setting a trend in counteracting increasing material and energy costs and demand is growing from manufacturers, logistics partners, craftsmen and consumers.

Information for this article provide by Siempelkamp.

www.siempelkamp-usa.com