SHS developed an industrial technology for the production of frameless lightweight panels
The wood-based products manufacturer Egger assumed the role of a pioneer and ordered in September of 2005 the first continuous production line for frameless lightweight panels from Siempelkamp.
A light design
The weight of panels and the optimization of resources have always been important issues to Siempelkamp Handling Systems (SHS), Wolfratshausen, Germany. With this in mind, SHS, which is closely involved in the design of new Siempelkamp lines for the wood-based products industry, rediscovered the honeycomb panel as a traditional and natural lightweight building element. Only now the SHS engineers have further developed it with today’s technological knowledge. The result is a frameless lightweight panel! This development can be compared to a small technical revolution: an old product idea was not only tailored to today’s industrial needs, but the necessary technology, machinery, and supplied products had to be newly developed.
During the development phase of machinery and technology, SHS was the sole risk bearer. With an investment of 25 million euros for a complete plant, Egger has now taken on the role of a pioneer in the market. This decision was preceded by market surveys and a very successful presentation of the first lightweight board “Eurolight” by Egger at the ZOW 2006 fair in Bad Salzuflen.
“Frameless” from continuous production
As the name gives away, the panel is produced without a frame on the newly developed 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. The thickness of the surface layer boards can range from 3 to 10 mm (1/8” to 3/8”).
The 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. However, because of a high ration 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. Thus, 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 ¼”) and a 10 mm to 90 mm (3/8” to 3 ½”) 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 lightweight panels per day (8 million m² p.a.) 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.
The process: During pass through the honeycomb structures are first decompressed and then cut to length. Glue will then be 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° 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 new production plant allows frames to be inserted into the panels, thereby making traditional furniture designs, hardware attachments, and joining solutions possible.
The Austrian 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.
Light, rigid, and best future prospects
The finished panel is impressive: The board thickness ranges from 16 to 100 mm (5/8” to 4”) with the same interior strength as that of solid panels, however, 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 kept. 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 therefore broad. Even large frameless lightweight panels can be handled manually with ease.
The SHS development of the industrial frameless, lightweight panel is a highlight which will effectively influence the furniture and interior finishing industries in the future. Important issues about hardware attachments and joining solutions are solved so that an industrial use of the panels in the furniture industry is without question. Numerous manufacturers from all sectors of the furniture industry have already expressed an interest in the product. The product is setting a trend in counteracting increasing material and energy costs. The demand for frameless lightweight panels is growing on the manufacturer, logistics partner, craftsman, and consumer side.
