Air-through and belt ovens for nonwovens and its minimum application unit
Air-through thermobonding ovens Particularly in the field of hygiene nonwovens, the trend goes towards products of a better quality with a smoother hand, more volume and of more uniform texture. Nonwovens producers are supported by the new Supra-Flow BA belt oven, with respect to producing such high quality end products. It guarantees a particularly gentle transport of the unbonded web. This is achieved by a sophisticated air circulation design. It is also characterized by minimum heat consumption, high flow uniformity and constant temperature distribution over the entire working width. The good accessibility of the oven chamber leads to a high maintenance friendliness. The dryer is available in working widths up to 4,600 mm. It is designed for production speeds of up to 250 m/min and thus offers potential for line optimization.
Typical end products, which are bonded on the Supra-Flow BA high-end thermofusion oven according to the air-through principle, are nonwovens for diapers (ADL, topsheet, backsheet), nonwovens for feminine hygiene and incontinence products, but also for filter nonwovens and special nonwovens.
Double belt dryer One year ago Brückner introduced the revised double belt oven Supra-Flow BX for thermofusion of high-loft nonwovens. The aim was to reduce the use of primary energy with a view to resource-conserving nonwovens production and thus to reduce production costs. Alongside this increase in efficiency, the re-construction of the air circulation with fewer individual parts was realized. The oven is suitable for the production of high-loft nonwovens, medium as well as highly compressed fiber boards made of natural, synthetic and/or recycled fibers. It is a convective oven system which works according to the air-through principle; in each compartment the flow direction can be individually adjusted according to the product requirement. In most cases the basic material beside the matrix fibers are binding fibers melting at low temperatures such as bi-component fibers (PET/CoPET, PP/PR) and PP. Thermoplastic or duroplastic powders can be used also as binders.
The Supra-Flow BX is particularly suitable for products with a higher weight, thickness and/or density and relatively high pressure losses during the flow through the product. The following processes can be implemented on the system: thermofusion (for bonding PP, PET/CoPET, PP/PE), heat-setting and drying. The oven is of particular interest to manufacturers of mattresses, duvets, inserts, insulation, furniture (upholstery, cushions), cleaning (dry and wet wipes, painter's cover foils), automotive components (headliners, thermal insulation, noise insulation, seat covers), thermal and acoustic insulation in the construction industry and carrier materials (floor coverings, technical coatings).
The Supra-Flow BE is particularly suitable for the gentle drying of binder-bonded lightweight nonwovens (e.g. high-quality nonwovens for the medical sector). For such lines, alongside the belt dryer, the company can also supply the foam padder, the cylinder dryer group and a smoothing calender downstream of the dryer.
Minimum application unit
Brückner has again improved and further developed its minimum application unit. The Eco-Coat unit has the following advantages over a padder: Low-Add-On technology (fabric moisture < 60 g/m²), low water consumption, high energy savings in the subsequent drying processes, low residual liquor (2.5 l/m working width) and thus fewer chemicals which have to be disposed of during a batch change.
The unit enables impregnation and precise one-sided Kiss Roll coating on the upper or lower side of the fabric web as well as functionalization such as hydrophobization or softener application by means of engraving roller pre-dosing. In addition, one-sided ink jet preparation is possible. Single-sided functionalization with a wide variety of finishing chemicals can be realized, especially for fashion and technical applications.