Due to a special formulation of materials with excellent processing characteristics, Doellken 3D Edgebands are easy to process either manually or by machine.
Straight processing of Doellken 3D Edgebands poses no problems on all conventional edgeband gluing machines. It must be ensured that neither edgeband conveyor nor feed roller will damage the edgeband. Rubberized rollers for edgeband feed through have proven their merit in these machines. 3D Edgebands require meticulous milling of the joints. This applies to DC 7XXR especially.
Work station processing
Doellken has developed a new material formulation, the Doellken 3D-BAZ edgeband.4, suited especially for processing of curved moldings on CNC controlled machining centers (BAZ) or on semi-automatic edgeband processing machines.
Doellken 3D-BAZ edgebands have a material formulation that is particularly suitable for machining, especially for processing of tight radii. As with every thermoplastic material, it is essential to ensure that the material is warm throughout when machining a radius. The surface print color of the Doellken 3D Edgeband is a significant factor in this case. Standard colors such as plain colors or wood finishes easily absorb heat via infrared radiation of the processing machines. Metallic colors, on the other hand, tend to reflect much of this infrared radiation. Additional sources of heat should therefore be available during machining. Hot air units and/or edgeband preparation ovens can offer excellent support to processing.
For work station edgeband processing, many machine manufacturers (e.g. IMA or HOMAG) recommend applying hot melt adhesive onto the edgeband directly. To prevent damage to the edgeband finish, Doellken and the machine manufacturers have together developed special adhesive application rollers. These gluing rollers are modifications of conventional steel rollers. Processing of edgebands (including all primed edgeband materials) using these special adhesive application rollers has been tried and tested. Machining centers which apply hot melt adhesive to the board (such as BIESSE or MORBIDELLI) do not need special rollers for adhesive application.
Rubberized rollers should always be used for conveyance and feeding of Doellken 3D Edgebands through the processing machines
Doellken 3D Edgebands and Doellken 3D-BAZ edgebands are consistently coated with a universal primer to assure perfect bonding to all suitable hot melt adhesives. Special dispersion adhesives may be used for manual gluing, provided the given pressing time is adhered to (see manual processing). Doellken 3D Edgebands may be glued using most EVA, PA, APAO or PUR5 based hot melt adhesives.
Adhesion quality is generally best using unfilled or partially filled adhesives. As with highly heat-resistant types of adhesive such as PUR6, APAO or PA hot melt adhesives, the low-shrink material formulation of Doellken 3D Edgebands deliver reliable adhesion, even at higher application temperatures.
This feature is especially advantageous near hobs and ovens in kitchens or for export of furniture in containers.
“Free shrinkage” of Doellken 3D Edgebands is excellent already even before gluing. The dimensional stability of Doellken 3D Edgebands is another advantage here: Vicat B 50 testing shows that softening of the material only starts at temperatures over 90 (± 3)°C.
It should be ensured with machine gluing that the glue hopper always has sufficient adhesive available. Apply the adhesive evenly and in sufficient quantities for beads of adhesive to be pressed out along the edges of the freshly glued edgebands, ensuring that the spaces between chips will be filled and gluing is full-surface. The amount of glue applied depends, among other things, on the density of the chipboard: the lower the density, the hotter the hot melt adhesive will be required.
The adhesive manufacturers recommended processing guidelines must be heeded. Depending on the adhesive type and base, the application temperature specified by the manufacturer may vary from 90°C to 210°C. Please note that the thermostats in the hot melt hopper are often inaccurate and may vary considerably from the actual temperature on the application roller. On request, we will gladly provide a list of hot melt adhesive types suitable for use in machining centers.
Doellken 3D Edgebands cannot be glued using PVAC glues and the cold activation method.
For best results fitting edgebands, work with boards and edgebands at room temperature (not below 18°C). Material stored outdoors should be warmed up overnight. If the boards or edgebands are too cold, the hot melt adhesive will cure before edgeband application. Draughts should for this reason also be avoided.
The optimal moisture content for further processing of the boards is between 7 and 10%.
Speeds up to 30 m/min. are easily achieved.
Considering machine parameters, the correct number and adjustment of the press rollers is paramount to achieving optimal appearance of the joint. To prevent gaps or cavities from appearing, the pressure of the rollers should be set high enough to ensure full-surface edgeband adhesion to the boards. The pressure rollers as such must be clean to prevent pressure marks on the edgebands.
Cross-cut blades should be sharp enough to cut the edgeband material cleanly, leaving a minimum overhang for cross-cut milling to facilitate final trim by milling.
Cross-cut saws should have their feed rate adjusted to allow clean cutting of the edgeband. Single-edged fine-toothed “ES” type saw teeth are advantageous, since they produce a neater cut through the edgeband than cross-cut saw blades with “WS” type alternating teeth, for instance.
Flush or radius milling
The overhang for cutting should be the same on both sides and not exceed 1.5 mm. The edgeband overhang should prefer- ably not exceed the edgeband thickness. Too much overhang will increase the risk of chipping. Special design effects may be achieved by using chamfer bits on Doellken 3D Edgebands. As a rule, multiblade tools with at least 4 to 6 blades and an operating speed of 12 000 – 18 000 rpm are recommended for chamfering.
Scraping of Doellken 3D Edgebands will yield excellent results with no stress whitening. To prevent stress whitening, plastic scrapings should not exceed 0.1 mm in thickness.
After machining, the material may be polished with a soft buffing wheel to achieve virtually any desired gloss. A high gloss is easily achieved with polishing paste. We will gladly provide a list of suitable types on request. Some machine manufacturers are offering mechanical polishing units. Please contact your machine manufacturer in this regard. Adhesive residuals may also be removed using electronically controlled release agent spray guns. It is essential when using auxiliary process agents (such as release agents) to ensure that they do not contain solvents and alcohols, since PMMA should not come into contact with these.
Thermoplastic edgebands generally require higher extraction power than duroplastic or melamine edgebands. Doellken 3D Edgebands have an advantage of lower electrostatic charging compared to other thermoplastic edgeband materials.
Riepe products should not be used with Doellken 3D Edgebanding.