8. MDF doors and drawer fronts for kitchen units

MDF is used for the manufacture of doors and drawer fronts with a wide range of decorative features.

A. Single Panel Paint Finishes

The good face and edge machining characteristics of MDF provide a wide range of opportunities for enhancing the appearance of simple painted doors and drawer fronts with premachined profiled edges and deep recessed surfaces. These visual features can be further emphasised by using contrasting colours to highlight the moulded edges.

Satisfactory machined blanks can be produced using hand feed routers fitted with a positioning jig to define the cutting profiles. Minor machining irregularities resulting from variable feed speeds can be removed using appropriate profile edge sanding treatments. High quality blanks can be produced in large numbers using a CNC router to profile the edges and cut out the surface grooves.

B. Frame and centre panel paint finish

Some of the difficulties of achieving sharp corners with cleanly machined profiles around the recessed face grooves in single panel doors can be eliminated by making the doors in two parts.

The door frame can be machined from a single piece of MDF with inside and outside moulded edges and a back surface rebate to accommodate a separate MDF panel which may be flat or machined with a raised centre. Alternatively, the frame can be constructed from separate rails and stiles with tongue and groove or dowel joints at each corner. This panel and frame may be finished together or alternatively, they can be finished separately to create a well defined two colour effect. The appearance and production advantages of this two piece construction with easy to sand profiled edges may however be offset by higher materials costs.

C. Wrapped doors and drawer fronts

MDF based doors with the appearance of solid wood doors can be manufactured using wood veneer wrapped MDF mouldings as the frame members and wood veneered MDF centre panels. The close control of colour and grain that is possible with wood veneers overcomes some of the problems of colour matching and the inevitable high wastage factor when using six or more solid wood pieces to make each solid wood door. The corner joints between the wrapped pieces are normally mitred with dowel or loose tongue reinforcement. Accurate mitre cutting and alignment of the pieces is essential as the 0.6 mm thickness of the wrapping veneer leaves little latitude for cutting back out of level joints. The centre panel may be flat veneered MDF or have a fielded edge profile achieved by bonding the wood veneers to a premachined MDF panel in a membrane press.

The high stability of MDF in response to moisture content changes in a typical kitchen eliminates the problems of joint opening and centre panel shrinkage associated with solid wood doors.

D. Membrane pressed doors

Doors and drawer fronts manufactured by laminating PVC foil over premachined panels in a membrane press are becoming increasingly popular. This high level of consumer acceptability can be attributed to the obvious protective effect of the PVC wrapped over two or preferably four edges against water ingress and the wide range of decorative effects resulting from the high level of formability of the PVC foil over the premachined MDF. A two colour feature resulting from the use of layered foils enhances the decorative effect.

E. Other constructions

Different embossing treatments can be applied to MDF panels to create textured surfaces for painted doors and drawer fronts or centre panels for use in painted or wrapped moulding door frames.

Melamine surfaced MDF, either smooth or textured, can be used for kitchen doors and drawer fronts. The exposed edges can be painted or finished off with strip edging. Softformed edges applied to MDF panels are free from the obvious show through effects that can detract from the appearance of softform edged particleboard panels.

The appearance of flat door panels can be enhanced by adhesive bonding foil wrapped MDF mouldings to the front surfaces.