Fig. 15 shows a bookshelf unit designed for a school library. It is constructed from manufactured board panels joined together. It is made in a shop. The pa...

(a) A suitable manufactured board for the panels of this bookshelf is MDF (medium density fibreboard). [1] MDF provides smooth, flat surfaces that accept paint and veneer finishes well, and it is available in the large sheet sizes needed for furniture panels. Plywood and chipboard are also acceptable alternatives.

(b) Two reasons why a manufactured board would be chosen instead of solid natural timber for this product:

1. Manufactured boards are available in large, flat sheets that do not warp. [1] Solid timber planks would need to be edge-joined to achieve the width of a bookshelf panel, and individual planks are prone to warping and cupping as humidity changes. Manufactured boards remain dimensionally stable.
2. Manufactured boards are generally less expensive than solid hardwoods of equivalent size. [1] They make efficient use of timber resources because they utilise wood fibres, particles, or thin veneers rather than requiring large sections of solid timber.

(c) Iron-on veneer edge banding is applied to the edges of manufactured boards for two reasons:

• The cut edge of manufactured board (especially chipboard or MDF) is rough, porous, and unattractive, exposing the raw fibres or particles. [1] The veneer strip covers this edge to give a neat, smooth, finished appearance that matches the face of the board.
• The exposed edge can absorb moisture, which would cause the board to swell, delaminate, or deteriorate over time. [1] The veneer strip seals the edge, protecting it from moisture ingress and extending the product's lifespan.

(d) One method of joining the shelf panels to the side panels in this bookshelf unit:

Dowel joint:

1. Holes are drilled in the edge of the shelf panel and matching holes are drilled in the inner face of the side panel at the corresponding position, using a dowelling jig to ensure accurate alignment. [1]
2. Fluted wooden dowels are coated with PVA adhesive and inserted into the holes drilled in the shelf edge. [1]
3. The shelf is then pressed into position so that the protruding dowels slot into the matching holes in the side panel. The assembly is clamped firmly and left for the adhesive to cure, creating a strong, concealed joint. [1]

Alternative methods include cam lock (knock-down) fittings for flat-pack furniture or biscuit joints using compressed beech biscuits.