Bent Wood

Bent wood are those made by wetting wood (either by soaking or by steaming), then bending it and letting it harden into curved shapes and patterns.

In furniture making this method is often used in the production of rocking chairs, cafe chairs, and other light furniture. The process is in widespread use for making casual and informal furniture of all types, particularly seating and table forms.

The process begins with the pressing of glued veneer layer in their predetermined shape.

Bending wood is a very complex process, before pressing it is decided whether the veneer are to be processed into plywood- if so then the veneers need to be placed on top of each other crosswise to the grain direction or if laminated wood need to be produced the individual veneer layer need to be placed parallel to each other.

Laminated wood can withstand huge tensile loads yields flexibly and then swing back into its old shape. Plywood is stable in form and has a very high rigidity.

Accordingly here in the pressing process the veneers must be attached to each other and laminated on top of each other. Any variance in the thickness within a shell is also applied here. Every model of wooden shell has its own forming tool. The glued veneers within the forming tool are subjected to very high pressure of up to 300 tones for a precisely calculated time. The duration of the press further depends on the mode of heating which can be done electrical heaters, or steam or maybe by high frequency.

Veneer layer which are glued under high pressure and heat forms a new shape with high static quality. However as per the requirement they can be made more or less flexible.

I. DEBARKING

Initially, the logs are of irregular shapes and are covered with layers of bark and dirt. To achieve a uniform cylindrical log, these raw logs are lathed whereby the barks are removed. This debarking process facilitates the next process whereby the resultant thickness of the veneer sheet can be regulated.

II. ROTARY CUT VENEER

The thickness of our veneer sheet is either 1.5 or 2 millimeters. Veneer sheets are rotary cut, in which the peeler block is rotated around its axis in a lathe, whilst a continuous veneer sheet is cut by a blade which is mounted parallel to the axis of the block.

Veneers sizes are cut according to customers’ requirement. The dimensions of veneer ranges from 16in X 16in (406mm X 406mm) to 38in X 72 in (965mm X 1828mm).

The rubber wood veneers are categorized into 2 grades, A and B. They are graded according to the surface quality. Grade A veneer has even tone (fair) in terms of color and lesser black spots on the surface. They are being used for furniture that is intended to display the natural wood grain. Grade B veneers are normally used as an inner layer, such as furniture that are wrapped with cushion.

III. CHEMICAL TREATMENT

Next, the veneer sheet is chemically treated to prevent wood decay or infection by insects and consistency in the product quality.

IV. DRYING PROCESS

The moisture content of the veneers will be significantly high after the chemical treatment. Hence, the chemically treated veneer will have to be dried using Mesh-Roller veneer dryer. The drying process will ensure that the glue applied during multiple layer compression will be effective and of consistent quality.

V. SANDING OF VENEER

The surface of every single veneer sheet has to be smoothen using specially made veneer sanding machine fitted with wide-belted drum sanders.

VI. STRIP JOINTING

The assembly of the veneer prior to pressing entails the jointing of the narrow strips of veneer, which are edge-glued to match the veneer sheets to the required size.

VII. BENDING / COMPRESSING

Glue is then applied to the inner piles or core, which in turn, are laid in between the outer veneers ready for bonding. High quality Class 1 E1 glue meant for application to interior layers is used.

Once the veneers are laid-up as assembly plywood sheets, they are fed into hydraulic presses. This brings the veneer into direct contact with the adhesive, where the application of heat cures the glue. The multiple-opening hot presses, with drying period ranging between 5 to 25 daylights and platen temperature between 80-180°C is being employed. Compared to a single opening, the overall pressing cycle time is much shorter and the pressure capacity is higher. Hot water or steam is used to heat the platens.

Bent Wood Products