Wood Lamination, the Basic Process in the Woodworking Industrty

Lamination is one of the fundamental processes in the wood industry. In the wood industry, logs are cut and split into boards in specific sizes. The wood boards are then dried to reach the moisture content standard before they are marketed to supply the wood manufacturing industry. You can find the wood MC standard for many products here: wood moisture content. These dried boards are then glued and laminated according to the required dimensions to form components for various wood products. The use of wide and large-sized wood boards in the wood manufactures is very rarely due to technical and economic reasons. The use of laminated is very common in the wood industry now because it gives many advantages compared to the wide and long wooden boards. 

maple laminated wood panel

Here are the advantages of using laminated wood:

• Better drying process

Wood must be dried to a certain standard moisture content to be used in the wood manufacturing industry. The process of drying wood is not easy; it takes a long time and must be done with good control to produce good-quality wooden boards. The drying time for this wood highly depends on the size of the wood. The drying process for the thick and large wooden planks will take much longer than the thin and small planks. Therefore, large wooden logs are cut and split to the smallest size before being put into the oven to dry. The drying wood in plank form will be much faster, easier, and cheaper than drying wood in big wood logs. 

• More stable

Wood is a natural material from trees; its properties depend on the growth of trees in nature. One wooden board could have variations in physical properties from one log to the others. The wood planks also have varied properties from the middle and edges. The wide board from one cut of wood logs tends to bend, crack, or split because of its varied physical properties. 

The laminated wooden boards that are made of many wood pieces will be more stable than the big wood pieces. Many pieces of wood that are well glued will strengthen each other’s and be more homogenous in one unit.  Thus, laminated wooden boards will generally be stronger and more stable than 1 piece of wood board. 

• More beautiful in appearance

Big wood boards can have color variations from one place to another. The older wood in the middle generally has a darker color than the edges; some parts of the wood even have a white color, while other parts have a dark brown color. Therefore, it is relatively difficult to get one panel with a uniform color from a big wood board.

The laminated wood is the simple solution for this problem. In the wood lamination process, the small-sized wooden panels are arranged and joined together to make large-sized panels. With the sorting process, the small panels used can be selected with more uniform properties. The bad wood pieces can be put aside and not used to form the good wood board. The same ideas are also used to make panels with uniform colors; the similar-colored wood pieces are used to make the big wood panel with more uniform color and grain look. 

• Cheaper prices

Price could be the most important reason for the use of laminated wood. To get a wide panel from one wooden plank, a large tree is needed, which will be very expensive. Large trees require a long time to grow and, of course, are hard to be found nowadays. But with lamination technology, wide and long wooden boards can be made from small-sized wooden boards from smaller-sized trees at a cheaper price.

Wood lamination Process

The wood lamination process in principle includes 3 things: surface preparation, applying glue to the surface, and pressing to maintain the wood bond during the glue drying. The drying process of wood glue is a crucial moment because it will determine the lamination process time. Therefore, instead of the tools for applying glue to the surface and pressing the wood, special equipment is developed to speed up the drying of the glue. There are several ways to speed up the drying process of wood glue and produce a tight wood bond. According to the wood drying process, there are 3 types of lamination machines: cold press, hot press, and high frequency press.

• Cold press

It is a wood lamination machine that does not use heating to speed up the drying process of wood glue. The pieces of wood that are joined together are pressed and waited until the glue used dries naturally. This tool is simple, easy to use, and has high flexibility, but the gluing process will take a long time according to the type and type of glue used. This tool can accommodate a variety of wood sizes, types of wood, and types of glue according to production conditions and needs. This tool is still widely found and used in the wood industry, especially for small-scale wood workshops that make products in small quantities and custom products

• Hot press

This machine uses heating to help speed up the drying process of wood glue. The machine is equipped with hot metal panels to heat the wood and glue so that the glue dries more quickly. This machine can speed up the lamination process and produce panels with strong adhesion. When the machine runs, a metal panel must be heated to a certain temperature (usually around 100 degrees C) while it is pressing the wood and glue inside. With the heat, the drying process of wood glue can take place more quickly, thereby reducing the waiting time for wood drying time. It is more suitable for the wood lamination for big volume jobs. 

• High-frequency press 

This tool uses radio wave frequencies as an auxiliary tool for heat transfer so that the glue heating process occurs more quickly. Microwaves with a certain wavelength are used to deliver heat energy through the wood directly to the glue and dry it. Using this tool will fasten the lamination process more quickly compared to a hot press, which uses heat convection to heat the glue and wood. This tool is widely used in the large-scale wood industry, which produces mass wood products.

Things to be considered in the laminated wood process

• Selection of wood 

Even though the wood lamination technology is used to improve the quality of wood, of course it does not mean all wood pieces can be used carelessly. Damaged and low-quality pieces of wood should be removed and not used. Pieces of wood that are too soft or have an imperfect shape should not be used because they will impact the quality of the board.

Make sure the wood being glued is dry and fulfill the standard MC according to the standards of the product to be built. It is recommended that all wood pieces that are glued together in one board have physically uniform properties (color, hardness, and MC). 

• Gluing process

The gluing process is one of the things that determines the quality of the resulting board. It starts with wood surface preparation; make sure that the surface of the wood to be glued is cut well; the surface should be flat, which allows the glue to be applied evenly on the surface with sufficient thickness. Next is the pressing process to unite the pieces of wood. Make sure the pieces of wood being joined are pressed with sufficient pressure according to the specifications of the glue used. 

The other important thing is the choice of glue; make sure the glue matches the specifications of the product and the type of wood. The products for outdoor uses will require special outdoor glue that has durability and strength to withstand the outdoor weather. While glue is for indoor products, the aesthetic and economic values will be important considerations for selecting glue.