What is HPL wood?

HPL stands for High Pressure Laminate, a type of wood commonly used in the musical instrument manufacturing industry.

HPL's main ingredient is kraft paper dipped in phenolic glue, pressed under high pressure (about 100 kg/cm2) and high temperature (150°C), the surface is decorative paper dipped in melamine glue.

HPL is often used to replace natural wood with many advantages that natural wood does not have.

History begin.

The history of HPL begins in 1896, Leo Baekeland - an American chemist, was the first to experiment with making HPL plates, this experiment was later patented around 1913 by Herbert A. Faber and Daniel J O'Connor, the first people to develop the Formica brand.

These early HPL panels came only in black or brown (the color of kraft paper, and were mainly used in the electrical industry due to its insulating properties).

By the 1930s, the appearance of HPL's colorful and patterned decorative surface helped it become a popular choice in many fields, especially those requiring durability and high aesthetics.

Today, many big brands use HPL to produce guitars.

The real boom of the HPL industry was after the end of World War II. Especially in the 1950s because at this time, HPL was recognized for its high aesthetics, practicality, ease of cleaning and durability. Also in these years, the materials market witnessed the development of HPL's unique anti-flammability function.

Structural ingredients.

HPL is usually composed of 3 layers: Surface coating, decorative paper layer and lower layer consisting of many kraft paper sheets pressed simultaneously under a temperature of 150°C and a pressure of 100kg/cm2.

Surface layer: Is the layer that creates a surface effect and protects the HPL panel when touched. Usually on the market there are glossy, rough, smooth or Synchronized effects according to the wood grain.

Decorative paper layer: A layer of textured and colored paper embedded with MUF (melamine urea formaldehyde) glue with high scratch and abrasion resistance properties. The grain and color of HPL panels are determined by this decorative paper layer.

Kraft paper layer: Includes many layers of kraft paper treated with phenol glue. The thickness of the HPL sheet depends on this layer. If you want to increase the thickness, increase the amount of kraft paper. Kraft paper is a type of highly durable paper, usually brown in color, creating a brown or black core layer typical of kraft paper.

HPL classification.

Regular HPL panels and gold-core copper HPL panels.

In general, HPL panels are composed of 3 layers such as the surface layer, decorative paper layer, and kraft paper layer. However, to suit the functional and aesthetic needs of the market, currently, HPL panels can be divided into two types as follows.

- Regular HPL panels.

The kraft paper used to make HPL panels is usually brown, but after being dipped in glue, it turns dark brown or black. That's why the back side of HPL panels is usually brown and black.

- Copper core HPL panels.

The problem is that when cutting V or L edges, the underside will be exposed when the HPL panel has a light colored surface such as white or cream. Therefore, HPL manufacturers have researched and launched a product line that meets this requirement, which are single-color white-core copper HPL panels, single-color gold-core copper, patterned white-core copper and core copper. golden wood grain.

Copper-core HPL panels are HPL panels with the underside and surface having similar color tones. For white-core copper HPL, white kraft paper is used, so the underside will be white, consistent with the surface with light tones such as white, cream, and light gray. For gold-core copper HPL panels, yellow kraft paper is used, so the underside will be yellow, consistent with the side with light wood tones.

The outstanding advantage of copper core HPL panels is high aesthetics. Instead of showing black borders like regular HPL panels, when using copper-core HPL panels, the product will be uniform in color.

Because the current market demand for HPL wood is very high, there are many manufacturers interested in this material.

Advantages of HPL wood.

Diversity in designs and colors: Because the layer decides the color pattern of HPL is decorative paper, this layer of paper is printed based on the design image on the computer. Therefore, HPL has the ability to simulate any pattern, shape of any material such as wood, stone, leather... with rough, glossy grain...

Flexible: Some types of HPL have the ability to be bent and glued to the core with post forming technique, this technique brings high aesthetics.

High durability, ability to withstand force, withstand grinding, withstand impact: The surface layer is a layer of transparent melamine glue that turns inert under specified temperature and pressure, helping to increase outstanding durability for the product. entire HPL surface.

High heat resistance: The heat resistance of the plate is very good. According to a study, HPL can withstand temperatures up to 180 degrees Celsius for up to 20 minutes.

Easy to clean: With a surface layer made from inert melamine plastic, HPL panels are very resistant to dust and easy to clean.

The price is lower than that of natural wood, suitable for the economic conditions of many consumers.

Environmentally friendly: HPL panels do not use natural wood, so they protect the forest environment.

Application in musical instrument production.

In the near future, due to global climate change and overexploitation by humans, guitars made of solid wood will be very expensive, and the mid- and low-range segments will gradually prioritize their use. HPL wood abounds.

Using modern scientific techniques, musical instrument manufacturers process HPL panels to obtain properties similar to the solid wood they imitate. For example, HPL Koa wood will have the same sound and appearance properties as solid Koa wood, HPL Rosewood will have the same sound and appearance properties as solid Rosewood, HPL Spruce wood will have the same acoustic properties and looks similar to solid Spruce wood...

Enya X1 EQ: Model contributed greatly to helping the Enya brand become famous around the world. Crafted with HPL Koa from the front, back and sides.

Disadvantages of HPL wood: The most obvious is that the resonance and sound quality will be a bit worse than that of solid wood. Martin guitar brand experts have rated the sound quality of HPL wood at 8/10 compared to solid wood.

In fact, a guitar using an HPL wood top and a guitar using a solid wood top when played together have the same feel, it is not easy to recognize the difference. This difference can only be seen clearly when you compare it with high-end guitars, which use selected, high-quality solid wood tops.