1. Introduction

In the plywood manufacturing industry, “core”  is referred to the material in the center of plywood. This is an important aspect that determined the quality and aesthetics of the product. Not everyone understand “core” correctly. What material is it made from, why is that important, today’s article will explain that to you.Besides, we will discuss about core veneer and glue – the two main components of the core – play an irreplaceable role in the process

2. Discussion

a. Definition and structure

Definition

“Core” is the center part of plywood, made from thin layers of core veneer arranged alternately. These layers will be bonded with each other by glue and heat pressed. Not only determines the durability and load-bearing capacity for plywood but also ensures the resistance for water or weather.

Structure

There are two main components for plywood core

1. Core veneer: Thin layers of wood arranged alternately with each other. The number of layer will be odd
2. Glue: Adhesive that links veneer layers together, creates a durable structure. Moreover, At the same time, the adhesive also offers features such as water resistance, moisture resistance, and weather resistance.

b. Things to know about core veneer

Core veneer

Roles

• Veneer takes the largest amount of percentage in plywood. As a result, it will be the main factor to determines the weights, durable and water resistance for the product
• After the thermal pressing process, some physical characteristics of wood, such as elasticity and bearing capacity, are still the same.

Classify the veneer based on the quality

• Veneer is classified based on certain aspects such as the quality of the face, preservation status and the amount of defects (dead knots, tears, etc.).
• These grades are:
  • Grade A: Smooth face, a few or without defects, well preserved, suitable for premium wooden products
  • Grade B and C: There are some minor defects but still ensure quality.
  • Grade D: Many defects on the surface, suitable for low – demand products

Thickness

• Around 1 – 2 mm, depends on the demands and requirements from buyers
• Veneer layers are usually made thicker to compensate for loss during pressing and sanding, ensuring the final product reaches the desired thickness.

Materials

• Acacia, eucalyptus, Manglietia conifera, pine, hevea are commonly used as core veneer in Vietnamese plywood.
• Characteristics
  • High load-bearing capacity.
  • Good durability, suitable for both interior and exterior use.
  • When producing high-quality products, a single type of wood is usually used consistently. Conversely, for cheaper products, a mixed core can be used to reduce the total cost.

Glue

Role
Besides being used as an adhesive, glue also determines important characteristics such as:

• Water resistance: Created by using some specific glue such as phenol or melamine
• Moisture and weather resistance: Helps the product be sustainable in different environmental conditions.

Classify the glues based on the usage

• Water – based glue: Ideal for affordable products
• Melamine glue: Increases moisture resistance, ideal for furniture products.
• Phenol glue: Used in products that are water-resistant and withstand harsh weather conditions.

The operating process of the glue

• During thermal pressing process, the high temperature causes the adhesive to cure, firmly bonding the layers of veneer together.
• The adhesive creates a durable bonding layer, ensuring the product withstands strong impacts without warping or peeling.

3. Conclusion

Core is an irreplaceable factor that determines the quality of plywood.From the core – which shapes the basic properties – to the adhesive, the element that provides a strong bond and additional features, everything needs to be carefully selected and processed to create a product that meets the highest standards.

Understanding the core not only helps you accurately assess the quality of plywood but also assists in selecting the right product for your usage needs, if you want to find high-quality plywood products, please contact AMC Vietnam for consultation and to receive the best products for all applications.