How is Plywood Manufactured Step by Step From Raw Wood

Plywood is a versatile composite building material, and we prepare it from thin layers of wood veneers glued together.

Although manufacturing plywood is a lengthy and time-consuming process, we can’t neglect its importance because Its manufacturing has positively impacted the economy, environment, and society and provides a durable and cost-effective wood.

We use it in construction, furniture, and various other woodwork.

 

Therefore, in this article, I will describe how is plywood manufactured step by step.

But always remember, the purpose of this article is only to understand the manufacturing process.

So, keep reading.

 

How is Plywood Manufactured Step by Step From Raw Wood

Types of Plywood

1. Softwood Plywood
2. Hardwood Plywood
3. Tropical Plywood
4. Aircraft Plywood
5. Decorative Plywood
6. Flexible Plywood
7. Marine Plywood
8. Structural Plywood
9. Exterior Plywood
10. Fire-Resistant Plywood
11. Moisture Resistant Plywood
12. Overlaid Plywood

Note: I have described all the types of plywood in another article How many types of plywood.

Plywood Manufacturing Process

1. Selection of Raw Material
2. Moisture Maintenance
3. Log Preparation
4. Cutting the Logs
5. Peeling the Veneers
6. Storing and Grading
7. Veneer Drying
8. Gluing the Veneers
9. Pressing and Bonding
10. Trimming and Sanding

1- Selection of Raw Materials

The journey of quality plywood begins with the selection of suitable raw materials. Hardwood and softwood logs are carefully chosen based on their grain patterns and moisture content.

We choose to cut the trees when they reach their acceptable maturity level.

The cutting process should done by trained harvesters. And transport the logs to the required place.

 

2- Moisture Maintenance

Moisture maintenance is a very important step in making standard plywood. For this purpose, we use different methods like water sprinkler systems or log pond systems.

Mostly, we use the second method and submerge the wood logs into the pond.

It will make it easy to cut down to size and peel.

In cold weather, we use hydro-thermal processing to complete this process. It consists of hot water to dip the logs.

Note: After moisture maintenance, all next processes will be done on industrial machines to continue along the production line. All the procedures are connected with each one.

3- Log Preparation

The loader will pick up logs from the log decks and place them on the chain conveyor to transport toward the debarking machine.

The debarking machine will rotate the wood log along its long axis to remove the bark with the help of grinding wheels with sharp teeth.

 

4- Cutting the Logs

The debarked logs will be transferred into the mill using a chain conveyor. The next process will be started when it is reached in the related section. The debarked logs will be cut into pieces using a massive circular saw to produce standard-length sheets.

 

5- Peeling the Veneers

After cutting, the logs will move automatically, one by one, to the veneer peeling process. In this step, a rotating lathe blade carefully peels the logs into thin layers known as veneers. These veneers’ thickness depends on the plywood’s intended final thickness.

 

6- Sorting and Grading

As the sheets emerge from the peeler, they are immediately scanned, and veneers are then sorted and graded based on their quality. This sorting process will identify the defects, such as knots or irregularities, to categorize them according to quality.

Higher-quality veneers are typically used for the core layers, while lower-grade ones are employed for the outer layers.

 

7- Veneer Drying

We had started the plywood-making process from the soaked logs. After making veneers, they are still wet.

So, we must dry the veneers because the wet veneers can be affected by fungal attacks. And it will damage the final quality of the plywood.

For huge quantities of veneers, industrial dryers are suitable.

 

8- Gluing the Veneers

Veneers move forward through the gluing machine. The gluing devices have spray guns that essentially roll the glue onto the face and back of the veneer. When the sheet passes through, the glue will be spread evenly on the back and face of the veneer.

The glued veneer is placed on top of the unglued veneer, then followed by the glued veneer. All the sheets together make the plywood. Glue consists of phenol formaldehyde and urea formaldehyde.

 

9- Pressing and Bonding

In this process, we apply pressure on the glued veneers. Pressing has two different ways.

• Cold press
• Heat press

The glued veneers are assembled into a stack with alternating grain directions for increased strength. Cold pressing prepares the veneers for hot pressing and also helps to flatten the veneers to ensure that the glue has been applied uniformly across the veneers.

Then, the stack is placed in a hydraulic press, and heat and pressure are applied. For a sturdy and stable plywood sheet, the machine applies hot pressure for a long time to create a strong bond between the veneer layers.

Additionally, the adhesive layer’s thickness is reduced.

 

10- Trimming and Sanding

After the pressing, the final inspection will be started. If any side and corner of the plywood find extra pieces. it will be trimmed using a cutter. For smooth and uniform texture, the sheets will be sanded. This whole process not only enhances the aesthetic appeal but also improves its quality.

 

Conclusion

The whole plywood manufacturing process is very complicated and a multi-step struggle that transforms carefully every selected log into versatile and reliable panels.

From the initial log preparation to the final finishing touches, each phase contributes to the overall quality and durability of the plywood.

Plywood sheets have become very popular in every constructive project because it has many positive attributes, like their eco-friendliness, strength, and versatility, making them a favored choice in numerous applications.

I am confident that this article was very helpful to you and that you learned a lot more.

Thank you for your time.

Best Wishes

 

Frequently Asked Questions

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