chapter 16 processes used to form woodmaterials. objectives two basic wood forming processes:...
TRANSCRIPT
![Page 1: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/1.jpg)
Chapter 16
Processes Used to Form WoodMaterials
![Page 2: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/2.jpg)
Objectives
• Two basic wood forming processes: bonding and bending.
• Composition boards: hardboard, insulation board, and particleboard.
• Particleboards: wood pieces and resin binder.• Engineered wood material: reconstituted
wood.• Plasticizing wood: steam or soaking.
![Page 3: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/3.jpg)
Bonding Processes• Bonding processes use heat and pressure to compact particles into sheet stock in
the production of wood composite board.• Composition boards: 3 major types – hardboard, insulation board, and
particleboard.• Hardboard: has high tensile strength, high density, and low water absorption.• Insulation board: manufactured using pulp wood and bagasse (sugarcane). Water
and chemicals are added to turn the fibers into a continuous mat. The mats are fed into a drier , then cut and trimmed to size in sheets.
• Particleboard: is a panel material composed of small discrete pieces of wood bonded together in the presence of heat and pressure by an external binder. About 40% of the particleboard used today is purchased by the construction industry for flooring underlayment. Most of the remaining 60% is used as core material by the furniture industry.
![Page 4: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/4.jpg)
Lamination Process
• Lamination is used extensively for the construction of plywood.
• It involves sandwiching sheets of wood together to form larger pieces.
• Veneer is thin sheets cut from expensive wood.• These sheets are used as the exposed layer that is
glued over a core of less expensive wood.
![Page 5: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/5.jpg)
Plywood
• Plywood is made by gluing a number of layers together at right angles to each other.
• ANSI (American National Standards Institute) standards specify the species, strength, type of adhesive, and appearance of plywood.
• Lamination produces much stronger product than solid stock.• Bending: Steaming or soaking is a better way to bend wood.
The stock is subjected to steam or soaked in boiling water till the moisture content reaches 20%. It is then placed in a forming jig that conforms to the desired shape. It is kept in that position till it cools and dries.
![Page 6: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/6.jpg)
Summary• Bonding processes use heat and pressure to compact particles into sheet
stock in the production of wood composite board.• Composition boards: 3 major types – hardboard, insulation board, and
particleboard.• About 40% of the particleboard used today is purchased by the
construction industry for flooring underlayment. Most of the remaining 60% is used as core material by the furniture industry.
• Veneer is thin sheets cut from expensive wood.• These sheets are used as the exposed layer that is glued over a core of
less expensive wood.• Lamination produces much stronger product than solid stock.• Bending: Steaming or soaking is a better way to bend wood.
![Page 7: Chapter 16 Processes Used to Form WoodMaterials. Objectives Two basic wood forming processes: bonding and bending. Composition boards: hardboard, insulation](https://reader036.vdocuments.us/reader036/viewer/2022082417/56649da35503460f94a903ec/html5/thumbnails/7.jpg)
Home Work
• 1. What are the 3 major types of composition boards?
• 2. What is veneer and where is it used?• 3. What is the advantage of lamination?