A crate is a large container used to transport or store items. The majority of crating materials are made of wood, although they can be of plastic or metals. A wooden crate is a self-supporting structure that may have wood sheathing covering it.
Crates have gained popularity because they allow fragile and valuable goods to be moved with ease and safety. They protect the items inside with their sturdy walls and are preferred when moving bulk items because they are easy to handle using lifting machinery like forklifts. The added benefit that crates offer is that they are often reusable.
All wooden crates are made of lumber and have a sheathing of plywood or OSB (Oriented Strand Board).
Whichever method is used, the considerations in crate manufacturing are as follows:
Easy to handle: Crates must be easy to handle as sometimes used to transport heavy goods. The crate design should be strong enough and allow forklifts and pallet jacks to move quickly, even if large or heavy.
Protection: This is the most important reason for using crates, and they should protect goods to prevent damage.
Jigging: A crate can be custom to make partitions for the various items to store or transport.
Features of a durable wooden crate
A well designed wooden crate meets the following criteria:
Appropriate labeling: A well-thought crate should have warnings and directional arrows.
Cargo fasteners: It should have latch closures or screws to fasten goods in the crate.
Skids: Skids keep the crate off the ground and prevent damage. Skids enable easy handling of crating material by machines, especially when the cargo is heavy and cannot be lifted off the ground by hands.
Handles: Handles fastened at a point where it is easy to lift the crate.
Crates using Plywood
Crates that are made from plywood (veneers of wood that are glued together with grains in a perpendicular direction in alternating layers) are becoming popular in crate manufacture because it contains low moisture content, making plywood convenient for outdoor uses.
Popular plywood types used in making crates are:
Softwood plywood: It comes from softwood plants like spruce and pine.
Hardwood plywood: It is made from hardwood plants and is known for its hardness, firmness, resistance quality, and inflexibility. It can bear heavyweight.
Tropical plywood: Tropical hardwood comes from a mixture of timbers from the tropics, and its qualities include evenness, strength, density, and thickness.
Decorative plywood: Also called overlaid plywood, and comes from woods of ash, oak, birch, mahogany, and maple.
Marine plywood: Marine hardwood is suitable in humid, moist, and wet places. It has small core gaps that do not allow the wood to trap water and is fungal resistant.
Plywood making process
The process of making good plywood to enable one to have strong crates follows several steps as follows;
Log selection: A log cut from a selected tree depending on the plywood required to make the crate. The chosen tree log is called a peeler, and it should have a large number of layers.
Layer formation: The peeler is cut into pieces to make sheets of veneer.
Heating: The sheets are heated to remove water.
Gluing: The dry sheets are glued together, patched, and then graded. Formaldehyde and urea-formaldehyde are used for gluing, while Furmecyclox prevents fungal attacks.
Baking: The glued plywood sheets are baked at a minimum temperature of 140 degrees Celsius and pressed at 1.9 MegaPascals.
Finishing: Any defects on the plywood removed. Pits, holes, and untrimmed edges are polished to make the final plywood. The plywood is then reshaped and cut into the required sizes.
Pros of plywood
Pros of using Plywood for crates:
- Cross graining inside the plywood prevents the split of the edges when nailed, makes the plywood stronger, and prevents unnecessary expansion and wood shrinkage. The board remains firm in all directions.
- The plywood cannot bend because of an odd number of plies that maintain balance inside the plywood.
Cons of using Plywood for making crates:
Plywood has several disadvantages that may keep it from being ideal in some situations:
- Phenol formaldehyde and urea used are known to cause cancer and are therefore harmful to human health.
- Plywood is not durable and strong like solid wood.
- Plywood can be attacked by insects after a long period and require resistance methods.
- Plywood gets destroyed on exposure to moisture or wet conditions for long periods.
OSB (Oriented Strand Board)
OSB differs from other plywood products because it has long strips of wood that are placed with its grain in many different directions instead of having different layers in alternating directions.
Making OSB
OSB making begins with the selection of a log which is then cut into strands. The strands are dried, organized, and treated with binders and wax. The strands are then grouped into big sheets and pressurized at high temperatures to form panels. The finished OSB board is certified for durability, strength, and uniformity. The panels are then cut into various sizes, and sometimes at different sizes based on customer requests.
Pros of using OSB for making crates:
Many crate manufacturers are choosing OSB sheathing over plywood because of the lower cost and higher strength.
The reasons why oriented strand board is overtaking plywood in the manufacture of crates include the following:
OSB features: OSB panels and boards can be custom ordered from the mill, unlike plywood. They have smoother surfaces, and nail lines are marked. Therefore the installation of OSB panels is more efficient and faster when joining to create crates. OSB panels do not experience cupping that is evident in plywood.
OSB board size selection: Custom-built boards are available on order to customers.
OSB composition: Most OSB boards come from fast-growing trees, therefore eco-friendly. On rare occasions are hardwood trees used to make OSB panels and boards.
Protection against the weather: Unsealed OSB boards may swell and warp. However, they shrink less than plywood boards when exposed to similar moisture content.
Cheaper than plywood: OSB boards and panels are less costly to manufacture and hence more affordable on the market when compared to plywood boards. See our article on The state of the OSB market in 2021
Cons of OSB in the crate making
Appearance: This one is debatable, but some people think that OSB boards do not look nice.
Health risks: OSB is manufactured using formaldehyde which is a poisonous chemical.
Heavy: It can be bulky than plywood, especially when several panels have to be used to make the crate.
Conclusion
There are many factors that will go in to choosing one type of wood over another, some of those factors are:
- Cost
- Strength
- Moisture resistance
If you're a crate manufacture contact Silvaris today to discuss your plywood or OSB needs while improving your bottom line through our bulk lumber distribution channels.
