Plywood Machine

How Plywood are Made?

The eucalyptus middle board is sent to the sorting area, and the core board, front panel and back board of each grade are selected according to the size, material standard and processing quality, and the qualified products are sent to the drying area to be dried by a drying machine to make it A certain moisture content meets the requirements of the gluing process. The dried middle board is sent to the jigsaw area, and the narrow and long middle board is spliced into a whole middle board or the short middle board is spliced into a long middle board with a middle board jigsaw machine. After drying, a considerable part of the middle plate has material and processing defects, such as knots, insect holes, cracks, etc., and must be sent to the finishing area for repairs to improve the grade of this part of the middle plate. Some defects in the middle plate cannot be improved even after repairing. , then remove the defect, reduce the size of the middle plate or change it to a core plate.After drying and sorting, a certain amount of glue is evenly coated on the surface of the board by a glue machine, and the face, back board and glued core board are combined into a board blank. After a period of aging and placement, it is The cold press is pre-pressed to make the veneers bond together, and the hot press is used for gluing in the heart-cutting area and in the hot pressing area. Due to the influence of raw material quality, operation level and equipment precision, some surface defects will appear in the plywood glued by hot pressing: 1) cracks; 2) degumming at edges and corners; 3) bubbles in the glue layer; 4) shedding knot holes; 5) The surface of the board is partially not smooth, and must be greasy, polished and repaired.There are different degrees of thickness deviation in the plywood after hot pressing, and there are many defects on the surface of the board, such as tape strips, stains, groove marks, etc., so the plywood should be sent to the sanding area for sanding treatment with a sanding machine . After the sanding treatment, the plywood enters the trimming area and is sawed by an edge sawing machine into finished products that meet the specifications and sizes. Then the finished products are inspected, graded, polished and repaired, and finally packed and entered into the finished product warehouse.

What is Plywood?

Plywood is made of three or more thin layers of wood bonded together with an adhesive. Each layer of wood, or ply, is usually oriented with its grain running at right angles to the adjacent layer in order to reduce the shrinkage and improve the strength of the finished piece. Most plywood is pressed into large, flat sheets used in building construction.

In general, Its standard size is 4feet*8feet (1220mm*2440mm), also some people produce the special size according to their markets.

Raw Materials:

The center layers are known as the veneer core. In plywoods with five or more plies, the inter-mediate layers are known as the crossbands. The outer layers of plywood is face veneer, and some will laminating melamine.

Plywood can made from hardwoods, and softwoods, or a combination of the two. Some common hardwoods include birch, beech, acacia wood, mahogany, oak, and teak. The softwood used to make plywood is poplar, pine and others.

The adhesive type used to bond the layers of wood veneer together depends on the specific application for the finished plywood.

Plywood Application:

Plywood has construction plywood, furniture plywood, marine plywood, some mainly used for building construction, some used for inner decoration, some use for packing.

Plywood Size:

The thickness range of Plywood board from 18 mm to 100 mm, some may produe 18mm, this is one common thickness, some may produce 30mm, 60mm, or more. Their application will be different. Although the core, the crossbands, and the face and back of a sheet of plywood may be made of different thickness veneers, the thickness of each must balance around the center. That can make sure the plywood quality is good.

The common size of plywood board usually is 4 ft (1.2 m) wide by 8 ft (2.4 m) long. Also some special size like the width 1700mm.

The Manufacturing Process:

Logs/Tree/Wood/Timber:

As i know, many plywood factory, they will plant trees by themselves, that can offer themselves logs, save cost, and protect the environment, this is a good idea. Or some will buy logs from local market or import wood, and different markets will use different logs, some use beech, some use birch, some acacia wood, some use albasia.

Wood Debarker& Veneer Peeling Machine & Veneer Stacker:

Through log debarker to remove wood bark, then offer to veneer peeling machine. Before start peeling, the blocks usually will be heated and soaked to soften the wood. The blocks may be steamed or immersed in hot water. This will be easier for veneer peeling machine working.

Then the heated blocks/logs are transported to the peeler lathe machine, where they are automatically aligned and fed into the lathe one at a time. The max speed of veneer lathe machine can be 80m/min, it is fast and high efficiency, and with the diameter become small, veneer peeling machine’s speed will become faster. And you can adjust veneer thickness and width through cnc screen, very convenient. the max log diameter can be 600mm, the remaining piece of wood, known as the peeler core, is ejected from the lathe and a new peeler block is fed into place.

The veneer peeling lathe has different size, if your max log length is 1300mm, then choose the 4feet veneer peeling machine are enough, if your max log length is 2600mm, then choose the 8feet veneer slicing machine is good, if your log length is longer, also no problem, because the factory can customize veneer machine.

The sections of veneer are then sorted and stacked according to grade. This may be done manually, or it may be done automatically using vacuum veneer stacker, using this machine will save two labors and improve work efficiency.

Veneer Drying Machine: 

The sorted sections are fed into a dryer to reduce their moisture content and allow them to shrink before they are glued together. Because after produced by veneer peeling machine, the veneer humidity are higher , some may 30%-40%, some may 70%, it is not suitable for making plywood, so need drying wood veneer. Most plywood mills use a mechanical dryer in which the pieces move continuously through a heated chamber. Veneer dryer machine has three types, they are veneer press dryer, veneer roller dryer and face veneer mesh dryer, according to your factory room, production capacity, veneer thickness, then choose the better and suitable one.

Glue spreader:

Coating glue on the surface of wood veneer by glue spreader, then assembled for a particular run of plywood, gluing the pieces together. The short sections of core veneer are then laid crossways on top of the glued back, and the whole sheet is run through the glue spreader a second time. Finally, the face veneer is laid on top of the glued core, and the sheet is stacked with other sheets waiting to go into the press.

Plywood Cold Press machine  & plywood Hot Press machine:

the glued plywood sheets are loaded first into cold press machine, its max opening is 1800mm, pressure can be 400t 500t 600t, then enter into hot press machine, hot press machine pressure can be 500t, 600t, 800t, 1000t, 1200t or bigger, and it can be 10daylights, 12daylights, 15daylights, 20daylights, 25daylights. the press machine squeezes plywood together under a pressure, while at the same time heating them to a temperature of about 109.9-150 C. The pressure assures good contact between the layers of veneer, and the heat causes the glue to cure properly for maximum strength. After a period of 10 minutes, the press is opened and the sheets are unloaded. Through this step, plywood become strong and good shape.

Plywood Edge Trimming Machine  & Plywood Sanding Machine:

The rough plywood sheets then pass through the plywood edge cutting saw machine, which trim them to their final width and length. The plywood saw machine be guide by infrared, and be controlled by micro-computer, automatic sawing and stacking plywood, very convenient.

The last step, sanding both sides of plywood by sanding machine. Because some place’s thickness are different in one piece plywood, so through sanding machine, their thickness will become accurate and balance, and at the same time, the surface of plywood will become smooth and bright.

The finished sheets are stamped with a grade-trademark that gives the buyer information about the exposure rating, grade, mill number, and other factors. Sheets of the same grade-trademark are strapped together in stacks and moved to the warehouse to await shipment.

Until now, the whole plywood manufacturing process has finished. Believe you have know clearly that how to produce plywood, and what kinds of plywood machine you need.

Our factory is China professional manufacturer of plywood machine and veneer machine with many years, with advanced technology, professonal engineers and workers, good sales team, we have ability and sincere offer you good and suitable plywood machine.