The creation of veneer is the most economical method of producing high quality wood and wooden images shown in the product.

The new technology may allow use of industrial wood plantation timber , wooden materials that were previously considered too small diameter wood for plywood production .

Technology laminated board production is basically based on technologies typically produce plywood . Plywood is made from layers of wood ( veneer ) bonded together by adhesives adhesive ( glue ) . This type of material is characterized by its ability to be designed and constructed for applications in construction or decoration , straight or curved shape . Plywood made ​​from common broadleaf wood used for decorative purposes . Plywood made ​​from coniferous wood ( coniferous ) is commonly used for building and structures .

Manufacturing process technologies laminated plywood covers the following 5 stages :

1 . Logs are peeled and cut to length required

2 . Logs are peeled veneer to create

3 . Dried thin chipboard and classification

4 . Thin chipboard coated with glue and be arranged to achieve the required thickness and heat press board

5 . Laminated plywood cut to the size required by customers

2 . Thin board production

2.1 Preparation of the cutting

Thin chipboard and veneer products are used to create the wood from broad-leaved and coniferous wood . Quality raw material for the production of wood veneer is evaluated based on the specific requirements of timber size , the quality , the mode of transport , storage and timber glass .

To meet these requirements by todays standards , veneer surface should appear at fault , uniform color and uniform structure . The thorough assessment and accurate quality logs is very important basis to achieve good quality veneer in the later stages of processing . The evaluation criteria allow the quality of the wood determines the kind of wood suitable for veneer production . The main characteristics of wood are considered as follows :

Geometrical parameters

Diameter wood materials directly affect the rate of utilization of timber and labor productivity . The smallest diameter of the wood used in the manufacture of plywood is often cultivated 18cm . For games not religious diameter smaller timber permitted

+ The taper as small as possible

+ Curvature as small as possible

+ The big and round as evenly as possible

Peeled and sliced ​​properties ( density , the cross grain , knots )

 + Afternoon grain : Wood grain as straight as possible . While there will be surface shape beautiful game

+ Wood Eye not affect the quality of the veneer , veneer margins , but also quality plywood affect stripping knife . If large eye diameter , set trurng veneer margins very low . Dry eyes after death can also become clear eyes . Despite the clear eyes , the eyes after death or while processing this veneer is very difficult . This work not only costly but also to reduce the intensity of veneer and plywood strength also decreases with

The characteristic use or display ( colors , images , structure , year round , woody )

+ Wood had no or little sense to distinguish core

 In wood technology peeled and sliced ​​, chunks of wood billets are usually heated in water bath or hot steamed to soften the wood , creating favorable conditions for the removal , veneered wood and veneer improve quality produce . The process of cooking and heating are varied , depending on wood density , size and plan the cutting heating plant . Temperature is often used as 50 - 90oC , heating time 25 - 36gio . However, some wood species have high density should be heated for several days .

But in fact the current board production stripping parts omitted for the sake of softening stage of stripping the wood boards when fresh , high humidity and relatively easy to peel board . The fresh peeled plywood will save energy and time to create veneer . However, if no softening stage design wood in plywood manufacturing processes may lead to some adverse follows :

- Not all the sources of fresh wood humidity necessary to peel board .

- Wood humidity low to defendant , when wrapped will increase the frequency of cracks , reducing the intensity as well as increasing veneer veneer crumbled rate

 - The local stresses in woody nature has not been offset by the softening temperature of wood , will cause tearing when peeled and sliced ​​veneer board

2.3 Production technology veneer

Peel board : board removal technology traditionally used large-diameter timber exploitation . However, due to the development of equipment and production technology , small diameter timber plantations have been used economically .

The machine has no religious or machine peeled peeled peeled center allows smaller diameter wood boards to strip religious traditions use ( husk clamp ) . However, the use of non- religious peeled drawback is also uncertainty about the thickness of veneer can be high due to the centerline position round logs and peeling knife is not high stability due to :

+ Movement of the cutting surface of the embryo depends on the timber, roundness , taper level , tumor extent and wood surface defect

+ The conditioning of the moving roller guide difficult

+ Stability of the cutting motion depends on the volume of wood embryo

Lang Lang and half- round game : In this technology , the raw material requirements are more focused in terms of the value of the final product . The special section corner wood , original , poetic images brought wood and wood colors suitable for decorative purposes .

2.4 Drying veneer

Veneer was created after peeling , slicing the usual high humidity and not suitable for coating glue . So veneer should be dried to less than 12 % moisture . This is the humidity level compatible with the glue and coated in accordance with the moisture content of plywood used .

There are many methods of drying veneer . Drying is the most common type of chamber is equipped with a long roller conveyor that help thin plank along the drying chamber . Heating and fan systems are arranged along the drying chamber to control temperature and humidity .

Most of veneer drying high temperature ( over 100 ° C ) using a heat source from steam heating systems . Heat is transferred to the air by heat exchange system . The drying system uses oil and gas are increasingly common in industry .

Here is a conveyor chamber model :

Because many boards tend to be thin wrinkled after drying for different surface densities on board , the thin boards that need to be flattened by the more pressing . Today pressed dryer has been developed with the ability to just pressed , just dried veneer .

2.5 Crop

After drying , veneer cropped size required to sell or plywood .

By truncating , errors on the part of veneer are also eliminated .

The veneer sheets are cut to size and are each set in sets 24-32 sheets

2.6 Selection and classification

During the manufacturing process , veneer can be classified according to the quality requirements for each use as follows :

- Quality of interior architecture

- Quality bedroom

- Quality of room

- Quality boards

- Quality Door

- Quality Wood

The quality systems that vary depending on the particular standards were created by each manufacturer in length , size and quality . The sub- classification can also vary in each level quality standards .

2.7 Quantification

Each episode veneer can be transported through the scanning and measuring devices to determine the length , number of panels , veneer and area .

2.8 Storage

- Dried thin chipboard should be stored in the warehouse temperature and humidity changes

- The veneer should be kept in place not exposed directly to the sun

2.9 Sewing and veneer

The veneer pieces can be paired together in the next game to make larger size panels and veneer pictures upon request . The addition of this link can be done by sewing machine with zipper side boards follow a zigzag path .

2:10 Jigsaw

Art jigsaw is made to recreate the image marbling of wood in a natural style or certain visual effects for decoration purposes . Here are some types of veneer puzzle :

Puzzle books

Random puzzle

Pair still

Square jigsaw

3 . Plywood production

3.1 Requirements for plywood

Standard plywood : plywood is typically used in indoor conditions , and is not suitable for outdoor purposes in a long time .

Moisture resistant plywood : Should be used for indoor applications where the demands are resistant to high humidity or occasional exposure to water .

Laminated plywood , used for products bearing size and high stability . Laminated plywood for the floor and bulkhead vessels also require high moisture resistant and durable outdoor conditions .

Rinse 3.2 adhesive

3.2.1 The plywood glue

The selection of adhesives for plywood production based on many factors such as price , structural work , moisture , temperature response requirements , contact fire , etc. ... The main type of glue commonly used in industry plywood include: ( 1 ) protein and ( 2 ) phenol - formaldehyde ( PF ) and urea - formaldehyde ( UF )

Adhesive proteins are created from plants and animals with the main ingredient is water , dried blood , bean flour , lemon , Na2SiO3 ( sodium silicate ) , sodium hydroxide ( caustic soda ) . Urea - formaldehyde glue that glues thermosetting composite with the main ingredient is water , foam reducing agents , fillers ( flour ) and urea - formaldehyde resin . Phenol - formaldehyde resin is also used as a thermosetting adhesive composite with the main components include the additive sodium hydroxide ( caustic soda ) and Na2CO3 ( soda ash ) .

Protein and urea - formaldehyde glue can be used only for indoor conditions ( not water-resistant glue ) , while phenol - formaldehyde glue is used for outdoor purposes ( waterproof glue ) .

In addition, Melamine Urea formaldehyde glue is kind of glue is used to denature the glue application with associated moisture and create bonds with brightly colored glue .

3.2.2 Rinse glue

Veneer surfaces should be flat and not subject to internal tension to ensure the glue is spread evenly over the surface and glued quality assurance .

The adhesive composition should be mixed carefully and strictly follow the manufacturers instructions

The amount of glue mix ingredients for each batch fact should be recorded as a basis for quality assessment after plywood .

The viscosity of the adhesive mixture should be determined to ensure strict accordance with the manufacturers requirements glue .

The amount of glue spread on the surface is glued critical parameters for process veneered boards , should be controlled within the limits required by the manufacturer and should be recorded at least once every working day

Surfaces coated with glue before veneer needs to be cleaned to avoid dust , oil , grease or sweat .

Due to the symmetry of plywood , so the use of glue should be balanced with the thin planks of plywood radial symmetry .

Glue coating machine is the most commonly used machines including two roller guide combined with glue to the surface coated veneer .

Dry content and viscosity of glue is the deciding factor to quantify quality as well as glue for veneer coated

3.4 Injection plywood

Depending on the type of glue is used , cold pressed or hot-pressed plywood will apply

When heat pressed boards , the most important factor to be considered is the moisture content of the veneer , the glue water , temperature , pressure and time presses .

In the process of plywood , both temperature and pressing time should be monitored and strictly controlled . Need to ensure adequate moisture in the game time needed to be liberated and curing glue , plywood ensure no blisters or explosion . When the greater thickness of plywood , the control elements as plywood technology requires rigorous optimization and control . For phenol formaldehyde glue , minimum temperature 120oC pressing need to ensure curing glue required .

The type of timber with a volume requires different time and different presses

The surface of the plywood table should be cleaned to avoid dirt and dust on the surface sticky boards after pressing

The surface cleaning of the presser foot so the quality is not acid .

3.5 The common problem when football cup game 

Many factors led to the separation bubble game after heat press , basically 3 main factors is the use of glue , plywood and process parameters veneer inappropriate :

- The mixed adhesive should be taken strictly as directed

- Coated with glue residue can lead to excess moisture in the heat press board

- White glue deficiency can lead to missing links in some parts glue in plywood

- High humidity veneer creates steam while plywood is too high , can cause blistering game

- Standby time pressed too long can cause hardening glue plywood before

- Sai doing some big boards thickness plywood quality is uneven , so the maximum is 0.1 mm

- Time is too short squeeze makes no glue cured .

3.6 Equilibrium and stability plywood

After heat press , plywood should be kept in standard environmental conditions in a certain period of time . This is the amount of time required for the curing of the glue boards are fully implemented . Moreover humidity of the game are well balanced .

Plywood should be kept in environmental conditions so that the moisture balance of the game ( EMC ) was about 10 % . EMC is board should be maintained until the plywood sanding and finishing .

3.7 Celebrities and cut plywood

The sanding boards should be controlled within limits to avoid sanding the edges , and the top surface of the plywood . If the board surface was causing too much sanding thin veneer surface reduces the bearing capacity of the surface boards .

There are many types of sanding machines are used for sanding plywood , popular machine types are identified by

Updated as sanding , cutting edge plywood in accordance with the order size and should be stored in warehouses with controlled conditions of humidity and air circulation

3.8 Complete plywood

This is an important step commonly required by different customers depending on the intended use as surface error and remove jewelry surface ,

4 . Checking quality plywood

Production technology and plywood products should be inspected according to the requirements of quality standards and technical expertise . The audit covers issues using glue , preparation and processing of materials , the moisture content of veneer , laminated pressure conditions , processes and quality plywood glued plywood of the end product together .