One-Step ,Two-step,Three-step Plywood Production Inspection
According to the traditional Plywood production in China ,explain some personal ideas and history of the plywood production :
One-step Plywood production : Veneer core platform and face veneers or films are hot pressed Simultaneously .At the same time ,after the veneer core lay-up and cold pressing ,then will Simultaneous put the face veneers or film on the cold pressed platform ,then Simultaneously put into the hot pressing plates and make the hot pressing together at the same time .In the plywood industry ,also called one time hot pressing plywood .
Advantages : manufacturing costs less
Disvantages : NO sanding ,no veneer core platform repairing and putty ,more manufacturing defects ,thickness are not even and thickness tolearance are big ,not smoothly .
Two-Step Plywood production : Veneer core platform lay-up finished,then put into the cold pressing lines and make prepressing to form the platform . After conditioning and cold pressing ,repair the surface core veneer overlaps and core voids .Then put the repaired platform to hot pressing production lines to solid the platform , after hot pressing ,the veneer core platform are already finished glue curing ,already solid .Then smoothly sanded the surface of the platform ,and repair again .After all the surface cleaning and repairing ,put the face veneer and film on the platform ,make the platform and film or face veneer Simultaneously in the hot pressing lines .We called it two times hot pressing plywood production also .
Three-Step Plywood production :1220x2440x18mm 11 Plies For example , Production sequence and steps:
- 9 Plies Veneer core platform cold pressing ,normally this 9-ply veneer core are long grain ,the top and bottom layer of core veneer are long grain normally 4 pieces crossband veneer Parallel with the wood grain .
2. 9plies Platform repairing
3.9Plies Platform Hot pressing
4.9Plies Platform repairing and sanding ,repairing
5. Last 2 plies of short grain core veneer are laminated on the top and bottom of the 9-ply hot pressed platform ,
6.then repairing ,cold pressing ,hot pressing again .
9.Smoothly calibrated sanding
10.Put the film or face veneer and then Simultaneously make the film or face veneer and platform hot pressed at the same time .
We also called three times hot pressed plywood .
Advantage : Have a good thickness tolerance control ,flatness and smoothness ,less manufacturing defects .
Disvantage : more manufacturing costs