5*8FT Heavy Type NC. Spindleless Veneer Lathe machine

Preparing wood segments for peeling

In order to make high-quality veneer, improve the veneer output rate and the productivity of the rotary cutter, the logs after entering the factory need to undergo processes such as sawing, heat treatment, peeling and wood section centering.

Plywood production requirements for logs

Log length

Log lengths are 4, 5, 6m and length tolerances are +6, -2cm.

According to the plywood specifications and quality requirements, the logs are cut into the required wood segments. At the same time, according to the defects of the logs, a reasonable sawing position should be determined to ensure the quality of the veneer and obtain the maximum utilization rate.

Log size

The log diameter directly affects the yield and labor productivity of plywood.

Yield;

The national standard stipulates that the minimum diameter of plywood is 26cm, and the diameter of the inspection ruler is advanced by 2cm.

The diameter of artificial fast-growing forest logs tends to be smaller.

Consider a chuckless rotary cutter to reduce the core diameter

(5mm, the diameter of the wood core of the rotary cutter with a card axis is generally 10mm)

Log quality

Log quality (first and second-class logs)

According to the defect type and size of the log itself, defects are roughly divided into two categories:

One is that it affects the yield of plywood: log bending, greater sharpness, mechanical damage, ring end cracks, scars, hollow rot

heart, etc.;

One is that it affects the quality of plywood: oblique texture, knots, swirls, discoloration, etc.

Raw wood

Influence of wood structure on plywood production

Annual rings: Ring-porous wood rotary cut veneer has a beautiful texture, but it is easy to penetrate the glue:

The loose-porous material rotary cut veneer is homogeneous and smooth, the organization is uniform and dense, and can be rotated

Thinly sliced veneer.

Heartwood and sapwood: The difference between heartwood and sapwood is obvious, its moisture content, wood

There are differences in hardness and expansion and contraction.

The pressure production process has an impact.

Wood rays: can increase the appearance of the veneer, but affect the bonding strength.

Effects of physical and mechanical properties of wood on plywood production

There is a little emphasis on the selection of rotary cutting tools. Too hard wood will cause great damage to the rotary cutter, and it is easy to crack during processing. The back of the veneer has large cracks:

When the wood is too soft, the veneer is easy to fluff when it is peeled, and the board surface is not smooth.

Effects of wood chemical properties on plywood production

The acid-base properties of wood (extracts) and buffer capacity are formulated

The plywood processing technology is meaningful and is closely related to veneer gluing and wood discoloration.

Judgment standard

Cutting performance and shrinkage; gluing properties of wood; economic benefits.

Conditions that should be met for the production of plywood species:

Able to unscrew a flat and smooth veneer;

Have a certain bonding strength;

Warpage deformation after drying is not serious: good material and few defects;

There is a certain amount of accumulation.

Main Parameter