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Bamboo plastic sheet process characteristics
- May 21, 2018 -

It is composed of a grooved thick and thick piece of bamboo glued together as a structural unit. The bamboo piece is prepared by screed planing. The “high temperature softening and squeezing of bamboo material” is the technical feature of the product. Bamboo plywood can be used as a common structural plate, but also can be used as a car floor through plate length and surface treatment.

Process characteristics

1. Preparation of grooved thick bamboo pieces

Bamboo glue board

Bamboo glue board

The large-diameter bamboos are cross-sectioned into bamboo segments, and the outer segments are milled into longitudinal segments of 2-4 blocks. The inner segments are then milled and steamed, softened, and then heated and pressurized on a single-ply flat-top press. Shaped bamboo expands into a plane. Finally, it is processed into a thick and thin bamboo piece without bamboo and bamboo yellow by double-faced planer.

2, set dry

In order to prevent the bamboo pieces from drying during the drying process, the flat bamboo pieces should be curled and deformed under the action of the lateral elastic restoring force, and the pressure drying process and equipment must be used to heat the wet bamboo pieces under pressure and remove them when the pressure is relieved. Moisture and free shrinkage.

3, bamboo sizing

A four-roller coating machine was used to apply a water-soluble phenolic resin glue to the bamboo roller. The amount of glue applied was 300-350 g/m2 (both sides). Adhesives can be added with 1% - 3% flour, soy flour, etc. as fillers. The filler can make the bamboo film easily form a film on the surface after the glue is applied, and it is not easy to produce the flow glue phenomenon during the hot pressing. After the curing, the brittleness of the glue layer can be improved.

4, group blank

The use of manual assembly, in strict accordance with the principle of symmetry, the principle of odd-numbered layers and the principle of adjacent layers of bamboo texture are perpendicular to each other. Requires the panel to use a good bamboo material, the material of the bamboo as the back plate. The bamboo surface of the surface and backboard is facing outward and the bamboo yellow is facing inward; when the core board is formed, the orientation of adjacent bamboo pieces is required to be alternately arranged according to bamboo green surface and bamboo yellow surface.

5, pre-pressing and hot pressing

(1) Preloading In order to prevent displacement of the slab caused by displacement of the slab into the hot press, defects such as stacked cores and detached seams are to be pre-pressed at room temperature before being hot-pressed in the slab. Synthesize a whole material.

(2) Hot pressing A hot-hot gluing process is adopted. The hot-pressing temperature is about 140oC, the unit pressure is 2.5-3.0 MPa, and the hot-pressing time is calculated according to the finished product thickness of the plate, which is generally 1.1 min/mm.

In order to prevent the "bubbling" phenomenon, a three-stage depressurization process is usually used in the later stage of hot pressing. The first segment was reduced from working pressure to “balanced pressure”, the second segment was reduced from “balanced pressure” to zero, and the third segment was opened from zero to hot platen.

6, plate length and surface treatment

Bamboo plywood is mainly used as the floor of the carriage, so the length of the sheet is required to be the same as the length of the carriage, and the length of the pressed sheet is shorter.

The length and surface treatment of the sheet include end milling bevels, bevel coating and lapping, thermo-compression bonding, longitudinal cutting, plate coating, and stencil screens. Press out web marks and other processes.