Is the quality of the paneling too poor? Fushen offers you a solution

First of all, it should be known that panel assembly is a systematic project. Any link will affect the quality of panel assembly. So, what factors affect the quality of panel assembly? Today, Fushen Woodworking Glue will analyze for everyone and explain how to solve the problem of poor quality of the panels.

1. Low curing agent:

The glue cannot be fully cross-linked, and the degree of cross-linking is low, which affects the bonding performance.

High curing agent

The active period of the glue is short and the glue layer is relatively hard.

The glue is not mixed evenly

The degree of gluing and curing speed are inconsistent, and the cracking rate of the glue line is high.

Solution

The weight ratio of the main agent to the curing agent is adjusted to 100:15

2. Thoroughly stir the main agent and curing agent before use

Ii. The Influence of the Active Period of the panel Adhesive

High working environment temperature and low relative humidity - short active period of glue

Low working environment temperature and high relative humidity - the active period of the glue is long

The reaction of glue that has exceeded its applicable active period: foaming, very poor fluidity, and a significant decrease in the adhesive force of the glue

The impact of using the above-mentioned glue on the quality of the plywood: low wood breakage rate, poor water/heat resistance, thick and obvious glue lines.

Solution

Adhere to the principle of using only as much as needed. Glue that has exceeded its active period should be discarded.

The following are the active periods of most glues:

At 20-25 ° C and 55-60% : less than 60 minutes

Less than 45 minutes at 25-30 ° C and 55-60%

Less than 30 minutes at 35-40 ° C and 55-60%

Iii. The Influence of Coating Methods and Coating amounts

When the amount of glue applied is insufficient:

Phenomenon: No glue is extruded from the glue seam or continuous teardrop-like glue drops cannot be formed

Insufficient adhesive or uneven application of the adhesive layer can directly affect the quality of the panel assembly

Solution

For hardwoods (such as red oak, white oak, and American hard maple), it is advisable to apply glue on both sides, with a coating amount of more than 150g/m ³ on each side.

2. Cork, especially wood with strong adsorption performance:

The amount of glue applied should be greater than 250g/m ³

3. Other woods:

The amount of glue applied is 220g-280 m ²

Iv. Impact of Opening Duration

If the open time is too long, it will result in overly thick glue lines and cause a lack of glue in the glue layer (too much glue is absorbed by the wood), and it cannot form a sufficient glue film.

Too short open time: The glue does not penetrate enough into the wood, making it prone to not adhering firmly.

Solution

1. Hardwoods (such as: red oak, white oak, American hard maple

6-10min; Wood with poor adsorption performance requires a longer aging time to form more glue nails

Softwood (such as fir, fresh pine, etc.)·4-6 minutes to prevent excessive absorption of the glue by the wood

V. The Influence of Moisture Content and Uniformity of Wood

Excessive variation in moisture content

The different stresses generated when wood shrinks during drying and expands when absorbing moisture (water) can easily cause cracking of wood or glue lines, as well as defects such as bending of boards and height differences at joints. Especially hardwood and other woods with relatively high stress (significant deformation).

Solution

The suitable moisture content for wood is 7-15%, but 8-12% is the best

The moisture content difference of wood on the same panel shall not exceed 2%

The moisture content difference between adjacent wooden strips on the same panel shall not exceed 1%

Vi. The Impact of Wood Surface Processing Quality

The adjacent surfaces of the wood are not at right angles or the processing error is too large:

(1) It is easy to cause uneven pressure during panel assembly (excessive pressure in some areas or no pressure in some areas can also easily lead to wood shortage or insufficient glue in some areas, thereby affecting the quality of panel assembly.

(2) The internal stress of wood is relatively large. After the pressure is released, the plywood is prone to cracking of the glue lines under the action of stress.

Solution

The glued surface of the wood should be flat, smooth, free of oil stains and not bent

2. The adjacent surfaces of the wood form right angles

The processing error of the wood bonding surface shall not exceed 0.5mm

Vii. The Impact of the Curing Period of Panel Assembly

Insufficient time for health preservation

During the subsequent processing and handling, the external force is prone to cause the rubber line to crack and the seam to sink.

Solution

After the panels are depressified, they should be cured for 24 hours before proceeding to the next processing step

The bonding strength of the panel after pressure relief shows a gradually increasing trend and reaches its peak after 168 hours. Under normal circumstances, the bonding strength of the panel can only be sufficient to resist the influence of external forces (such as cutting, forming and sanding, etc.) after 24 hours of curing after pressure relief.

Viii. Impact of Pressure on Wooden Boards

The pressure on the wooden board is insufficient

It is prone to cause problems such as end cracking, spongy glue lines, thick glue lines, and shiny glue lines.

Solution

Increase the pressure and make it uniform, especially the pressure at both ends of the plywood (softwood :3-8kg/cm ²; hardwood :6-13kg/cm ²)

Fushen Woodworking Adhesive is a brand of woodworking adhesives under Guangdong Fushen Chemical Co., LTD. It covers water-based environmentally friendly single-component, high-performance wood veneer adhesives, panel gluing adhesives, assembly adhesives, pressing board adhesives, etc., integrating R&D, production and sales.

Fushen was founded in 2005 and has been dedicated to the field of woodworking adhesives for many years. It is committed to developing environmentally friendly and high-performance adhesive products to catch up with international professional standards and is hailed by the wood products industry as "China's Expert in wood veneer adhesives".