The wood grain color of the WPC coextrusion layer can be adjusted by the following methods:
1. Choose different masterbatches
1）. Principle
- Masterbatch is a plastic colorant made of a high proportion of pigments or additives and thermoplastic resins that are well dispersed. By choosing masterbatches of different colors, a specific wood grain color can be given to the WPC coextrusion layer.
- For example, by choosing masterbatches of different shades such as brown, yellow, and red, you can mix wood grain colors similar to different woods, such as oak, walnut, cherry, etc.
2）. Operation method
- According to the required wood grain color, add an appropriate amount of masterbatch to the raw materials of the WPC coextrusion layer. Generally speaking, the addition ratio of masterbatch is between 1% and 5%, and the specific ratio can be adjusted according to actual conditions.
- When adding masterbatch, make sure to stir it evenly to ensure color consistency. You can use a high-speed mixer or the mixing section of the extruder to stir so that the masterbatch and the raw materials are fully mixed.
2. Adjust the co-extrusion process parameters
1）. Temperature control
- Different temperatures will affect the color performance of the wood-plastic co-extrusion layer. Generally speaking, higher temperature will make the color darker, and lower temperature will make the color lighter.
- For example, in the co-extrusion process, if you want to obtain a lighter wood grain color, you can appropriately reduce the temperature of the extruder. But be aware that too low a temperature may cause the quality of the co-extrusion layer to deteriorate, such as delamination, rough surface and other problems.
- Therefore, it is necessary to determine the appropriate temperature range through experiments according to the specific equipment and raw material conditions to achieve the desired wood grain color.
2）. Extrusion speed
- The extrusion speed will also affect the color of the wood-plastic co-extrusion layer. Generally speaking, faster extrusion speed will make the color lighter, and slower extrusion speed will make the color darker.
- This is because the change in extrusion speed will affect the residence time and heating degree of the raw materials in the extruder, thereby affecting the color performance.
- Similarly, it is necessary to determine the appropriate extrusion speed through experiments to obtain the ideal wood grain color.
3）. Pressure adjustment
- The pressure during the co-extrusion process will also have a certain effect on the color. Properly increasing the pressure can make the co-extrusion layer more dense and the color will become darker accordingly.
- However, too high pressure may cause equipment damage or defects in the co-extrusion layer. Therefore, it is necessary to adjust according to the actual situation to find the appropriate pressure range.
3. Use different wood grain embossing
1）. Principle
- The surface texture of the wood grain embossing will directly affect the wood grain effect of the wood-plastic co-extrusion layer. By choosing different wood grain embossing, different wood grain colors and textures can be obtained.
- For example, some wood grain embossing has a deeper texture, which can give the co-extrusion layer a deeper wood grain touch; while some wood grain embossing has a lighter texture, which can produce a lighter wood grain effect.
2）. Operation method
- According to the required wood grain texture, select a suitable wood grain embossing roller. When installing the embossing roller, make sure that the embossing roller is firmly installed to avoid loosening or deviation during the co-extrusion process.
- At the same time, pay attention to the cleaning and maintenance of the embossing roller, and regularly clean the impurities and residues on the surface of the embossing roller to ensure the clarity and stability of the wood grain.
4. Post-processing
1）. Sanding and roughening
- After the production of the wood-plastic co-extrusion layer is completed, the wood grain color and touch can be adjusted by sanding and roughening.
5. Precautions
1）. Color stability
- When adjusting the wood grain color of the wood-plastic co-extrusion layer, pay attention to the color stability. Different environmental factors, such as light, temperature, humidity, etc., may cause color changes.
- Therefore, when selecting materials such as masterbatches and coatings, products with good weather resistance and stability should be selected to ensure that the color will not change significantly during long-term use.
2）. Coordination with the overall design
- The adjustment of wood grain color should be coordinated with the overall design style. Consider the use of the product, environment, customer needs and other factors, and choose the appropriate wood grain color to achieve the best visual effect.
3）. Quality control
- In the process of adjusting the wood grain color, strictly control the quality of the product. Ensure that the thickness of the co-extrusion layer is uniform, the surface is smooth, defect-free, and the color is consistent. The product quality can be monitored by regular testing and sampling inspection.
