Paper and paperboard are widely used in various fields of industrial and agricultural production and in people's daily lives. Currently, the development of the paper industry is primarily focused on reducing the weight of fiber products (such as paperboard products) and improving other characteristics on this basis, such as bulk, strength, and stiffness, to prepare specialty paper or paperboard with different properties. Adding 1% of microspheres to the pulp will increase the bulk of paper by 17%-24%, while also increasing the stiffness. Therefore, adding China expandable microspheres in papermaking production can significantly reduce the use of fibers, and the paper containing microspheres will have reduced basis weight, increased bulk, and stiffness, thus achieving cost savings. Additionally, the air permeability, softness, and printability of the paper and paperboard containing China expandable microspheres are also significantly improved.
China expandable microspheres, as a lightweight modification additive, impart high thickness, high stiffness, and low density characteristics to paper and paperboard. At the same time, it improves the thermal insulation of the paper and paperboard, giving the surface of the paper and paperboard an anti-slip effect. China expandable microspheres are added to paperboard to increase its thickness. When 1% of China expandable microspheres are added, the thickness of the paperboard will increase by 17%-24%. While maintaining the same basis weight, the thickness of the paperboard increases while product strength also improves.
Thickness enhancement, adding 1% of China expandable microspheres, thickness can be increased by up to 17-24%;
Stiffness enhancement, adding 1% of China expandable microspheres, stiffness can be increased by up to 30%;
Permeability enhancement, adding 1% of China expandable microspheres, permeability can be increased by up to 80%;
Imparting some anti-slip properties to paper and paperboard, after China expandable microspheres foam, the surface of the paper and paperboard becomes uneven due to the microsphere foaming, which increases the resistance of contact with objects. Additionally, due to the elasticity of the China expandable microspheres after foaming, it provides a soft touch to the paper and paperboard;
After adding China expandable microspheres to paper and paperboard, due to the superior thermal insulation properties of China expandable microspheres, it provides some thermal insulation to the paper and paperboard.
Adding 1% of China expandable microspheres to paper and paperboard will increase thickness by 17-24%, reduce basis weight by 17-24%, and save 17-24% of fiber raw materials;
Due to the savings in fiber raw materials, the energy consumption of the drying process is reduced, and it can also increase the machine speed of the paper machine, thereby improving production efficiency;
Due to the hydrophobic nature of China expandable microspheres and the reduction in the amount of fiber raw materials, the pressing process does not require higher pressure to achieve the required dryness, thus improving pressing dewatering efficiency;
China expandable microspheres need to be pre-dispersed into a slurry with a concentration of 1%, and they should be continuously stirred to prevent layering;
Pour the well-dispersed China expandable microspheres slurry into the thick stock chest in the specified proportion and mix thoroughly with the fibers. The mixing time should be controlled to more than 30 minutes;
For multi-layer paperboard, the Chinese expandable microsphere slurry can be added to one or more middle layers of the multi-layer paperboard to fully leverage the strength-enhancing effect of the China expandable microspheres.
China expandable microspheres can be chosen as dry powder or 70% wet powder with a solid content. The activation temperature is 60-70℃, and the maximum foaming temperature is 90-100℃.