Absorbent kraft or impregnating paper is a crucial component in the production of high-quality laminated materials. This special type of kraft paper possesses controlled absorbency, meaning it has a high degree of porosity. It is typically made from clean low kappa hardwood kraft and must exhibit good uniformity, formation, and profile to ensure the overall quality and consistency of the laminate.

The absorbent kraft paper used in laminates is usually in the range of 80-120 g/m2. To achieve the desired strength and durability, multiple plies of this paper, typically 2-4, are stacked together. This arrangement ensures that the laminate can withstand various external forces and maintain its integrity over time.

One of the primary purposes of absorbent kraft paper in laminates is to act as a substrate for impregnation. Impregnation refers to the process of saturating the paper with resins, adhesives, or other chemicals to enhance its strength, moisture resistance, and overall performance. The absorbent nature of the kraft paper allows it to effectively absorb and retain these impregnating substances.

The absorbent kraft paper used for laminates must meet certain specifications to ensure optimal performance. It must have a high absorbency rate, allowing it to quickly and efficiently soak up the impregnating substances. Additionally, it should have good uniformity, meaning that its porosity and absorbency should be evenly distributed across its surface. This ensures that the impregnating substances are evenly dispersed throughout the laminate, resulting in a consistent and reliable end product.

Furthermore, the absorbent kraft paper must have a good formation. This refers to the arrangement and distribution of fibers within the paper. A well-formed paper exhibits uniform fiber distribution, which contributes to the overall strength and stability of the laminate. It also ensures that the impregnating substances can penetrate the paper evenly, enhancing the bond between the layers and improving the laminate’s performance.

The profile of the absorbent kraft paper is another important factor to consider. The profile refers to the surface characteristics of the paper, such as smoothness and roughness. A good profile promotes the uniformity of the laminate, as it allows for better adhesion between the layers. It also ensures that the impregnating substances are evenly distributed, preventing any weak spots or inconsistencies in the final product.

In conclusion, absorbent kraft or impregnating paper plays a vital role in the production of laminates. Its controlled absorbency, good uniformity, formation, and profile contribute to the overall quality and performance of the laminate. By effectively absorbing and retaining impregnating substances, this specialized paper enhances the strength, durability, and moisture resistance of laminated materials.