Double-roll compaction is a process to create extensible paper and paperboard suitable for replacing plastic in 3D forming applications. Understanding the macro- and micro-mechanisms governing the compaction process allows increasing the stretch potential while maintaining sufficient strength and bending stiffness. In this work, we approach the compaction process of paperboard with micro-mechanical methods featuring the unprecedented level of details otherwise inaccessible with currently available experimental tools. The loading scheme is based on experiments and continuum level simulations. The different levels of compaction and their continuous impact on the fibers’ geometry, void closures, and irreversible deformation of the fibers are thoroughly characterized. We find that the structural changes are concentrated in the fibers oriented within 30 degrees of the direction of compaction. The deformation accumulates primarily in the wall of the fibers in the form of irreversible strains. The spring-back effect beyond the compaction is negligible. For the first time, the role of normal and frictional fiber-to-fiber interactions in the compaction process is investigated and quantified. The frictional interaction between the fibers has a surprisingly low impact on the outcome of the compaction process, and the normal interaction between the fibers has a dominant response. The consequence of this finding is potentially limited impact of the surface modifications targeting the friction.

双辊压实是一种制造可延展纸和纸板的工艺，适用于在 3D 成型应用中替代塑料。了解控制压实过程的宏观和微观机制可以增加拉伸潜力，同时保持足够的强度和弯曲刚度。在这项工作中，我们使用微机械方法来处理纸板的压实过程，该方法具有前所未有的细节水平，否则目前可用的实验工具无法获得。加载方案基于实验和连续水平模拟。对不同程度的压实及其对纤维几何形状、空隙闭合和纤维不可逆变形的连续影响进行了彻底的表征。我们发现结构变化集中在与压实方向成 30 度方向的纤维中。变形主要以不可逆应变的形式积聚在纤维壁中。压实之外的回弹效应可以忽略不计。首次研究并量化了正常和摩擦纤维间相互作用在压实过程中的作用。纤维之间的摩擦相互作用对压实过程的结果的影响非常低，纤维之间的正常相互作用具有主导响应。这一发现的结果是针对摩擦的表面改性的潜在影响有限。变形主要以不可逆应变的形式积聚在纤维壁中。压实之外的回弹效应可以忽略不计。首次研究并量化了正常和摩擦纤维间相互作用在压实过程中的作用。纤维之间的摩擦相互作用对压实过程的结果的影响非常低，纤维之间的正常相互作用具有主导响应。这一发现的结果是针对摩擦的表面改性的潜在影响有限。变形主要以不可逆应变的形式积聚在纤维壁中。压实之外的回弹效应可以忽略不计。首次研究并量化了正常和摩擦纤维间相互作用在压实过程中的作用。纤维之间的摩擦相互作用对压实过程的结果的影响非常低，纤维之间的正常相互作用具有主导响应。这一发现的结果是针对摩擦的表面改性的潜在影响有限。纤维之间的摩擦相互作用对压实过程的结果的影响非常低，纤维之间的正常相互作用具有主导响应。这一发现的结果是针对摩擦的表面改性的潜在影响有限。纤维之间的摩擦相互作用对压实过程的结果的影响非常低，纤维之间的正常相互作用具有主导响应。这一发现的结果是针对摩擦的表面改性的潜在影响有限。