Process for producing sandwich structures with particulate material pattern

A method for determining the equipment design and process parameters for a process for selectively positioning particulate material onto a surface of a web material while said web material is moving at a production speed, the method comprising the steps of:

• a.) providing a set of physical equations forming a physical model, wherein the set of physical equations is connected by interaction boundary conditions;
• b.) selecting a set of fixed boundary conditions;
• c.) providing a set of predetermined model targets;
• d.) selecting a set of variable boundary conditions;
• e.) performing calculus operations on the physical equations by using the initial operating conditions and variable boundary conditions, wherein the calculations are performed by employing a computer device;
• f.) transforming the calculus results into a model output which is readable to a human analyst directly or by a means of a computing device;
• g.) comparing the model output to predetermined model targets and determining the deviation therebetween;
• h.) modifying the set of variable boundary conditions using computational equations for minimizing the deviation between the model output to predetermined model targets;
• and
• i.) repeating steps d.) through h.) until a preset exit criterion is met;
• wherein the set of fixed boundary conditions are selected from the group consisting of:
• transferring a cluster of particulate material into a receiving region of a transfer device, whereby the receiving region of the transfer device defines a particulate cluster pattern;
• holding the cluster of particulate material on the transfer device by applying vacuum to the transfer device;
• moving the receiving region of the transfer device to a discharging region of the transfer device;
• guiding the web material over a carrier support structure;
• deforming the web material by the carrier support structure such that an indentation is formed in the unsupported regions, thereby forming a pattern in the indentation corresponding to the particulate cluster pattern;
• forming indentations in the web material on the carrier support structure by applying vacuum to the web material;
• expelling the cluster of particulate material from the transfer device toward the indentation in the web material;
• depositing the cluster of expelled particulate material on the deformed web material;
• applying a cover material to the carrier material and the cluster of particulate material, thereby forming a sandwich structure;
• and bonding the web material and the cover material to each other;
• wherein the model targets are selected from the group consisting of:
• a target cluster design pattern;
• the quantity of particulate material in the cluster;
• the basis weight of the cluster of particulate material;
• a distribution of the particulate material clusters on the web material;
• and the production speed;
• and
• wherein the variable boundary conditions are selected from the group consisting of:
• a shape of the particulate cluster pattern on the receiving region of the transfer drum;
• vacuum required in the transfer device for holding the particulate material;
• a pattern of air flow of the particulate material cluster as it is expelled toward the carrier material;
• air flow required to expel the particulate material clusters toward the web material;
• deformation of the web material by applying vacuum to form the indentations;
• and a trajectory of the particulate material cluster as the particulate material cluster is expelled toward the carrier material.