Doing More With Less: Adhesive’s Role in Core

Market trends are moving toward thinner disposable hygiene products that also have better performance. The question is, how can we do more with less? The answer lies with adhesives. 

In thinner cores, adhesives take on a bigger role and add more value. We like to call them smart adhesives, and in traditional cores they: 

• Help prevent core shifting 
• Hold the acquisition distribution layer (ADL) in place
• Stabilize the fluff/SAP (or SAP only) core matrix 
• Seal the core wrap (if one is used)
• Bond materials to prevent shifting

While every material in a disposable hygiene product plays an important role, knowing how and where to use adhesive can truly impact overall core integrity and performance. Important points to consider when building a thinner traditional core include:

Wrap Materials — A nonwoven wrap offers faster absorption but does not reduce the risk of core crack leakage. A tissue wrap has slower absorption, but active users stay drier.  

Adhesive Placement — Top core adhesive can slow down liquid absorption in to the core. Bottom core adhesive can improve durability and speed up absorption.  

Add-on Level — When using the spray method, we find there is no difference between 2 gsm and 4 gsm of adhesive add-on that is applied. With the multi-slot method, increasing adhesive add-on from 2 gsm to 4 gsm strengthens core integrity and enhances performance. 

Channel and Compound/Pre-compound Cores

The channel core—another design that provides a thinner core—uses adhesive to create channels between the absorbent core materials. Specially formulated adhesives may be required to provide the level of static peel force needed.

In compound and pre-compound cores, the centre layer is a fluffy nonwoven combined with SAP powder. This composite is bonded with adhesive to a top and bottom layer of tissue or nonwoven.

Today’s many types of disposable hygiene cores are complex and intricate systems. That’s why it is important to seek the assistance of core experts early in the process. Bostik knows both disposable hygiene products and their adhesives inside and out. We can guide you in selecting the right adhesives as you move forward toward ever-thinner cores.