From: Gary Jones (firstname.lastname@example.org )
Date: Fri, 21 Jun 2002 12:30:17
I am aware of some toxicity issues related to one type of hot melt adhesive, but it is more of a worker exposure during application. From a recyclability standpoint, there are several types of hot melts which are easier to recycle.
The recyclability of the adhesive is dependent in part of the type of repulping process that will be used. There are two principal types of repulping and they are washing/screening and floatation. Floatation has become more popular because it can accommodate a wider variety of waste paper types and contaminants while producing a cleaner and brighter paper.
An alkaline soluble hot melt is compatible with an alkaline washing repulping process. There are some problems if a subsequent wash uses acidification in conjunction with adhesive precipitation. There have been some hot melts, specifically the polyurethanes or reactive hot melts and vinyl graft copolymers that are more compatible with the screening process. Conventional EVA hot melts seem to easily recycled when the floatation process is used for repulping.
In terms of which hot melt to use, you need to balance the performance with the recyclability of the system that will be used. Since floatation has become more popular, the EVA type might be a better choice. You should check with the vendor of the adhesive to see if they have any supporting information about recyclability.