Adhesives migration from

Mitogen activated protein kinase (MARK) cascades are three kinase modules activated by phosphorylation. The three kinase modules are composed of a MAPK, a MAPKK, and a MAPKKK. There are multiple members of each component of the MAPK cascade that are conserved from yeast to human. Activation of selective MAPK modules by specific stimuli regulates cell functions such as gene expression, adhesion, migration, differ entiation, and apoptosis. 

Couchman, J.R., Rees, D.A. (1979). The behavior of fibroblasts migrating from chick heart explants Changes in adhesion, locomotion and growth, and in the distribution of actomyosin and fi-bronectin. J. Cell Sci. 39, 149-165. 

On the other hand, if the mbber contains paraffin wax, the surface treatment with sulfuric acid promotes its migration to the surface creating a weak boundary layer able to produce poor adhesion. Solvent wiping with petroleum ether after surface treatment removes this antiadherent moiety but a progressive migration from the bulk to the mbber surface with time occurs. 

Fig. 4.6(a) Migration of LHRH neurocrine cells prenatal transportation along the track of extra-bulbar VN axons (caudal branch). CB, cribriform plate FB, forebrain cell types, TAG-1, transient axonal surface glycoprotein and N-CAM, neural cell adhesion molecule (from Yoshida et al, 1995). 

Although 2,3-benzofuran is a component of coumarone-indene resin and this resin has been approved by the FDA for use as a coating on citrus fruits, as a component of food-preparation utensils, and as an adhesive in food packages (see Table 7-1), no information was located confirming that coumarone-indene resin is currently used on food in the United States. Furthermore, no data were located to indicate that 2,3-benzofuran migrates from the resin into foodstuffs. 

Research on chemical migration from other types or components of packaging material - e.g. glass, wood, cork, coatings, adhesives - has been carried out sporadically. There is now a concerted UK programme to study chemical migration from these so that problems can be identified and dealt with in a consistent way (Working Party on Chemical Contaminants from Food Contact Materials and Articles, 1999). 

Low bonding agent film weight Migration from polyurethane Contamination of bonding agent-coated parts Use heavier or multiple adhesive coats Substitute more compatible ingredients Check unbonded specimens for oil or dust Avoid overspray or excessive use of mold release... 

Plasticizer migration from the vinyl part into the adhesive bond line can degrade the strength of the joint. Adhesives must be tested for their ability to resist the plasticizer. PVC can be made with a variety of plasticizers. An adhesive suitable for a certain flexible PVC formulation may not be compatible with a PVC from another supplier. Nitrile rubber adhesives have been found to be very resistant to plasticizers and are often the preferred adhesive for flexible PVC films. However, certain epoxy adhesive formulations have also been found to provide excellent adhesion to flexible PVC substrates. Several such starting formulations are presented in Table 16.7. A comparison of the performance of several classes of adhesive when bonding PVC to itself and to various other materials is given in Table 16.15. 

This chapter provides examples of adhesive types used to make food packaging materials. It details the potential for chemical migration from adhesives and how the safety of these substances can be, and has been, tested experimentally. 

Chemical migration from food packaging adhesives... 

Migration from water-based adhesives and solvent-based adhesives... 

Water-based adhesives are used in the production of paper and cardboard food packaging. Migration of adhesive components from such packaging has been assessed. Migration levels into a food simulant (Tenax) were lower than the specific migration limits for plastics which were used to provide a convenient, informal way of assessing the results. Migration to foodstuffs would be expected to be even lower than into the Tenax simulant used, because food will not be in direct contact with the adhesive surfaces. 

GRUNER, A. and PIRINGER, o.. Component migration from adhesives used in paper and paperboard packaging for foodstuffs. Packaging Technology and Science, 1999, 12, 19-28. 

Chemical migration from adhesives used in food contact materials and articles. CSL report for the FSA, 2005, FD05/18. 

Published data on migration from laminating adhesives... 

Table 16.5 Aromatic amine migration from polyurethane adhesives (Lawson 1994)...

---