u201c green u201d glue stick formulation that includes at least one starch casein and optionally a mixture of naturally occurring fatty acids application_number US 201213541208 A description one or more exemplary embodiments of the present invention are now described although the following detailed description contains many specifics for purposes of illustration a person of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention accordingly the following embodiments of the invention are set forth without any loss of generality to and without imposing limitations upon the described invention the present invention provides a glue stick formulation that is based primarily on sustainable materials two exemplary naturally occurring polymers are used to formulate this product namely starch and casein starch e g dextrin and casein phosphoproteins are the two primary ingredients used in this formulation to provide the glue stick of this invention with its bond strength the combination of these two polymers also provides a balance of important product characteristics including firmness finger tack and easy application of the glue stick to a paper surface additional ingredients include palmitic acid and myristic acid which have melting points of 62 9 u00b0 c and 54 4 u00b0 c respectively a soap mixture made with these two naturally occurring fatty acids provides desired properties for the base of the glue stick including firmness and ease of application and is compatible with both the starch and casein components the finished formula provides a product that has a high level of sustainable materials without sacrificing the key properties outlined above having generally described this invention a further understanding can be obtained by reference to a specific example detailed below which is provided for.