aside from the exemplary embodiments disclosed below , this invention is capable of other embodiments and of being practiced or being carried out in various ways . thus , it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings . moreover , the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion , restriction , or disclaimer . in general , the subject invention is heat sealing multiple layers of material at different temperatures at various locations . a sheet of material may be a laminate and have one face of material , or layer , with a heat sealing temperature that is higher than the heat sealing temperature of the opposite face of material , or layer . one embodiment of the subject invention is article of manufacture 2 , fig1 . sheet 5 is laminate where layer 6 and layer 7 are heat sealable at different temperatures . heat seal 8 is formed by heating layer 3 and sheet 5 to a first temperature at which a seal between layer 3 and layer 6 is effected . heat seal 9 is formed by heating layer 4 and sheet 5 to a second temperature , which is different than the first temperature , and at which a seal between layer 4 and layer 7 is effected . in one particular embodiment , flexible ported pouch 10 , fig2 , has a top pouch sheet 20 and a bottom pouch sheet 22 each made of heat sealable material . in one exemplary embodiment , the material is low density polyethylene ( ldpe ) and is heat sealable between 225 - 275 degrees f ., but other heat sealing sheets or heat sealing laminates can be used . in some other embodiments , pouch sheets 20 and 22 may be a single heat sealable sheet or heat sealable laminate folded about an axis to create top sheet 20 and bottom pouch sheets 22 . port 26 , also fig2 , has a top port sheet 30 and bottom port sheet 28 each made of heat sealable material . in the exemplary embodiment in fig4 , top port sheet 30 is a laminate having one layer 42 with a low sealing temperature and the opposite layer 44 having a high sealing temperature . likewise , bottom port sheet 28 is a laminate having one layer 38 with a low sealing temperature and the opposite layer 40 having a high sealing temperature . in this exemplary embodiment , layers 38 and 42 which form the exterior face of port 26 are made of ldpe and are heat sealable between 225 - 275 degrees f . while layers 40 and 44 which form the interior of port 26 are made of high density polyethylene ( hdpe ) and are heat sealable between 325 - 375 degrees f . other heat sealable sheets or heat sealable laminates may be used for port sheet 28 and port sheet 30 as long as the interior of port 26 is heat sealable at a temperature that is higher than the heat sealing temperature of pouch sheets 20 and 22 . this prevents the sealing of the interior of port 26 where it intersects with pouch 10 at gap 12 . port sheet 28 and port sheet 30 may , in other embodiments , be a single heat sealable sheet or heat sealable laminate folded about an axis to create top port sheet 30 and bottom port sheet 28 . in fig2 , port 26 is interposed between top pouch sheet 20 and bottom pouch sheet 22 at gap 12 . fig3 shows port edge heat seal 32 and port edge heat seal 34 between top port sheet 30 and bottom port sheet 28 . in the exemplary embodiment in fig4 , layer 44 of top port sheet 30 and layer 40 of bottom port sheet 28 are heat sealed at port edge heat seals 32 and 34 . preferably , these heat seals are effected between a temperature of 325 - 375 degrees f . in other embodiments , if port 26 is formed using a single sheet or laminate folded about an axis , only one heat seal would need to be effected along the open edge of the folded sheet . top pouch sheet 20 , fig2 , is heat sealed to bottom pouch sheet 22 along periphery heat seal 24 at a temperature which is lower than that of the temperature used to seal port 26 at port edge heat seals 32 and 34 . in fig3 , where periphery heat seal 24 intersects with port 26 at gap 12 , heat seal 36 is formed between top pouch sheet 20 and top port sheet 30 and heat seal 37 is formed between bottom pouch sheet 22 and bottom port sheet 28 . in the exemplary embodiment in fig4 , where periphery heat seal 24 intersects with port 26 at gap 12 , heat seal 36 is formed between top pouch sheet 20 and layer 42 of top port sheet 30 and heat seal 37 is formed between bottom pouch sheet 22 and layer 38 of bottom port sheet 28 . it is preferable that heat seals 24 , 36 and 37 are effected at a temperature between 225 - 275 degrees f . this seals the exterior of port 26 to pouch 10 at gap 12 without sealing the interior of port 26 along gap 12 . the exemplary embodiment of a dual layer film baffle system manufacturing process 60 is shown in fig5 . roll 70 dispenses heat sealable sheet 72 in parallel with heat sealable sheet 74 which is dispensed by roll 71 . in the exemplary embodiment , heat sealable sheet 72 and heat sealable sheet 74 , fig6 , are laminates . layers 73 and 76 are made of a low temperature heat sealable material , ldpe , and are sealable between a temperature of 225 - 275 degrees f . layers 77 and 75 are made of a high temperature sealable material , hdpe , and are sealable between a temperature of 325 - 375 degrees f . sheet 72 and sheet 74 , fig5 , are brought together at high temperature and perforation station 78 . at this point , sheet 72 and sheet 74 are heated to create heat seal 79 , fig7 , latitudinally across the sheets at some interval 81 dependent upon the desired length of baffles 90 and 91 , fig8 . interval 81 may , for example , be one inch . also at station 78 , fig5 , the now sealed sheets are perforated at interval 81 and immediately preceding heat seal 79 to create perforated line 80 across the sheets . roll 82 , fig5 , dispenses low temperature sheet 84 onto sheet 72 while roll 83 dispenses low temperature sheet 85 onto sheet 74 . sheets 84 and 85 may be made of ldpe and are heat sealable at a temperature of 225 - 275 degrees f . the sheets are brought together at low temperature sealing station 88 where low temperature seal 86 is effected between sheet 84 and 72 and low temperature seal 87 is effected between sheets 85 and 74 . these low temperature seals also cross the sheets latitudinally and are spaced at interval 81 . sheets 84 and 85 , fig9 , are then spread apart . this causes baffle 90 , fig8 , to separate from baffle 91 at perforated line 80 . the end result is a plurality of two piece baffles between sheets 84 and 85 . the two pieces of the baffle are joined to each other at high temperature seal 79 and joined to sheet 84 and 85 at low temperature seals 86 and 87 . although specific features of the invention are shown in some drawings and not in others , this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention . the words “ including ”, “ comprising ”, “ having ”, and “ with ” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection . moreover , any embodiments disclosed in the subject application are not to be taken as the only possible embodiments . in addition , any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed : those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents , many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered ( if anything ), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents , and / or there are many other reasons the applicant cannot be expected to describe certain insubstantial substitutes for any claim element amended . other embodiments will occur to those skilled in the art and are within the following claims .