The effect of heat sealing temperature, time, and pressure on the heat sealing strength of five commercially available packaging films has been evaluated in order to obtain the strongest peelable seal for ‘easy-open’ packaging applications. The mechanical and physical properties of the seal are evaluated. An innovative method and technique to measure the heat sealing properties of different packaging materials is outlined. Inflection points on the temperature-time sealing profile were obtained and determined to be equivalent to the fusion temperature. The fusion temperatures correlated well with the highest peel strength of seals made at the experimentally determined temperatures. The highest peel seal strength has been achieved at a temperature near the fusion point, but below the melting point. The seals made above the fusion point result in weld seals. The pressure has limited effect on the sealing properties of the sealed films in the range tested for this work. The method has been found to be applicable to design of peelable heat seals for many packaging materials and seems to have promise as a method of process measurement and validation for heat seal processes. The project foresees the potential use of this method into other widely used packaging materials, and the method can be useful in the Hazard Analysis and Critical Control Point (HACCP) system for heat sealing processes.

To obtain a proper heat seal is an important requirement in packaging, since seal failure is a more frequent cause of product deterioration than the package itself. Different kinds of seal, such as peelable or non-peelable, can be obtained by changing the conditions under which a material is sealed. Therefore, identifying these conditions is very important. A new technique, the method for measuring temperature of melting surface (MTMS), was used to predict the strongest peelable seal on various packaging commercial films. The temperature of the seal interface was measured using a thermocouple. The time-temperature profile, which was obtained by means of a thermocouple, was electronically processed so as to obtain the derivatives of the profile. The inflection point, also called the fusion point, was located on these profiles. This inflection point is associated with the physical change of the state of the material being sealed. The inflection point analysis was done using two different methods: (a) the MTMS method, based on the second derivative of temperature data with time; (b) 'Table Curve' software, based on nonlinear regression. This technique was successfully used to evaluate widely used packaging films such as LDPE, HDPE, LLDPE and CPP. The inflection point for these films was identified and the seal strength was verified using a universal testing machine. This method appears to be applicable to design the strongest peelable heat seals for many packaging materials. It also seems to have promise as a method of process measurement and validation for heat seal processes. Copyright

This study attempts to explore the value-added applications of corn gluten meal (CGM), the inexpensive byproduct from corn based ethanol industries. The byproducts, CGM, was plasticized using glycerol/ethanol mixture, denatured by the addition of guanidine hydrochloride (GHCl), and then blended with poly(caprolactone), PCL, a synthetic commercial biodegradable polymer. Extrusion followed by injection molding was adopted to fabricate the newly blended green materials. The processing conditions affected the performance of the blends. The GHCl modified corn gluten meal was characterized by IR spectroscopy. The developed materials were characterized through their thermomechanical, tensile, and Izod impact strength measurements. The effects of processing conditions on properties of blends were investigated. One of the promising outcomes of this research was that the GHCl modified corn gluten meal based bioplastic, on blending with PCL had a substantially higher percent elongation. Scanning electron microscopy (SEM) analysis revealed better compatibility of PCL with GHCl modified plasticized CGM. The percent elongation and impact strength of the blended material was found to be higher than high-density polyethylene (HDPE).