Polyamide is a popular polymer form which is used for the manufacturing of flexible packaging film. This form of film has numerous applications due to its quality properties such as its mechanical strength, transparency, thermoformability and barrier strength. As it has become a popular choice in the packaging industry, is important to know that the material we are receiving for packaging or for the manufacturers that the material exhibit all its features and offer the best of quality or not. In, this blog section we will be discussing about one such property of the film which is very much useful in the packaging industry, ‘the heat seal strength’. We will be sharing information on the accurate estimation of its seal quality using an efficient packaging testing instrument such as lab heat sealer.
Why are polyamide films considered for packaging?
Polyamide is widely used for manufacturing flexible packaging film. It is the foremost choice of major companies in this vertical due to its multiple properties including its high heat distortion temperature, high flexibility and toughness it offers, good barrier to oxygen, chemicals and aroma substances, high level of transparency and thermoformability. The wide range of beneficial properties is because of the presence of the amide group in the polymer chain, which leads to strong intermolecular adhesion through hydrogen bonds. These strong attractive forces between the molecules result in high melting point and heat resistance, high mechanical properties like strength & stiffness, high barrier to oxygen, carbon dioxide and many solvents and aroma materials. It is majorly used for packaging of foods which are sensitive to oxygen, such as meat, processed meat (sausage, bacon), smoked fish, cereals, cheese and dairy products.
Testing the Heat seal quality
The technical and quality assurance team of packaging specifies packaging material characteristics in terms of its functional and barrier properties, such as Oxygen Transmission Rate for an oxygen sensitive product. Despite these testing, the highest risk to pack integrity and shelf life can be failures in the pack heat seals or closures. Therefore, testing the heat seal strength is a major necessity in the industry.
Heat Seal parameters are easily evaluated using the formula i.e. Heat Saleability is equaled to the addition of parameters such as Temperature, Pressure and Time. Maintaining an optimum heat sealing conditions in production and recognising the true cause of poor sealing remains a challenge for many. Measurement of heat sealing parameters is done by creating controlled sealing conditions with the help of a precise Laboratory Heat Sealer according to ASTM F2029.
Polyamide film manufacturers who test the heat seal parameters of producing a film on a regular basis as part of a well-managed quality system are expected to deliver the best quality in the market and gain a chain of satisfied clients.