Pharmaceutical products are of great importance as they are related to the healthcare and wellbeing of the patients. There are a variety of drugs that are used for treatment of an array of diseases. As the pharmaceuticals are so critical the manufacturers need to ensure that every step is taken to keep the quality of the products they produce. This being said, one of the most important factors that the pharmaceutical products can be affected from is the quality of the packaging that is used for pharmaceutical products.
There are many different factors that can affect the safety of the products during the transportation process as well as during storage of the products for a long time. When the packaging boxes are stacked in the carriage for transportation, there is a possibility that a variety of forces are acting upon them such as compression forces, crashing forces and bursting force. To survive such forces, it is important that the packaging boxes used for the pharmaceutical products are imparted with enough strength that ensures the survival of the boxes during such instances without any damage. There are many different factors at play when it comes to deciding the strength of the packaging boxes. There is the quality of the raw materials, manufacturing process adopted and the quality testing procedures used for assessment of the packaging box that decide the best strength and quality of the box.
Bursting strength of a material is the amount of force that it can bear without facing any damage or burst when it is subject to bursting force acting upon it. The manufacturers of the packaging boxes used in the pharmaceutical industries need to test the bursting strength of the materials that they use for manufacturing the boxes. Normally cardboards and corrugated sheets are used for manufacturing of the packaging boxes for pharmaceutical products because they have enough strength that can keep the products protected ion extreme harsh situations. The bursting strength of the corrugated sheets is the major element that ensures the better strength of the boxes that are used for packaging. The manufacturers need to test the quality of the corrugated boxes with the help of highly advanced quality testing instruments such as bursting strength tester.
Testing the bursting strength with Mullen Test
Mullen test or bursting strength test is the standard test that is used for determining the bursting strength of the corrugated sheets to ensure the quality and strength of the end products which in this case is the box used for packaging of pharmaceutical products. The manufacturers have to ensure that they are using the best precautions to ensure the accuracy and correctness of the procedure to make sure that the packaging materials is of great quality. In the Mullen test, the specimen is taken and is subjected to a bursting force that is applied on it’s through a rubber diaphragm with the help of a fluid which normally is glycerine. The force applied until the failure of the specimen which gives the bursting strength of the specimen. This bursting strength value is used for calculating the burst index and bursting factor of the specimen. The burst factor and bursting index are the units that are used for depicting the grade and strength of the material. The Mullen test is performed with a highly sophisticated and accurate testing instrument called as bursting strength tester.
Bursting strength tester is a highly accurate testing instrument that is used for performing Mullen test and calculates the quality of the specimen by giving the bursting strength of the specimen. The instrument is equipped with a serrated clamp that is good enough to provide high grip with anti-slippage which is necessary for ensuring precise testing of the products, In addition to that, the instrument comes in several different models from digital model to analogue model. There is also a computerized model available with manufacturers that allow you to download the data to computer and depict the test data in a graphical format for accurate analysis. The diaphragm that is used in the instruments is made for natural soft rubber. The hydraulic pressure that is created in the instrument, it is created with the help of lab grade glycerin which can be replenished when needed. The rubber diaphragm that comes with the instrument is also easily replaceable.
Performing the Mullen Test
To perform the Mullen test, first of all you need to prepare the specimen by cutting a circular disc from the sample. The circular disc should have a diameter greater than the clamps so that perfect grip with minimum slippage is provided which is necessary for accurate testing. Once the specimen is ready, place it on the clamp and ensure secure gripping of the specimen. Once the specimen is in place, you need to press the button indicating “Press To Start” to start the testing procedure. This will start exerting a bursting force on the specimen. As the hydraulic pressure increases, you will see that the numbers on the digital display of the instrument are increasing. This is the measure of the force exerted on the specimen. Once the specimen is burst, the pressure decreases and the reading on the digital display are fixed. This gives the bursting strength of the specimen which is then further used for testing the bursting index and bursting factor of the specimen using the following formula.
Bursting Factor Formula for Corrugated Box
Once the Mullen test is performed and the bursting strength of the specimen is calculated, you can easily calculate the bursting factor and bursting index of the specimen with simple formulas. The formula for bursting factor is given as:
Burst factor = Burst strength (gf/cm2) / Grammage (grams/m2)
Here, the bursting strength is the derived from the Mullen test and Grammage is the GSM of the sample. The formula for calculating the bursting index is similar to the bursting factor. The only difference is that the bursting index is expressed in terms of pressure or kPa and Grammage. The formula that gives bursting index is as follows:
Burst Index = Burst strength (kPa) / Grammage (Kg/m2)
Here, the bursting strength obtained from Mullen test is converted in kPa from gf/m2. The grammage again is the GSM of the material. GSM is given in kg/M2 and can easily be calculated with the help of a GSM cutter and a weighing scale. Once these formulas are applied and the bursting index and factor are calculated, there is very critical information about the strength of the materials can be obtained which can easily be used to optimize the performance of the materials to a great strength.
With the help of the bursting strength tester, the manufacturers of the pharmaceutical packaging materials can easily ensure that the packaging boxes they are manufacturing is capable of bearing the harsh impacts that may be exerted on them during various conditions so that the perfect safety and quality of the products could be ensured and the best healthcare products could be provided to the patients.
Sanjay Sharma, a technocrat by heart and an industrialist by profession, has always been obsessed with machines and has dedicated his whole life to developing better and better machines for industries. Check our Testing Instruments range with bursting strength tester, box compression tester etc.