For a long time, liquid (flowable or sprayable) products have been delivered and marketed in plastic bottles like those which are made up of polyesters. The bottles which are used in delivering liquid products are often stacked vertically on top of one another during transportation or storage in a warehouse or at the point-of-purchase display. Due to these situations, the bottles can experience a top load resulting in buckling of bottles.
The resistance of the bottles to vertical load depends upon the quality of products and the particular stacking configurations. Low quality plastic bottles with limited or negligible top loading resistance can easily get damaged and lead to product loss, especially when they carry heavier liquids. Also, poor quality bottles having liquid products, when placed at the bottom of a stack may experience continuous top loading forces and may buckle or even totally collapse, leading to economic loss and the labor costing for clean-up, or damage to the vehicle in which the collapse occurred. Hence a proficient top load tester must be used as a part of quality testing prior and post the final production.
Type of bottle which delivers high top load resistance
Bottles having a smooth curved and continuous body wall are known to have better top loading strength. When the bottle body is built of interconnected walls, it can easily generate transition edge between the walls gradual in order to improve the top load strength of the bottle. Thus, bottles with curved and rounded body structure are usually preferred for having better top loading strength than bottles with abrupt transitions which form relatively “square” profiles and deliver low resistance to top load forces. It has been discovered that gradual thickening of the sidewall, improves bottle strength against laterally imposed stacking and crushing loads, such as experienced in a vending machine.
Testing the resistance strength
Top Load Tester is an advanced technological testing instrument with semi-automatic motorized operations. It evaluates the compressive buckling load into digital format.
The digital display provides a live test result for faster evaluation to save time and energy of the operator. The testing bottle will be placed between the inverted concave jaws for zero slip gripping. It is used for evaluating the load bearing ability of the PET containers/bottles when subjected to an extreme load from the vertical direction.
