Currently, the heat sealing time can only be performed at 70 hits per min, which means that only 70 units can be heat sealed per minute. This is well below the standard requirement of 165 per min for slow machines and 600 per min for fast machines. Heat sealing is when a hot blade hits the 2 papers and blends/fuses them together. Traditionally with pulp paper, it is done by adding or laminating another layer of plastic onto the paper to give the heat sealing effect.
The issue we have faced which is now being worked on at the product development stage is that when the hot blade hits the paper, the heat is transferred and absorbed by the calcium carbonate. The natural properties and characteristics of the calcium carbonate, (also applicable for most stones) is to absorb the heat without immediate releasing factor. Therefore currently when the hot blade hits the paper, the heat is absorbed by the calcium carbonate without immediate release, resulting in the indirect effect of the HDPE and shrinkage of the paper.
At this moment we will be bringing the raw material and will be performing treatments in-house using nanotechnology to treat the original rich mineral component at the molecular or atomic level, hence decreasing the heat absorbency ratio of the mineral with the hope that the treated calcium carbonate portion behaves according to our requirements.
This aspect of the finished product is undergoing further development and testing.