From our results, we have found out that adding liquid starch to recycled paper pulp does make the finished recycled paper stronger. However, it took 2 and 6 more hours for the paper pulps with 30ml & 60ml of liquid starch to dry than the paper pulps with no liquid starch, respectively.
4.1 Analysis of results
Adding liquid starch to recycled paper pulp makes the finished recycled paper stronger. When searching for a simple procedure to make recycled paper, we realised that many websites recommended adding liquid starch to the recycled paper pulp to help prevent ink from soaking into the paper fibres. In the WikiHow website for How To Make Paper, it stated that ‘If you don't add starch, the paper will be highly absorbent, and your ink will likely bleed quite easily.’ Reading this, we think that the liquid starch absorbs unnecessary liquid (such as ink) and keeps the paper dry to prevent it from falling apart when it has finished drying. Our theory is that because paper is a solid, it would not be able to completely dissolve into a liquid when making the paper pulp. The liquid starch would fill up any gaps in the paper pulp and act as a glue to hold the paper together as it dries, making the finished recycled paper stronger.
4.2 Key findings
Adding the liquid starch to the paper makes it stronger while it also makes the paper pulp take longer to dry.
4.3 Explanation of key findings
Paper cannot be completely liquified. Soaking it in water simply allows the cellulose fibres to come apart.(Yahoo! Answers (2015, February 18) How can I dissolve paper?) The liquid starch would act as a glue and bind the cellulose fibres together in the paper pulp, causing the finished paper to be stronger.
4.4 Evaluation of Hypothesis
Our hypothesis is ‘The greater the amount of liquid starch used to make the recycled paper, the stronger the recycled paper is.’. As seen in the bar graph and in the table, the paper batches with more tablespoons of liquid starch added to them are, on average, better able to hold more weights before tearing. Through some research, (Yahoo! Answers (2015, February 18) How can I dissolve paper?)we have found that paper cannot be completely dissolved in water, but the cellulose fibres would just come apart in the water. The liquid starch would act as a glue and bind the fibres together, causing the finished paper to be stronger. This shows that our hypothesis is correct.
4.5 Areas for improvement
Areas of improvement
When making the paper...
Some papers were slightly thicker than others
We could have been more precise when making the thicknesses of the different papers equal.
This would ensure a fairer test when testing the strengths of the papers.
When testing the strength of the paper...
We did not take the place where we put the weights on the paper into consideration, hence the different papers were tested for their strength at different places.
We could have made it a point to test each paper at the same point, e.g. in the centre of each paper.
Some of our papers did not have equal thickness throughout the paper, so our results were not completely accurate when we tested the papers for their strength.
When tabulating the results...
We did not tabulate the results in the metric system, and had to rewrite all the values after checking the rubrics.
We could have thoroughly read through the rubrics before tabulating our results
This would save us time as we would not have to rewrite all the values in our report and tables.