Why Isn't My Cloth Dyeing? (Science Fair Project 2018-2019)

Error Analysis

Error Analysis

Oliver (LAST NAME) and Andrew Heffner

            With any experiment, there are errors. To start off, there are systematic errors; errors in the way the experiment was carried out. Firstly, the temperature of the water in the bucket could have varied from bucket to bucket when we put the cloth squares in them. Even though we measured the temperature, it may not have stayed consistent as the the temperature of the bucket of water would inevitably decrease as time progressed according to the temperature of the room and the amount of thermal energy the air had. Since we had to put detergent into the dye, there was going to be bubbles when the bucket was stirred. The bubbles could have affected how much dye the cloth squares could reach to absorb. There's also the factor of how the bucket was stirred. If it was stirred vigorously, slowly, and the direction which it was stirred. When the cloth pieces were being dyed in the bucket, there was no space in which to see the cloth squares because of the bubbles, but you could feel that some cloth pieces clumped together more than others, the wool especially. When they clump together, then the dye can't reach the pieces evenly. Additionally, some cloth pieces were thicker than others, so the dye also couldn't be absorbed as evenly as possible. Going along with the theme of evenly distributed dye, some cloth pieces frayed when they were cut, so they would be slightly smaller than anticipated. Some also curled up when they were being dyed. There is also the time of how quickly we drained the water. There was the definite inconsistency that the times varied from draining time from one batch to another. With the first batch, we went slowly and causally, making sure not to lose any pieces. With final batches, we went much faster and smoother as we had more experience with draining the cloth squares.

             With systematic errors out of the way, let's move onto measurement errors. Measurement errors are errors with the measurement instruments. There is the error of not a consistent amount of detergent because some of it had stuck to the measuring cup. Also, the cloth pieces may have been maybe a 1.12 on our color scale, but we would not be able to catch the slight difference with our untrained eyes. Another error that may not be consistent is the water and dye. Even though we measured, there could be a drop or two of water that was added or missing, same for the dye. Additionally, going back to stirring, we may have stirred the dye for a minute longer or shorter from one bucket than another. The cloth squares might have also been a little smaller or a little bigger compared to others. They also might not have been perfect squares.

           There are also random errors. The packages of dye may have been less effective or more effective throughout packets. They may have been more moist or dry, which would change according to the humidity of the room and the temperature. The nylon could have had other materials and chemical substances mixed in it which could have affected how much it absorbed the dye. The wool could have come from an animal who produced a lot of body oil, hence coating the fibers and making them less impervious to dye. These are all not preventable and could result in variations of the color value throughout the experiment.

           Now that all the errors have been covered, there is one more category that needs to be explained. It is simply that each type of cloth was made for different reasons than others were made for. Cotton is used in clothing, bed sheets, and other types of items, so it makes sense that it would be the most receptive of the dye. Unlike cotton, nylon is not often used in clothing by itself, it's usually mixed with other materials that not only repel dye but also fail to absorb water. Nylon is used as a substitute for silk in primarily hot air balloons. The dying manufacturers had even warned in the directions to not use polyester for it's unabsorbed qualities. Polyester and nylon just couldn't hold up their natural-fibered counter parts.