The Miswak Toothbrush is a toothbrush with bristles that we innovate using
miswak and a handle made of plastic material. Polypropylene type plastic
material made from a combination of propylene monomers. Miswak Toothbrush
Research was conducted using an injection molding system. In the injection
molding process for the manufacture of miswak toothbrushes, product shrinkage
defects often occur due to the inappropriate temperature and injection pressure.
This study aims to determine the effect oftemperature and injection pressure time,
and the interaction between temperature and injection pressure time on the
weight and dimensions of the Siwak Toothbrush product using polypropylene
material. The method for data collection is experimental and actual data
processing methods. This study used temperature variations of 230 °C, 235 °C,
240 °C, 245 °C, 250 °С, 255 °C and 260 °C, and the injection pressure time was
12 seconds. The results of this study indicate that the lightest Siwak Toothbrush
product weight is produced from a combination of the lowest level of the
independent variable temperature of 230 °C and the highest of 260 °C. Produces
the smallest product dimension shrinkage using a temperature of 235 °C, with the
following results, product length shrinkage: – 1.74%, product width shrinkage: -
1.26 %, high shrinkage product: - 7.15 %, shrinkage in diameter of 1 siwak: –
0.15% and shrinkage in diameter of 2 miswak: – 1.15 %, and produce the
smallest product weight loss using a temperature of 235 °C, with the following
results, product weight loss: -3.33%.
Keyword : Injection Molding, Injection Temperature Variation, polypropylene.