Generally speaking, colour pipette is composed of dozens of components, but for users, they usually only need to understand a few important components, namely the body, handle, sealing ring, and piston.
Next, let me briefly introduce the different functions and characteristics of these components of the colour pipette.
colour pipette
Body: The body needs to be corrosion-resistant and wear-resistant, and at the same time, this component also requires very low thermal conductivity. If the hand holds the pipette for a long time, it is possible that the temperature inside the pipette will be transmitted to the internal components through the gun body, causing the temperature inside the pipette to rise and the air pressure to increase, thereby affecting the accuracy of the pipette. Therefore, the material of the gun body is mostly plastic, among which PVDF (polyvinylidene fluoride) is a better material;
Handle: The requirements for handle are generally divided into the following two points: 1) Wear resistance: The lower end of the handle needs to constantly rub against the suction head; 2) Impact resistance: In China, due to the use of low-quality suction heads in most cases, a large amount of force is required when installing the suction heads. In order to solve these two problems, some brands use metal materials at the lower end or even the entire handle of their sleeve; Some brands put effort into design to reduce friction between the handle and the suction head, and to minimize the force required to install the suction head, thus lowering the material requirements for the handle.
Pistons: There are generally three reasons for the material of pistons, namely stainless steel, plastic, and ceramic. Among them, stainless steel has good mechanical processing performance, is easy to achieve sealing, has high strength, is not easy to deform, and can ensure very high accuracy. It is a common choice for pipettes, but its disadvantage is poor corrosion resistance; The advantage of plastic lies in its easy molding and low cost, but the disadvantage is that it is prone to deformation and difficult to maintain high sealing, thereby reducing the accuracy of the pipette; The outstanding feature of the latter ceramic is corrosion resistance, but it is difficult to process and the piston surface cannot be as smooth as stainless steel. Therefore, the help of lubricants is essential to maintain sealing. Moreover, if the piston is used as a small range pipette, its mechanical strength will be poor due to its small diameter.
Sealing ring (installed on the piston). Because the sealing ring may be "attacked" by various chemical media and have a significant impact on its sealing performance, it needs to maintain its youthfulness for a long time, so it is made of corrosion-resistant and non deformable materials such as PTFE (polytetrafluoroethylene).
