Teflon Dispensing Needle: Uncovering Its Subtle Manufacturing Process

In the microcosm of precision manufacturing, dispensing is a pivotal process, and the Teflon dispensing needle is the core component to achieve accurate dispensing. With its unique non-stick, chemical stability and other advantages, it has made its mark in electronics, medical, semiconductor and many other fields. Today, let us explore the Teflon Dispensing Needle's delicate manufacturing process.

Raw materials are carefully selected

Teflon, scientifically known as polytetrafluoroethylene (PTFE), is a key material in the manufacture of dispensing needles. When choosing raw materials, manufacturers will strictly control its purity and performance indicators. High purity Teflon ensures that dispensing needles have excellent non-stick properties and chemical resistance. Imagine if the purity of the raw material is not up to standard, the presence of impurities may weaken the properties of Teflon, resulting in glue residue and clogging in the needle, affecting the accuracy and efficiency of dispensing. Moreover, different application scenarios have different requirements for Teflon raw materials, such as molecular weight distribution and other characteristics, for example, in electronic chip dispensing, the raw materials need to have more stable performance to ensure that the needle will not have any adverse effects on the chip in high-precision dispensing operations.

Pre-treatment opens the door to processing

Due to the special physical properties of Teflon, it can not be directly melt processed like ordinary plastics. Therefore, the pre-processing link becomes an important start in the manufacture of Teflon dispensing needles. First, the raw Teflon material is cold pressed, which is like using a mould to ‘compact’ the loose material and initially shape it into a blank close to the desired shape. This step requires precise control of pressure and time. Too much or too little pressure and too much or too little time may result in an uneven density of the blank, which in turn affects subsequent processing and the quality of the final product. Next, the cold-pressed blanks are sintered to allow the Teflon particles to bond more closely with each other at high temperatures to enhance the strength and stability of the blanks and prepare them for subsequent moulding processes.

Moulding process to shape precise forms

Extrusion

After pre-treatment, Teflon blanks are turned into tubes through the extrusion process. In this process, the blank is fed into a specially designed extruder and, under high temperature and pressure, is extruded into a tube like toothpaste. But this ‘toothpaste’ process is not so simple, and requires precise control of the extruder's temperature, pressure and extrusion speed and other parameters. If the temperature is too high, Teflon may decompose, destroying its molecular structure and properties; if the temperature is too low, smooth extrusion cannot be achieved. Pressure and extrusion speed must also be properly coordinated to ensure that the extruded Teflon tube has uniform wall thickness and internal diameter, otherwise it will directly affect the dispensing precision of the dispensing needle and the smoothness of the glue.

Precision Processing

The extruded Teflon tube is just a basic form, to become a real dispensing needle, precision processing is also needed to shape the tip part. With the help of high-precision CNC lathes, grinders and other equipment, one end of the Teflon tube is finely machined. Operators need to precisely control the machining parameters according to the design requirements, so that the dimensions of the needle tip, such as the hole diameter and angle, can be made to the nearest millimetre. For example, in some semiconductor packaging dispensing applications that require high precision, the aperture error of the needle tip must be controlled at the micron level, so as to ensure that the amount of adhesive dispensed each time is precise and accurate, and to satisfy the high-precision requirements of chip packaging.

Surface treatment to enhance performance

Smooth treatment

Even though Teflon itself already has good non-stick properties, in order to take the performance of the dispensing tip to the next level, its surface needs to be further smoothed. Chemical polishing or physical grinding can be used to remove minor surface imperfections and burrs, smoothing the inner and outer surfaces of the needle. As a result, the glue is less resisted as it passes through the needle and can flow out more smoothly, reducing the residue of glue inside the needle and improving the consistency and efficiency of dispensing.

Enhanced wear resistance

In practice, Teflon dispensing needles are frequently exposed to a variety of glues and fluids, and in order to extend their service life, they are also treated with a surface treatment that enhances wear resistance. By coating a layer of special wear-resistant material on the surface of the needle, or using ion implantation and other technologies to change the microstructure of the surface of the needle, making it more wear-resistant. In this way, even in long-term high-frequency dispensing operations, the needles can maintain good performance, reducing the frequency of replacement and saving production costs.

Strict Inspection to Ensure Quality

Appearance Inspection

The manufactured Teflon dispensing needles are firstly inspected for appearance. Through manual visual inspection or with the help of automated visual inspection equipment, carefully check whether the surface of the needle is smooth and flat, with or without cracks, bubbles, deformation and other defects.