Can Carbon Fiber Heating Tubes Enhance Blow Molding Machines?

Plastic bottles are now widely used across various industries in daily life, including the beverage industry, daily chemical industry, food industry, household goods industry, and pharmaceutical and chemical industries. Plastic bottles have become the dominant type of container in contemporary society, having long replaced traditional glass or metal bottles. The production of plastic bottles requires PET multifunctional blow molding machines. The working principle of the blow molding machine is to heat the plastic preform to a certain temperature, and then use a special process to blow it into the desired shape and size. So, can carbon fiber heating tubes be used in blow molding machines? The answer is yes.

Common Heating Tubes in Blow Molding Machines

Currently, the most commonly used heating tubes in blow molding machines are tungsten filament infrared heating tubes. However, infrared heating tubes have a drawback: due to the tungsten filament slowly sublimating at high temperatures and reacting with trace amounts of oxygen in the protective gas, the heating filament will eventually burn out over time, which is an unavoidable issue.

Why Can Carbon Fiber Heating Tubes Be Used in Fully Automatic Blow Molding Machines?

1. Similar Shape and Structure:

Carbon fiber heating tubes share the same shape and structure as infrared heating tubes. Both have similar external structures and materials, which can be made from either transparent quartz tubes or ruby quartz tubes. All the advantages of infrared heating tubes, such as acid and alkali resistance, high temperature tolerance, quick startup speed, and low thermal inertia, are also present in carbon fiber heating tubes.

2. Differences in Heating Elements:

The key difference lies in the heating element material. Infrared heating tubes use tungsten filaments, while carbon fiber heating tubes use carbon fibers. Carbon fiber is a new material that has gained popularity in the last decade due to its excellent physical and chemical properties, and it is widely used in various fields. The biggest advantage of carbon fiber over tungsten filament is that under the protection of inert gas or in a vacuum environment, the physical properties of carbon fiber are much more stable—several times more stable than tungsten filament. This means that as long as the vacuum environment is maintained, carbon fiber heating elements can operate continuously, a significant advantage that tungsten filaments cannot match.

3. Spectral Performance:

Tungsten filament infrared heating tubes, after being adjusted by external quartz tubes or other parameters, can control the wavelength between 1.06-1.2 µm. In contrast, carbon fiber heating tubes have a radiation range of 1.5-15 µm. This wavelength range has a larger overlapping area with the infrared spectrum absorbed by the functional groups in plastics, which is why the analysis of plastic components often uses infrared spectrometers. Therefore, carbon fiber heating tubes are more suitable for heating plastic parts.

Although infrared heating tubes currently perform quite well, which is why many manufacturers have not introduced new carbon fiber heating tube blow molding machines, the main concerns are heating effectiveness and lifespan. However, these concerns are largely unnecessary.