Hot air applications are used widely in various systems across industries, offering versatility and precision in numerous processes. These systems are crucial in achieving temperature-dependent outcomes from food production to manufacturing, research, and healthcare.
Secomak’s controlled hot air applications and solutions are ideal for digital printing, shrinking, curing, and systems requiring industrial ovens. Our range of industrial hot air heaters and blowers can be combined in assorted configurations to achieve a system’s ideal hot air output.
It’s one thing having hot air, but it’s another matter to control it precisely. In many industries, achieving but not exceeding a desired temperature is essential to obtain the desired result. Additionally, the heating rate must be considered to avoid thermal shock. Thus, it’s vital that the controlled heat application adheres to its settings and is adjustable as needed.
Achieving Perfection in Digital Printing
Digital printing techniques like inkjet and laser printers rely on precise temperature control to ensure the quality and durability of printed materials. One of the ways controlled hot air is used in digital printing is to dry and fix ink or toner. Here’s how:
In inkjet printing, liquid ink is sprayed onto a substrate, e.g., paper or fabric. The ink must dry quickly to ensure it adheres to the substrate and doesn’t smudge. To speed up drying, hot air is directed at the printed area to evaporate the liquid solvent in the ink, leaving behind only the colour on the substrate.
Laser printing uses toner, which consists of tiny particles of pigmented plastic powder. Once the toner is applied to the paper, it must fuse to its surface. This is achieved by using controlled hot air to heat the paper and toner to a specific temperature, causing the toner’s plastic particles to melt and adhere to the paper. This process is known as “fixing” or “fusing.”
Aside from drying and fixing ink and toner, controlled hot air is used in digital printing in the following ways:
- Maintaining print quality: Controlled hot air is sometimes used to maintain a stable temperature within the printing system to ensure ideal ink viscosity, promoting correct and consistent ink flow.
- Preventing paper curling: Sometimes, the high temperatures during the printing process can cause paper to curl or warp due to moisture evaporation. Controlled hot air can prevent this issue by evenly distributing heat across the paper and minimising temperature-related distortions.
- Enhancing colour vibrancy: A digital printing technique called dye-sublimation uses controlled hot air to improve the vibrancy and durability of printed colours. For this technique, heat turns solid dye particles into a gas that permeates the printing substrate, becoming a permanent part of the material.
Shrinking: Striking the Right Temperature Balance
Controlled hot air is commonly used in packaging in the heat-shrinking process. Heat shrinking involves applying controlled heat to a thermoplastic material to cause it to shrink and conform tightly around a container or object. The heat-shrinking process is widely used in various industries for packaging, labelling, bundling, and securing products.
For heat shrinking to work, the material used must be heat-shrinkable. Common materials include polyethylene, polypropylene, PVC, and PTFE. Once printed, the material is converted to a sleeve, cut to size, and slid over the object or container.
During the next step, controlled hot air is applied to the sleeve to cause it to soften and shrink to conform to the object it covers. A heat gun is suitable for small-scale shrinking, but a hot air drying machine or heat tunnel is better suited for large-scale manufacturers.
Each controlled heating method must precisely control temperature and airflow to ensure even and consistent shrinkage. If the temperature is too low, the material won’t soften and shrink enough to conform to the object it covers. On the other hand, if the heat is too intense or uneven, it can cause the material to melt, distort, weaken or compromise the object.
The World of Polymer Curing in Manufacturing
Polymer curing is a heat-dependent step in manufacturing and processing polymers, which helps transform raw polymer materials into their final solid and durable forms. This process is fundamental in industries that manufacture composites (e.g., aerospace) and produce adhesives and coatings.
Once a polymer is prepared and applied or moulded, it requires controlled heat to cure it to its final state. The temperature and duration of heating are carefully tailored and maintained according to the specific polymer being cured and the desired outcome. This is because the temperature and duration of heating will impact the polymer’s strength, hardness, and chemical resistance.
Controlled heat is crucial in the polymer curing process for the following reasons:
- It activates catalysts and curing agents that facilitate cross-linking and polymerisation,
- It increases energy input,
- Controlled heat allows manufacturers to tailor the properties of the cured polymer to meet specific requirements,
- It provides uniformity through even heat distribution, ensuring even curing throughout the polymer and preventing defects and inconsistencies in the final product.
For deeper insight into how Secomak’s controlled heating solutions can help with polymer curing, check out our Marshall Aerospace Composite Curing case study.
Ovens: The Classic Controlled Hot Air Systems
Controlled hot air systems in industrial ovens are used for baking, drying, curing, and heat treatment applications. These systems use industrial heaters and blowers for precise temperature control and uniform heating. Some examples of industrial ovens and their uses are discussed below:
- Ageing ovens: Ageing ovens accelerate the ageing or drying process of rubber, plastics, and adhesives. This system’s controlled hot air helps maintain consistent conditions essential for reliable testing and quality control.
- Annealing ovens: They work by heating materials to specific temperatures and then cooling them slowly to relieve stress, improve the material’s properties, or enhance their machinability.
- Batch ovens: Batch ovens are versatile for various heat-treating processes, including curing, drying, and preheating.
- Cleanroom ovens: Cleanroom ovens are used for applications such as semiconductor manufacturing. They feature controlled hot air systems to maintain strict cleanliness and temperature requirements.
- Composite curing ovens: These are used in the aerospace and automotive industries to cure composite materials. This ensures components’ structural integrity and quality, e.g., carbon fibre composites.
- Continuous conveyor ovens: These ovens (or heat tunnels) feature a conveyor belt system that transports products through a heated chamber. The controlled hot air system ensures even and consistent heating for products, e.g., food items, automotive components, and electronics.
- Convection ovens: These ovens use fans to circulate hot air evenly throughout the chamber. They are commonly used in baking and cooking to ensure uniform heating and consistent results.
- Drying ovens: Drying ovens remove moisture or solvents from materials like textiles, ceramics, and pharmaceutical products. Controlled temperature and airflow are essential for efficient and uniform drying.
- Powder coating ovens: Powder coating ovens use controlled hot air to cure powdered coatings on various surfaces. Temperature control is essential to achieve the desired finish and durability of the coating.
- Vacuum ovens: These ovens combine controlled hot air with reduced atmospheric pressure to facilitate processes, e.g., drying, degassing, and curing sensitive components or materials.
Conclusion
As is evident, controlled hot air plays a critical role in many applications across many industries. It is used for curing, fixing, shrinking, baking, cleaning, and many other applications. These applications require precision in heating and airflow to manufacture consistent and reliable materials and products.
If your business needs controlled hot air or your hot air is less regulated than you’d like, contact Secomak to tailor the perfect solution.
