With the surge in popularity of vacuum insulated bottles, their shapes have diversified remarkably. You might wonder how these bottles are made. Let’s delve into the manufacturing process known as “hydroforming.”
What is Hydroforming?
The hydroforming process is an advanced manufacturing technology for manufacturing hollow integral components by internal high-pressure molding.
The principle is to take the pipe as a blank, with water as the transmission medium, the water with ultra-high-pressure force into the pipe, so that it produces pressure on the inner wall of the pipe, with the punch sealing the ends of the pipe, the use of axial feed for pipe forming to provide filler, so that the outer wall of the pipe is completely tight to the mold cavity, so as to obtain the desired shape of the part.
Not only insulated cups, stainless steel pipe tee, copper pipe tee, stainless steel clamping pipe, automotive shaped fittings (such as corrugated pipe), bathroom faucets, kettles and other common daily tube parts and supplies are basically made using the water uplift molding process.
This internal pressure causes the tube to expand against the inner walls of a mold cavity. The tube ends are sealed with punches, which apply axial force to ensure the tube conforms precisely to the mold shape. This process allows for the creation of the desired part shape.
Hydroforming is not just used for vacuum insulated bottles; it’s also employed in producing stainless steel and copper tees, stainless steel press-fit pipes, automotive components like bellows, bathroom faucets, and hot water kettles, among other tubular parts commonly seen in everyday life.
Hydroforming Steps for Insulated Bottles
Material Preparation:
1.Choosing Materials: Typically, both the inner and outer walls of the thermos cup are made from stainless steel due to its excellent corrosion resistance and mechanical strength.
2.Preparing the Tubes: Stainless steel tubes, usually cylindrical in shape, are selected and prepared. The dimensions and thickness of the tubes are chosen based on the design specifications of the final product.
Initial Shaping:
1.Mechanical Processing: The stainless steel tubes are pre-processed to approximate the target shape and dimensions. This step primarily involves conventional machining techniques such as cutting, turning, or milling to achieve a smooth, blemish-free surface.
High-Pressure Fluid Injection:
1.Loading into Molds: The pre-shaped stainless steel tube is placed into a mold. The mold’s internal shape matches the final desired shape of the thermos cup.
2.Injecting High-Pressure Fluid: High-pressure fluid (usually water or another suitable liquid) is injected into the tube. The pressure can reach several thousand bars, causing the metal tube to expand and conform tightly to the mold’s interior surface, forming the complex shape required.
Shaping and Cooling:
1.Maintaining Pressure: Once the metal tube fully conforms to the mold, it is held under pressure for a specified period to stabilize the shape and reduce any elastic recovery effects.
2.Cooling: The component is then cooled down, which helps to solidify the shape and prevent deformation after pressure release.
Releasing Pressure and Removing from the Mold:
1.Pressure Release: After the shaping is complete, the high-pressure fluid is slowly released to avoid any sudden shape changes or damage.
2.Removing the Formed Component: The newly formed metal part is extracted from the mold.
Post-Processing:
1.Trimming and Surface Finishing: The formed component undergoes further processing to trim excess material and refine the surface. Techniques such as polishing, sandblasting, or electroplating may be used to achieve a high-quality finish.
2.Assembly and Vacuum Sealing: The inner and outer walls of the thermos cup are assembled together and welded to create a vacuum seal. This vacuum layer is crucial for the thermos cup’s insulating performance, effectively minimizing heat transfer.
Advantages of Hydroforming
Reduced Forming Steps:
In the hydroforming process, the punches not only seal the tube but also provide axial force, which helps in material feeding and enhances the tube’s forming capability. This allows for multi-section parts to be formed in a single operation. Moreover, the good overall integrity of hydroformed parts means that the amount of welding required is reduced. Some hydroformed components may not require assembly welding at all.
Higher Material Utilization and Weight Reduction:
Hydroformed parts typically require only one set of molds, while traditional stamping and welding often require three or more steps and additional molds, which significantly increases tooling and subsequent manufacturing costs. Fewer steps lead to less process waste. Hydroformed parts can achieve up to a one-third reduction in weight compared to stamped and welded assemblies, and material utilization can improve by about 40%.
High-Quality Products:
Parts made using hydroforming have excellent integrity, leading to higher strength and stiffness. The reduced number of welds means fewer stress-concentrating weld joints, resulting in higher-quality parts.
Reduced Pollution:
Hydroforming is an environmentally friendly forming technique. Compared to traditional stamping and welding, it generates less noise pollution and creates a better working environment. Hydroforming is faster, simpler, more efficient, and less costly than traditional tube processing methods. Additionally, it allows for a greater variety of shapes and higher degrees of customization.
This process not only meets the aesthetic and functional needs of various consumers but also brings better economic returns for businesses and water bottle manufacturers. Consequently, hydroforming is set to become the mainstream technique for tube processing.
Examples of Hydroforming Applied in Insulated Bottle Manufacturing
In the production of insulated bottles, the hydroforming process is particularly effective for shaping the inner and outer walls. Here’s how some renowned brands utilize this technology:
Hydro Flask and YETI:
These brands employ hydroforming techniques to manufacture the inner and outer walls of their bottles. This process imparts exceptional strength and insulation performance to the bottle bodies.
The hydroforming method enables the creation of bottles in a seamless manner. This reduces the risk of liquid leakage and enhances the product’s durability and aesthetics.
Overall, hydroforming technology provides a highly efficient, precise, and quality-driven solution for insulated bottle manufacturing. It ensures that modern insulated bottles are not only functionally superior but also visually appealing.
