Some of the modern gadgets that make our lives more comfortable every day have been made possible by vacuum forming. Without this versatile manufacturing process, life-saving medical devices, food packaging, and automobiles might look very different.
Vacuum forming is a manufacturing method for making plastic products. During the vacuum forming process, the plastic sheet is heated up and then, by suction, it is drawn around the mold, enclosing its surface.
Vacuum forming is used for a wide range of manufacturing tasks, from small custom parts made on benchtop devices to large parts made on automated industrial equipment.
Thermoforming is a manufacturing process in which plastic sheeting is heated to a highly elastic state, then molded with a mold and then cut to form the final part or product. Vacuum forming and blow molding are two types of thermoforming. The main difference between blow molding and vacuum forming is the number of molds used.
Vacuum forming is the simplest type of thermoforming of plastics, in which one mold is used and air is pumped to obtain the desired geometry of the part. It is perfect for making products that need to be precisely shaped on one side only, such as food packaging or electronics packaging.
Locking: A sheet of plastic is placed in a clamping frame and locked in place.
Heating: The plastic sheet is softened with a heat source until it reaches the appropriate forming temperature and becomes malleable.
Air evacuation: The frame, with a heated, flexible plastic sheet, is lowered over the mold and pulled out by evacuating the air from the other side of the mold. For negative (or convex) shapes, tiny holes must be drilled in the kinks so that the air can effectively pull the thermoplastic sheet into the corresponding shape.
Cooling: After the plastic has spread around / in the mold, it should cool down. In the manufacture of large items, fans and / or cold fog are sometimes used to speed up this stage of the production cycle.
Removal: After cooling, the plastic is removed from the mold and removed from the frame.
Finishing: The finished part must be cleaned of excess material, and its edges can be cut, sanded or smoothed.
Affordable price
Particularly for small batch production (250-300 units per year), vacuum forming is generally more economical than other production methods such as injection molding of plastics. The affordable cost of vacuum forming is largely due to the lower cost of manufacturing tooling and prototypes. Depending on the surface area of the parts to be manufactured and the size of the clamping frame, injection molding tooling can cost two to three times more than plastic thermoforming or vacuum forming tooling.
Preparation time
Vacuum forming offers faster turnaround times than other traditional production methods because tooling can be made faster. Vacuum forming tooling typically takes half the time to fabricate than injection molding tooling. If 3D printers are used to create the molds, production times can be reduced even further.
Flexibility
With vacuum forming, designers and manufacturers can test new designs and create prototypes without high overhead or time delays. Molds can be made from wood, aluminum, structural foam or 3D-printed plastic, so they are relatively easy to replace and / or modify compared to other manufacturing processes.
Manufacture of sterile and food grade materials
Vacuum forming is often used by manufacturers to produce food containers and medical products because it produces plastics that can be sterilized or kept clean. For example, high density polyethylene (HDPE) is often used for vacuum forming food storage containers.
In addition, due to the resistance of HDPE to acidic compounds, it is a suitable material for vacuum forming cleaning agent containers. Vacuum forming plastics for medical devices are used to make items that can be sterilized and meet strict medical and / or pharmaceutical regulations.
While vacuum forming offers significant benefits, it also has certain limitations. The vacuum forming method can only be applied to parts with relatively thin walls and simple geometries. In this case, the wall thickness of the finished parts can be uneven, and concave parts requiring deep drawing are difficult to manufacture using vacuum forming.
In addition, while vacuum forming is often the most cost-effective option for small to medium batch production, in the case of high batch production, other plastic production methods can be more cost effective.
In the realities of modern society, it is difficult to spend even one day without colliding with an object that was obtained as a result of vacuum forming. This manufacturing process is used to produce a wide variety of parts for a wide variety of industries, including:
Automotive and transport
Vacuum forming is used to make various parts for cars, buses, ships and aircraft. In the automotive industry, everything from floor mats to bumpers to even truck platforms is vacuum formed.
Vacuum forming allows automotive companies to produce parts in a variety of colors and specifications, while allowing designers to test new prototypes during development.
Molds for vacuum forming made of wood
Wooden molds are much more durable than clay molds and can withstand from several hundred to several thousand uses. Wooden molding is also used to produce industrial boxes and containers for machinery.
Packaging and stands
If you buy an item that comes in a plastic package that matches it, the chances are good that the package was vacuum formed. Razors, toothbrushes, electronics, makeup, and cleaning products often come in vacuum-formed packaging.
In addition, marketing racks, marketing racks, and end-to-end product displays in grocery stores are often vacuum formed.
Food packaging
Vacuum forming is often used to make food packaging because it can process plastics that come in contact with food into products that are easy to disinfect.
Fruit containers, plastic egg boxes, and cracker stands are often vacuum formed.
Consumer goods
The spectrum of consumer products manufactured using vacuum forming is very wide. It includes items such as toys for children, travel goods and home furnishings.
The medicine
Medical devices and components, which must be sterile or resistant to contamination, are often vacuum formed and include medical packaging, pharmaceutical pill holders, hospital bed components, and the exterior of MRI and CT machines.
Custom products and special effects
Vacuum forming is used in various industries to create custom and one-off items, such as props for special effects.
A wide variety of thermoplastics are used for vacuum forming. Among the most commonly used plastics:
Acrylic (PMMA)
Acrylonitrile Butadiene Styrene (ABS)
Polycarbonate (PC)
Polyethylene (PE)
Polyethylene terephthalate glycol (PETG)
Polypropylene (PP)
Polystyrene (PS)
Polyvinyl chloride (PVC)