Many clients throughout the Valmy area have heard the term vacuum forming, but they do not know what it really means, and they don’t know what it does or how it can help them in their business. Vacuum forming is a procedure that can shape performance plastic sheet materials into many different forms, and it is one of the best ways to make a host of different plastic products.
How Does it Work?
A type of thermoforming, vacuum forming, is a process by which a plastic sheet or thin sheet of plastic, such as a PVC sheet, is heated up so that it becomes malleable. The heating process includes the use of aluminum plates and infrared heaters. The heat application will come from the top and the bottom so that it is uniform and will provide the best results.
Once the heat finally reaches the proper temperature (which can differ based on the thickness of the sheets in use) the vacuum will mold the sheets to form the product. The vacuum is able to provide an airtight environment, which is going to be better for the overall molding process.
Products from Vacuum Forming
With this type of thermoforming, one could create countless types of products, and you may find that your company could benefit greatly from the process. One of the most common products using vacuum forming today are children’s plastic toys, but that’s just one of the possibilities. Product packaging is another option, and it is one most companies that create, manufacture, package and sell products could use. Most of the plastic items that you see around the home and office have gone through some type of thermoforming, and it’s often the vacuum process.
Valmy Best Plastic Sheet Supplier
Plastics cover a broad field of organic synthetic resin and may be divided into two main classifications - aerospace thermoplastics _ and aerospace thermosetting plastics. Thermoplastics may be softened by heat and can be dissolved in various organic solvents.
Thermoplastics may be softened by heat and can be dissolved in various organic solvents. Two kinds of transparent thermoplastic materials are commonly employed in windows, canopies, etc. These are known as acrylic plastics and cellulose acetate plastics. Cellulose acetate was used in the past but since it is dimensionally unstable and turns yellow after it has been installed for a time, it has just about passed from the scene and is not considered an acceptable substitute for acrylic. Acrylic plastics are known by the trade names of Lucite or Plexiglas and by the British as Perspex and meet the military specifications of MIL-P-5425 for regular acrylic, MIL-P-8184 -~ 184 for craze-resistant acrylic.
Aerospace Thermosetting Plastics.
Thermosetting plastics do not soften appreciably under heat but may char and blister at temperatures of 240 to 260 'C (400 to 500 °F). Most of the moulded products of synthetic resin composition, such as phenolic, urea-formaldehyde, and melamine formaldehyde resins, belong to the thermosetting group. Once the plastic becomes hard, additional heat will not change it back into a liquid as it would with a thermoplastic.
Storage and handling.
Because transparent thermoplastic sheets soften and deform when they are heated, they must be where the temperature will never be excessive.
Transparent acrylic plastics get soft and pliable when they are heated to their forming temperatures and can be formed to almost any shape. When they cool, they retain the shape to which they were formed. Acrylic plastic may be cold-bent into a single curvature if the material is thin and the bending radius is at least 180 times the thickness of the sheet. Cold bending beyond these limits will impose so much stress on the surface of the plastic that tiny fissures or cracks, called crazing, will form.
Simple Curve Forming. Heat the plastic material to the recommended temperature, remove it from the heat source, and carefully drape it over the prepared form. Carefully press the hot plastic to the form and either hold or clamp the sheet in place until it cools. This process may take from ten minutes to one-half hour. Do not force-cool it.
This type of forming is normally used for such parts as canopies or complex wingtip light covers, and it requires a great deal of specialized equipment. There are four commonly used methods, each having its advantages and disadvantages.
Stretch forming. Preheated acrylic sheets are stretched mechanically over the form in much the same way as is done with the simple curved piece. Special care must be taken to preserve uniform thickness of the material, since some parts will have to stretch more than others.
Male And Female Die Forming. This requires expensive matching male and female dies. The heated plastic sheet is placed between the dies which are then mated. When the plastic cools, the dies are opened.
Aerospace Vacuum Forming Without Forms. Many aircraft canopies are formed by this method. In this process a clamp with an opening of the desired shape is placed over a vacuum box and the heated sheet of plastic is clamped in place. When the air in the box is evacuated, the outside air pressure will force the hot plastic through the opening and form the concave canopy. It is the surface tension of the plastic that shapes the canopy.
Aerospace Vacuum Forming With A Female Form. If the shape needed is other than that which would be formed by surface tension, a female mould, or form must be used. It is placed below the plastic sheet and the vacuum pump is connected. When air from the form is evacuated, the outside air pressure will force the hot plastic sheet into the mould and fill it.
Polystyrene Sheets: It Has Many Uses
We use many products with little to no regard as to how they came to be. One such product is called polystyrene. This is a type of polymer plastic that is used in manufacturing, construction, and for household items that we use everyday. Polystyrene sheets can be molded to specific shapes and sizes and are used in a variety of ways. It can be made into all different types of colors, but is most commonly found to be white or clear.
In manufacturing and construction, polystyrene sheets are used as a packing material. Think of the box your fragile electronics come in. There is usually that hard foam surrounding your purchase, protecting it from bumps and drops, right? This is an insulator formed from expanded polystyrene sheets. In construction, polystyrene sheets are used as molds for concrete or other building materials. They are also used as a form of insulation.
When thinking of it's household uses, you can bet that polystyrene sheets are used in ways that you would never believe! Those little Styrofoam cups we drink from are made from that product. The yogurt you may have eaten for lunch was put into a cup made from it too! Polystyrene is used to make CD and DVD cases, molded to form the handles for disposable razors, and used in many toys that your children may have. It is also a popular product used in many craft materials.
So, why is this stuff so great? For a lot of reasons!
It is lightweight and very easy to work with.
It can be molded into virtually any shape or size, come in large and small sheets or blocks, and can fit easily into a box.
It is a good insulator, protecting objects from water and water vapor, as well as fungus and mildew.
It protects fragile objects from drops, bumps and scratches that may otherwise cause damage.
Polystyrene sheets are available for purchase in many home improvement stores for personal use. You can cut them to the size you need quite easily, or they may be able to cut them at the store, just ask the salesperson if they offer the service. For large quantities used for more commercial purposes, companies on the Internet will be able to fill your order to your exact specifications.