Many clients throughout the Alpine 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.
Alpine 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.
Vacuum Forming With a Vacuum Formable Plastic Sheet
Plastic corrugated or corrugated plastic as it is commonly referred, is one of the main products used in the reusable packaging industry. Sure, there are other items in this packaging sector such as molded totes or heavy gauge thermoformed plastic trays, but nothing says returnable packaging quite like plastic corrugated. Virtually anything that is made of paper corrugated can be duplicated using corrugated plastic. These items include plastic corrugated boxes, stackable totes, corrugated plastic partitions and dunnage, as well as material handling carts and racks using this resilient material as a main component.
The following tips regarding plastic corrugated will help you think like packaging professional the next time a reusable packaging application crosses your desk.
1. Try different styles of plastic corrugated containers before purchasing a production quantity to make sure you have all of the features your project needs. The best catalog descriptions in the world are no substitute for testing corrugated plastic in real situations.
2. Test different thicknesses of plastic corrugated with your particular application. Corrugated plastic is available in thicknesses ranging from 2mm to 13mm. You may be able to save money by using thinner material.
3. Check to see if your supplier has stock sheets of plastic corrugated from which they can produce your corrugated plastic containers. This will result in a quicker lead time.
4. Compare prices between using a stock sheet of plastic corrugated which is then die cut to your container size and having custom run corrugated plastic sheets for your project. Custom run plastic corrugated sheet sizes should be more efficient for your supplier to run which will result in a lower price per container.
5. Consider applying a printed label instead of direct printing or silk screening on plastic corrugated. Labels on plastic corrugated can look just as nice, will last longer, and cost less than silk screening on corrugated plastic.
6. Ask if a utility or recycled grade of corrugated plastic is available. Utility plastic corrugated is less expensive than virgin material.
7. Evaluate the cost of running a small production run of plastic corrugated (less than 100 pieces) using sample making equipment instead of purchasing a die. There could be a significant price difference.
8. Consider having plastic corrugated partitions and dunnage rod locked so they don't come apart. Corrugated plastic dividers made this way are more stable and last longer.
9. Test plastic corrugated against your product to make sure it doesn't scratch. Plastic corrugated is generally non-abrasive but there are some products that are susceptible to scratching. For these applications use plastic corrugated lined with a non-abrasive coating such as spunbond fabric or even cross link foam.
10. Consider corrugated plastic for internal dunnage that traditionally has been done using wood, steel, or aluminum. Recent advances in plastic corrugated technology allow it to be nailed, screwed, and bolted which results in reusable packaging that is incredibly strong yet lightweight.
In closing, these tips should help the novice as well as the seasoned veteran find alternatives to paper packaging while reducing their cost. In this day and age of pressure for cost reductions, plastic corrugated returnable packaging solutions can help any company improve their bottom line.