Plastic Thermoforming FAQ

Plastic thermoforming is the process where we heat a thermoplastic sheet to a formable temperature, then form it into a mold according to your drawing. Under a certain temperature curvature, vacuum pressure and time, the plastic products will be formed into your desired and good quality shapes.

WeProFab is one of the top thermoforming companies who can manufacture thermoforming products for a wide range of applications, such as thermoforming packaging, plastic toys, material handling trays, plastic pallets, plastic guards, dunnage trays, plastic bezels, plastic totes and bins, polycarbonate shields, acrylic domes, signage, different kinds of plastic components, plastic enclosures, plastic housings, and many custom thermoforming products.

WeProFab is the thermoforming manufacturer who has both vacuum forming and pressure forming technologies.

During the vacuum forming, a plastic sheet will be stretched on the female mold with a cavity, the vacuum forming equipment will heat the plastic sheet to a specific softening point, then the vacuum pressure force the plastic sheet to form into the mold to have the right shape.

During the pressure forming process, it is not only the vacuum that helps in forming the thermoplastic sheet into the female mold but also an air pressure on the other side that forces it onto the mold. Forces on both sides enable us to handle heavy gauge sheets as well as textures and other details for more precise dimensions.

WeProFab is a leading thermoforming plastic manufacturer who can handle thin gauge thermoforming and heavy-gauge thermoforming. Thin gauge thermoforming uses the continuous thermoforming machine with die-cut online to produce plastic packaging and trays. Heavy-gauge thermoforming uses thick plastic sheets to do vacuum forming or pressure forming to make large and heavy plastic products such as plastic enclosures, plastic trays, polycarbonate shields, and many other plastic products.

WeProFab is also one of the thermoforming plastic sheet suppliers who can handle many different plastics. We can thermoform acrylic to products such as acrylic domes and acrylic bathtub. We can thermoform polycarbonate into polycarbonate shields and polycarbonate domes. We can do ABS thermoforming for ABS enclosures and ABS housing. We can handle thermoforming Cellulose Acetate for ski goggles inner lenses. We can thermoform polypropylene for PP packaging. We can thermoform PETG for PETG tray. We can do PVC thermoforming for PVC packaging box. We can do polystyrene thermoforming for polystyrene cups.

We are the custom thermoforming company who can make your required thermoforming plastic products according to your drawing and specification.

Plastic Thermoforming: The Ultimate FAQ Guide

What is Plastic Thermoforming?

It refers to a manufacturing process that involves heating of plastic material to a pliable forming temperature to form a particular shape inside a mold.

It is then cooled and trimmed to form a useful product.

Thermoforming plastic- Photo courtesy: Custom Part Net

Can You Recycle Thermoformed Plastic?

Yes.

As long as it is a thermoplastic, you can thermoform to any shape by melting it again and shaping it into any shape.

What Plastic is Used for Thermoforming?

They are quite a number and some of the best to go for include the following;

• PVC – It is a commonly used polymer formed with suspension polymerization. One of its outstanding features is a strong hard structure, which makes it suitable for withstanding extreme temperatures and impact. It is also relatively affordable.
• HDPE – It refers to a relatively strong thermoformed plastic which comprises of petroleum. It has a remarkable strength to density ratio, which makes it an idea for a wide range of applications, including cable installations and water pipes.
• PET – It is ideally one of the most common types of plastic used in thermoforming, especially for the production of bottles and synthetic fibers. To increase the resistance of PET, you need to ensure that dry it appropriately once you mold it into shape during thermoforming.
• ABS – It is also another commonly used type of plastic material for the thermoforming process. It comprises butadiene, acrylonitrile, and styrene. It is resistant to a wide range of elements, including heat and can handle extreme temperatures.
• PETG – This refers to a variation of PET plastic, which can be easily molded during thermoforming to form shapes for different applications.
• HIPS – This is a low-cost type of plastic that is also known as polystyrene commonly used for foamed or rigid plastic. It has a brittle and clear composure, which makes it suitable for protective packagings such as bottles, clamshell containers, and disposable cutlery.
• Polycarbonate – It is popular for its strong and durable properties. It can substitute glass in most applications.
• Acrylic – If you cannot afford polycarbonate, then acrylic is a better alternative. It is stronger than glass.

The exciting aspect of these materials used for thermoforming is that they are generally of a higher quality and relatively durable than plastics used for the molding process.

What are the Benefits of Thermoforming Plastic?

It has several advantages and here are some of the most common ones;

 Thermoforming plastic – Photo courtesy: Bio Plastic

• Provides high flexibility and adaptability to a wide range of customer needs
• Makes it easy to attain in-production product augmentations
• Relatively affordable since it utilizes low tooling costs, given that it only requires one mold half
• Provides short lead times, usually ranging between 2 to 6 weeks
• Provides a competitive advantage from a flexible tooling design
• Makes it possible to optimize the process as well as the materials to attain cost-effectiveness
• It is also easier to make relatively large parts hence wider design scope
• Compatible with different types of engineered thermoplastics
• The process allows for extensive options for finishing textures as well as patterns
• Results in high-quality injection molded parts within the shortest time possible
• It can maintain dimensional tolerances for different part sizes

What are the Disadvantages of Thermoforming Plastic?

• A possibility of the plastic sheet breaking during the process at a pliable state is usually high as a result of excessive stretching under some temperatures. It thus leads to wastage, which culminates in a high cost of production.
• Common internal stresses for most parts with sharp bends and corners hence making it somewhat difficult to produce.
• It can as well be a costly method of the production process, especially when you over-rely on using higher quality plastic sheets.
• Only one side of the part is usually defined by the mold in thermoforming plastics.
• It is not ideally environmentally friendly, especially when seeking the best packaging containers since it can extensively use bio-degradable plastics in the process.

How Many Plastic Thermoforming Techniques are there?

There are 3 types of plastic thermoforming techniques which include the following;

• Vacuum forming – It is the method where a vacuum is formed between the thermoplastic sheet and the mold cavity. Typically, in this case, vacuum pressure often forces the material to fit into the mold and then create the profile of the part.
• Pressure forming –It refers to the application of pressure at the material’s backside to help to force it inside the mold.
• Mechanical forming – It involves the mechanical forcing of the plastic sheet around or into the mold using uninterrupted contact. There is a central plug that pushes the material into the mold cavity, then forcing it to form the desirable profile.

What is the Difference between Thin-gauge and Heavy-gauge Plastic Thermoforming?

• The thickness of plastic material in thin-gauge thermoforming is usually 1.5mm or less.

On the other hand, the thickness of plastic material in heavy-gauge thermoforming is usually 3mm r greater.

• Thin-gauge thermoforming is normally roll-fed into the thermoforming machine, whereas heavy-gauge thermoforming is often sheet-fed into the machine.
• The typical applications for heavy-gauge plastic include industrial equipment covers, electronic equipment enclosures as well as medical device enclosures.

Thin-gauge thermoforming, however, is used in applications surrounding food containers, disposable utensils, and clamshell packaging, among others.

• The heavy-gauge plastic thermoforming process provides relatively large and thick packaging products that need more durable containers.

The light-gauge plastic thermoforming process, however, allows for attractive smoother and fashionable packaging.

Is there Maximum Thickness for Plastic Thermoforming?

 Thermoforming process

Typically, we work with plastic materials of a thickness of 0.500”.

However, it is also important to understand that we don’t necessarily work with materials thicker than 0.500”.

However, we can as well machine parts from comparatively thick materials on our in-house CNC routers

Does Plastic Thermoforming have Part Size Limit?

Not really. Any plastic material which has an appropriate ideal length can undergo the thermoforming process.

What is the Difference Between Thermoplastic and Thermosetting Plastics?

Thermoplastic vs thermoset

The differences are quite several and include the following;

• It is easier to synthesize thermoplastic through an addition polymerization process. On the other hand, thermosetting plastics can only be synthesized condensation polymerization.
• Thermoplastics ordinarily have a low melting point as well as low tensile strength, whereas the melting points for thermosetting plastics and tensile strength too are relatively high.
• Thermoplastics have secondary bonds in between their molecular chains whereas thermosetting plastics, have primary bonds between its molecular chains.
• Several techniques are used for processing thermoplastic, which includes injection molding, rotational molding, thermoforming process, and extrusion process, among others.

On the other hand, compression molding and reaction injection molding are the key techniques used in processing thermosetting plastics.

• The molecular weight for thermoplastic is comparatively lower than that of the thermosetting plastic.
• You can easily soften thermoplastic repeatedly. On the other hand, thermosetting plastics can never be re-softened once it becomes hard.
• In molding operation, thermoplastic never undergoes any chemical changes as opposed to thermosetting plastics, which easily undergo chemical changes.
• Thermoplastic is linear polymers, whereas thermosetting plastics are cross-linked polymers.
• Thermoplastics are also soft and flexible, whereas thermosetting plastics are hard and brittle.

How Does Thermoforming Process Steps Work?

Typically, heating and forming are the key steps involved;

• Heating happens and is attained by grinning electric heaters. These heaters are positioned on one or both sections of the starting plastic material at a distance.
• Once the sheet becomes soft, it is placed over a concave. Afterward, the vacuum draws back a softened workpiece to the cold hollow.
• The type of polymer sheet is what determines the duration it takes for the entire heating cycle for softening it.
• The product is then cooled, and then all the surplus parts of the plastic are then trimmed.
• At this point, the part formed which still remains in the clamp frame is eliminated from the forming tool.
• Mechanical, pressure and vacuum thermoforming are the three categories for accomplishing the steps in the thermoforming process.

What is the Difference between Plastic Thermoforming and Plastic Injection Molding?

• Plastic thermoforming is suitable for the production of smaller quantities. On the other hand, plastic injection molding is used for high-quantity production runs.
• Plastic injection molding ordinarily produces products as finished pieces, whereas the thermoforming process needs secondary finishing processes to produce the ideal aesthetics.
• Plastic injection molding can be used to produce a wide range of plastic materials, whereas thermoforming tend to have limitations regarding the specific types of plastic it can work on.
• Plastic injection molding is suitable for the production of relatively small, complex, and more intricate parts since it can allow difficult geometries and larger tolerances.

On the other hand, thermoforming only accommodates relatively simple geometries and smaller tolerances too.

How Do You Choose Plastic Thermoforming Machine?

You need to understand various elements that surround the selection of an ideal plastic thermoforming machine.

In most instances, the choice is guided by your specific needs, and some of these factors include the following;

 Plastic thermoforming machine

• General weight and size
• Type of motor and its capacity
• Air pressure and consumption
• Maximum forming area
• Maximum forming depth
• Cooling water consumption
• Servo power
• Working speed
• Noise and stroke range

What are Thermoforming Plastics Products?

They refer to the product parts that are created from the thermoforming process.

Some of these products include;

• Plastic bins
• Re-usable industrial crate
• Customized exterior door panels
• Headlight covers for automotive
• Plastic pallets
• Plastic totes
• Customized plastic wheelbarrow
• Pallets for engine blocks

Are there Quality You Should Check during Plastic Thermoforming?

Most definitely.

Most of the quality issues in plastic thermoforming are often as a result of inadequate and improper tooling.

• Warpage is one of the quality issue usually caused by irregular temperature-controlled tool design and manufacture. So it leads to uneven heating and cooling of the surface area of plastic material.
• Chill marks is the other quality issue often caused by improper temperature regulation and vacuum venting in tool design. Trapped air thus leads to wavy undulations on the surface of the plastic.
• Dimensional inconsistencies caused by variable temperature-controlled design is the other quality issue to look into. If not checked, it results in inconsistent shrinkage of the plastic material.
• Texture and gloss variation quality usually arising from insufficient tool surface finishing. This quality issue leads to the porosity of the tool surface, gloss reduction, and unwanted surface texture.
• The cause of discrepancy in part thickness is insufficient vacuum venting particularly in tool design and manufacture. It is a quality concern that leads to irregular venting culminating in inconsistency in thickness.

Why Work with WeeTect for Plastic Thermoforming?

• Because at Weetect, you’ll find a wide range of plastic thermoforming techniques suitable for producing your particular product which suits your needs.
• You can get samples of our product upon request, which makes it possible for you to make up your mind and choose what you specifically need.
• We have the ability to manufacture and transport various plastic thermoforming products to various destinations in most parts of the world.
• At Weetect, we use highly computerized plastic thermoforming machines, which play great role in the production of high-quality products.
• We adhere to all the quality and safety standards in the production process and for our products hence making us the leading company to partner with.

Does WeeTect Have Custom In-house Tooling for Plastic Thermoforming?

 Plastic thermoforming tooling

• Most definitely. It is because, at Weetect, we understand that different clients have different preferences for various plastic thermoforming products.
• So the custom in-house tooling for plastic thermoforming helps in making it possible for customization of a wide range of products depending on your specific needs.

What is WeeTect Lead-time for Plastic Thermoforming?

• In most instances, you will work together with our sales and engineering officials to enable us to understand time constraints come up with all possible ideas to meet or exceed your expectations.
• Plastic thermoforming is quite an involving procedure; Weetect’s plastic thermoforming lead time can be between 2 to 8 weeks.
• This is entirely dependent on numerous factors, including the type of prototype, design, and specific development of the mold.

What is Twin Sheet Thermoforming Plastic?

It refers to a manufacturing process for plastics, which involves heating and formation of two plastic sheet materials simultaneously into their respective molds and then press them together quickly.

Can You Control the Two Sides of Thermoformed Plastic?

Typically, during the plastic forming process in thermoforming, it is only possible to control one side of the part.

The reason is basically that it is quite easier to control the section of the workpiece, which is created against the mold with close tolerance.

It is difficult to control the side away from the mold, but you can, however, predict the possible occurrence on the uncontrolled side.

The preferable approach of dealing with tolerance necessities on the unregulated side is by trimming and assembly.

What Parts are Suitable for Twin Sheet Thermoforming?

Enclosures, large panels, housing, and many more are ideal for twin sheet thermoforming.

Essentially, tooling costs for such parts seem to be reasonably affordable.

What Types of Plastic Thermoforming Molds Can You Use?

1. Machined Aluminum Molds

These are types of molds that are ideally manufactured for parts that are relatively shallow and have small ratios.

Aluminum is commonly used for the manufacture of molds, which in most instances, can be tied to closer tolerances.

During the forming process, mounting of aluminum molds on a temperature regulating base allows it to control the mold temperature.

You can as well machine female or male aluminum mold.

This is irrespective of whether they are pressure formed or vacuum formed.

They are the same molds which you can the texture to possibly offer a distinct feature like loose cores, inserts as well as pneumatic cores.

2. Cast Aluminum Molds

These are the types of molds cast at a foundry from a composite material formed by a pattern machine.

So it happens that temperature settings are fixed into the sides and back of the cast aluminum dies at the foundry.

Cast aluminum dies are usually designed for components with relatively great draw quotients.

They might either be female or male and also a vacuum or pressure formed.

Some of the common features of this type of mold include inserts, loose and pneumatic cores as well as texture, among others.

3. Composite molds

They are designed for cost-effective, short production runs and prototyping in mold construction.

They tend to produce parts that must be assessed for fitness, function, and form.

It is also possible that composite molds might be altered to assess the ideal changes as far as design is concerned.

They are typically for vacuum formation only and are not controlled by temperature.

Additionally, they have a restricted life span.

When Should You Choose Pressure Forming Instead of Vacuum Forming?

Ideally, both processes are suitable for different conditions and particular needs.

Pressure forming vacuum forming – Photo courtesy: Visual pak companies

Pressure forming: It is suitable when you are concerned with aesthetics. This type of process forms parts that have detailed textures and crisps features. It is more or less the same as what happens in injection molding.

So it happens that its tooling and production are seemingly simpler and also faster than injection molding.

Vacuum forming, on the other hand, is suitable for products that are simple and don’t necessarily need details.

It is thus ideal when you are working on a tight budget as well as time constraints.

It is also suitable for shorter runs and items with comparatively large dimensions and low volume.

In most instances, industrial vacuum forming is used as an ideal replacement for other custom forming processes that use sheet metal, wood, or glass.

So as you can see from the descriptions of these two processes, the selection is purely based on your particular needs.

When is Thermoforming Fit for Plastic Fabrication?

Almost everything is somewhat suitable for plastic thermoforming fabrication.

It is fit when you

have to consider tooling costs and components with features in most instances restricted to one section of the part most fitting for thermoforming.

Can WeeTect Add Cosmetic Features to Thermoformed Plastic?

Yes. Some of the cosmetic features that you can attain from Weetect include sharp, crisp detail which contains tolerances.

Other Weetect thermoformed plastic cosmetic features include undercuts formed in inserts, custom colors, logos, and texture, among many more.

How Does the Cost of Plastic Thermoforming Compare to Other Plastic Fabrication Techniques?

• The overall cost of different types of plastic fabrication techniques obviously depends on a myriad of factors hence the expected variation among the techniques.
• The molds used for creating thermoplastic materials are designed based on several elements such as complexity life expectancy, finish, and tolerance, among others.
• So, in general, you’ll realize that thermoforming tooling is comparatively cheap than other plastic fabrication techniques like injection molding.
• You can use molds, which happen to be as cheaper as a few dollars, of course, depending on particular requirements.
• Plastic thermoforming is also economical, especially when dealing with low to medium applications.

How Does Negative Mold Compare to Positive Mold?

Positive mold for thermoforming – Photo courtesy: SINOTECH

Negative mold – Photo courtesy: SINOTECH

• A negative mold has bowl-shaped craters, whereas positive mold has a convex shape. Additionally, the design for positive mold is to trap the entire molding resin when the mold closes.
• Concrete mold formation involves pulling a mold sheet over a master model hence creating a shape above the level of clamping of that particular mold sheet.
• On the other hand, negative mold formation is where the shapes tend to occur under the clamping level of the mold sheet.

What is WeeTect Minimum Part Quantity for Plastic Thermoforming?

Production minimums for WeeTect tend to vary significantly depending on set up times as well as the complexity of the part.

In that case, we can only do a few parts in need be, particularly for prototyping.

So, in general, at WeeTect, we have a flexible MOQ

On the other hand, our minimum material is often dependent on minimum production run for the specific material.