Plastic covers

31 May 2023

Overview of covered topics

Update – February 2024

Production of plastic enclosures constitutes an important element of modern industry. Especially in industries where functionality, aesthetics, and lightweight devices play a crucial role, plastic enclosures offer excellent customization possibilities, allowing for better alignment of the product with specific market requirements and expectations. When planning to commission the production of custom enclosures, it’s important to understand the key aspects that influence the choice of the appropriate production technology. In this article, you will learn what to pay attention to in order to achieve the best results in terms of production costs, functionality, and aesthetics of plastic enclosures.

Plastic cover for heat pumps

By reading the article, you will learn:

  • What factors are important in the production of plastic enclosures?
  • What technologies are used to produce plastic covers?
  • Universal or custom covers – which choice is better?
  • What materials are used in the production of covers?
  • How is the production of large-scale covers different from smaller ones?

Functionality of the cover

The first factor to consider is functionality. This means answering several basic questions, such as:

  • What requirements must the plastic cover meet?
  • Does it need to provide protection against mechanical damage, moisture, or other factors?
  • Should it have special openings for cables?
  • Does it need to be watertight?
  • Will it be used indoors or outdoors?
  • What assembling elements are needed?
  • Can a universal cover be used, or should it be custom-made for specific needs?

Determining a few basic parameters is key in choosing the right production technology and material

Custom plastic enclosure – production technologies

Custom plastic enclosures can generally be produced using two main technologies, namely injection molding and thermoforming. Each of these technologies has its unique advantages, and the choice between them depends directly on the specific needs and design requirements of the given enclosure.

Injection Molding vs. Thermoforming in Plastic Enclosure Production

Plastic enclosures made using injection molding technology will differ from those made using thermoforming technology. Below, we’ve described the basic differences:

Enclosure Size

Plastic enclosures made using injection molding technology are often much smaller, with smaller overall dimensions than those made using thermoforming. In the case of smaller, more complex enclosures, injection molding is more commonly used, while for larger, simpler constructions, thermoforming technology is more cost-effective.

Enclosure Precision

Another difference is the precision of execution – smaller and more complex plastic covers are made using injection molding, while larger and simpler structures are made using thermoforming.

Production Volume

A decisive aspect is also the declared target quantity of the product. Injection molding technology is dedicated to serial and large-scale production, where the minimum annual requirement is from 20,000 pieces upwards, while for thermoforming, the target quantities are smaller, most often around 100 pieces per month.

Housing Material

Another aspect determining the choice between these two technologies is the plastic material used and its form. It is important to remember that the form of the material used in injection molding technology differs from that in thermoforming technology. In the case of injection, there are small granules, called granulate, whereas in thermoforming, we deal with sheets of foil. The granulate is universal for every injection molding machine, but the foil sheet must be chosen based on the dimensions of the heating window of the thermoformer on which the plastic enclosure will be produced, which is why it may be less readily available than granulate. Another matter is material minimums – basic colors (e.g., in black, white) are generally available without a specific minimum, but for specific colors (e.g., pink, light green, neon, etc.), these minimums are much higher.

Granulate, from which a black plastic enclosure can be made

In exceptionally some cases, depending on the type of enclosure, it’s also possible to manufacture them using the rotomolding technology. The characteristic feature of this technology is that the objects made with it are hollow inside.

Prototype plastic covers are created using 3D printing or machining technology. However, they would not be cost-effective for serial production.

Universal or custom covers? What is the implementation cost and lead time for custom covers?

Universal covers are those that can be used for many products. This means production with multiple applications in mind. Such a universal cover has both advantages and disadvantages.

Universal enclosure – advantages

Universal covers have advantages such as a lower cost and shorter production time. They are designed to be compatible with various sizes and shapes of products. Therefore, universal covers can be used for a wide range of electronic devices.

Universal enclosures – drawbacks

Universal covers also have disadvantages that are worth considering. These include:

  • Lack of optimization for a specific product. Since universal covers are designed to fit various types of products, they may not provide an optimal fit for specific requirements and specifications. In some cases, a universal cover may need to be modified to meet the individual needs of a particular product.
  • Possibility of limiting functionality. Universal covers may not provide full functionality for some advanced products or devices. They are often designed in a general way to fit a wide range of applications, which can lead to certain compromises in terms of specialized functions or product features.
  • Aesthetics and branding. In some cases, using a universal cover can make it challenging to create a unique product appearance and build a consistent visual brand identity. If aesthetics and branding are important to a company, the use of a universal cover may limit customization possibilities and the ability to stand out in the market.

The use of universal covers has both its advantages and disadvantages. Before making a decision, it’s worth thoroughly analyzing the individual needs and requirements of the product and considering whether a universal cover will be the best solution, taking into account both functional and aesthetic aspects.

The answer to whether universal plastic covers will work for your case you can find in a separate article. In this post, universal covers are named catalog products.

Custom plastic enclosures – benefits

Custom plastic enclosures can also be produced to meet dedicated individual needs. Custom plastic enclosures offer the possibility of adaptation to specific requirements and preferences of the customer, allowing for the creation of non-standard solutions perfectly tailored to particular devices. Thanks to this flexibility, it is possible to design enclosures that not only meet functional requirements but also stand out with aesthetics and originality. Personalization can include various aspects, from dimensions and shape, through the choice of material and color, to special properties such as increased protection against mechanical damage and specific insulation characteristics.

Don't wait!

Tailor the technology to your needs to reduce plastic production costs.

Custom plastic enclosures – production costs

The most crucial factor to consider is the initial implementation cost, in the form of mold production. Injection molds are much more expensive than molds in thermoforming technology. This is, of course, due to the specifics of each technology.

The cost of an injection mold for conventional injection ranges on average from 60 to even 100 thousand. (For more information, read the article) PLN – everything obviously depends on the target product. Molds for less complex and smaller items will be cheaper, likely in the range of 60-80 thousand PLN, while larger ones with a more complicated structure can reach from 80 to over 100 thousand PLN. The average completion time for a traditional injection mold ranges from 12 to 16 weeks.

universal covers for electronic circuits, featuring holes for assembling screws.

There is also an alternative method, specifically the method of interchangeable inserts, where the cost of molds can be up to 50-60% lower (on average 30-60 thousand PLN). However, it’s important to remember that not every cover can be made using this method. The main limitation of this technology is the geometry of the product – it cannot be very complicated – mainly because the injection process is then less optimal, which consequently means that the product is more expensive. It’s also important to consider the intended demand – it cannot be large-scale. The average time for completing an interchangeable insert is much faster than for a traditional injection mold, taking about 4-5 weeks.

In thermoforming technology, there are also two options for mold production – traditional, made of steel or aluminum, and wooden.

Traditional molds (steel or aluminum) are more expensive than wooden ones – their cost is usually around 6-10 thousand PLN, whereas for a wooden mold, the cost is between 1 to 3 thousand PLN. The average completion time for both types of molds is similar, ranging from 2 to 4 weeks.

However, it is important to remember the specifics of each type of mold. A wooden mold is suitable for smaller production runs and less complex products, while traditional molds are chosen for larger production series and products with a higher degree of complexity.

When producing plastic covers, attention should be paid to the assembly elements. A plastic cover can be equipped with threaded inserts, elements for “press-fit” assembly, etc. In the case of housings for printed circuit boards, it’s also crucial to properly plan the assembly elements, and their design affects the production cost.

What materials are most commonly used in the production of covers?

A plastic cover can be produced using various materials. When selecting a plastic, it’s important to consider the requirements of the intended product.

In thermoforming technology, the most commonly used material is ABS or recycled ABS. This material is easily thermoformed and is durable, which is why it enjoys the greatest popularity.

In injection molding, the range of materials is much broader – covers are made from polyolefins (PP, PE) as well as ABS, PS, PET, and polyamides (such as PA6 or PA12), and even from biodegradable materials like PLA.

Read: Which thermoplastic materials are the cheapest? Check the prices and properties of popular thermoplastics

An unconventional but increasingly popular material used in the production of plastic enclosures is plastic with the addition of fiberglass. Fiberglass enhances the hardness of the final product. It’s used in various proportions, but most commonly, it’s added at 15 or 30%. This makes the produced items highly resistant.

When selecting the right material, it’s crucial to consider the environment in which the part will be used, its function, and purpose. If you don’t have a specific material in mind or lack experience in this area, we’ll be happy to suggest a suitable one, along with a description of its characteristics.

Can the covers be used outdoors?

When designing plastic enclosures, it is important to consider environmental conditions. Plastic enclosures can be used outdoors, but it is crucial to inform us about this in advance. This is very important, as plastic reacts poorly to sunlight, specifically to UV radiation. Under its influence, they yellow (in the case of white elements) and lose their properties (e.g., they become brittle). Is there a way to prevent this? Certainly! It is sufficient to add a UV stabilizer, which provides an appropriate level of protection, ensuring that the produced enclosures are safe and can be used outdoors.

What is ABS+PMMA plastic material?

This material is most commonly used for enclosures intended for outdoor use. It’s based on ABS material, which is coated with PMMA. This coating not only gives the product a pleasant light reflection but, more importantly, makes it suitable for outdoor use. Such a product doesn’t yellow and retains its properties despite UV radiation exposure. At Plastipol, we have extensive experience in producing elements from this material.

A cover made from ABS + PMMA material

What color can the cover material be?

All colors in the RAL color chart are available for the housing material. However, it’s important to remember that there are minimum material order requirements, especially for non-standard colors such as light green, pink, or neon shades, which tend to be higher.

How does the production of smaller covers (e.g., for electronics or sensors) differ from the production of larger ones (e.g., for heat pumps)?

When designing large-scale covers, there are different challenges compared to standard covers, like those used in electronics. For these larger covers, steel sheet often becomes a preferred material choice due to its suitability for bigger structures.

Below are the 3 main differences:

The first and most significant difference is the technology used to manufacture the cover. For covers like those for electronics, injection molding is the dedicated manufacturing technology, whereas for covers like those for heat pumps, thermoforming is used.

A large-scale plastic cover

The next difference is the level of complexity/precision. Covers used in electronics or sensors are usually much smaller and at the same time much more complex. Covers for heat pumps, on the other hand, need to accommodate all necessary components while also ensuring proper cooling and airflow, hence they are larger.

Adding a UV stabilizer is another aspect that differentiates these two types of covers. In the case of thermoformed covers for heat pumps, a UV stabilizer is often added for outdoor use assurance. For covers used in electronics, this step is not required as they are typically used indoors, often without exposure to light.

A plastic cover can consist of several components, and it’s only after their assembly that it becomes complete. An example of this can be seen in covers for heat pumps.

A plastic cover for heat pumps can come in various sizes.

In which industries are covers most commonly used?

Due to the fact that covers are a fairly universal product, they can be used in virtually any industry.

Industries where covers are most commonly used include:

  • The medical industry (e.g., covers for medical equipment, dental equipment components, inhalers, electrocardiographs, laboratory equipment).
  • The electronics industry (e.g., covers for electrical equipment, such as remote controls or televisions).
  • The food industry (e.g., covers for containers).
  • automotive industry (e.g., dashboard, door panels, center consoles, engine covers, side mirrors, bumpers)
  • household appliances industry (e.g., washing machines, refrigerators, dishwashers, microwaves).
  • cosmetic industry (e.g., skincare product covers or perfume containers)
  • sports industry (e.g., helmets, protectors)

In addition to the industries mentioned above, plastic covers are also used in many other sectors.

Plastic enclosures for electronics

In the production of electronic enclosure systems, key elements include durability, precise craftsmanship, lightweight design, and attractive appearance. It is essential to use plastic material resistant to external factors and mechanical damage, while also providing effective electrical insulation. Precision in execution, such as accurate cutouts or mounting holes, is crucial for functionality and ease of component installation. The lightweight construction of the enclosure is particularly important in portable electronic devices, where every gram affects user comfort and reduces transportation and distribution costs. Additionally, an ergonomic and aesthetically appealing enclosure design enhances the device’s utility value and is decisive in consumer products, where appearance often influences purchasing decisions.

Can recycled material be used in the production of covers? Environmental aspect.

Certainly! Recycled material, such as ABS regranulate, is often used in the production of covers. Read more here.

It’s a recycled material made from a mix of various waste sources and blended with the original material. It usually comes in black color, which is achieved by adding a black pigment. This helps to achieve a consistent color, especially because the recycled waste materials can have different colors.

At Plastipol, environmental sustainability is a top priority for us, and we make every effort to ensure that our production practices are environmentally friendly. To achieve this, we implement a closed-loop system where materials that become waste are collected and granulated for reuse in our production processes. Furthermore, we always encourage our clients to consider using recycled or biodegradable materials.

Ordering covers at Plastipol

At Plastipol, we manufacture custom plastic covers tailored to individual needs. We do not provide universal covers as part of our services.

Don't wait!

Tailor the technology to your needs to reduce plastic production costs.

What information is needed for a quotation?

The preliminary information needed for a quotation at the initial stage is universal for both injection molding and thermoforming technologies.

In the later stages of the process, each customer is assigned a project manager who coordinates the project in a comprehensive manner. They ask the necessary and personalized questions to be able to present the final offer at the end.

At Plastipol, we value customer relationships, which is why each project manager is available to their clients and is happy to assist with any doubts regarding the project or the manufacturing concept, as well as answer any questions that may arise.

The basic information necessary for preparation includes:

  • target quantity of covers (annually/quarterly/monthly)
  • desired material – if you don’t have experience in material selection, we are happy to assist in choosing the right one!
  • 3D model (preferably in .step format) and/or a technical drawing of the detail. There is also the option to send us the physical element to our address – in that case, we will take all necessary measurements or scan the detail to have a full understanding of it.
  • application and conditions of use of the product
  • deadline for completing the order
  • information regarding any special requirements (if applicable)
  • the preferred color

How does the quotation and production process work?

The first step is receiving an inquiry from you – we respond to inquiries within an hour.

The next step is assigning an individual Project Manager (PM) to the specific project, who will contact you to clarify key aspects.

Preparing a quote is the next step. The time required for this depends on the number of elements being quoted and their level of complexity, but on average, it takes from 1 week up to a maximum of two weeks.

If, after receiving our offer, you are considering implementing production but still have doubts due to wanting to test the enclosure before starting high-volume production, we always propose making prototypes using 3D printing. In this case, there is no need to create a mold beforehand. The produced elements will fully reflect the dimensions of the final enclosure. The only difference will be the surface texture – it will not be uniform, but most often slightly rough, due to the specifics of this technology.

In case of accepting the offer, we start the mold production. The duration of this phase depends on the chosen technology (traditional injection molding takes an average of 12-16 weeks, interchangeable inserts take 4-5 weeks, while in the case of thermoforming, the production time is approximately 2 to 4 weeks)

After the mold is produced, you will receive prototypes for approval. The time for accepting the prototypes or providing any feedback is one week. In the absence of a response, the prototypes are considered accepted.

After the prototypes are approved, the production process begins, which depends on the demand.

Is it possible to design a cover based on a concept?

Yes, it is possible. It would be helpful if you have a concept of how the housing should look. This can be a preliminary sketch or a photo.

At Plastipol, we also offer a design service that allows us to create a project for your dream housing based solely on dimensional measurements and an initial description.

Plastic cover - injection mold

However, we need information about the declared number of target elements and the intended use and conditions of the enclosure, as this information will enable us to select the appropriate material and technology. Our designers will be happy to create a unique design of your concept in a special engineering program that allows for the presentation of the appearance of the final product in both 2D and 3D.

We also conduct strength analyses to confirm that the designed product meets specific requirements.

Plastic enclosure – benefits

Plastic enclosures are well-regarded in the market due to numerous benefits. Their main advantage is significantly lower weight compared to metals or other materials, which directly contributes to increasing the functionality of final products. Another asset is their competitive retail price, making plastic enclosures an economical choice. Furthermore, the production process of these enclosures is efficient, especially when molds are already prepared, enabling faster production pace and facilitating product introduction to the market, which is particularly crucial in industries such as electronics.


Summary

We have discussed various factors to consider in the production of plastic covers. The first of these is the functionality of the housing. Factors such as protection against damage, the presence of openings for cables, sealing, and suitability for indoor or outdoor use have been highlighted.

We then discussed the technology of plastic enclosure production, highlighting injection molding and thermoforming as the main methods. Key factors in choosing the production technology for enclosures include the intended quantity, size, and precision of execution. Much also depends on the type of enclosure, which is particularly important in the case of electronic devices, where not only high resistance but also lightweight and precision fitting to complex electronic components are required.

The advantages of universal covers are lower cost and shorter production time, but they may not optimally meet the requirements of a specific product and may limit functionality and aesthetics. Therefore, it is often worthwhile to create a custom cover tailored to your needs.

Are you considering the production of plastic housings? Consult your project with us and get the necessary knowledge to save on your production.

Adam Bernacki

Adam Bernacki

Technical director at Plastipol Poland. Popularizer of knowledge about plastics processing. Industry experience gained through education at Scandinavian polytechnics, work in global corporations in the plastics industry, and by managing technical issues in a Polish company. Specialist in plastics batch and mass production technologies. Author of articles and industry texts for clients in various industry sectors. Training Advisor.