Knowledge Base

What is Tooling?

Visit our Tooling & Patterns page HERE

Tooling, often called machine tooling, involves shaping, cutting, or forming materials to produce precise components. It acts as the foundation for manufacturing processes by providing the necessary tools to create high-quality products with tight tolerances. A useful analogy is comparing tooling to a cake tin: just as the tin shapes a cake, tooling shapes manufactured parts.

What is Prototype Tooling?

The stage of production tooling is met when you require a higher volume of parts and the design has been proven and approved. Before that stage you would utilise prototype tooling, which is useful if you need to test how your component fits and performs before you move into the production phase, which has higher cost and time implications.

Our customers use prototype tooling for the production of samples or parts of a complete product. The process of prototype tooling often involves iterations of the initial design to get the tool right in what would be a testing environment. At ASM Tech we have the expertise to advise and help you get to the desired product and can make the CAD changes here or use your updated files supplied.

Hard Tooling or Soft Tooling?

Soft Tooling is typically made from materials like polyurethane model board or even 3D printed and is best suited for producing low to medium volumes of parts. It is commonly used for prototyping or creating complex patterns due to its flexibility and lower cost. However, soft tooling has limited durability and requires frequent replacement during production of long runs. 

Hard Tooling is crafted from robust materials such as aluminium or metal filled epoxy resin. It is designed for high-volume production runs due to its durability and ability to withstand repeated use. While hard tooling takes more time and resources to create, it offers long-term cost efficiency by reducing the need for frequent replacements. 

Benefits of Prototype Tooling

Prototype tooling offers significant advantages in product development. By investing in prototypes, you accelerate time-to-market, reduce the risk of costly rework, and enhance product quality. Prototyping enables thorough design testing, facilitates material experimentation, and fosters collaborative feedback. This streamlined approach saves both time and money in a production environment.

Materials Used in Tooling

Tooling is available in a number of materials, including:

• Light Grade Model Board: Very low volume or prototyping. 

• High Grade Model Board: Low to medium volume. 

• Metal Filled Epoxy Resin: Medium to high volume production. 

• Aluminium: High volume and complex applications. 

To select the correct material, we consider the following 4 points when advising you:

1. Material/plastic required for the moulding

2. The accuracy and tolerances of the final product

3. The durability and strength required

4. The total production run volume

3D Printed Tools

The emergence of 3D printing to create moulds for vacuum forming, is gaining popularity with its production speed and lower costs. Its suitability is in low volume runs, custom parts, and the production of prototypes. There’s a range of materials available giving further flexibility in it’s application to tooling. At ASM Tech we have 3D printing facilities onsite, so contact us for more information.

Tooling Terms and Processes

Draft Angles

The forming of plastic over a vertical surface can presents issues for both the forming quality and part removal. Applying a draft angle to a mould or a die is when you add a degree of taper to the vertical surfaces. When designing, it’s important that draft angles are allowed for on the vertical surfaces to enable smooth part extraction and reduce production run times.

If you have a design or idea, but are unsure of how to add draft angles, we can help and advise on how to incorporate these into your design.

Undercuts

Undercuts are features that project inwards or outwards from the mould surface, and can it make it impossible to remove the formed part directly. Undercuts require additional mechanisms (e.g., slides, cores) for part ejection, increasing mould complexity and cost. If a design must have an undercut, a possible solution is to have a draft angle at the opposite end to the undercut to help with the part removal.

Draw Ratios

The ‘draw ratio’ is the ratio between the length/width of a part and its depth.

With deeper moulds, you also need to be aware of their spacing on the mould when they are imposed multiple times on a tool. Deeper parts can be more challenging to form and may require thicker plastic sheets.

Use and Application of Radii

Radii is the introduction of rounded corners instead of sharp angles to the mould design. This change can Improve material flow during forming, reducing stress points and the risk of part distortion, which leads to more efficient production runs.

Ribs and Bosses

These are reinforcing elements added to the mould design to improve the strength of the formed part and can prevent bending or breaking. Ribs provide lateral support, while bosses create raised areas for attachment points or alignment features.

Texture

Surface texture on a moulding can be achieved through one of 2 ways, either the use of a sheet of textured material or by you can add texture into the mould design. The drawback of adding it to the mould can be an increase in production time and therefore higher manufacturing costs.

What is 3D printing?

3D printing, also known as additive manufacturing, is the exact opposite of the traditional way of making objects. Instead of machining or "subtracting" material to form an object - much like how a sculptor cuts away clay - 3D printing adds layer upon layer of material to build an object, but only where it’s needed. Product designers and engineers upload a digital (CAD) file to a 3D printer, which then prints a solid 3D object.

How much does it cost to 3D print?

Factors affecting the cost of a 3D printed part include the type of material to be used, the size of the part and the density of the print. If high strength is not needed then a lower density of print can be used which will reduce the amount of material required. For applications where a more robust part is required then a higher density of print will be selected.

What materials can be 3D printed?

We offer a wide range of materials at our 3D printing service including PLA, PET and ABS. We can offer a range of colours for your 3D printed parts.

How fast can you 3D print parts?

Depending on size and geometry, we can have parts turned around in as little as three days. We do offer an express service, please contact us to find out more about improving your lead times.

Are 3D printed parts strong?

By increasing the print density a 3D printed part can be robust enough to withstand the forces involved as a vacuum forming tool. A higher density, whilst increasing the strength, does however increasing the amount of material used. This will increase the cost and the time to produce.

Are there size limitations for 3D Printing?

We are adding to our equipment portfolio on a regular basis and advances in machine capabilities are increasing build sizes. Also, a large component can be printed in several parts that can be assembled into a much larger final construction.

3D Printed Moulds

Many businesses are turning to 3D printing to create moulds for vacuum forming, because it offers a fast turnaround time and low price point, especially for shorter runs, custom parts, and prototype designs. 3D printing also offers unmatched design freedom to create complex and intricate moulds. 

Combining 3D printed moulds with vacuum forming allows you to enhance the production process by improving its flexibility, agility, scalability, and cost-efficiency. Validate your design and material choice prior to transitioning to mass production and produce custom or limited series of end-use parts with vacuum forming and 3D printed moulds.

See our Tooling Page HERE for more information on moulds

Which file types can I upload?

You can upload STL, OBJ or STEP files, these are the standard files used in the 3D printing industry.

Note: As STL files do not contain information on what measurement unit was used to create the model, it is important that you know which measurement unit your 3D program uses - mm, cm or inches before you export it.

Once you’re done with the export, you can upload a 3D design for printing and confirm the measurement units in mm, cm or inches.

What is 3D printed support material?

Some 3D printing technologies use support material to hold a part in place while it is being 3D printed. The need for support material is largely based on the geometry of the design. Parts with large overhangs will require support material.

Supports are printed at the same time as the part and are positioned as to have minimal effect on the surface quality. We remove support material as part of our standard service.

I don’t have a 3D computer model, can you still help me?

We offer a full CAD design service and can create 3D files from descriptions, drawings and reference images.

See our Design Page HERE for more information on CAD and Design

You can submit an enquiry today with your project details, and we will get back to you with a quote ASAP.

What is Vacuum Forming?

Visit our Vacuum Forming page HERE

Vacuum forming is a technique that transforms flat plastic sheets into three-dimensional shapes through the application of heat and vacuum pressure.

Here's a simplified breakdown of the process:

1. Heating: The plastic sheet is heated to a pliable state, typically within a temperature range of 100 to 225 degrees Celsius.

2. Drape and Form: The heated plastic sheet is then carefully draped over a mould, often crafted from wood, machined aluminium, or structural foam. A vacuum is then applied, pulling the plastic sheet tightly against the contours of the mould.

3. Cooling and Setting: Once the plastic has conformed to the mould shape, it is allowed to cool and solidify, locking in the desired three-dimensional form.

This method facilitates the production of a wide range of complex plastic components, offering both efficiency and cost-effectiveness.

Female or Male Mould?

• Female Moulds involve placing the thermoplastic sheet within the mould cavity. This method is typically favoured when achieving precise outer dimensions is critical.

• Male Moulds utilise the drape-forming method, where the thermoplastic sheet is positioned over the mould. This approach generally yields superior accuracy for intricate internal details and dimensions.

What Material is Best for Vacuum Forming?

A common question we receive is, "Which material is best for vacuum forming?"

Vacuum forming utilises thermoplastics, a class of plastics that soften and become pliable when heated and then solidify upon cooling.

Here are a few thermoplastics for vacuum forming, commonly used by ASM Tech:

• High-Impact Polystyrene (HIPS): Renowned for its flexibility and ease of moulding, HIPS can be shaped into a wide variety of intricate forms.

• Polycarbonate (PC): A remarkably tough material, polycarbonate exhibits excellent resistance to flames, chemicals, and water. These properties make it an ideal choice for applications in the medical and food processing industries.

• Polyethylene Terephthalate Glycol (PETG): Has good impact resistance, durability, and its ability to retain detail and withstand repeated stress. Ideal for packaging, medical trays, and protective covers.

• Acrylonitrile Butadiene Styrene (ABS): Combines toughness with good heat resistance, allowing for precise moulding of complex shapes. A preferred choice for automotive panels and durable consumer products as it can easily be post-processed.

Vacuum Formed Material Types 

Vacuum formed components can be created from the wide range of plastic materials listed below : 

• High Impact Polystyrene (HIPS) 

• Acrylonitrile Butadiene Styrene (ABS) – Embossed/Pinseal 

• Acrylonitrile Butadiene Styrene (ABS) – Smooth 

• Acrylonitrile Butadiene Styrene (ABS) – Flame Retardant 

• Polypropylene Copolymer (PP) 

• High Density Polyethylene (HDPE) 

• Conductive Polystyrene (CPS) 

• Conductive High Density Polyethylene (CHD) 

• Acrylic Capped ABS (ACC) – Pinseal 

• Rigid PVC – Film 

• Polycarbonate 

• PETG 

• Kydex 

Is Vacuum Forming Cost Effective?

A key advantage of vacuum forming is its exceptional cost-effectiveness. The reusability of moulds significantly reduces production costs, as they can be used repeatedly to manufacture multiple units of the same component. This makes vacuum forming a highly economical method for plastic fabrication. The availability, choice and cost of the plastic sheets also makes the production of short and long runs cost effective compared to the alternatives.

Forming Terms & Processes

Thermoplastic forming uses specific terminology and if you’re unsure on what certain terms mean, here’s a quick guide to the different phrases used within the thermoplastics industry.

• Thermoplastics

  This refers to a style of plastic made from polymer that becomes mouldable at a certain temperature and solidifies when cooling.

• Thermoforming

  This is a generic term which describes the process of transforming a sheet of plastic into a three-dimensional shape with the combination of heat, vacuum and pressure.

• Vacuum Forming

  This process involves forming a part by heating and stretching plastic across a mould using a vacuum.

• Clamping

  The clamp frame is critical for secure sheet holding during the moulding process. It must be robust enough to withstand the weight of thick sheets, the rigours of high-temperature environments.

• Heating Systems

  While infra-red elements are common, modern vacuum forming machines often employ quartz-style heating elements. These offer several advantages over older ceramic elements, including lower thermal mass, faster heat-up times, and greater responsiveness to temperature adjustments.

  Machines can incorporate multiple heating zones, allowing for precise temperature control across the sheet. This ensures even heating and prevents excessive thinning, crucial for producing high-quality parts.

  They can also be fitted with digital pyrometers, these monitor and control temperatures across the heating elements, the sheet, and the oven itself. This enables operators to finely tune the heating process for optimal results.

  Quartz-based heating elements offer several benefits, including reduced energy consumption and improved overall production efficiency, ultimately contributing to a higher quality finished product for our customers.

• Plug Assist

  Plug assist is employed when a standard vacuum draw cannot evenly distribute the thermoplastic sheet across all areas of the mould cavity. This is particularly beneficial when intricate cavities require precise material placement.

  A plug, typically made of wood or metal, is inserted into the mould cavity prior to vacuum application. This pre-forms the sheet, ensuring even material distribution and preventing excessive thinning in critical areas. Once the plug is in place, the vacuum is applied to complete the forming process.

  This technique enhances the accuracy and quality of the final product by ensuring that all areas of the mould are adequately filled with material.

• Vacuum Forming

  Once the thermoplastic sheet is draped over the mould, a vacuum is applied to draw the sheet into contact with the mould surface.

  A vacuum pump will efficiently evacuate the air trapped between the sheet and the mould. For larger machines, a vacuum cylinder or reservoir is incorporated alongside a high-volume pump to ensure rapid vacuum application. This minimises the risk of the sheet cooling prematurely, which can lead to rejected or faulty parts.

• Cooling and Release

  Adequate cooling is crucial after forming to ensure dimensional stability. Premature part release can lead to deformation and rejection.

  To accelerate cooling, machines may incorporate high-speed fans that are activated immediately following the forming process. Some systems also utilise a fine mist of water sprayed onto the formed part while the fans are operating. Recent advancements in cooling technologies, such as refrigerated water cooling and water-cooled mould components, significantly enhance cooling rates, enabling faster production cycles.

  For crystalline polymers such as polypropylene (PP), high-density polyethylene (HDPE), and polyethylene terephthalate (PET), controlled cooling within the mould is essential to regulate the crystallisation process and ensure optimal part quality.

Trimming and Finishing

Once the formed part has been formed on the press, it can go onto post forming processes and these options include:

• Trimming: Using a laser cutter or a 3- or 5-axis CNC machine for precise and efficient part finishing.

• Assembly: Gluing, combining moulded parts, or incorporating secondary materials.

• Reinforcement: Strengthening the part through welding with other moulded or raw plastic materials.

The most suitable trimming method will be determined on an individual basis, considering factors such as the type of material, the size and complexity of the part, the required production volume, and the desired final specifications.

If you have any questions regarding our Vacuum Forming services, contact us today.

Visit our Recycling & Materials page HERE

There’s a huge choice of material that can be used in the vacuum forming process. The following is a comprehensive list of the materials that can be used, and the different attributes they have. Talk to ASM Tech about your requirements and we can advise on the most suitable and cost-effective options.

Before choosing here are points to consider, to help select the correct material:

• Cost

• Electro Static Discharge (ESD) Requirements

• UV Resistance

• Chemical Resistance

• Coatings applied to materials for ESD protection

• Durability

• Heat Deflection

High Impact Polystyrene (HIPS)

A lower cost material which is easy to form and comparable in price to PVC Clear. Styrene is readily available in black and white but can also be offered in a range of colours. Styrene is more rigid than PVC with the possibility of cracking on corners with reuse. 

High Density Polyethylene (HDPE)

A slightly softer material with good impact strength, and excellent chemical resistance. It is also good for low temperature applications. Disadvantages include tendency to warp which make it difficult to use for trays that need to be flat for automation applications. Also very difficult to bond to HDPE. 

Polyvinyl Chloride (PVC)

A durable and low-cost material with good chemical resistance. Can be clear or colour tinted. Easy to process and can be recycled. Disadvantages are that PVC generally has a de-nesting agent allowing trays to be separated when nested. This is an applied coating which often includes silicone. Due to silicone coating, may not be good option for medical applications depending on sensitivity of application. 

Polyethylene Terephthalate Glycol (PETG)

A clear Polyester with excellent strength for use in packaging trays. Common applications include medical and optics. It may have a de-nesting agent similar to PVC which can be silicone. Also available with an Anti-Static Coating, Inherently Anti-Static, or Un-Coated. 

Polypropylene

Polypropylene has unique chemical resistance properties, and resists heat allowing it to go through some sterilisation processes like autoclave. Often used in medical applications. Polypropylene is a softer material and it can be difficult to maintain flatness.

Polycarbonate

A clear material with good light transmission properties. Excellent resistance to impact making it suitable to applications relating to safety e.g. safety goggles. Lightweight with high heat resistance properties.

Acrylonitrile Butadiene Styrene (ABS)

Excellent impact resistance and available in a range of colours. High strength and easy to form and shape. Good chemical and electrical resistance properties. Easily recycled but does not stand up well to UV exposure making it unsuitable for exterior use unless properly protected.