Commercial and Industrial Processes: Die Cutting, Screen Printing, Sublimation Printing and CNC Routing

This lesson explores key commercial and industrial manufacturing processes as required by AQA GCSE Design and Technology (8552), Section 3.2.9. You need to understand how each process works, what materials it is suitable for, and when it would be used in industry.

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Die Cutting

What Is Die Cutting?

Die cutting is a manufacturing process that uses a shaped blade (called a die) to cut materials into specific shapes. It works like a giant cookie cutter — the die is pressed into the material with great force, cutting through it in one operation.

How It Works

1. A die is made by bending steel strip (called rule) into the required shape and mounting it onto a wooden or metal base.
2. The material (card, paper, fabric, foam, thin plastic) is placed under the die.
3. A press forces the die down through the material, cutting the shape in one action.
4. Creasing rules can be built into the same die to score fold lines at the same time.

Applications

Application	Material	Example Product
Packaging nets	Corrugated card, paperboard	Cereal boxes, pizza boxes
Labels and stickers	Self-adhesive vinyl, paper	Product labels, bumper stickers
Gaskets	Rubber, foam, felt	Engine gaskets, seals
Fabric shapes	Woven and non-woven fabrics	Shoe uppers, appliqué shapes

AQA Exam Tip: Die cutting is most often examined in the context of packaging. If asked how a packaging net is produced in industry, describe the die cutting process including the die, press and creasing rules.

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Screen Printing

What Is Screen Printing?

Screen printing (also called silk screen printing or serigraphy) is a printing process that uses a mesh screen to transfer ink onto a surface. It is one of the most versatile printing methods and can be used on paper, card, textiles, ceramics, metal and plastics.

How It Works (Step by Step)

1. A design is created and transferred to a transparent film (positive).
2. A mesh screen is coated with light-sensitive emulsion and allowed to dry in the dark.
3. The positive is placed on the screen and exposed to UV light. The emulsion hardens where light hits it.
4. The screen is washed out — the unexposed emulsion (under the design) dissolves, leaving open mesh in the shape of the design.
5. The screen is placed on the material, ink is applied to the top, and a squeegee is drawn across the screen, pushing ink through the open areas.
6. The material is removed and dried (or heat-cured for textiles).

Advantages and Disadvantages

Advantages	Disadvantages
Vibrant, opaque colours on any background	One screen per colour (multi-colour designs are expensive)
Can print on almost any flat surface	Set-up time is relatively long
Low cost per print in medium/large batches	Not economical for very short runs
Thick ink layer gives a high-quality finish	Fine detail is limited compared to digital printing

Real-World Examples

• Band t-shirts and promotional clothing
• Posters and art prints (e.g. Andy Warhol's screen-printed artworks)
• Printed circuit boards — solder resist layer is applied by screen printing

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Sublimation Printing

What Is Sublimation Printing?

Sublimation printing (also called dye-sublimation) is a digital printing process where heat converts solid dye into a gas that bonds permanently with polyester fibres or specially coated surfaces.

How It Works

1. A design is printed onto special sublimation transfer paper using a printer loaded with sublimation inks.
2. The transfer paper is placed face-down on the product (polyester fabric, coated mug, phone case, etc.).
3. A heat press applies heat (approximately 180–200 °C) and pressure for 30–60 seconds.
4. The heat causes the solid ink to sublimate (turn directly from solid to gas) and penetrate the surface of the material.
5. When cooled, the dye returns to a solid state, permanently bonded within the material.

Key Features

Feature	Detail
Materials	Polyester fabric (minimum 65% polyester), polymer-coated ceramics, metals, MDF
Colour	Full-colour, photo-quality images with no limit on the number of colours
Durability	Dye is embedded in the material — will not crack, peel or fade as quickly as surface prints
Limitations	Only works on white or very light-coloured polyester; cotton does not work

Applications

• Sportswear — full-colour sublimated jerseys (e.g. football kits, cycling jerseys)
• Personalised gifts — mugs, phone cases, mouse mats, photo panels
• Soft signage — fabric banners and flags for exhibitions and retail

AQA Exam Tip: Sublimation is different from screen printing because it is a digital process (no screens needed) and the dye is embedded IN the material rather than sitting ON the surface. This distinction is commonly tested.

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CNC Routing

What Is CNC Routing?

CNC (Computer Numerical Control) routing uses a computer-controlled machine to cut, engrave and shape materials. The router spindle holds a rotating cutting tool that moves along three axes (X, Y and Z) following instructions from a CAD file.

How It Works

1. A design is created in CAD software (e.g. 2D Design, Fusion 360, VCarve).
2. The CAD file is converted into G-code (machine instructions) using CAM software.
3. The material is clamped to the CNC router bed.
4. The CNC router follows the G-code to cut out the shape, using the correct speed and depth settings.

Materials and Applications

Material	Application Example
MDF	Shop signs, decorative panels, furniture parts
Plywood	Flat-pack furniture components, architectural models
Acrylic	Display stands, illuminated signs, prototypes
Aluminium	Lightweight metal parts, electronic enclosures
Foam (modelling board)	Architectural models, packaging inserts

Advantages and Disadvantages

Advantages	Disadvantages
Extremely accurate and repeatable (± 0.1 mm)	High initial cost of equipment
Can produce complex 2D and 3D shapes	Requires CAD/CAM skills
Ideal for batch and mass production	Tool wear on hard materials
Minimal waste compared to hand cutting	Cannot produce hollow enclosed shapes

AQA Exam Tip: CNC routing is a popular topic. Be ready to describe the full workflow: CAD design → CAM toolpath generation → material setup → CNC cutting → finishing. Knowing the correct sequence earns marks.

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graph LR
    A[Designer creates artwork] --> B["CAD software<br/>2D Design / Illustrator / Fusion 360"]
    B --> C{Process choice}
    C -->|Cutting card| D1["Die cutter<br/>or laser cutter"]
    C -->|Print on paper / textile| D2["Screen printing<br/>or sublimation"]
    C -->|Cut wood / acrylic / metal| D3[CNC router]
    D1 --> E1["Steel rule die or<br/>laser G-code"]
    D2 --> E2["Screens exposed<br/>or transfer paper printed"]
    D3 --> E3["CAM software<br/>generates G-code"]
    E1 --> F[Material loaded]
    E2 --> F
    E3 --> F
    F --> G[Process runs]
    G --> H["QC: registration,<br/>tolerance, visual check"]

Comparing the Four Processes

Process	Primary Material	Scale	Digital?
Die cutting	Card, paper, fabric, foam	Batch / mass	No (physical die)
Screen printing	Paper, textiles, plastics	Medium batch to mass	Semi (screen from CAD artwork)
Sublimation printing	Polyester, coated surfaces	One-off to medium batch	Yes (fully digital)
CNC routing	Timber, board, acrylic, aluminium	One-off to mass	Yes (CAD/CAM driven)

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Summary