Design & Technology 0445 | Paper 3 Mock 01 | Materials

(a) Name the thermosetting polymer commonly used to make the decorative laminated surface labelled A [1]

Melamine / melamine formaldehyde [1]. This thermosetting polymer is produced as thin decorative sheets that are bonded under heat and pressure to a substrate (typically chipboard or MDF) to create laminated worktops and surfaces.

(b) State two properties of this thermosetting polymer that make it suitable for a kitchen worktop surface [2]

Any two from the following, each worth [1]:

• Heat resistant / does not soften when heated - as a thermoset, melamine formaldehyde has permanent cross-linked bonds that do not break down with heat, so hot pans placed on the surface will not cause it to deform or melt.
• Scratch resistant / hard surface - the high surface hardness resists scratching from knives, utensils, and abrasive cleaning, maintaining its appearance over years of use.
• Waterproof / moisture resistant - it does not absorb water, preventing swelling, warping, or degradation in the wet kitchen environment.
• Stain resistant / easy to clean - the smooth, non-porous surface does not absorb food stains, grease, or cleaning chemicals, and can be wiped clean easily.
• Can be produced with a decorative/coloured finish - melamine sheets are available in a wide range of colours, patterns, and textures (including wood grain and stone effects), giving designers visual flexibility.

(a) The item of PPE shown in Fig. 19 is safety goggles (eye protection) [1]. The diagram shows two circular lenses connected by a bridge and fitted with side arms, which is the characteristic shape of protective goggles used in a workshop.

(b) Safety goggles must be worn during activities such as drilling, grinding, soldering, sawing, or using a lathe [1]. These are any workshop operations that produce chips, sparks, flying debris, or fine particles that could enter the eyes and cause injury.

(a) CNC stands for Computer Numerical Control. [1]

In a CNC system, a computer reads a set of coded numerical instructions (the CNC program, written in G-code) that control the movement of the machine tool. The program specifies exact coordinates, feed rates, spindle speeds, and tool paths. This allows the machine to cut, drill, or shape materials with very high precision and repeatability, without the operator needing to guide the tool manually for each operation.

(b) The software used to create the digital instructions (tool paths) for the CNC machine is CAM (Computer Aided Manufacture) software. [1]

CAM software takes a digital 3D model (usually created in CAD - Computer Aided Design software) and converts it into a set of machine-readable instructions. The CAM software allows the user to specify cutting strategies, tool selection, feed rates, and depth of cut. It can simulate the machining process on screen before the program is sent to the CNC machine, helping to identify potential collisions or errors before any material is cut.

(a) When using a belt sander, the student should wear two of the following items of personal protective equipment:

• Dust mask or respirator [1] - The belt sander generates fine wood particles that become airborne. Inhaling these particles can damage the lungs and cause respiratory conditions, so a dust mask filters them out before they are breathed in.
• Safety goggles or eye protection [1] - Fine dust and small wood chips thrown up by the rapidly moving sanding belt could enter the eyes and cause irritation or injury. Goggles create a sealed barrier around the eyes.

Ear defenders or hearing protection are also acceptable, since belt sanders produce significant noise that can damage hearing over time.

(b) The belt sander produces fine wood dust as it abrades the surface of the timber [1]. This dust is harmful if inhaled, potentially causing respiratory problems such as asthma or, with prolonged exposure, more serious lung conditions. The dust extraction unit draws the airborne particles away from the working area through suction, protecting the health of the user and keeping the workspace clean and safe for others nearby [1].

(a)

1. Suitable operation for box A: Glue and assemble the mitre joints (apply PVA adhesive, clamp the frame in a picture-frame clamp, and allow to set). This is the logical next step after the joints have been cut and checked for accuracy. [1]
2. Purpose of the decision box: The decision box is a quality check point where the accuracy of the mitre joints is inspected. If they fit accurately, the process moves forward; if not, the flow loops back to re-cut the joints. This feedback loop prevents poorly fitting joints from progressing to permanent assembly. [1]
3. One quality check after assembly: Check that the frame is square by using a try square at each corner or by measuring the two diagonals (equal diagonals confirm a square frame). Other valid checks: verify overall dimensions match the specification; visually inspect for gaps in joints or surface defects; check the frame lies flat on a known flat surface. [1]

(b)

1. Purpose of the foam insert: The foam insert protects the product from damage during transit by absorbing shocks and vibrations. It is shaped to hold the product securely, preventing movement inside the box. [1]
2. Two items of printed information on the packaging:
   • Product name and brand name, for retail identification and display. [1]
   • Handling instructions such as "Fragile" or "This way up", to inform handlers how to treat the package. [1]
3. Why a barcode label is used: A barcode allows electronic scanning for stock control and tracking through the supply chain (monitoring inventory, reordering). At the point of sale it speeds up checkout and reduces human error in pricing.

(c)

1. Purpose of a work order: A work order sets out the sequence of operations, tools, materials, and timings needed to manufacture a product. [1] It acts as a planning document that ensures every worker follows the same process, contributing to consistency and efficiency in production.
2. One additional piece of information: Any one of: quantity to be produced; quality control checkpoints; specific machine settings; materials and sizes required; estimated completion time; name of the operator responsible. [1]

(d)

1. Name of Item X: Safety goggles (eye protection). They protect the eyes from flying debris, chips, sparks, and dust generated during workshop operations. [1]
2. Workshop activity where Item Y (ear defenders) should be worn: Using a pillar drill, lathe, planer/thicknesser, circular saw, belt sander, or any machinery generating sustained high noise levels that could cause hearing damage. [1]

Item Y is ear defenders (hearing protection). The two padded cups seal around the ears and are connected by a headband, reducing noise to a safe level during loud workshop operations.

(a)

1. Name the process: The process shown is press forming (also known as stamping or die cutting). A sheet of metal is placed between a punch and a die, and the press forces the punch down to cut or shape the metal into the required profile. [1]
2. One advantage in a factory: It is fast for large quantities; once the die is made, each pressing takes only seconds. Components are identical and accurate, reducing waste compared with hand cutting and making it cost-effective for mass production. [1]

(b)

1. Scale of production for a single 3D-printed prototype: One-off production. A single, unique item is made, typically at higher unit cost but without the expense of moulds or tooling. [1]
2. Two advantages of 3D printing a prototype rather than making by hand:
   • Complex shapes (internal cavities, thin walls, organic curves) can be produced that would be difficult or impossible to achieve by hand, since the printer builds layer by layer. [1]
   • The prototype is made directly from a CAD file with high dimensional accuracy; design changes can be implemented quickly by modifying the digital model and reprinting. [1]
3. Why 3D printing is unsuitable for 100 000 identical phone cases: 3D printing is slow (each case is built layer by layer over minutes to hours), making very high volumes impractical in terms of time. The unit cost remains constant regardless of quantity, whereas injection moulding has a high initial tooling cost but very low per-unit cost at scale, making it far more economical for mass production.

(c)

1. CNC stands for: Computer Numerical Control. A computer reads coded instructions (G-code) to control the machine tool's movements with high precision and repeatability. [1]
2. Software for creating digital CNC instructions: CAM (Computer Aided Manufacture) software. CAM converts a CAD model into machine-readable tool paths, specifying cutting strategies, feed rates, and depths of cut. [1]

(d)

1. Purpose of a jig: A jig holds and locates the workpiece while guiding the cutting tool, ensuring every component is manufactured identically without the need for individual marking out. [1]
2. Advantage of using a jig for batch quantities: It ensures accuracy and consistency, with all features produced in exactly the same position on every component. It also speeds up production because less time is spent measuring and marking out each piece, and less skilled operators can produce accurate work. [1]
3. Part labelled 'stop' and its function: The stop (end stop / location stop) positions each workpiece against a fixed edge so it is placed in exactly the same position before the operation begins, guaranteeing identical positioning across the batch. [1]

(e)

1. Process shown: Injection moulding. Granules of thermoplastic are heated until molten, then injected under high pressure into a steel mould cavity. The plastic cools and solidifies into the shape of the mould. [1]
2. One product made using this process: Plastic bucket, bottle cap, toy, phone case, comb, ruler, or plastic chair (any suitable mass-produced thermoplastic product). [1]

(f)

1. Scale of production: Mass production (also called continuous production). This is the manufacture of very large quantities of identical products on a continuous or near-continuous basis. [1]
2. Two advantages of mass production compared with one-off production:
   • Lower unit cost: The high initial investment in tooling, moulds, and automated machinery is spread across a very large number of units, drastically reducing the cost per item. In one-off production, all setup costs apply to just one item. [1]
   • Consistency and quality: Automated processes and fixed tooling produce identical products with minimal variation. Every chair meets the same specification, reducing waste and rework. One-off production relies more on individual skill, leading to potential variation. [1]
   • Speed: Automated production lines operate continuously at high speed. 50 000 chairs per week would be impossible to achieve with one-off methods.
   • Less skilled labour: Automated systems require operators rather than highly skilled craftspeople, reducing labour costs.

Two safety rules that must be followed when using the pillar drill:

1. Keep the safety guard in place [1] - The guard, visible in Fig. 20 around the drill bit area, prevents the user's hands, hair, or clothing from coming into contact with the rotating chuck and drill bit. It also contains any debris thrown up during drilling.
2. Clamp the workpiece securely to the drill table [1] - If the material is held by hand, the rotating drill bit can catch and spin the workpiece violently, causing injury to the user. A clamp or machine vice holds the material firmly in position.

Other valid safety rules include: tie back long hair to prevent it being caught in the rotating parts; do not wear loose clothing, jewellery, or ties; wear safety goggles to protect eyes from flying chips; and ensure the correct drill bit is fitted and tightened in the chuck before starting.

The metal used to make the electrical wire shown in Fig. 11 is copper. [1] Copper is the standard metal for electrical wiring because it is an excellent electrical conductor, meaning electricity flows through it with very low resistance. This efficiency reduces energy losses as heat and ensures reliable delivery of current. Copper is also ductile, so it can be drawn into thin wires without breaking, and it is malleable, allowing the wire to be bent and routed around corners and through conduits during installation. Additionally, copper has good resistance to corrosion, so the wire maintains its conductivity and integrity over a long service life.

(a) Name the process used to produce this curved shape [1]

The process is laminating (lamination) [1]. Multiple thin strips of wood are glued together and bent around a shaped former, producing a strong, permanently curved component.

(b) Describe the stages of this process [4]

1. Thin strips of wood (veneers) are cut to the required width and length [1]. They must be thin enough to bend without breaking.
2. Adhesive (such as PVA or synthetic resin) is applied evenly to both faces of each strip [1]. Even coverage prevents dry spots that would weaken the laminate.
3. The glued strips are placed together and positioned in a former / jig that has been shaped to the required curve [1]. The former determines the final shape of the component.
4. The assembled strips are clamped firmly in the former using G-clamps or sash clamps, applying even pressure along the full length. The adhesive is left to dry completely before the finished laminate is removed from the former [1].

(c) Give one advantage of this process compared to steam bending [1]

Any one from the following for [1]:

• The finished shape is stronger than a single piece of steam-bent wood because the alternating grain directions of the laminations reinforce each other.
• There is less spring-back - steam-bent wood tends to partially straighten when released from the former, whereas laminated wood holds its shape because each strip is individually glued in position.
• Tighter curves can be achieved - individual thin strips can bend to a much smaller radius than a single thick piece.
• Different types of wood can be combined for visual effect, mixing lighter and darker veneers for a decorative layered appearance.

(a) The stock form shown at C is a channel (also called U-channel or C-section). [1]

The cross-section shows a U-shaped profile: a flat base (web) with two upstanding flanges. Channel section is commonly used in structural steelwork for framing, shelving brackets, and supports where one open side is acceptable or where other components slot into the channel.

(b) The stock form shown at D is an I-beam (also called I-section or RSJ - rolled steel joist). [1]

The cross-section shows a central vertical web with horizontal flanges at both top and bottom, forming the characteristic I shape.

(c) An I-beam has a much greater resistance to bending (higher stiffness) than a flat bar of the same weight of material. [1] This is because the material is concentrated at the top and bottom flanges, positioned as far as possible from the neutral axis (the centre of the cross-section). In bending, the highest stresses occur at the outermost surfaces. By placing material where stress is greatest and removing it from the centre where stress is lowest, the I-beam uses material far more efficiently. A flat bar distributes its material uniformly across a thin cross-section, so most of the material contributes little to bending resistance. For horizontal shelf supports that must carry heavy loads without sagging, the I-beam provides a stronger, lighter solution. [1]

(a) A suitable metal for the body of the saucepan is stainless steel. [1] Aluminium is also an acceptable choice.

(b) One property that makes this metal suitable for a saucepan:

Stainless steel is a good thermal conductor, allowing heat to transfer efficiently from the hob through the base and walls of the pan to the food inside. [1] It is also resistant to corrosion, meaning it will not rust or react with acidic foods, making it safe for cooking and easy to clean. If aluminium is chosen, its key advantage is being lightweight while still conducting heat effectively.

(a) Reinforced concrete is classified as a composite material because it is made from two different materials combined together to create improved properties [1]. The concrete (a mixture of cement, sand, aggregate, and water) acts as the matrix, while the steel reinforcing bars act as the reinforcement. Neither material alone would perform as well as the two together.

(b) The role of the steel bars relates to how concrete handles different types of force. Concrete is strong in compression (it resists being crushed) but weak in tension (it cracks easily when pulled apart or stretched) [1]. When a beam is loaded, the top surface is compressed while the bottom surface is stretched. The steel bars, which have high tensile strength, are positioned in the lower part of the beam to resist the tensile forces, preventing the concrete from cracking and allowing the beam to support bending loads without failure [1].

(c) Two advantages of using reinforced concrete in building structures:

1. Very strong and durable [1] - reinforced concrete can withstand large compressive and tensile loads, and it lasts for decades with minimal deterioration, making it suitable for structural elements such as beams, columns, and foundations.
2. Fire resistant [1] - unlike steel, which loses strength at high temperatures and can buckle, concrete does not burn and retains its structural integrity during a fire, providing important protection for the building and its occupants.

Other valid advantages include: it can be cast into any shape using formwork or moulds; it is relatively low cost compared to an all-steel frame; and it requires low maintenance once set.

(a) Selecting the most suitable polymer for each product using the table of properties:

Product X (shampoo bottle):

• The most suitable polymer is HDPE (high-density polyethylene). [1]
• HDPE has good chemical resistance, so it will not react with or be degraded by the shampoo or other toiletry chemicals inside. It is also tough and stiff, meaning the bottle holds its shape and resists splitting when squeezed. [1]

Product Y (garden planter):

• The most suitable polymer is polypropylene. [1]
• Polypropylene is lightweight, making the planter easy to move around the garden, and it has good fatigue resistance, so the planter can withstand repeated stresses from being moved, filled with soil, and exposed to outdoor temperature changes without cracking. [1]

Product Z (plug casing):

• The most suitable polymer is urea formaldehyde. [1]
• Urea formaldehyde is a good electrical insulator, which is essential for safety in an electrical plug, and it is heat resistant, so the casing will not soften or deform from the heat generated during electrical use. [1]

(b) The difference between thermoplastic and thermosetting polymers relates to their molecular structure and behaviour when heated:

• A thermoplastic can be repeatedly heated and reshaped because it softens when heated. [1] Its polymer chains are held together by weak intermolecular forces that break on heating and re-form on cooling, allowing the material to be recycled and remoulded multiple times.
• A thermosetting polymer undergoes a permanent chemical change (cross-linking) when first heated and moulded. [1] Once set, the strong covalent cross-links between polymer chains cannot be broken by reheating, so the material cannot be reshaped or recycled by melting.

(c) One environmental consideration when disposing of thermoplastic products:

Thermoplastics can be recycled by collecting, sorting, melting, and re-moulding them into new products. [1] This reduces the volume of plastic waste sent to landfill and conserves the crude oil from which the polymers are originally derived, lowering the demand for raw materials and reducing the environmental impact of extraction. [1]

Alternatively, if thermoplastics are sent to landfill rather than recycled, they are not biodegradable and persist in the environment for hundreds of years, occupying landfill space and potentially breaking into microplastics that harm wildlife and ecosystems.