Timbers, Metals & Polymers Flashcards
(290 cards)
1
Q
What are the two main types of wood used for timber?
A
Hardwood from deciduous trees and softwood from coniferous trees.
2
Q
Name three examples of hardwood.
A
Maple, Teak, Oak.
3
Q
Name three examples of softwood.
A
Redwood, Balsa, Spruce.
4
Q
What is the general characteristic of hardwood?
A
Hardwood tends to take longer to mature before it can be felled.
5
Q
What happens to tree trunks after being felled?
A
They are stripped of their bark and cut into usable planks in a sawmill.
6
Q
What affects a plank’s risk of warping or twisting?
A
A plank’s cut affects its risk of warping or twisting, as well as its cost.
7
Q
What is a Through and Through Cut?
A
A cost-effective and quick cut that can warp and twist easily.
8
Q
What is a Quarter Cut?
A
A complex and expensive cut that creates a lot of waste and is used in high-quality furniture.
9
Q
What is a Baulk Cut?
A
A very simple cut that is not very versatile, used in posts and beams.
10
Q
What are PAR planks?
A
Planks that are planed for a smooth finish and are suitable for use where a quality finish is required.
11
Q
What is seasoning in timber?
A
Seasoning is the process of removing moisture from newly cut (green) timber to prevent rot, splitting, and warping.
12
Q
What is air seasoning?
A
Air seasoning is a natural method of drying timber by stacking planks under a roofed, unwalled shelter with stickers to allow air circulation.
It takes around a year to dry 25 mm planks of wood.
13
Q
What is kiln seasoning?
A
Kiln seasoning is a method that uses heat, steam, and pressure to speed up the drying process of timber. It is faster but more expensive than air seasoning.
14
Q
What are manufactured boards?
A
Manufactured boards are made from fibres, chips, blocks, or sheets of wood bonded together with adhesives.
15
Q
What is plywood?
A
Plywood is made by gluing alternate layers of wood (veneers) together at 90 degrees to each other.
16
Q
What is Medium-Density Fibreboard (MDF)?
A
MDF is created by breaking down woodchips into a pulp, mixing it with glue, and compressing it.
17
Q
What is chipboard?
A
Chipboard is made from small chips of wood that are compressed and glued together.
18
Q
What is a common use for manufactured boards?
A
Manufactured boards are often created from waste or recycled materials and are used in furniture manufacturing.
19
Q
What are the properties of different types of timber?
A
Different types of timber have varying properties such as strength, hardness, and durability that make them suited for different purposes and commercial products.
20
Q
What are the requirements for wooden toys?
A
Wooden toys need to be durable to withstand being thrown, hit, and dropped. They should also be hard enough not to splinter easily to avoid harming small children.
21
Q
What types of wood are commonly used for toys?
A
Hardwoods, such as beech and oak, are commonly used for toys due to their hardness and durability.
22
Q
What are the advantages of hardwoods for toys?
A
Hardwoods are easy to paint and unlikely to break into small parts that may pose choking hazards.
23
Q
What materials are commonly used in flat-pack furniture?
A
Manufactured boards are commonly used in flat-pack furniture because they are cheaper and easy to assemble and disassemble.
24
Q
What is a disadvantage of flat-pack furniture compared to solid wood furniture?
A
Flat-pack furniture is generally not as strong or durable as solid wood furniture and is prone to moisture damage.
25
What is the benefit of veneers in flat-pack furniture?
Veneers give the appearance of a quality piece of furniture at a significantly reduced price compared to solid wood.
26
Why is wood seasoned?
Wood is seasoned to alter its moisture content and create properties suited to its intended use.
27
What is the effect of reducing the moisture content of wood?
Reducing the moisture content of wood can make it stronger and less likely to rot.
28
What is the advantage of unseasoned wood?
Unseasoned wood is cheaper and easier to shape.
29
What are the stock forms of timber?
Timber is available in planks, boards, and strips in a range of stock sizes.
30
How are timber measurements typically listed?
Measurements are usually listed as length x width x thickness (mm).
31
What is planed timber?
Planed timber is smoother than rough-cut timber but is also more expensive.
32
What happens during the planing process?
Planing removes around 2-3 mm of material from each side of the timber.
33
What are mouldings used for?
Mouldings are used for frames, architraves, and skirting boards.
34
What are manufactured boards commonly available in?
Manufactured boards are most commonly available in standard 2400 x 1220-mm sheets.
35
What are dowels?
Dowels are cylindrical timber rods used to join pieces of wood together.
36
How does the thickness of manufactured boards vary?
The thickness generally increases in 3-mm increments (e.g., 6 mm, 9 mm, 12 mm).
37
What are woodscrews used for?
Woodscrews are used to temporarily join two pieces of wood together.
38
What materials are woodscrews typically made from?
Woodscrews are usually made from brass or steel.
39
What types of screw heads are available?
Woodscrews have different shaped heads such as slotted, Pozidriv, Phillips, and Allen (hexagonal).
40
What is the first step when joining two pieces of wood with screws?
Drill a pilot hole through both pieces of wood. This hole should be slightly narrower than the thread of the screw.
41
What is the purpose of a clearance hole when joining wood?
Drill a clearance hole through the top piece of wood. This hole should be slightly larger than the shank or thread of the screw.
42
What should be done if using a countersunk screw?
A countersunk hole should be drilled to the depth of the screw.
43
What are hinges used for?
Hinges are used to allow doors, windows, and lids to open and close.
44
What materials are hinges commonly made from?
Hinges are commonly made from brass, steel, or plastic.
45
What is a butt hinge?
The most common type of hinge for windows and doors, a butt hinge is usually recessed into the surfaces.
46
How does a hush hinge differ from a butt hinge?
It works like a butt hinge but is screwed directly onto the wood. It is easier to position but not as strong.
47
What is a concealed hinge used for?
Commonly used inside cabinets, a concealed hinge is easily adjustable but often needs to be recessed into one of the surfaces.
48
What are knock-down fittings?
Knock-down (KD) fittings are joints that are often used in the assembly of flat-pack furniture.
49
What is a characteristic of knock-down fittings?
They allow quick assembly and disassembly, but they are not as strong as permanent joints.
50
What tools are typically used with knock-down fittings?
They are usually assembled using simple tools such as screwdrivers and hex keys.
51
What is a corner block fitting?
A corner block is placed in the corner where two pieces of wood join at 90°. Screws are then screwed through ready-made holes to hold the block fitting and two pieces of wood in position.
52
How does a cam lock work?
A disk (cam) is placed into a pre-drilled slot in one piece of wood, and a peg is inserted into the other. The peg slots into the side of the cam, and as the cam is turned, it grips the peg pulling the two pieces of wood together.
53
What is a barrel nut?
Also known as a cross-dowel fitting, a barrel with a screw thread (barrel nut) is placed into a pre-drilled hole in one piece of wood, and a screw is placed in the other. The screw is then tightened, pulling the two pieces of wood together.
54
What are surface treatments and finishes applied to timbers for?
They are applied to improve appearance and enhance properties such as durability.
55
What is the purpose of painting wood?
To change the colour of wood and to add protection.
56
What preparation is needed before painting wood?
Cleaning and sanding the wood to provide a smooth, clean surface.
57
What is the purpose of priming wood before painting?
To seal the wood so the paint sticks to the surface better.
58
What is an undercoat in painting?
An undercoat is applied before the top coat to mask previous colours and help the top coat stick.
59
What type of paint is usually used for the undercoat?
A thinner, less expensive paint.
60
What are the characteristics of oil-based paints?
They are hard-wearing and water-resistant but take a long time to dry.
61
What are the characteristics of water-based paints?
They are not very durable but are easy to work with and dry quickly.
62
What happens to polyurethane paints when exposed to air?
They harden, making them very durable.
63
What is varnish used for?
To provide a hard, protective finish to wood while allowing the grain to be seen.
64
What should be done between each coat of varnish?
The surface of the wood should be sanded lightly.
65
What finishes are available for varnish?
Matt, satin, and gloss finishes.
66
What are varnishes containing polyurethane used for?
To protect surfaces against heat and moisture, commonly used on interior wood.
67
What is tanalising?
A process where preservatives are added to wood to protect it from rot, decay, and insects.
68
What is the process of tanalising wood?
Wood is placed in a tank, a vacuum is created, the tank is flooded with preservative, pressure is applied, excess preservative is drained, and the wood is left to dry.
69
What are some properties of metals?
Metals have varying properties such as strength, hardness, toughness, and malleability.
70
What factors should be considered when choosing metals for products?
Cost, availability, and the environment should also be considered.
71
Why is stainless steel commonly used in cooking utensils?
Stainless steel is durable, dishwasher-safe, flame- and heat-resistant, resistant to rust and corrosion, aesthetically pleasing, and safe to use with food.
72
What are the properties of high-carbon (tool) steel used in hand tools?
High-carbon steel is strong, tough, resistant to abrasion, and malleable.
73
What is a drawback of stainless steel in cooking utensils?
Stainless steel is a relatively poor conductor of heat.
74
How is the heat conduction issue in stainless steel utensils addressed?
Utensils often have a copper or aluminium core to improve heat conduction.
75
How does the composition of steel affect its properties?
The amount of carbon and other elements in steel affects its properties; for example, chromium is added to increase corrosion resistance.
76
How can the properties of metals be modified?
Properties can be modified through heating and cooling.
77
What is quenching in relation to medium- and high-carbon steel?
Quenching is a process that hardens steel through heating and rapid cooling, but it also makes the steel brittle.
78
What is annealing?
Annealing is a process that softens metal to make it more malleable and ductile by heating it to a specific temperature and allowing it to cool slowly.
79
Can the annealing process be repeated?
Yes, the annealing process can be carried out repeatedly whenever the metal becomes hard and brittle again.
80
Where are most metals found?
Most metals are found in ores within the Earth's crust.
81
What must be done to metals before they can be used?
They must be extracted and refined before they can be used to make products.
82
What determines the extraction method of metals?
The extraction method used depends on the metal's properties.
83
How are metals extracted from ores in a blast furnace?
The ore is heated to such a high temperature that the metal separates from the other substances in the ore.
84
What is an example of a metal extracted using a blast furnace?
Iron is extracted from iron ore by heating the ore to a temperature above the iron's melting point.
85
What is electrolysis in metal extraction?
Electrolysis involves passing an electrical current through the ore to separate the metal from the other substances.
86
Why is electrolysis expensive?
A huge amount of energy is needed for electrolysis.
87
What metal is commonly extracted using electrolysis?
Aluminium is extracted from aluminium oxide using electrolysis.
88
What is the purpose of refining metals?
To obtain a pure metal by separating any impurities from the metal.
89
What is distillation in metal refining?
The metal is heated to its boiling point, evaporating and leaving behind impurities with higher boiling points.
90
Which metals are commonly refined using distillation?
Distillation is used with metals that have low boiling points, such as zinc and mercury.
91
What is liquation in metal refining?
The metal is heated to its melting point, melting while impurities with higher melting points remain solid.
92
Which metals are commonly refined using liquation?
Liquation is used with metals such as tin and lead.
93
What must designers consider when creating a metal product?
Designers must consider the stock forms available because metals can be difficult and costly to manufacture in custom-made forms.
94
What are common stock forms of metals?
Common stock forms include: Rod, Sheet, Flat Strip, Tube, Angle, Channel, Strip.
95
How are measurements of metals usually given?
Measurements are usually given in millimetres (mm).
96
How is metal wire measured?
Metal wire is measured by standard wire gauge (swg). The lower the gauge, the bigger the size.
97
What is the equivalent of 14 swg in mm?
14 swg is equivalent to 2.03 mm.
98
What is the equivalent of 12 swg in mm?
12 swg is equivalent to 2.64 mm.
99
What tools can be used to measure swg values?
Wire gauge tools can be used to measure swg values.
100
What are rivets used for?
Rivets are used to join pieces (usually sheets) of metal.
101
How can rivets be installed?
Rivets can be installed manually using a hammer. The rivet is inserted through a pre-drilled hole in both materials.
102
What happens to the rivet after installation?
The head of the rivet is flush against one side, and the other end is shaped into a head using a hammer.
103
What is a rivet?
A rivet is a fastener used to join materials together, commonly used in airplanes and bridges.
104
What is the purpose of a machine screw?
Machine screws are used to temporarily join parts together.
105
What is a nut?
A nut is a fastener with a threaded hole that pairs with a bolt.
106
What is a bolt?
A bolt is a type of fastener that fits into the threaded hole of a nut.
107
What materials are nuts and bolts usually made from?
Nuts and bolts are usually made from carbon steel and sometimes coated.
108
What shapes do nuts typically have?
Nuts are usually square or hexagonal shaped.
109
What is the function of a washer?
Washers are used with machine screws and nuts to spread the load and prevent loosening.
110
What are the common types of machine screws?
Common types include slotted, Phillips, and hex.
111
What is the significance of the thread size in machine screws?
The thread size must match the size of the hole for proper fit.
112
What is a rivet gun?
A rivet gun is a tool used to insert rivets.
113
What is a rivet's function?
Rivets are used to pull materials together with high force.
114
What are rust tests?
Rust tests are available in a range of shapes and sizes depending on the function.
115
What are metals susceptible to?
Metals are susceptible to damage through corrosion, which occurs as a result of chemical reactions between the metal and the surrounding environment.
116
How can surface treatments and finishes help metals?
Adding surface treatments and finishes such as paint can help protect metal and improve its appearance.
117
What is the first step before adding treatments or finishes to metal?
Before treatments or finishes are added to a metal, it is first smoothed and cleaned with abrasives and chemical cleaners.
118
What is dip coating?
Dip coating involves covering a metal with a thin layer of plastic.
119
What temperature is the metal heated to in dip coating?
The metal is heated to 180-200°C.
120
What happens to the plastic powder in dip coating?
The fluidised plastic remaining on the metal melts and sticks to the surface to give a smooth, shiny finish.
121
What are common applications of dip coating?
Dip coating is often used to cover tool handles and wheelchair parts.
122
What is powder coating?
Powder coating involves spraying plastic powder onto a metal part and heating it.
123
How is the dry powder spray applied in powder coating?
The dry powder spray is applied with an electrostatic gun, which gives the spray an electrical charge.
124
What happens to the powder in powder coating after application?
The coated metal is then heated in an oven to fuse the powder to the metal surface.
125
What is a benefit of using electrostatic charge in powder coating?
The use of electrostatic charge allows coatings to be applied to even the most complex shapes and ensures a smooth, even finish.
126
What are common applications of powder coating?
It is commonly used for wheels, bike frames, and outdoor play equipment.
127
What is galvanising?
Galvanising is a process used to protect a base metal such as iron or steel from corrosion.
128
How does galvanising protect the base metal?
This is done by coating the base metal with a more reactive metal, such as zinc.
129
What does the zinc barrier do in galvanising?
The zinc forms a barrier over the base metal that protects it from moisture and oxygen, which cause corrosion.
130
What is hot-dip galvanising?
Hot-dip galvanising involves submerging the base metal entirely in molten zinc.
131
What are common items that are galvanised?
Gates and metal pails are often galvanised.
132
What are most plastics made from?
Most plastics are man-made polymers that are synthesised from crude oil.
133
What is crude oil composed of?
Crude oil is made up of a large number of hydrocarbon molecules that are not very useful when combined.
134
What process is used to refine crude oil?
Crude oil is refined through a process called fractional distillation.
135
What is fractional distillation?
Fractional distillation involves separating the hydrocarbons in crude oil into fractions.
136
What is the basis of fractional distillation?
Fractional distillation works on the basis that each fraction has a different boiling point and condenses at a different temperature.
137
What are some fractions obtained from fractional distillation?
Fractions include petroleum gas, petrol, naphtha, diesel, kerosene, fuel oil, lubricating oil, and bitumen.
138
What is the purpose of cracking?
Cracking is used to break down the separated fractions into monomers.
139
What are some individual hydrocarbons produced during cracking?
Individual hydrocarbons include ethylene and propylene.
140
What is polymerisation?
Polymerisation is the process of joining monomers together to make longer polymer chains.
141
What is an example of a polymer formed through polymerisation?
Ethylene monomers can be joined together to form polyethylene.
142
What properties do plastics have that make them suitable for different commercial uses?
Plastics have different properties such as strength, toughness, durability, and insulation. When choosing plastics, cost, availability, ease of manufacture, and environmental impact should also be considered.
143
What are the properties of polypropylene that make it ideal for use in seats?
Polypropylene is tough, lightweight, and has a good strength-to-weight ratio, allowing it to withstand a person's weight. It is easily coloured and moulded into different shapes.
144
In what environments can polypropylene be used?
Polypropylene can be used in school, dining, and outdoor environments due to its waterproof nature and resistance to corrosion and chemicals.
145
How do thermosetting plastics compare to thermoplastics?
Thermosetting plastics are usually more brittle and rigid than thermoplastics but are good electrical insulators and resistant to heat and fire.
146
What is urea formaldehyde used for?
Urea formaldehyde is a hard electrical insulator that is heat- and fire-resistant, making it ideal for use in electrical fittings.
147
What is the purpose of stabilisers in plastic products?
Stabilisers are used to prevent UV degradation by absorbing UV radiation and emitting it as heat, protecting the chemical structure of polymers.
148
What are plasticisers and flame retardants used for?
Plasticisers increase flexibility in polymers, while flame retardants inhibit flame production and prevent the spread of fire.
149
What are the stock forms of plastics?
Plastics are available in the following stock forms: Sheet, Rod & Tubes, Foam, Film, Granules, Powder.
150
What are the uses of sheet plastics?
Uses: Line bending, signage, roofing, vacuum forming.
151
What are the uses of rod and tube plastics?
Uses: Machining, curtain parts.
152
What are the uses of foam plastics?
Uses: Packaging, seating, flotation aids.
153
What are the uses of granules?
Uses: Food packaging, vacuum forming.
154
What are the uses of powder?
Uses: Injection moulding, casting.
155
What are the uses of film plastics?
Uses: Dip coating, spray coating, 3D printing.
156
How are plastics measured?
Measurements are usually given in millimetres (mm): length x width x thickness. Thickness is also measured by gauge, and powder and granules are measured by weight (g).
157
What are standard components made from?
Many components made from woods and metals are also made from plastics.
158
Why are plastic components favored over metal?
Plastic components are usually favored on items where rust and corrosion are an issue.
159
What can be used for added strength in plastic components?
Plastic components with metal cores can be used for added strength.
160
What are machine screws used for?
Machine screws are used to temporarily join parts together.
161
How do machine screws differ from tapered screws?
Machine screws have a uniform diameter along the entire length of the shank, as opposed to tapered screws, which narrow to a point.
162
What variations do machine screws come in?
They are available with different head shapes (e.g. countersunk) and driving methods (e.g. Phillips) and in varying widths and lengths (measured in millimetres).
163
What are nuts and bolts used for?
Nuts and bolts are used to join materials together, including wood, metal, and plastic.
164
What is a nut?
A nut is a fastener with a threaded hole.
165
What is a bolt?
A bolt is a type of screw that fits the thread in a nut.
166
What shapes do nuts and bolts typically have?
They usually have a square or hexagonal head.
167
What tools are used to tighten nuts and bolts?
Tools such as spanners or socket wrenches are used.
168
What materials are nuts and bolts commonly made from?
They are commonly made from carbon steel or coated with zinc, but plastic varieties are also available.
169
What are some types of plastic used for nuts and bolts?
Plastic varieties include nylon, PVC, and PET.
170
What advantage do plastic nuts and bolts have?
Their resistance to corrosion and lightweight properties are advantageous.
171
In what applications are plastic nuts and bolts ideal?
They are ideal for electronic applications due to their non-conductivity.
172
What is a key difference between metal and plastic nuts and bolts?
Plastic varieties have an endless array of colors available.
173
What are hinges used for?
Hinges are used to allow objects to open and close.
174
What is a disadvantage of plastic hinges compared to metal hinges?
Plastic hinges are not as strong as metal varieties.
175
What is an advantage of plastic hinges?
They are lightweight and will not rust.
176
What are plastic butt hinges commonly used for?
They are used for light-duty openings, furniture, and cabinet doors.
177
What is an advantage of plastic butt hinges?
They do not corrode or require lubrication.
178
What do plastic continuous hinges replace?
They are used as an alternative to metal piano hinges.
179
What is a common application for continuous hinges?
They are used for hatches and lids.
180
What is a feature of plastic concealed hinges?
They allow for silent use and are fixed to the inside of the cabinet door.
181
What material are the plastic components typically made of?
They are typically made of nylon.
182
What are the characteristics of plastics regarding finishes?
Plastics are usually self-finishing and do not require extra protection, as they are resistant to corrosion and rot. Any added finish is generally for aesthetic purposes.
183
What is the process for polishing plastic?
To polish plastic, rough edges are first filed, then the plastic is rubbed with abrasive paper or a buffing wheel with a polishing compound. This can remove fine surface scratches.
184
What are some common printing methods for plastics?
Common printing methods for plastics include offset lithography, flexography, and screen printing.
185
What is heat transfer printing?
Heat transfer printing involves applying a design to the surface of plastic with a heat press using a special film with a heat-sensitive adhesive.
186
What is a vinyl decal?
A vinyl decal is a design printed on a vinyl sheet with an adhesive coating, transferred to a surface using heat or water.
187
How are vinyl decals created?
Vinyl decals are created by feeding vinyl sheets through a printer and cutter, using specialized computer software to design them.
188
What materials can be shaped and formed?
Wood, metals, and polymers can be shaped and formed through cutting, abrasion, and addition using a variety of tools, equipment, and processes.
189
What is the purpose of a rip saw?
Rip saws are used to cut parallel to the grain.
190
What is the purpose of a cross-cut saw?
Cross-cut saws are used to cut against the grain.
191
What is a tenon saw used for?
Cuts accurate straight lines in small pieces of wood and provides a smooth cut.
192
What is a hacksaw used for?
Has a hard, high-carbon steel blade so it can cut through metal; also available in a junior size for smaller cuts.
193
What is a coping saw used for?
Can cut intricate curves in thin materials but is difficult to control; has a blade that can snap easily.
194
What is the first step when cutting materials?
Secure the material with a clamp, or by placing it in a vice to prevent it from moving while the material is being cut.
195
How should you mark the material before cutting?
Make a mark in the material you want to cut by dragging the saw backwards a few times; this will provide you with a guide to start sawing.
196
What technique should be used while sawing?
Use the full length of the blade when sawing, and don't press down too hard. Let the blade do the work!
197
What is a band saw used for?
A band saw is a machine tool that is used to make straight and curved cuts in wood, but can also be used to thin wood into sheet.
198
What is a jigsaw?
A jigsaw is a handheld power tool that is used to make straight or curved cuts. Blades are interchangeable, so it can be used to cut wood, metal, and plastic.
199
What is a router used for?
A router is a power tool that is used to cut decorative edges, grooves, and shapes into wood. Handheld and larger machine types are available.
200
What are drills used for?
Drills are used to make holes in materials.
201
How does a drill operate?
A trigger is pulled, which turns on an electric motor and causes the attached drill bit to rotate.
202
What is a power drill?
Power drills can be used with a wide variety of drill bits to drill holes in woods, plastics, and metals.
203
What is a cordless drill?
Cordless forms are available that are more portable than corded versions, but they are generally not as powerful.
204
What is a pillar drill?
Pillar drills have far more accuracy than cordless drills and can drill bigger holes through harder materials.
205
What are drill bits?
Drill bits are available in a wide range of sizes and types.
206
Why is it important to select the correct drill bit?
It is important to select the correct drill bit for the desired job based on the target material and the size and depth of the required hole.
207
What is a flat bit used for?
Used to drill large, deep, flat-bottomed holes in wood and plastic.
208
What is a twist bit used for?
Used to drill small holes in wood, metals, and plastics.
209
What is a countersink bit used for?
Used to make holes for countersunk screw heads and bolts.
210
What is a Forstner bit used for?
Used to drill large, flat-bottomed holes in wood and plastic.
211
What is a lip and spur drill bit?
A type of twist bit that can be used on wood and contains a drill point to help keep the bit still for accurate drilling.
212
What is a center punch used for?
Used with pillar drills to drill large, flat-bottomed holes.
213
What is a bradawl used for?
Sometimes, it helps to mark the target materials with a bradawl (wood) or a centre punch (metal) to guide the drill bit.
214
What is an important safety tip when drilling?
It is important to select the right drill speed to prevent overheating (the bigger the drill bit, the slower the speed). The material should also be clamped down firmly.
215
What are chisels used for?
Chisels are used to cut or shape wood, stone, and metal. They are long-bladed, bevel-edged hand tools struck with a hammer or mallet to remove material.
216
What is chiselling?
Chiselling involves forcing the blade into the target material to carve or cut it.
217
What is a safety tip for chiselling?
Ensure that the blade is sharp and that the wood is securely held in place.
218
What is planing?
Planing is used to shape and smooth material, usually wood, by shaving off thin layers until the desired shape and feel are achieved.
219
What types of planers are available?
Manual hand planers and electric planers are available. Electric planers are quicker but less accurate than manual ones.
220
What is sanding?
Sanding involves rubbing abrasive paper against the surface of the material to shape and smooth it.
221
How can sanding be performed?
Sanding can be performed by hand or using machines.
222
What are the different grades of sandpaper?
Coarse paper is ideal for heavy sanding, while extremely fine sandpaper is used for smoothing surfaces and removing small imperfections.
223
What is a belt sander?
A belt sander is a powerful machine used to smooth wood, metals, and plastics more quickly and effectively than hand sanding.
224
What is a disc sander?
A disc sander has a powered disc of abrasive paper that spins at high speed to smooth surfaces and remove old finishes.
225
What is a safety tip for using sanders?
Dust extractors must be switched on to reduce the risk of fire and inhalation, goggles must be worn to protect the eyes, and fingers should be kept away from abrasive materials.
226
What is a breach of copyright law?
Photocopying or scanning an image is a breach of copyright law.
227
What is the purpose of a file?
Files have a serrated (toothed) surface that removes material when rubbed over a target material.
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What types of materials can files be used on?
Files can be used on a variety of materials and are available in different forms.
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How do larger teeth on files compare to smaller teeth?
Files with larger teeth remove more material than those with smaller teeth, which are better suited for smoothing.
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What is a lathe used for?
A lathe is used to shape materials such as wood and metal by spinning the material at varying speeds.
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What tool is pressed against the material on a lathe?
A wood-turning chisel is pressed against the spinning material to remove material.
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What are common items made by wood turning?
Common items include chair legs, table legs, and bowls.
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What is CNC in the context of lathes?
CNC stands for computer numerical control, which allows lathes to execute pre-programmed sequences to shape materials.
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What do milling machines use to remove material?
Milling machines use rotary cutters to remove material.
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What tasks can milling machines perform?
They can drill, bore, machine edges, cut grooves, and smooth surfaces.
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What materials are milling machines primarily used with?
Milling machines are primarily used with metals but can also be used with wood and plastics.
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What are the two main types of milling machines?
The two main types are vertical mills and horizontal mills.
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How is the spindle axis positioned in vertical mills?
In vertical mills, the spindle axis is positioned vertically.
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How is the spindle axis positioned in horizontal mills?
In horizontal mills, the spindle axis is positioned horizontally.
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Can milling machines use CNC?
Yes, some milling machines use CNC to execute pre-programmed sequences to shape materials.
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What are soldering, brazing, and welding?
They are processes that permanently join materials together.
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What is soldering?
Soldering involves joining metal with a filler (usually an alloy of lead and tin) that has a relatively low melting point. The filler is melted using a soldering iron and applied to the parts that are to be joined.
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What is brazing?
Brazing is carried out at a higher temperature than soldering and lower temperature than welding. Before the metal is joined, it is cleaned, and flux is added to prevent oxidation. The joint is heated, and a brazing rod of a different metal is then melted against it.
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What is welding?
Welding is the strongest way to join metal or plastics. It melts the base material and the filler. Heat is applied to the materials at the joint to melt and fuse them together. A welding rod is used to strengthen the joint.
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How are plastics welded?
Solvents are used to weld plastics by temporarily dissolving them.
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What is 3D printing?
3D printing is a form of 'additional manufacturing' in which thin layers of thermoplastic are used to build a physical object from a digital design. This is achieved through CAD/CAM technology.
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What materials can 3D printers use?
Some 3D printers can print with materials such as metal and ceramics.
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What is the future potential of 3D printing?
It is hoped that in the future, it will be possible to produce food and even human body parts using 3D printers.
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What is wood lamination?
Wood lamination involves gluing thin sheets of wood, or veneers, together in layers to add strength and create bent and curved wooden boards.
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What products are made using wood lamination?
Lamination is used to make products such as roof beams, toys, and curved pieces of furniture.
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How does moisture content affect wood bending?
The higher the moisture content, the easier the wood is to bend.
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What is steam bending?
Steam bending is a technique where wood is soaked temporarily and bent by placing it in a steam box.
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How long should wood be steamed for bending?
Wood should be steamed for around an hour per 25 mm before being bent into place.
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What is line bending?
Line bending is a process used to bend thermoforming plastics such as acrylic, which cannot be bent when cold.
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How is line bending performed?
A plastic sheet is heated over a strip heater and then carefully bent along the heated line once it is flexible.
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What happens to plastic after line bending?
Once cool, the plastic will keep its shape.
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What tools are used to bend metals?
Metals can be bent using tools like a sheet metal folder, which uses punches and dies.
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What is annealing in metalworking?
Annealing involves heating a metal above its recrystallization temperature and then cooling it slowly to increase ductility.
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What is the purpose of annealing?
Annealing is used to return metal to its workable form after it becomes stressed and prone to cracking.
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How can sheet metals be shaped?
Sheet metals can be shaped using a stamping press, where a pressing die is pressed down with great force.
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What is casting?
Casting is used to mould materials into shapes, primarily metals and thermosetting plastics.
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What is the casting process?
The casting process involves pouring molten material into a shaped mould and removing it once it has cooled and solidified.
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What is sand casting?
In sand casting, the mould is made using a pattern placed inside a box filled with moulding sand.
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What happens after the box is filled with sand in sand casting?
The box is opened, the pattern is removed, and molten material is poured into the cavity.
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What are runners, risers, and sprues?
They are specially designed channels that allow air pockets to escape and the metal to flow freely during casting.
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What is created using CAD/CAM technology in casting?
Complicated dies can be created using CAD/CAM technology.
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How is plastics casting different from metal casting?
In plastics casting, a mould is filled with a liquid synthetic resin, which then hardens.
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What is die casting?
Die casting involves forcing molten metal or thermosetting plastic under high pressure into a mould cavity.
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Can thermosetting plastics be cast without heating?
Yes, in some cases, thermosetting plastics can be cast without heating by mixing resin with a hardener.
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What is vacuum forming?
Vacuum forming is used to mould thermoforming plastics such as high-impact polystyrene (HIPS).
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What is the process of vacuum forming?
A plastic sheet is heated, then a vacuum pulls it onto a mould, and once cooled, the mould is lowered.
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What products can be created using vacuum forming?
Vacuum forming is used to create various plastic products, including packaging and food containers.
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What is moulding?
Moulding is a process used to shape materials into specific forms.
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What is blow moulding?
Blow moulding is a process used to create hollow plastic objects, such as drinks bottles.
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How does extrusion work?
Extrusion is carried out by pushing plastic through a die in a continuous stream.
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What is a parison in blow moulding?
A parison is a softened plastic tube inserted into a mould, which expands when air is blown into it.
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What happens after the parison expands in blow moulding?
The mould is opened to release the moulded plastic.
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What is injection moulding?
Injection moulding is used to create a wide range of plastic products, from model kits to dustbins.
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What is the role of the hopper in injection moulding?
Plastic granules are fed into a hopper and then released into an injection chamber.
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What happens to plastic pellets in the injection chamber?
The plastic pellets are heated until they melt.
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How is molten plastic injected into the mould?
A screw in the injection chamber turns, forcing the molten plastic into the injection mould.
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What happens after the plastic has cooled in injection moulding?
The mould is opened to release the moulding.
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What is extrusion?
Extrusion is a process where plastics and some metals, such as aluminium, are shaped by forcing them through a die.
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What materials are commonly used in extrusion?
Plastics and some metals, such as aluminium.
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How is extrusion similar to injection moulding?
Both processes involve shaping materials, but extrusion forces material through a die instead of filling a mould.
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What are some items created through extrusion?
Items created through extrusion include plastic pipes, curtain tacks, wire insulation, and medical equipment.
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What is drape forming?
Drape forming is a process used to shape a thermoforming plastic sheet over a mould.
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What are common applications of drape forming?
Drape forming is used to make vehicle bumpers and curved shower screens.
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What are the steps in the drape forming process?
1. A plastic sheet is heated until soft.
2. The softened plastic sheet is placed over the mould.
3. The plastic sheet takes the shape of the mould and is left to cool.
4. Once cool, the plastic retains the shape of the mould.
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Why is drape forming considered cost-effective?
Drape forming is cost-effective due to the low cost of tools and equipment, and it allows the material to retain its thickness.
