revision Flashcards
Treatments applied to timbers for use outdoors
- Danish oil
- Danish oil dries to a clear, transparent finish that maintains the natural appearance of the timber
- Danish oil penetrates the surface of the timber to replenish the essential oils lost through weathering and seals the surface, to protect the timber
- Danish oil creates a hard-wearing and durable, waterproofing finish.
- Danish oil is water and moisture resistant.
-Danish oil helps to prevent drying, warping and splitting
(- Danish oil is a suitable finish for interior and exterior use ) - Danish oil is a suitable finish for use on food preparation surfaces (since it is a food safe)
- it is non-toxic, making it suitable for use on toys
- It also improves the sheen and glossiness, which helps produce the beauty and appearance of timbers.
Describe in detail an appropriate method of finishing the seat of the chair. In your answer you should refer to a specific finish and explain why it is suitable (5 marks)
Varnish
- available in clear matt, satin and gloss finishes
- helps to enhance the grain to give a richer colour
- exterior varnish resists the cracking, peeling and blistering that is common to weathering
- provides high protection against UV light and water penetration
Application - for the best finish, the surface should be thoroughly prepared filling any cracks and sanding for the smoothest application.
E.g. Polyurethane/ acrylic varnish - provides a hard, tough, waterproof finish. Clear finishes allow for the grain to be seen through the finish
Yacht finish - suitable for woods that are outside all year around such as doors, window frames. increases the toughness, hardness and weather resistance
Wood Preserver -
- provides waterproofing as well as protection against rot and decay
- resistant to mould, algae growth and woodworm attacks
- UV protectors that can help against fading, and the natural greying process
Method for finishing the seat:
- sand the timber material with varying grades of timber material
- remove dust from the surface
- application of the finish with a brush, in the direction of the grain
Explain the process of pressure treatment for woods (6 marks)
Pressure treatment is a process that forces wood preservatives or fire-retardants into the wood.
These processes are considered the best and most effective method to extend and preserve timber life.
Preservatives protect the wood from attack by wood ingesting insects; like termites, and wood rot caused by fungal decay.
Fire-retardant treatments help the wood to quickly char when exposed to flame, reducing the smoke and flame that occurs in a fire.
What is a pressure-treated timber?
Pressure treatment is a preservative process that enhances the timber’s protection. The process includes placing the timber in a vacuum chamber, which removes all the air from the cells in the timber. Once this has been completed, the vacuum will force chemical preservatives deep into the wood. The treatment uses new chemicals that don’t harm the soil and the treatment boasts impressive results and benefits.
These include:
Protection From the Environment
Untreated wood left in moist or wet conditions is known to soften quicker, this allows fungus, bacteria and other micro-organisms to take root, slowly decomposing the wood. Even the smallest amount of moisture can cause problems, as fungus can attach itself to wood easily. The powerful preservatives used in the pressure treating process have anti-fungal and anti-insect properties that penetrate deep into the wood to protect it from environmental decay.
Longevity
Timber that has been left untreated, decays at a much faster rate than that of a timber that has been treated. The pressure treatment process creates a shield around the wood, therefore you don’t have to be worried about it being exposed to the elements and can be used outdoors all year round as it is protected from rain, hail and snow.
Cost-effective
Although compared to untreated wood, pressure treated timber is more expensive, the price is worth it due to the broad spectrum of protection it provides. The longer lifespan makes it more cost effective in the long term.
Low Maintenance
Pressure treated timber can be installed and then left for a long period, with little maintenance. As it is resistant to insects, water and fungus, there isn’t a lot that you need to worry about, therefore it is a low-maintenance option for your garden.
Environmental Friendly
Although the timber is preserved with chemicals, it still has many qualities that are beneficial to the environment. The number one reason why it’s environmentally friendly is due to its longevity. The increased lifespan of the pressure treated wood means that fewer trees need to be harvested to produce replacement products. In addition, copper (reclaimed as a by-product of the recycling industry) is used in the treatment process, reusing an element that would otherwise be discharged into the environment.
Decorative
Pressure treated timber doesn’t need to be coated with layer upon layer of paint or preservatives, allowing the natural beauty of the wood to be clearly seen. The natural look is an attractive feature for many homeowners and a reason why wooden products are a favourite for many gardens. If however you prefer a more colourful display, you can easily paint or stain the timber once it has weathered, allowing you to coordinate with the colour scheme of your garden, safe in the knowledge the timber’s protective layer is more than just skin deep.
Pressure treatment helps protect wood for up to 50 years from rot, insect and fungal attack and weathering
Suitable for products such as decking and outdoor cladding applications
Quality control during the injection moulding process
Factors that must be controlled:
- dimensional stability: the product’s dimensions have to be exact, especially when you have components that need to fit together
- colour: increasing/decreasing the temperature can affect a product’s colour. The colours should match as closely as possible
- finish and gloss: being consistent here is important because it ensures quality and helps build trust with clients
Problems that can affect quality control:
burn marks - parts may be overheated, which can cause discolouration and parts that are dark brown/ black/ red
- insufficient plastic added - this can cause there to be incomplete, as there areas on the product where insufficient plastic is produced
Advantages of Rotational Moulding
- Consistency: the constant rotation of the mould coats the walls evenly during the heating and the cooling process
- Low cost (tooling): rotomould tooling can be crafted from low- cost metals (such as aluminium)
- Efficiency: parts are moulded as one solid piece, eliminating the need for joining techniques, such as welding or other fabrication processes
- Finishes: The rotomoulding tooling accommodates surface finishes such as fine-detailed textures, logos, symbols and lettering
Disadvantages of Rotational Moulding
- Low repeatability: the soft metal used in the rotomould tooling must be replaced after 3,000 cycles
- High cost (labour and raw materials): materials - costs include required additives as well as the cost of grinding the material into a powder
labour - automation is not yet used for rotational moulding, which requires greater labour intensity than other manufacturing processes - High cycle times - at 8 rotations per minute, rotomoulding can take up to 3 hours to complete one part.
Environmental impact of single use plastics (1)
Marine Pollution: A significant amount of single-use plastics end up in the ocean, where they pose a threat to marine life and the ecosystem. Plastic debris can be ingested by marine animals, leading to injury or death, and it can also be mistaken for food, leading to the spread of toxic substances through the food chain.
2. Plastic Waste: Single-use plastics generate a large amount of waste, which can take hundreds of years to break down in the environment. This waste can clog waterways, harm wildlife, and release toxic chemicals into the soil and water.
4. Resource Depletion: The production of single-use plastics requires the use of non-renewable resources, such as oil and natural gas, and contributes to the depletion of these resources. In addition, the production process releases greenhouse gases, contributing to climate change.
5. Microplastics: When single-use plastics break down in the environment, they release tiny particles of plastic known as microplastics. These microplastics can be ingested by marine life and enter the food chain, causing harm to wildlife and potentially to humans as well.
6. Soil Contamination: Single-use plastics can also leach toxic chemicals into the soil, contaminating it and harming the health of plants, wildlife, and even
humans who consume the contaminated crops.
7. Landfill Space: The accumulation of plastic waste in landfills takes up valuable space and can leach toxic chemicals into the surrounding soil and groundwater.
Environmental impact of single use plastics (2)
- Energy Use: The production and disposal of single-use plastics requires a significant amount of energy, contributing to greenhouse gas emissions and climate change.
- Human Health: Plastic pollution can also pose a risk to human health, as toxic
chemicals from plastic waste can leach into the soil and water and contaminate crops and drinking water. In addition, the inhalation of
microplastics has been linked to respiratory problems and other health issues. - Microplastics in Drinking Water: Studies have found microplastics in drinking
water, raising concerns about their impact on human health.
Arts and Crafts movement
Designers drew inspiration from medieval craftmanship, reflecting natural forms and textures in items such as wallpaper
Designers focused on the natural beauty of timber in the production of hand-crafted furniture
The industrial revolution caused huge social change, reducing the reliance on craftmanship and increasing the use of machine tools
KEY FEATURES OF THE ARTS AND CRAFTS MOVEMENT
Appreciation of the beauty of materials: the Arts and Crafts movement was keen to highlight the unique nature of materials such as the grain in solid oak. They resented the ornamentation of machine produced products, which often hid the aesthetic beauty.
Hand produced using craft skills: concerned that the machine produced objects of the industrial revolution heralded the end of craftmanship, the Arts and Crafts movement took inspiration from the hand produced natural forms of medieval Europe
Art deco movement
KEY FEATURES OF ART DECO DESIGN
Sunburst motifs: these rays or segments radiating from a central point were commonly seen in architecture and surface patterns
Ziggurat (stepped pyramids): the ziggurat is an element often seen in Art Deco architecture, especially the ‘skyscraper’ designs of New York, where buildings were restricted by the 1916 zoning resolution to reduce the impact on light visible in the streets below. The zoning resolution required regular ‘setbacks’ as the height of the building increased, thus reflecting the ziggurat structures of ancient civilisations
Simple geometric forms: these were a distinct change from the natural realism associated with Art Nouveau
Health and safety at work act
The Health and Safety Act (1974) is the main piece of legislation for British health and safety law. To comply, all employers must ensure that all employees and visitors to the workplace are protected in terms of health, safety and welfare.
In general, employers should ensure the following:
- the workplace is safe and free from risks to health
- welfare facilities (such as first aid) are provided
- dangerous items and substances are stored safely and removed from use if necessary
- machinery is safe to use, maintained and in good working order
- training, information and adequate supervision is provided as necessary
- appropriate safety signs are provided as necessary.
Safe working practices usually cover the following aspects:
- Training: employees should be trained in the safe use of work machinery and trained to carry out safely any process that is required in their job.
- Machine maintenance and guarding: all machinery should be part of a regular maintenance programme in which parts are inspected for wear, blades are replaced and items such as gears are lubricated.
- Extraction systems: if a workshop produces and dust/fumes then extraction must be provided.
- PPE: employers should ensure that PPE is available to all employees
- Accident reporting: employers must have a record of any accident, and must report this via RIDDOR (reporting of injuries, disease and dangerous occurrences regulations 2013) to the HSE
Importance of prototype production
- assembly of components can be tested during the development of a product. also checks that parts fit together
- design ideas can be shared, and these can be given to potential customers, who can give feedback and can suggest improvements/ modifications that can be made.
- Virtual modelling can be used to stimulate a manufacturing process, for example to check that a product will be machined properly.
- CFD (Computational Fluid Dynamics) can be used to stimulate the flow of fluids/gases in or around a product. (e.g. a vehicle can be tested in a simulated wind tunnel to evaluate the drag (wind resistance) created by air flow over the external surface. designers can then use these results to improve aerodynamics.
- saves time and money
- Finite element analysis (FEA) uses computer modelling to carry out component stress analysis to simulate things such as vibrations, shocks which can highlight any potential weak points in a product.
- Rapid prototyping is a fast way of making 3D models which is less expensive.
Explain three ways in which prototypes are used when designing products
Prototypes can improve the overall understanding of a design. Rapid prototypes help to illustrate the final product, allowing the design to comprehend the product’s function and target audience.
Prototypes can minimise design error and identify faults. By using prototypes, design teams can make changes early, which means that the cost and extra work is reduced, and it is quicker and more efficient.
Prototypes allow for user testing (+focus groups)so that they customise their design for their target market ang gain client feedback.
computer models can be used to calculate volumes, weights, tensile strengths
Allows users to interact with the product.
Buying trends of mass-produced furniture
Impact of technology:
- technology is changing the way that furniture is being manufactured. Technology allows for:
- customisation
-quality control -> software can be programmed to automatically detect and correct production ideas, reducing the likelihood of defects and improving the quality of the finished product.
- sustainability - CAD software can help to optimise designs for efficient use of materials, reducing waste
Consumers today are looking for furniture that is easy to assemble, transport and store. Mass -produced furniture manufacturers have responded by designing furniture that can be easily disassembled and reassembled, as well as furniture that can be flat-packed for easy shipping and storage. This requires changes in the production process and the development of new manufacturing techniques.
Demand for customisation: consumers today place a high value on uniqueness, customisation and personalisation, so they might want furniture that reflects their individual styles/tastes.
Buying trends of mass-produced furniture
