Wood Finishing

We finish timbers to:

1. protect them from rottonig
2. make them more aesthetically pleasing

Types;

Wood stain varnishs

• Varnishes- these have a polyurethane varnish combined with wood stain-it sits on the surface of the timber rather thean being absorbed into it.Each layer applied darkens the timber.
• Water based- these are resisted to fading and resisted to uv light. it is best appiled after sanding like a sealer
• Acrylic varnish- quick drying and non-toxic, avaliable in gloss, satin and matt finishes
• Exterior- this varnish is specially formulated microporous varnish - it lets the wood timbers breathe - mirco pours
• Polyurethane varnish- its a plastic coating
• Yacht - this is water resistance against sea and fresh water so is good from coating boats with.

Oils

• dansil oil
• finshing oil
• lisned oil
• teak oil
• lemon oil

Polishing

• french polishing
• wax polishing

PAINT

Tantalizing- this is were wood timbers are impregnated with a preservative solution under high vacuum pressure in an industrial vessel.

Wood joints

Dowel Joints
Dowel Joints are a very common joint as they are alot better than a mortise and tenons.The ends of the rails or feet can be shaped to fit the curve of the legs before drilling holes for the dowels to be inserted.They are used to ensure accuracy. the dowels themselves are often made from a hardwood called ramin and come in a range of diameters from 4 - 25mm.

Finger Joint
Finger Joints are like dowl joints but is attacted to the parts that need to be joined. They look like combs and are fairly easy to make as there are no dovetail-type angles, the Large gluing area gives the joint its strenght. This joint is ideally suited to industrial situations where it is produced using machine tools.

Dovetail Joint
Lapped
There are two different types of Dovetail joints.one is the dovetail lapped joint, it is like the finger joint but are more dovetail like hence the name.Havling joints are often found in frame constructions. Wood of equal thickness is used for both parts of the joint. A dovetail halving is sometimes used instaed of a T-halving in situations where increased strenght is needed.

Doveltail Through Joints

theses are ideal for corners as its more asthetically pleasing, the tapered shape of the "tails" resist the forces applied to the joints when the drawer is in use.Apart from being a strong joint in some situations dovetails are used primarily their decorative qualities.

Mortise and Tenon
Corner mortise and tenon joints are used on tables and frount legs of chairs where two rails are joined to a single leg at each corner.the ends of the tenons are mitred where they meet inside the leg.
Haunched mortise and tenons are often used when joining corners of frames,or rails to the ends of legs.The tenon is offset to prevent it breaking through the end grai of the leg or stile. The haunch, which forms a small integral tongue on the tenon, supports the top edge of the rail.

Moulding Timbers

Steam bending
Steaming is an effective method of softening or plasticizing wood so that it may be molded for craftsman and industrial applications, such as the manufacture of furniture.
planks of timbers are placed in a room called a steam box then heat and moisture is applied making the fibres in the wood expand making it easy to bend or form with a mould or a jig. by clamping them all together. Once in moulds heated,and moisture added they are leaved outside to let the extra moisture evaperate ready to use the the outcome in furiture.e.c.t.

Vaccum bag
A form of laminateinting.
The layers of the veanear are placedon a mould and put inside a tought plastic bag (so it's harder to rip or tear) a vaccum pump is used to suck air from the bag and the bag is then suck down onto the veanears hold them firmly.

Laminating
Sticking layers of timbers together to form a stronger timber. Its strong because it's glued together but the gain needs to run in different ways- opposite ways on different layers.

Other ways: instead of uses layers of wood stuck together with glue, people also have the use of aluminium sheet and a honeycomb shaped material glue together.
When wood is cut into thin Veaners it can be bent around a mould and formed into complex shapes. It would not be possible to produce many of the shapes made with a soild block of wood.

Manufactured Boards

Manufactured Boards

Hardboard
Made of wood fibre which is extracted from chips and pulp of the waste from wood. Also known as HDF (High Denstiy Fibreboard)
Uses:
-Some furinture
-Cabinates
-Counter tops

Thickness:
-3mm

Blockboard
Made of a compound wood board consisting of nearly square strips of softwood placed side by side and sandwiched between veneer panels, often of hardwood.
Uses:
-Shelves
-Tables
-Some doors

Thickness:

- 30mm

Chipboard
Made of different sides chips that are stuck together with glue.
Uses:
-Flooring
-Sheds
-Counter tops

Thickness:
- 18mm

MDF (Medium Density Fibreboard)
Made of hard and soft wood fibres stuck together with glue.
Uses:
-Kennel roof
-Sheds
-Flooring

Thickness:
-24mm

Plywood
Made of two or more layers glued and pressed together with the direction of the grain alternating.
Uses:
-Furinture
-Shelves
-Doors

Thickness:
-6mm

Timber theory

Timber theory

Timbers is a general name for wood materials and comes in many types
-softwoods
-hardwoods

both are renewable only if people continue to plant them.

Softwoods
-Fast to grow
-Evergreen
-Grows in cold climates
-Commonly used
-Cost effective
-Easier to machine
-Get more trees grown than hardwood trees
(the quiker they grow the more cost effective they are)

Hardwoods
-Takes longer to grow
-More dense - gain
-Grows in hot climates
-Deciduious
-EXPENSIVE
-Very big
-Indiginious ( Native to country)

SEASONING;reduces moister
Air drying- it is where the timer is leaved out to dry on its own so natuarlly get dry. It costs less but can easily split or crack, and it extremly slow!

Kilm drying- it is wheretimbers get stacked up on each other and put into a kilm (oven) where we can control the heat that gets put into it.It can cost abit more as you are using heat to dry the timbers out.

Product Reaserch uses and manufacturing

Plastic bottles:PET PolyEthylene Terephthalate

Plastic Bottles

• Needs to be Hyginic
• Needs to be Durable
• Needs to Non-Toxic
• Needs to hold a Liquid

Made by Blow Moulding:


Lego:ABS Acryliconitrile Butadience Styrene

Lego

• Needs to be Non-Toxic
• Needs to be Durable
• High heat resistance
• Can be died to differenet colours
• Needs to be Impact resistance

Made by Injection Moulding:

Action Figures:ABS Acryliconitrile Butadience Styrene

TMNT Action Figures

• Needs to be Non-Toxic
• Needs to be Durable
• High heat resistance
• Can be died to differenet colours
• Needs to be Impact resistance

Made by Injection Moulding:

Lunch boxes/tubaware:PP PolyPropylene

Tubberware

• Needs to be Hygenic
• Needs to be Non-Toxic
• Needs to be Heat resistance
• Can be died to change colours

Made by Injection Moulding:

Rugby balls/sports balls:

Rugby Ball

• Needs to be Non-Toxic
• Needs to be impact resistance
• Needs to be Durable

 Made by Rotational Moulding


Food packaging:PP PolyPropylene

Plastic Food Containers

• Needs to be Hygenic
• Needs to be Flexible
• Needs to be Non-Toxic
• Needs to be Clear
• Needs to contain food/liqiud

Made by Vacuum Moulding:

Hard Hats:HDPE High Desity Polythylene

Hard Hat

• Needs to have a High impact resistance
• Needs to be Non-Toxic
• Can be change for different colours
• Need to have comfort
• Need to keep people safe
• Needs to be Durable
• Waterproof

Made by Injection Moulding:

Plastic Moulding

Plastics Moulding

Vacuum Moulding

This is a process that is used to manufacture a variety of products in thermoplastic materials. A mould,which is usedfor prducing the interior panels of lorry cabs, is attached to a platen (support plate)
The platen and mould are then lowered and rigid thermoplastic sheet material is clamped onto an air tight gasket and usually heated from above.One the thermoplastic sheet is softened enough then the air is blown in to raise the sheet in a slight bubble before the platen is raised bringing the mould into contact with plastic.Any air trapped between the platen and heated plastic sheet is then evacuated by a vacuum pump. Atmopheric pressure acting over the top surface completes the forming process by pressing the plastic sheet on to the mould. Once the plastic sheet has been cooled down below freezing pointthe air flow is reversed to lift the forming off the mould.
Line Bending


Blow Moulding


Compression Moulding



Injection Moulding

This is a process like Extrustion Moulding as the plastice pellets are put into a hopper that go to a heated barrel, while the mould is being clamped the machine.the heated up plastic is then injected in to the mould. Once mould is filled the cooling process begins and once mould is cooled down the mould is ejected and the process starts again.



Extrustion Moulding

This process can be compared to squeezing toothpaste from a tube.It is a continuous process used to produce both solid and hollow products that have a constant cross-section. E.g: Window Frames, Hose Pipe, Curtain Track, Garden Trellis. Thermoplastic granules are fed from a hopper by a rotating screw through a heated cylinder. The tapered shape of the screw compacts the plastic as it becomes plasticized.This part of the process is similar to the heating and compacting stages in the injection moulding process.The difference being that the softened materials material is allowed to flow out through a die in a continuous stream rather than be pumped intermittently in measured amounts into a mould.The die which is fitted to the end of the extruder barrel determines the cross-section of the extrusion.
Rotational Moulding

 
Rotational Moulding is a process used mainly to manufacture hollow shaped products such as footballs, road cones and storage tanks.
The machine has three arms which rotate about a fixed central point. Each arm stops in turn at one of three stations. Moulds are attached to end of each arm and are rotated continuously.The only time the moulds are not being rotated is when they are positioned at station 1 which is where the proess both begins and ends. At station 1 the mould is either being loaded with thermoplastic powder or the finished moulding is removed to start the process again. The cooling chamber is at station 3 and oven chamber is at station 2. The Temperture goes up to 230-400c whilst being rotated and the roational speed is between 2 and 20 r.p.m.

Jigs,Templates: these are imporant because they keep everything the same.

Polymer Theory

Monomers     ->    Polymerisation     ->   POLYMER
Monomers join together to form a long chain of molecules called polymers ( plastic )

Thermo setting plastics;
Has no links
- they soften when heated and can be remoulded so or more recyclable then thermosetting
Types of thermoplastic;
-ABS - Acrylonitrile Butadiene Styrene
-CA - Cellulose Acetate
-Nylon - Polyamide
-PMMA - (acrylic)
-PP -Polypropylene
-HIPS - High Impact Polystyrene
-PS - Polystyrene
-LDPE - Low Density Polyethylene
-HDPE - High Density Polyethylene
-uPVC - Polyvinyl Chloride
-PVC - (unplasticised flexible) Polyvinyl Chloride
-PET - Polyethylene Terephthalate
-PC - Polycarbonate

Thermoplastics;
Has links so less movement
-it can be moulded into a shape but can not be remoulded
Types of thermosetting plastics;
-Expoxy Resins - surface coatings, encapsulation of electronic components adhesive
-Melanie - Tableware,Decorative laminates
-Polyester Resins - Castings, used in GRP
-Urea formaldehyde - Electrical fittings, adhesives

Polymers are;
-Good electrical an thermal insulator
-Good strength to weight ratio
-Generally good resistance to atmosphere and chemical erosion
-Low melting point
-Lightweight
-Available in a wide range of colours and transparency ( due to different a pigments)
 -Two main categories thermoplastic and thermosetting plastics

Improving the properties of plastics;
-Fillers; bulking- reduces cost and you get more of the product eg: sawdust crushed quartz and limestone - in also strengthens it
-Flame retardants; flame resistance less likely to catch fore or slow the flames down
-Anti Static agents; reduce the effects of static charges that can build up on a product - used in synthetic carpets
-Plasticisers; these make the materials less brittle
-Stabilisers; reduce the effect of ultra violet light found in sun light

Assignment 2

Assignment 1

I should never have purchased Skull-candy in-ear headphone!
The other week my earphones stopped working through one of my favourite songs I had had them for years and it was clear to me it was time for some new ones so I decided I wanted a pair of black and pink in-ear headphones made by Skull-candy as my sister said they have a longer life span and are good quality and I had to get in ear ones because they were better than the outer-ear.

I brought my expensive in-ear pink Skull-candy headphones for £15 to me that is a lot of money for a pair of headphones normally I would spend £5 or less for my other pairs in the past,  but these WERE meant to be worth it. But they weren't!

I don't know if it was just the pair i purchased but they stopped playing sound within five days, the sound quality was poor and fuzzy they burse my eardrum within ten minutes of using them, as well as they never fit into my ear properly, I would have to hold them in just so they would stay so I could listen to one of my favourite songs that sounded like an alien trying to make contact with earth for the first time!

Even thought they look aesthetic pleasing they were not ergonomically good enough for me personally and will not be purchasing them again.