Tanalising

 

Tanalised timber is a type of timber that is usually impregnated under pressure with highly toxic substances such as arsenic in order to protect it against rot and termites. This treatment process ensures deep penetration into the timber cells, for a longer-lasting protective results against fungal decay and insect attack.

Joints

 

The basic mortise and tenon comprises two components: the mortise hole and the tenon. The tenon is cut to fit the mortise hole exactly and usually has shoulders that seat when the joint fully enters the mortise hole. The joint may be glued, pinned, or wedged to lock it in place.

 

 

 

The wooden dowel rod used in woodworking applications is commonly cut into dowel pins, which are used to reinforce joints. Dowel-based joinery typically uses fluted dowel pins. A fluted dowel pin has a series of parallel grooves cut along its length. The fluting provides channels through which excess glue can escape as the dowel is inserted, thereby relieving the hydraulic pressure that might otherwise split the timber when the mating pieces are clamped together.

 

Dovetail joint is a joint most commonly used in woodworking joinery. Noted for its resistance to being pulled apart (tensile strength), the dovetail joint is commonly used to join the sides of a drawer to the front. A series of pins cut to extend from the end of one board interlock with a series of tails cut into the end of another board. The pins and tails have a trapezoidal shape. Once glued, a wooden dovetail joint requires no mechanical fasteners.

A half lap joint or a halving joint is a technique of joining two pieces of material together by overlapping them. A lap may be a full lap or half lap. In a full lap, no material is removed from either of the members to be joined, resulting in a joint which is the combined thickness of the two members.

A finger joint is a joint made by cutting a set of complementary rectangular cuts in two pieces of wood, which are then glued. It is stronger than a butt or lap joint, and often contributes to the aesthetics of the piece. Alternate names include box-pin joint or box joint.

Steam bending

To steam bend wood the wood must have a high moisture content to begin with, hard woods are better to use for bending rarther than soft wood. It is easier to bend wood with the grain as it is less likley to crack and break.


The applied heat and moisture makes the wood pliable enough to easily bend around a mould to create a specific shape. The moulding process is usually done by clamping the strips of wood to a positive form, with the strips of wood often reinforced on the outside with a metal band to prevent blowout. The method has been used in the manufacturing of a diverse range of products.



This is a sime home made steam box

This is a product created by steam bending






Drying of timbers

Air drying refers to the drying of wood from the wind and the sun, wood is stacked on stickers and placed in a mannor that allows wind to blow through it. This is comonly used only for previsional drying befor it is put into a kiln as it is a long prossess which can get very expensive.

kiln drying is when timber is stacked in the same way however it is placed in a chamber where the airflow, temperature and humidity are controlled. the three main types of kiln are conventional, dehumidification and solar. The airflow in the kiln chamber is very important. The velocity of the air over the wood affects the drying rate and provides even drying.

Differant types of moulding

Homework

Injection moulding

Injection moulding consists of small plastic granuals getting melted down until it is runny enough to be pushed into the mould and fill the complete shape. when the plastic is cooled the mould opens up releasing the moilded shape and this can be completed over and over and get the exact product over and over again.

Purpose of a jig/mould

 

the purpose of a jig/mould is to increase efficiancy and imppove safty of the working area and create more accurate products ate the end of it. 

plastic/polymers

themoplastic:

no links between polymer chains. they can get re shaped over and over again also they are recyclable

thermosetting:

can not be changed after being moulded once so they are hard to recycle


Summary of plastics

good thermal and electrical insulators

good straight against weight ratio

doesnt decompose

low melting point

available in wide range of coulers and transparancy

two main catagories thermoplastic and thermosetting


Ways to improve properties of plastics

Fillers: fillers are used to bulk up plastics to make them stronger for lower cost.

Flame retardents: used to reduce the risk of combustion

Anti static agents: reduces the effect of static charges

Plasticisers: makes material less brittle and improves the flow properties

Stableisers: reduce the effect the ultra violet light has uppon the object


Close loop production



Types of thermoplastics

ABS -  Acrylonitrile butadiene styrine
CA - Cellulose acetate
NYLON - Polyamide
PMMA - Acrylic
PP - Polypropalene
HIPS - High impact polystyrene
PS - Polystyrene
LDPE - Low density polyethylene
HDPE - High density polyethylene
UPVC - Polyvynal chloride
PVC - Unplasticated flexible polyvynal chloride
PET - Polyetheylene terepheluate
PC - Polycarbinate

Types of thermosetting plastics

Epoxy resins: surface coating, adheasives
Malamine formaldahide: table ware, decorative laminates
Polyester resins: castings
Urea fomaldahide: electical fittings, adheasives

Miniture chair project

assignment 1 - I should never had purchased

Apple Iphone headphones


A few months ago I purchased a set of apple headphones as I am a keen listener of all types of music however I should have never bought these because they are terribly designed and I believe do not fit the purpose they were designed for. Although these are a very iconic piece of technology in the current time although to become this iconic the design has some bad aspects.


For starters the ear pieces I believe are the incorrect shape to fit any type of ear I should have listened to my friends who they did not fit as well. In addition the sound quality of these headphones is terrible and although they are not the most expensive headphones on the market I would expect them to be reasonably good. Furthermore the cable that is used is very prone to tangling and can cause a lot of distress when trying to listen to music and to top of this terrible product the build quality of these headphone are dreadful and broke within a month of me having them, one ear piece broke off and the wire due to a lot of knotting split and broke.


All in all  I believe that apple needs to rethink the design of their product and possibly create a new one.