1.5 The uses of finishes

self finishing

A material that requires no further coatings or finishing processes

self coloured

a material that has an acceptable colour after processing

applied finish

a substance applied to the material after processing

laminating

the process of bonding two or more layers of material together to form a thicker and stronger section.

encapsulation - the sheet is encased by a polymer pouch

surface coating - liquid or film, they coat the paper to protect it

embossing

Creates a raised design on the surface of paper or card, there are two dies, male or female, the substrate is held between them until the area is formed

debossing

The reverse of embossing, so that the image is sunk into the substrate, rather than being raised, uses the same method.

foil blocking

A paper finishing process which uses heat and pressure to apply a metallic foil to papers and boards, uses a heated die that prints the foil on similarly to embossing

Varnishing

A coating applied after printing to provide a clear protective surface.

UV varnishing

provides a very smooth finish, usually high gloss or matt, and abrasion and chemical resistant.

applied to a sheet via a set of rollers, then passed under UV light to cure

the ink must be completely dry before use

spot vanishing

varnish is only applied to specific area, a plate applies the varnish to the specific spots.

screen printing

a technique in which stencils are applied to fabric stretched across a frame and paint or ink is forced through the unblocked portions of the screen onto paper or another surface beneath

flexographic printing

Least expensive, uses rolls of substrate that allows for continuous print runs

advantages of flexographic printing

High print speed

suitable for long runs

prints on a wide variety of substrates

low maintenance

disadvantages of flexographic printing

Cost of printing plates is high but they last

takes a large amount of substrate to set up

time consuming to make any alterations to the print content

offset lithographic printing

A printing method in which inked images are offset or transferred from one surface to another.

advantages of offset lithographic printing

consistent high image quality

higher volume prints

quick and easy production of printing plates

long life printing plater

disadvantages of offset lithographic printing

expensive set up costs

only suitable for porous substrates

digital printing

printing by plate less systems that are imaged directly from digital files, usually using lasers and toner; ink-jet systems and other processes are less common forms of digital printing.

polymer finishing

polymers are considered self finishing

adding colour in the moulding process

pigments can be added to polymers during the manufacturing processes so no finishes need to be applied

acrylic spray paints

An additional finish that can be used to enhance aesthetics, can act as protection against UV and allows for different colour options to customize products

over mouldings

When a second polymer is moulded over specific parts of the original polymer e.g. toothbrush, can use two injection moulding moulds or twin shot where the polymers are added together within the same mould

metal finishing

Metals have oxide layer and acts as a barrier, steels are an exception as it allows for moisture in to rust(porous)

cellulose and acrylic paints

Provide a colour or textured finish to a product

electroplating

Using a metal to coat a cheaper base metal to give a protective layer and enhance aesthetics.

The product and donor metal are placed in a container with electrolyte solution when the direct current is applied the product attracts the donor metal

polymer dip coating

Metal product is heated to 230 degrees and dipped into the tank of fine polymer powder with air blowing through it so there is an even coating

metal dip coating

Like polymer dip coating

Tin - sheets of steel are passed through molten tin at 320 degrees

zinc - called galvanising, dips steel into molten zinc at 460 degrees

powder coating

thermoset polymer powder is positively charged and attracted to the negatively charged product. It is then baked to melt the powder and given an even coating.

varnishing

Varnishing provides a clear finish to protect the metal and allow the colour of the base metal to show through

Sealants

Tough polymer based that protect polished surfaces from decay and tarnishing

preservatives

Used to protect against decay, discoloration, or spoilage applied with a cloth, spray or immersion

anodising

a way of protecting aluminium from corrosion, by deliberately creating a layer of aluminium oxide over it

cathodic protection

A technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell.

polyurethane varnish

an exceptionally hard, abrasion-resistant, and chemical resistant varnish made from a plastic resin of the same name

water based paints

A wood finish which provides protection and colour , as well as improving toughness and hardness

stains

Used to help enhance grain patterns and add colour

colour wash

A wood finish which colours a wood without hiding the grain

wax

Increases woods hardness and toughness with a clear finish

pressure treating

A wood finish which protects wood from rotting and insect attack, by using a vacuum and pressure to force preservatives into the wood

yacht varnish

For outdoor application, increases toughness, hardness and weather resistance

danish oil

A wood finish which maintains the natural appearance of the wood as well as enhancing the grain

teak oil

A wood finish is used for outdoor wood products as it added a weather resistance as well as preventing fungus and insect attack

substrate

the material which print ink is applied to