1.5 The uses of finishes Flashcards
Laminating
When paper is thread through a desk top laminator and heat sealed, leaving a polymer (PET and EVA) sheet over with a boarder around the edge (encapsulation). Can also be applied through a liquid with a roller or spray or film laminating made of PP with an adhesive.
Embossing
Raised design on surface of paper or cards. Used for greeting and invitation cards as well as packaging. Uses a male and female die made from stainless steel. Substitute is placed under pressure. An embossed area can have ink or foil applied, without any of these its called a blind emboss.
Debossing
Opposite of embossing and produces an imprint of the paper or card,
Foil Blocking
Application of heat and pressure to a metallic paper (oil) to create areas of depth and texture. Uses a heated die in which the design is stamped onto he material through the foil. Heat allows the foil to stick. If too much heat or pressure is applied the foil will bubble. Too little heat and the foil wont stick to the substrate
Varnishing
Clear, non-pigmented ink used on pre-coated papers to enhance colour. some offer protection against dit,fingerprints and water. Only suitable for ore-coated papers as these will not soak up the ink.
Spot Varnishing
Varnish applied in specific areas through plates. Used with varnish and UV varnish
Screen Printing
Used for posters, display boards and t-shirts.Image to be printed is created o a screen made of mesh held by a frame. a different screen is needed for a different colour. The substrate is placed over the machine bed and the screen is placed on top. Ink is forced through the mesh through a squeegee.
Flexographic Printing
Uses flexible printing plates wrapped around rotating cylinders on a web press. Water based ink is transferred to the plate cylinder by anilox roller and onto the impression cylinder to the plate cylinder
Offset Lithography Printing
Oil and water don’t mix. Plates are treated to be hydrophillic. The substrate is sheet fed onto the printing machinery. Printing placed produced by a computer by a laser. Ink is applied to the printing plate that printing onto a blanket roller.
Digital Printing
Used in flyers and business cards, ideal for mass customising such as printing specific names on drinks cans due to fast drying inks. The ink sits on top of the paper. Looks similar to large photocopies with great speed and efficiency.
Adding colour to the moulding process
Polymers are considered to be self-finishing as they require no additional finishing process once manufactured. Surface textures produced from mould.
Polymer Dip Coating
Used on wire coat hangers, dishwasher racks. Metal is heated to 230C and then dipped into a tank of fine polymer powder which has hot air (fluidisation bath). Which provides an even coating on the product. THe polymer powder melts.
Metal Dip Coating
Same as polymer dip coating but for metal. Typically used for low carbon steel protecting it from rust. The molten material is called the donor material. Tin is plated at 320C to prevent food cans from corroding. Zinc platings or galvanising is done at 460C used for beams gates and animal pens.
Powder coating
Product is statically charged (negatively). Thermoset polymer is positively charged. The charge attracts the power to the product. The product is heated in the oven to give even spread. Much more hardwearing than paint. Used in machine bodies, dishwashers and refrigerators and applying colour to metal gates and fencing.
Water Based Paints
Apply with a brush, roller or spray.
Wood knots should be treated with knotting and undercoat applied before application.
Provides protection
Stains
Used to help colour and enhance the grain. Stains are water-based and can be used to colour an inexpensive wood make it look like a more expensive timber or merely to add colour while allowing the grain to show but no protective properties.