In printing, anti-set-off spray powder is used to make an air gap between printed sheets of paper. This enables the ink to dry naturally and therefore avoid the unwanted transfer of ink from one printed sheet to another. The problem can occur with most types of printing.
Anti-set-off spray powder is generally made from natural starches from plants and vegetables. There remains a demand for soluble powders (sometimes known as vanished powders) based on natural sugars[1] which are often used when the final printed sheet is to be varnished. In addition there is still a relatively small amount of powder made from minerals (e.g. Calcium Carbonate, rather than Talc) used in offsetlitho printing; however these mineral powders are not so popular because of the potential health implications and abrasive properties.
Spray powder is used to separate printed sheets to enable air to naturally dry the printing ink. The diameter of the powder used is relative to the density (g/m2) of the stock (paper or board) being printed. For 150 g/m2 paper the ideal anti-set-off spray powder would be 15 μm in diameter, for 200 g/m2 20 μm, through to 70 μm for heavy board (700 g/m2).
Most manufactures of spray powder offer both coated and uncoated powders. Uncoated powders are generally less expensive and are based on natural food-grade starches typically derived from corn (maize), wheat, semolina, potato, tapioca and rice depending on the diameter required. Coated powders use the same range of raw materials but are encapsulated with a minuscule amount of natural coatings which enable the powders to flow freely though the spray guns on sheet-fed offset-litho printing presses. Enhanced versions of these coatings are used to give specific electrostatic (anti-static) and hydrophobic properties.
Spray powder is not used on rotary presses including rotary letterpress, web offset (often used for printing magazines), flexographic (often used for printing flexible packaging and labels) or gravure (often used for printing long-run catalogues). Similarly, spray powder is not generally used in sheet-fed (silk) screen-printing, ink-jet or toner based digital printing. In the UK, many Carrom players use a version of anti-set-off spray powder from the printing industry[citation needed] which has specific electrostatic properties with particles of 50 micrometres in diameter.
As health and safety has become more important to the environment and to the work forces, a small number of anti-set-off spray powder manufacturers had introduced highly clarified powders by 2007, in advance of EU legislation.[2] This new generation of powders have typically less than 3% of particles of less than 10 μm and almost no particles below 5 μm which are generally regarded in the industry as dust. To put this in context typical human hair is 20 – 40 μm.
The printing industry regards anti-set-off spray powder as a necessary evil. Ideally printers would prefer not to use it, but it remains the only practical way to ensure a stack of printed paper at the end of a printing press does not set-off. In recent years there has been an emergence of printing presses which use inks that are cured (dried) with powerful UV lamps. As each sheet is individually dried there is no need for spray powder. However, as these machines require specialty inks which are much more expensive than conventional inks, and the UV lamps use a significant amount of energy, the vast majority of new sheet-fed presses sold in 2007 still used anti-set-off spray powder.
Other usesedit
In addition to its use in the printing and packaging industry, spray powder is also used in the manufacture of float glass to enable the large sheets to slide easily over each other. It is also used in the manufacture of plastic food wrap and similar products to help prevent pieces of plastic from sticking together because of static electricity. In the UK, many carrom players use a version of anti-set-off spray powder from the printing industry[citation needed] which has specific electrostatic properties with particles of 50 micrometres in diameter.
^ . – Russell-Webb. Archived from the original on 2007-08-09. Retrieved 2007-07-04.
^(PDF). – Berufsgenossenschaft. Archived from the original (PDF) on 2007-04-11. Retrieved 2007-07-03.
April 15, 2024
anti, spray, powder, printing, anti, spray, powder, used, make, between, printed, sheets, paper, this, enables, naturally, therefore, avoid, unwanted, transfer, from, printed, sheet, another, problem, occur, with, most, types, printing, generally, made, from, . In printing anti set off spray powder is used to make an air gap between printed sheets of paper This enables the ink to dry naturally and therefore avoid the unwanted transfer of ink from one printed sheet to another The problem can occur with most types of printing Anti set off spray powder is generally made from natural starches from plants and vegetables There remains a demand for soluble powders sometimes known as vanished powders based on natural sugars 1 which are often used when the final printed sheet is to be varnished In addition there is still a relatively small amount of powder made from minerals e g Calcium Carbonate rather than Talc used in offset litho printing however these mineral powders are not so popular because of the potential health implications and abrasive properties Spray powder is used to separate printed sheets to enable air to naturally dry the printing ink The diameter of the powder used is relative to the density g m2 of the stock paper or board being printed For 150 g m2 paper the ideal anti set off spray powder would be 15 mm in diameter for 200 g m2 20 mm through to 70 mm for heavy board 700 g m2 Most manufactures of spray powder offer both coated and uncoated powders Uncoated powders are generally less expensive and are based on natural food grade starches typically derived from corn maize wheat semolina potato tapioca and rice depending on the diameter required Coated powders use the same range of raw materials but are encapsulated with a minuscule amount of natural coatings which enable the powders to flow freely though the spray guns on sheet fed offset litho printing presses Enhanced versions of these coatings are used to give specific electrostatic anti static and hydrophobic properties Spray powder is not used on rotary presses including rotary letterpress web offset often used for printing magazines flexographic often used for printing flexible packaging and labels or gravure often used for printing long run catalogues Similarly spray powder is not generally used in sheet fed silk screen printing ink jet or toner based digital printing In the UK many Carrom players use a version of anti set off spray powder from the printing industry citation needed which has specific electrostatic properties with particles of 50 micrometres in diameter Contents 1 Modern developments 2 Other uses 3 See also 4 External links 5 ReferencesModern developments editAs health and safety has become more important to the environment and to the work forces a small number of anti set off spray powder manufacturers had introduced highly clarified powders by 2007 in advance of EU legislation 2 This new generation of powders have typically less than 3 of particles of less than 10 mm and almost no particles below 5 mm which are generally regarded in the industry as dust To put this in context typical human hair is 20 40 mm The printing industry regards anti set off spray powder as a necessary evil Ideally printers would prefer not to use it but it remains the only practical way to ensure a stack of printed paper at the end of a printing press does not set off In recent years there has been an emergence of printing presses which use inks that are cured dried with powerful UV lamps As each sheet is individually dried there is no need for spray powder However as these machines require specialty inks which are much more expensive than conventional inks and the UV lamps use a significant amount of energy the vast majority of new sheet fed presses sold in 2007 still used anti set off spray powder Other uses editIn addition to its use in the printing and packaging industry spray powder is also used in the manufacture of float glass to enable the large sheets to slide easily over each other It is also used in the manufacture of plastic food wrap and similar products to help prevent pieces of plastic from sticking together because of static electricity In the UK many carrom players use a version of anti set off spray powder from the printing industry citation needed which has specific electrostatic properties with particles of 50 micrometres in diameter See also editlithography Set off printing See also PrintingExternal links editLearn about printing International Paper Glossary of printing terms International PaperReferences edit Soluble Powder Russell Webb Archived from the original on 2007 08 09 Retrieved 2007 07 04 bg spray powder quality testing PDF Berufsgenossenschaft Archived from the original PDF on 2007 04 11 Retrieved 2007 07 03 Retrieved from https en wikipedia org w index php title Anti set off spray powder amp oldid 1166883188, wikipedia, wiki, book, books, library,
