Search results
Results from the WOW.Com Content Network
The density can be calculated by dividing the grammage of paper (in grams per square metre or "gsm") by its caliper (usually in micrometres, occasionally in mils). [1] The "ISO 534:2011, Paper and board — Determination of thickness, density and specific volume" indicates that the paper density is expressed in grams per cubic centimeter (g/cm ...
Paper weight is sometimes stated using the "#" symbol. For example, "20#" means "20 pounds per basis ream of that kind of paper". When the density of a ream of paper is given in pounds, it is often accompanied by its "M weight" (M is 1000 in Roman numerals). The M weight is the weight (in pounds) of 1000 cut sheets.
Set-off is measured at two different time intervals, 0.35s and 3s. A freshly printed surface is pressed against a paper after 0.35s and after 3s. Then the set-off density is measured. The idea behind selecting these two timings is to know what will be the set-off when the materials are used in a high-speed press and a low-speed press.
In the US, paper density is usually measured in "pound per reams" (of 500 sheets). Typical Letter paper has a basis weight of paper of 20 or 24 pounds (9.1 or 10.9 kg) – the weight of 500 sheets (a ream) of 17-by-22-inch (431.8 by 558.8 mm) paper at 70 °F (21 °C) and at 50% humidity. [ 3 ]
The telephone cables have a large number of conductors that are individually insulated. The paper needs to be thin (30-40 g/m 2). A normal power cable needs more insulation and therefore paper with higher paper density is used, normally 60-190 g/m 2. The paper needs to be strong, elastic, uniform and free of holes or debris.
Machine-finished coated paper (MFC) has a basis weight of 48–80 g/m 2.They have good surface properties, high print gloss and adequate sheet stiffness. MFC papers are made of 60–85% groundwood or thermomechanical pulp (TMP) and 15–40% chemical pulp with a total pigment content of 20–30%.
This is then passed between hard pressure rollers (supercalendered) to further increase the density, creating a paper called glassine. The glassine is treated with starches, alginates or carboxymethyl cellulose (CMC) in a size press to fill pores or treat the paper chemically to make it fat repellent. Basis weights are usually 30–50 g/m 2. [1]
Advertisement for Ansco Cyko photographic paper, 1922. Photographic paper is a paper coated with a light-sensitive chemical, used for making photographic prints.When photographic paper is exposed to light, it captures a latent image that is then developed to form a visible image; with most papers the image density from exposure can be sufficient to not require further development, aside from ...