Paper Quality Control and Testing Methods
Quality control is an important aspect in the paper manufacturing process to guarantee the high quality of the produced papers on the market. Paper is also one of the most common products, used in the printing industry, for packaging, and thousands of other purposes; therefore, it requires strict examination for different parameters and properties. Testing confirms that the paper produced is of right quality and that it will perform a given task as required. The following discussion outlines the graphical display of paper testing and specifications, methods and, an overview of the approach to quality control in paper production.
General Paper Testing and Specifications
General paper testing comprises of several techniques used in determining the nature and performances of paper. They make sure that the paper meets certain quality and test standards which have been set. Other critical tests on paper include; weight, thickness, moisture content and many more attributes. These tests are useful in identifying characteristics such as the paper’s resistance and the result on the paper’s usability specifically in particular applications.
A key area of concern of paper manufacturing quality control is to make certain paper possesses suitable technical characteristics necessary for some particular sector. This means learning the right applications to use different kinds of paper and testing paper in a laboratory for its performance in those application. Following are some of the most important quality testing parameters of paper.
Paper Quality Control System (QCS)
In the paper manufacturing, having a sound paper Quality Control System (QCS) is mandatory in any manufacturing company. It assists in the supervisory of all product fabrications’ stages starting from material receiving to paper product output. It can also be ascertained that the QCS assists in optimizing the high quality of the paper through a constant control of the variables throughout the production process. Total Quality Management (TQM) is also implemented in the QCS as well meaning that the exclusive control of each batch of paper is improved constantly to meet the required industry standards.
Important Quality Testing Parameters of Paper
- Bursting Strength of Paper: This test shows actual pressure and stacks how much stress paper can sustain. Paper is compressed until it pops, and the degree of compression is documented. Specifically burst strength is an important measure of the paper’s performance in terms of stress under usage especially in cases such as packaging.
- Short Span Compression Testing: Short span compression testing is very important to papers used in packaging and boxes because they reveal how effectively the paper can take compression in short spans. This test enables manufacturers to check how the paper based products will perform under the handling stress or pressure of stacking.
- Ring Crush Test: The Ring Crush Test used also measures the compressive strength of paper besides the compression test. In this test, a small piece of paper is placed in a circular holder and loaded with force in compression until it fails in buckling. This test is important for examining the strength of corrugated paper which is used in most packages.
- Tear Strength/Resistance: Tear strength or resistance means the strength or ability of the paper to resist tearing. This is a significant test to establish the extent to which paper can afford to be torn when being printed or used in packaging. Papers that are used in packaging especially requires high tear strength because the material is likely to be torn.
- Water Absorbency & Cobb Test: The Cobb Test is a test that is used as a measure of water absorbency of paper. This test determines the amount of water that a paper sample will take up to in a given time. This feature is crucial in packaging applications as well as prints where ink penetration plays an important role.
- Ash Testing: Ash is a procedure that reveals the proportions of fillers in materials or the amount of inorganic materials in the paper. In practical terms ash content of paper impacts its printability, smoothness and strength to a certain extent. Ash testing assists manufacturers to find out the best formulation of paper according to the intended use.
- Contrast Ratio Method of Opacity Measurement: Transparency refers to the printability property of papers to obscure or reveal the text or image on the other face of a sheet. There is a method called the contrast ratio in the measurement of opacity with regards to sheets of paper. They include papers with higher opacity which are favored for use when making double sided prints.
- Paper and Ink Testing: To determine the compatibility of a paper with many types of inks that are used in the various forms of printing it is requisite to carry out paper and ink tests. Coating performance is evaluated through trial and error testing of its absorption rates and ink dry times as well as the color variation. The success of the print quality heavily depends on the paper-ink interaction…….Know More