This article introduces how to use a paper thickness gauge to measure paper thickness and apparent density. Thickness refers to the vertical distance between the two surfaces of paper under standard pressure, while apparent density is calculated by dividing the basis weight by the thickness, reflecting the compactness of the paper. During measurement, it is necessary to apply the specified pressure to the sample using the thickness gauge under standard temperature and humidity conditions, read the stabilized values, and average multiple readings. Calculating apparent density requires combining basis weight data. During operation, attention should be paid to instrument calibration, sample flatness, and environmental control, and standards such as ISO and GB should be followed to ensure accurate results. These data are crucial for paper quality control and performance evaluation.
2026-04-07
The contact angle measuring instrument evaluates wettability by measuring the contact angle of a liquid droplet on the surface of paper, based on the principle of Young's equation. The measurement commonly employs the sessile drop method, requiring control over sample flatness, environmental conditions, and droplet volume, while also considering the influence of surface roughness. Paper wettability is affected by factors such as fiber composition, sizing agents, surface treatments, and the test liquid. This measurement can be used to optimize paper formulations, control quality, and guide applications in fields such as printing and packaging. When using the instrument, attention must be paid to limitations such as surface heterogeneity and liquid penetration, ensuring consistent measurement conditions to enhance result comparability.
2026-04-07
This article introduces a method for detecting the total chlorine content in pulp using a microcoulometric titrator. The principle involves generating a titrant through electrolysis, which reacts with chloride ions produced after sample combustion. The chlorine content is precisely calculated by monitoring the electrical charge. The detection process includes sample preparation, instrument calibration, combustion decomposition, and titration calculation. During operation, conditions such as temperature and gas flow must be controlled to ensure accuracy. This method offers high sensitivity, making it suitable for trace chlorine analysis, and complies with multiple industry standards. It effectively supports pulp quality control and environmental monitoring.
2026-04-07
This article introduces the application of the ash determination muffle furnace in the detection of inorganic substances in pulp. The muffle furnace burns off the organic matter in the sample at high temperatures, leaving behind inorganic residues as ash, which is used to analyze the content of fillers and metal ions in the pulp. The detection must be carried out according to standard methods, including sample drying, incineration, and weighing, while controlling parameters such as temperature and time. During operation, care should be taken to prevent sample splashing, ensure complete oxidation, and regularly calibrate the equipment to guarantee accurate results. This method provides an important basis for evaluating pulp quality and production processes.
2026-04-07
This article introduces the method of measuring the conductivity of pulp water extracts using a conductivity meter. Conductivity reflects the content of soluble ions in the pulp and is used to evaluate washing effectiveness and the impact of water quality. The measurement is based on the principle of solution conductivity, utilizing a conductivity meter and calibration with standard solutions. The procedure includes sample preparation, instrument calibration, measurement, and temperature compensation. Key considerations include the condition of the electrode, temperature control, and consistency of extraction conditions. This method helps optimize the papermaking process, improve product quality, and adheres to relevant international and domestic standards.
2026-04-07
This article introduces the method for determining the dry matter content of pulp using an electric thermostatic drying oven. Dry matter content is a key indicator for evaluating pulp quality. The principle of determination involves evaporating the moisture in the pulp through heating and calculating the content based on the mass difference before and after drying. The main steps include: preparing and weighing a dry weighing bottle, placing the pulp sample into it and weighing it again, then drying it in a 105°C oven until a constant weight is achieved, and finally cooling and weighing the dried mass for calculation. During operation, it is essential to strictly control the temperature, ensure complete drying, handle the samples quickly to prevent moisture absorption, and cool the dried samples in a desiccator. This method is simple to operate, yields reliable results, and is a classic approach commonly used in laboratories.
2026-04-07
The laboratory pulp wet disintegrator is a device used to simulate the industrial pulping process. It disperses pulp fibers into individual fibers or small fiber bundles through mechanical action, while also promoting fiber swelling and fibrillation, thereby providing standardized samples for subsequent performance evaluation. Its core principle involves treating the pulp using shear and friction forces between the rotor and stator, with processing intensity adjustable through parameters such as time and concentration. This equipment is suitable for various types of pulp and requires adherence to standard operating procedures, along with regular maintenance and calibration to ensure data accuracy. It is widely used in papermaking research and development, quality control, and educational applications, with technological advancements trending toward automation and online monitoring.
2026-04-07
The dry pulp zero-span tensile strength tester is a device used to measure the intrinsic strength of pulp fibers. By clamping the fibers at nearly zero distance and stretching them to the point of rupture, it directly measures the tensile properties of the fibers, avoiding the influence of fiber length and bonding forces. This instrument is widely used in industries such as papermaking, non-woven fabrics, and composite materials to help evaluate raw material quality and optimize production processes. The test results can be used to predict product strength and provide critical data for quality control. Operation must adhere to relevant standards, ensuring environmental stability and standardized procedures to guarantee data accuracy.
2026-04-07
This article introduces the method of measuring the tensile strength of wet pulp using a zero-span tensile strength tester. Traditional testing is mostly conducted after the pulp is dried, but wet-state testing can more directly reflect the bonding potential between fibers. This instrument accurately measures the intrinsic bonding strength of fibers by stretching wet pulp sheets under near-zero-span conditions, eliminating the influence of fiber slippage. The article details the testing principles, required equipment, specific operational steps, and key factors affecting the results, such as pulp dryness and fixture alignment. This method is primarily used to evaluate the fiber bonding capacity of different pulps, study the effects of processes and additives, and holds significant value for research, development, and production control in the papermaking industry.
2026-04-07
The Canadian Standard Freeness Tester is used to measure the drainage properties of pulp, which is an important indicator for evaluating pulp quality. The instrument operates on the principle of gravity filtration, measuring the drainage rate of pulp suspension under standard conditions to determine the freeness value. During operation, it is necessary to dilute the sample, control the temperature, and keep the instrument clean. The results, after calculation using a formula and temperature correction, reflect the state of pulp fibers and provide guidance for adjusting production processes. This method is widely used in the papermaking industry, but it may have limitations for pulp with extreme freeness values, requiring comprehensive evaluation in combination with other tests.
2026-04-07
The Valley beater is a laboratory device that simulates industrial pulping, altering the morphology of pulp fibers through mechanical action to influence paper properties. During operation, parameters such as beating pressure, consistency, and time must be controlled, and the beating degree is used to quantify the results. It is suitable for various types of pulp, but the process needs to be adjusted according to fiber characteristics. Regular maintenance and calibration are crucial to ensuring experimental accuracy. This equipment provides effective support for studying the relationship between beating and paper properties.
2026-04-07
This article introduces the standard method for measuring pulp freeness using the PFI mill. Freeness is a key indicator of the degree of pulp fiber processing, directly affecting paper quality. The method simulates industrial refining with the PFI mill, shearing fibers by controlling the clearance and revolutions of the rotor, and then calculates freeness by measuring drainage time with the Schopper-Riegler tester. The procedure includes preparing standard pulp samples, setting refining parameters, conducting the refining process, and finally measuring and recording the data. The experiment requires strict control of pulp consistency, temperature, and environmental conditions, along with regular equipment maintenance to ensure accurate results. This method is highly standardized and provides reliable reference for paper production.
2026-04-07
The Bauer-McNett classifier is a standardized method for fractionating pulp suspensions through a series of screens with varying apertures, separating fibers by length and morphology. Its principle is based on the interaction between fiber length and screen aperture size, where shorter fibers readily pass through the screens while longer ones are retained. The fractionation process requires control over parameters such as consistency, water flow rate, and time to ensure reliable results. The fractionation outcomes can be used to assess pulp processability and paper quality; for example, long fibers influence paper strength, while fine fibers affect smoothness. However, this method has certain limitations, such as potential inaccuracies due to fiber morphology, necessitating complementary analytical techniques for comprehensive interpretation.
2026-04-07
This article introduces the application of the paper absorbency tester in evaluating the sizing degree of paper. The instrument quantifies the paper's resistance to liquid penetration by measuring the penetration time or diffusion area of liquid on the paper surface, thereby objectively assessing the sizing degree. The article explains the importance of sizing degree for paper durability and printing effects, and provides a detailed description of the tester's operating procedures, key influencing factors, and relevant industry standards. It also points out current technological limitations, such as lower testing efficiency for highly sized papers, and looks forward to future development directions, including potential integration with image analysis and intelligent algorithms.
2026-04-07
This article introduces two testing modes of the paper compression strength tester: ring crush test and flat crush test. The ring crush test is primarily used to measure the longitudinal compressive strength of paper, making it suitable for cylindrical structures like corrugated paper cores. It involves rolling a strip of paper into a ring and conducting a crushing test to calculate the ring crush strength. The flat crush test evaluates the compressive performance of paper in the planar direction and is commonly applied to materials such as boxboard. It involves compressing a flat sample and recording the maximum load to determine the flat crush strength. Each mode has its applicable scenarios and standards. During testing, attention must be paid to environmental conditions, instrument calibration, and sample preparation to ensure accurate results. These methods provide an essential basis for paper quality control.
2026-04-07
There are two types of paper stiffness testers: single-beam and double-beam structures. The single-beam type operates on the cantilever principle, offering simple operation and fast speed. It is suitable for testing uniform materials such as thin paper, but it may be affected by local variations in the sample. The double-beam type uses symmetrical loading, providing a more uniform bending force and more stable results. It is suitable for thick cardboard or anisotropic materials, though its operation is slightly more complex. The choice between the two should be based on testing standards, sample thickness, and precision requirements.
2026-04-07
The electronic paper tensile strength tester is used to evaluate the mechanical properties of materials such as paper under tensile conditions. The specimen is clamped by fixtures and stretched at a constant speed by a servo motor, while sensors measure the tensile force and elongation data, automatically calculating tensile strength and elongation at break. To ensure accuracy, it is essential to regularly calibrate the instrument's force, displacement, and speed systems using tools such as standard force gauges and displacement blocks, with errors generally kept within ±1%. The recommended calibration interval is one year, and daily maintenance should include maintaining a stable environment and keeping the fixtures clean.
2026-04-07
There are three main principles of paint film adhesion testers: The cross-cut method involves cutting a grid and then peeling with tape to evaluate shear adhesion using a grading system, which is suitable for rapid on-site inspection. The scratch method uses a stylus to apply a load and measures the critical load, quantifying the coating's bonding strength under combined stresses, and is commonly used in laboratories for hard coatings. The pull-off method involves vertically pulling a test dolly to directly measure the normal bonding strength, with results expressed in megapascals, making it suitable for precise evaluation of critical coatings. The selection should be based on a comprehensive consideration of coating characteristics, substrate type, and testing objectives.
2026-04-07
The paint film solvent resistance tester quickly evaluates the degree of paint film curing by simulating solvent wiping. The principle is that a fully cured paint film has a high crosslinking density, which resists solvent dissolution. During testing, the instrument drives the wiping head to rub the surface of the paint film with fixed parameters. By recording the number of wipes required to penetrate the film or the changes in its condition after wiping, the degree of curing is indirectly inferred. This method is simple to operate and fast, making it suitable for on-site quality control. However, the results are influenced by factors such as the solvent and environmental conditions. As an indirect measurement, it should be calibrated in combination with other methods.
2026-04-07
The paint film pencil hardness tester is an instrument used to assess the scratch resistance of coatings. It operates by scratching the coating surface with a pencil of known hardness under a fixed load and evaluating the hardness grade based on whether scratches are produced. This method is fast and intuitive, adhering to standards such as ISO and ASTM. During operation, factors such as the condition of the coating, substrate, and load must be controlled to minimize errors. It is widely used in industries such as automotive, household appliances, and construction materials for comparing and screening coating quality. However, this test primarily reflects low-stress scratch performance. In practical applications, it is often combined with other tests such as wear resistance and impact resistance to provide a more comprehensive evaluation of coating performance.
2026-04-07
