Packaging plant printing surface roughness treatment

Packaging plant paper and cardboard roughness and smoothness of the same, and paper printability is closely related to affect the ink handling process on the paper surface, thus affecting the visual appearance of the printed appearance. Roughness is generally determined using the air leakage method, which is subdivided into the Bengtsson method and the printing appearance method. Bengtsson method is under the specified experimental conditions and operating pressure, the measurement of the air flow rate between the ring plane or cardboard passing through the measurement head, in milliliters per minute, the measurement results are generally known as the Bengtsson roughness. Printed appearance method is in the specified pressure conditions, the paper or cardboard appearance and the average gap between the plane of the measurement ring, to microns indicate , the printing plant to determine the results are generally known as the printing appearance roughness. Printed appearance method is applicable to all can form a good seal with the protective ring surface of the measurement head of the printed paper and cardboard.

Printed appearance roughness determination in accordance with GB/T22363-2008 "paper and cardboard roughness determination (air leakage method) Bengtsson method and printed appearance method" in the printed appearance method. The principle is to place the specimen between a metal ring-shaped plane measuring head and a flexible liner, the inner ring surface and the outer ring and the specimen form a sealed space. Under the effect of the pressure difference between the two measurements of the measurement surface, the airflow between the measurement surface and the specimen passed. Packaging company after comparing the pressure difference between the flow over the measurement surface and the pressure difference that occurs through the known damping to determine the air flow rate to micron indicates the air gap .

The principle of operation of the experimental device apparatus for printing surface roughness is as follows.

From the controlled pressure of the gas source out of the gas first through an airflow damping, Chongqing packaging plant and then through the probe finally discharged into the atmosphere, with a sensor to determine the flow through the airflow damping and flow through the measurement surface of the pressure difference, the two pressure differences with the change in roughness, and the signal will be converted to micron indicates the roughness.

Air source: Air pressure scale between 300kpa~600kpa, supplying clean, oil-free and water-drop-free air.

Measuring head: consists of three stainless steel ring surfaces of the same plane that have been ground. The width of the central ring surface or measurement surface should be 51μm, the useful length is (98±0.5mm). the width of any point of the other two protection rings should be at least not less than 1000. the radial distance between any point of the two rings should be (152±10) μm. the measurement ring surface is located in the middle of the two rings, the deviation should be within ±10μm.

The three ring surfaces should be installed on the seal seat, the structure of which allows air to enter from the gap between the inner protective surface and the measurement surface, and discharge from the gap between the outer protective surface and the measurement surface, the back of the seal seat should be flat, and with air in and out of the hole then the plane to form a mating surface.

Tension spring protective ring mounted on the outside of the protective ring, when adjusting the collet pressure, should be added to the force exerted by the tension spring (usually not 9.8N).

Pad rest: contains a steel metal disc of known quality with a groove for inserting a resilient pad, the diameter of which should be at least 10mm larger than the diameter of the outer protective surface of the Chongqing packaging plant. the quality of the resilient pad and pad rest should be considered when initially adjusting the clamping pressure.

Two elastic pads: two different types of pads, available double-sided tape fixed in the groove.

Soft liner: elastic, made of a layer of synthetic rubber offset printing pad, its thickness is at least 60μm, glued to a fiber fabric pad consisting of a total thickness of (2000 ± 200) μm. the whole pad has an external hardness of (85 ± 6) IRHO (World Rubber Hardness Unit).

Hard liner: elastic, usually made of polyester film edge bonded to a cork offset pad or similar material. There is a very small vent hole to prevent air from sealing between the film and the pad. After composition the liner has an external hardness of (95±2) IRHO