Quality Policy >> Quality Control Measures

All the Coated Duplex Boards and Newsprint manufacturing units are equipped with laboratories having state of the art equipments for testing critical parameters that define the standard quality of products.

 

Quality Control - Finished Product - Double Coated Duplex Boards

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Introduction

N.R. Agarwal Industries Limited, is dynamic force in the coated board production industry striving to improve existing technology while maintaining established high standards. To ensure quality a specialized quality control department tests board 24 hours a day at every stage in the production process. Records are monitored to compare and project future paper runs.

Quality Management System

We defined it as a network of administrative procedure design to deliver a quality product to the customer to their satisfaction level. Within this framework the roll starts from the quality of the input raw material, pulp and the waste paper, wet end additives, coating chemicals are analyzed and inventory is allowed only when it meets the respective specified norms.

Objective

The ultimate objective of all quality control endeavors is to provide quality assurance for the finished product that do not meet the pre-standardized level in terms of dimensional, physical, optical & strength parameters is trapped and placed in substandard grades. The system followed by four stage inspection procedure.

1. Stock Preparation

It becomes more essential to maintain various properties of the pulp processed in order to achieve the key parameters as far as strength as well as run ability is concerned hence pulp samples are drawn from different street of prescribed locations and results are fed back to stock preparation for information and necessary correction. Similarly various wet and chemicals dosage are optimized by testing the strength/concentration of the active ingredient.

2. Machine Dry End

The board machine does not have on line cutter hence a jumbo roll of 7 to 8 MT is taken out about an hour interval. At the stage of inspection a sample of full width is drawn for through analysis. When the quality is manufactured for the final product the various parameters are checked for every roll. The vide verity of board grades with the different uses and properties, demands a multiplicity of test methods. Most of the properties that determine the usefulness of board are not physical absolutes. Therefore, measurements are often depend on the instrument or equipments used and on the details of the test procedures. The same are summarized below.

Die Cutter Punch
A specimen of accurate circular size 100 cm 2 in area is precisely drawn for measurement of the basis weight of the board sample through out the CD profile. The specimen is weighted on the electronic balance of lease count 0.1mg to know the basic unit i.e. GSM (g/m 2 ).

Caliper Tester
This gives a perpendicular distance between two surfaces of board, determined under an applied deal weight load of 1 kg. The rapid and accurate measurement displayed on pushbutton operation. Lorentzen and wetter ( Sweden ) make equipment confirms the Tappi standard T-441.

Stiffness Tester (Taber Type)
Instrument measures the force required to bend a specimen of board towards the angle of 15 degree. The average value of circular scale reading in clockwise and anti clockwise rotation is taken. Stiffness is measured in both direction MD and CD. Applicable standard – Tappi T-489.

Bursting Strength Tester
This measures the bursting pressure (hydraulic) require rupturing a sample of board under standard conditions. Standard applicable Tappi T-403, make – Lorentzen & Wetter , Sweden .

Tearing Resistance Tester
The value indicates the mean force required to continue the tearing of an initial cut based on Elmendorf principal as per Tappi standard T-414. Instrument make – Universal Engineering Corporation (Indigeneous).

Internal Ply bond Tester
The TMI make Z direction toughness tester measures the bonding force required to separate the board from the plies in between. As our board is made up of total 8 layers it becomes very important to know the location of delaminating tendency alongwith the degree of measurement. The instrument indicates the value in psi or kpa, which is converted in j/m 2 for reporting. Make – TMI , USA .

Bekk Smoothness Tester
The value obtained in seconds on the tester is correlated with PPS roughness. Basically it gives volume of air that escapes from the clamped surface of the specimen in unit time. The instrument displays time in seconds to pass 10 cc of air through the clamped surface. Make – Buchel , Germany .

Technibrite Brightness Tester
The microprocessor based equipment measures reflectance value at a wavelength 457 mm so called brightness under the specified conditions, it is used in determining the brightness of pulp, waste papers, clays, coated board etc. The instrument reads and displays colored value in red, yellow, blue and green tint alongwith opacity and CIE, ASTM whiteness in visible spectrum. Model – TB IC , USA .

K & N Ink absorbency
The fall in reflectance value after applying the K & N Ink when allowed to absorb by the board surface for specific time. It gives an idea about varnishable characteristics of board. Make – K & N Laboratories, USA .

Surface Oil Absorbency Tester
The patra type tester determines the oil absorbtivity capacity of the surface of board that the time required in seconds for absorption of the oil film to its 75% of dryness under standard condition.
Make Universal Engineering Corporation (Indigenous)

K-Control Coater
This is mainly used for coating draw down. Varnish liquors of different types, variable coating formulations, and surface sizing agents can be applied on the substrate by means of the motorized bar coater to know the surface and optical characteristic of board. The concentration of variable additives can be standardized before processing them in the plant. Make Fiber Tech (Indigenous).

IGT Printability Tester
The instrument used in multipurpose applications. The numeric value of IGT pick velocity indicates the surface strength of uppermost layer as well as coating to top layer. This is what correlated with the printing speed of offset machine i.e. the capability of the surface to the extent to get blister. The model AIC2 by IGT repro test BV, Netherlands has other attachments, which enables to measure the intensity of fluff buildup, the stain length gives an idea about varnish holds out as well as printability.

Creasibility Tester
The patra type board creaser guides about the proper selection of creasing rules corresponding groove width in according to the caliper range. In appropriate condition the board is checked for creasing quality. Make Toggle Press , UK .

Glosser Meter
Goss causes board to reflect light and contributes to optical smoothness of the board enhance a printed image through luster, glare and polish. The photo volt type meter measure the specular reflectance value at 75 degree angle in incidence. Print point of view it becomes more essential to know the gloss value of the coated surface as its impact come on to the print gloss, varnish gloss and overall appeal. (Indigenous).

Ash Tester-Muffle Furnace
Optimum quantity of fillers added in pulp suspension. The use of the fillers makes the board opaque, brighter, glossy. Board sample is burned and the percentage of fillers is determined by the amount ash remaining. The furnace is also useful in raw material testing in inorganic gravimetric analysis. (Indigenous).

 

3. Conversion

This is the most important stage of inspection where the jumbo roll is placed on the sheet cutter or rewinder machine to convert in the order size in sheet or reels respectively. During conversion in sheets the samples are drawn very frequently and when any defective material is noticed due to short coming in quality, quality control relays feed back to the process for rectification and simultaneously finishing house for pending the substandard quality until clearance is given. If any converting defects like size variation, physical distortion/ damage the particular material is allowed to book in substandard grade.

Being the cellulosic fiber is hygroscopic in nature the dimensional stability is greatly influenced by the climate condition with respect to the temperature and room humidity.

One of the final inspections for sheets board is the determination of relative humidity in the air between the sheets in a pile. Paper absorbs or emits moisture in a balancing process with the surrounding atmosphere even though the air is restricted. It allows for the ideal measure of the percentage of moisture between adjacent sheets inside the pallet it is also an indicator of ambient condition best suited for board.

 

4. Finishing

This is the last stage of inspection where the sheets are manually counted by the finishers. The marked defective portion is sorted out and keeps separately and booked in substandard grades depending upon the defect intensity. The size and the cross cut (the difference of diagonal size), the ream weight etc are checked randomly. Similarly the rough edges, damaged cores / interlocked reels are not allowed to put the material in the first quality.

Market Complaints
We welcome customer's feedback to inform and update manufacturing process and to constantly ensure customer satisfaction. Feedback is first received by the sales department, the service staff analyze printing difficulties described by the customer. If a solution is not readily available the customers submits the board samples from his order and testing figure are gathered from the quality control. The submitted information is compared to the testing figure of the supplied order through complete review and analysis the solution is found. Quality control recommends and explores possible causes. Customer's feedback is analyzed and monitored to continuously advance and promote high quality board.