Inspection of base paper by the hottest carton fac

2022-08-08
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The carton factory inspects the base paper

the carton factory must inspect the purchased base paper according to the purchase plan of base paper required to confirm whether its quantity and quality meet the agreement. Inspection purpose: the disc is fixed on the experimental machine by bolts through the step hole. First, it prevents unqualified base paper from entering the factory, and minimizes the loss caused by base paper problems in production. Second, it understands the performance of base paper through inspection, and then makes a correct choice, so as to minimize the cost and ensure the quality of finished products

base paper inspection is carried out according to the following process:

first, verify whether the delivery code sheet is consistent with the purchase plan, and whether the arrival quantity is consistent with the delivery code sheet. The variety, quantity, specification and number of pieces of base paper can be confirmed on the spot. The weight can be weighed by weighing. The deviation must be controlled within ± 3 ‰ (three thousandths), and the deficiency should be deducted

secondly, check whether the label of the roll paper is clear, whether the package is stained, and whether the base paper is damaged and damp. If there is damage or dampness, it shall be deducted. The specific method is as follows: if the damage and dampness occur on the side of the rolled paper, count from the outside to the inside to the layer without damage and dampness, for example, there is n=32 layer (there is no damage and dampness from the 33rd layer), then measure the distance d from the 16th layer to the axis, for example, d=0.55m, and then combine the specification l of the rolled paper (unit: m) and the base paper quantitative g (unit: g/m2), to obtain the weight W = g that should be deducted × L × (2 × three point one four × D) × N (unit: kg). If the damage or dampness occurs on the end face of the rolled paper, it is generally not allowed to exceed 2 cm, otherwise it will be treated as return

third, check whether there is a significant mark on the end face of the roll joint, whether the roll end face is flush with the shaft core, whether the roll shaft core has a deflated core, whether the two end faces of the roll are the same in diameter, whether the tightness of the rewinding and the two end faces are the same, whether the binding of the roll is in line with the standard, whether there is a color difference in a batch of rolls, etc

fourth, check the moisture content of rolled paper with a pin moisture meter. Sample according to GB and GB. The inspection shall be carried out on the two end faces of the rolled paper, and three reference points shall be taken evenly, and the insertion depth shall not be less than 0.6cm. Take the average of the test values of these six points as the moisture content of the rolled paper. In the base paper supply contract, the delivery moisture is generally specified, such as (8.0 ± 2.0)%. The moisture content of the tested roll paper is qualified within the range of delivery moisture, otherwise it shall be treated as agreed by both parties. Generally, it is necessary to ensure that the equipment is normally put into use and deduct the excess moisture. The specific method is as follows: if the moisture content M1 of the rolled paper exceeds the upper limit of delivery moisture Ma, and the weight of the rolled paper is w, the weight to be deducted is w × (M1Ma)/Ma; If the moisture content M1 of the rolled paper is lower than the lower limit MB of the delivery moisture, the rolled paper must be put on line for trial use. If it does not affect the normal production and the quality of the finished product, it will be treated as qualified, otherwise it will be returned. It is worth mentioning that the moisture content of the rolled paper is tested when the rolled paper is accepted in the factory. The on-site follow-up is also required when it is used in the workshop, that is, quality tracking. If any problem is found, contact the supplier in time to solve it

fifth, the performance test of base paper. Since general carton factories do not have the conditions for constant temperature chamber testing, and the timeliness of inspection should be considered, normal inspection should be adopted. As long as there are no obvious defects on the surface of the rolled paper, samples can be taken at the second layer, and the quantitative, ring compression strength, bursting strength, crack length, water absorption and other technical indicators can be tested according to the methods proposed in relevant national standards. Quantitative testing of the main epidemic prevention and control work has been carried out to see whether there is excess or insufficient gram weight; The ring compression strength and bursting strength test are the most critical. The test results adopt the regression analysis method (see the article "the influence of moisture content on the strength of corrugated board" for details), and then refer to the agreement of both parties to know whether it is qualified; Testing the crack length is mainly to understand the tensile strength of the base paper, which can be used as the main basis for whether the tile line is applicable; Water absorption determines the adhesion performance of base paper, printability, and the severity of the impact of atmospheric moisture, and so on. Other aspects, such as tightness, smoothness, folding resistance, flat compression strength, oil permeability, etc., shall be inspected according to specific needs

finally, carefully record the inspection results of each batch of base paper, analyze and compare, retain excellent suppliers (stable quality, reasonable price, timely supply), and remove unqualified suppliers from the supplier list. The inspection results of the base paper can be used as an important reference for the configuration of the base paper of the tile line paperboard

here, another method of quantitative testing with ring compression strength samples without quantitative sampler is introduced

because the size of the ring compression strength specimen is longitudinal × Transverse = 15.2cm × 1.27cm, its area is 19.304 cm2, and the total area of five ring compression strength samples is 96.52cm2, so weigh the total mass m of N ring compression strength samples, convert it into the mass of five ring compression strength samples, expand it by 100 times, and then divide it by 0.9652 to obtain the quantitative w of the structural composition of base paper 1 and spring tension compression fatigue testing machine

for example, if the total mass of 10 ring compression strength samples measured is m = 2.89g, then the quantitative weight of base paper is w = 100m/(2 × 0.9652) = 149.7 g/m2, i.e. 150 g/m2. If the total mass of 8 ring compression strength samples measured is m = 3.84g, then the quantity of base paper is w = 100m × 5/(8 × 0.9652) = 248.7 g/m2, i.e. 249 g/m2. This test method is especially suitable for quantitative and strength testing of small samples

tips for quantitative inspection of base paper

the quantification of paper and paperboard (also known as gram weight, g/m2) is one of the most basic technical indicators. Generally, enterprises will be equipped with quantitative sampler, take 10 circular paper samples with an area of 100cm2, weigh them in turn, and calculate the quantitative value through the formula. Now some enterprises directly use the paper knife to take 10 × When weighing a 10cm2 square paper sample, there will be relatively large errors, which cannot guarantee the authority of the test results, and will also cause unnecessary contradictions between paper enterprises and carton enterprises. If there is no special quantitative sampler, it is not a big problem, because now many enterprises have environmental pressure test sampler, which can completely replace the quantitative sampler. It can do both quantitative testing and environmental pressure testing. The specific operation methods are as follows:

equipped with an electronic balance of 110g at the maximum weighing, with an accuracy of 0.01g

cut 8 samples at equal intervals along the longitudinal direction on a paper sample, and the area of each sample is 15.2 × 1.25cm2, the area of 8 samples is 15.2 × 10cm2, 8 samples are weighed together, and the quantitative value is obtained by dividing the weighed value by 1.52 and multiplying by 100

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