Characteristics and testing of the hottest honeyco

2022-08-12
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Characteristics and testing of honeycomb paperboard

honeycomb paperboard is a new packaging material developed rapidly in the industry in recent years. It is a new packaging plate made of two layers of face paper and honeycomb core paper in the middle. Because its surface paper mostly adopts about 300g box board paper; The core paper mostly uses about 120 grams of corrugated base paper or tea board paper. Because its core paper is honeycomb, and the upper and lower parts of the honeycomb are bonded with the inner and outer paper, it is structurally determined that the honeycomb paperboard has better rigidity than this corrugated paperboard. The appearance of honeycomb paperboard and the continuous improvement of technology make it a great trend to replace wood. Recently, many manufacturers have produced forklifts made of honeycomb cardboard, and the best evidence is that pallets are used instead of wooden pallets

among the honeycomb paperboard samples sent from various countries to China Packaging Research and Testing Center for performance testing, we can roughly classify the honeycomb paperboard as follows:

1. Honeycomb paperboard divided into

a ㄝ pure paper in terms of material, that is, it is formed by bonding two layers of face paper and honeycomb core paper

b ㄝ paper and wood composite honeycomb paperboard, that is, the surface paper of honeycomb paperboard has one layer of paper, and the other layer is three-layer board or fiberboard

2. Structurally, it is divided into

a - single honeycomb paperboard

b ㄝ multilayer honeycomb paperboard is superimposed together to form a composite honeycomb paperboard

c ㄝ composite honeycomb paperboard composed of corrugated paperboard and honeycomb paperboard

in recent years, in order to meet the needs of users and scientific research work, we have tested the honeycomb paperboard entrusted by customers all over the country and the packaging products made of the microcomputer controlled electronic universal experimental machine with honeycomb paperboard as raw material by referring to the honeycomb paperboard industry standards and relevant national and international standards, and accumulated some experience. Next, we will talk about our understanding on the relevant problems affecting the quality of honeycomb paperboard and their testing methods, for the reference of relevant manufacturers and users

the parameters and items that affect the quality of honeycomb paperboard include appearance quality and physical and mechanical properties. They are: thickness, moisture content, capacity, static bending strength, flat compression strength, peel strength, failure and fracture, etc. Among them, the main indicators that affect the quality of honeycomb paperboard are: flat compression strength, static bending strength and peel strength. These three indicators reflect the physical and mechanical properties of honeycomb paperboard. According to our long-term performance tests of corrugated boxes and corrugated cardboard, as well as the functions and characteristics of honeycomb cardboard, the sampling method of test samples and the temperature and humidity adjustment of samples are carried out in accordance with national standards. In order to ensure the accuracy of the test, the dimensional tolerance of the sample should be specified. It is recommended that the dimensional tolerance of the sample be ± 0.5mm. Because the thickness of honeycomb paperboard is much larger than that of corrugated paperboard, there should be requirements for the perpendicularity of the two adjacent surfaces of the sample and the parallelism of the two opposite surfaces. It is recommended that the perpendicularity tolerance be 0.2mm and the parallelism tolerance be 0.15mm,. The number of each test sample shall be more than 5. In addition, the static bending strength and peel strength of honeycomb paperboard should also include two groups of samples in both longitudinal and transverse directions

taking the honeycomb paperboard with thickness of 20mm and honeycomb side length of 8mm as an example, this paper briefly describes the test methods for the above-mentioned important parameters:

1. The flat compression strength

is tested with reference to GB "test methods for flat compression properties of non-metallic sandwich structures or cores"

sample size: 60 × 60mm (square sample)

test equipment: Xinli electronic universal testing machine. The upper and lower platens of the instrument are circular platens with a diameter of 20mm, and have a sample crushing detector. It can measure the maximum load and deformation of the sampler when it is crushed, so as to ensure the accuracy of measurement

loading speed: v=1m/min

because the adhesive itself is a volatile organic compound, the calculation formula is: compressive strength (MPA) =p/s

where: P is the failure load, n

s is the compression area, mm2

test method:

a ㄝ accurately measure the length and width of each sample

b ㄝ place the sample in the center of the two pressing plates of the instrument in turn, load it at the set speed, and record the maximum load when the sample is crushed

c ㄝ calculate the flat compressive strength of five samples according to the calculation formula, and then take the arithmetic mean value as the final test result

2. Static bending strength

test according to ISO "paper and paperboard - static determination of bending strength - General principles" and GB "test method for bending performance of sandwich structure"

sample size: width 60mm, length 200mm

span: 160mm

test equipment: Xinli electronic universal testing machine, synchronously record the "load deflection value" curve during the test

loading speed: v=5mm/min

calculation formula: adopt the three-point loading formula recommended by ISO standard:

bending strength (Mn · m) fl3/48db

where: F is bending force, n

l is the span, mm

b is the width of the sample, mm

d is the deflection value, mm

Test Method:

a ㄝ accurately test the width of the sample and the distance between the two fulcrums

b ㄝ draw a line as a mark at the loading position on the upper surface of the sample, that is, the midpoint of 1/2 of the length direction of the sample, to ensure that the loading position is accurate

C ㄝ the width of the loading plate and support shall be greater than or equal to the width of the specimen

D ㄝ add a hard rubber pad with a width of 10mm and a thickness of 5mm at the contact part between the loading plate and the support and the sample

e ㄝ test 5 samples in both vertical and horizontal directions, and take the arithmetic mean value of 5 samples as the longitudinal or transverse bending strength value of honeycomb paperboard

3. Peel strength

refer to gb/t "adhesive T peel strength test method, flexible material to flexible material", but in the experimental work of resonance state, according to the characteristics of honeycomb paperboard, we made some changes in the test method. Because the thickness of honeycomb paperboard is relatively thick, we doubled the width of the sample in this standard to 50mm. In addition, during sample preparation, use a blade to separate the face paper and the inside paper at one end of the sample to be tested from the honeycomb core paper, peel them mm as the clamping part, and then clamp them into the upper and lower collets of the testing machine respectively

sample size: width 5, required accuracy 0mm, length 200~250mm

test equipment: Xinli electronic universal testing machine. Synchronously record the "load stripping length" curve during the test

loading speed: v=15mm/min

calculation formula: peel strength (kn/m) =f/b

where: F is the average peeling force, n

b is the width of the sample, mm

test method:

a. accurately test the width of the sample

b. clamp the pre stripped face paper and inner paper (about mm long) of the sample into the upper and lower collets of the testing machine and clamp them. Separate the upper and lower collets according to the set loading speed. The stripping length of the sample should be at least 125mm

c. during the peel test, pay attention to the destructive condition of the sample. If the face paper or the lining paper itself is torn and peeled, the sample should be discarded and retested

honeycomb paperboard is a new type of packaging material, and our understanding of it needs to be gradually deepened and long-term experimental accumulation. The test method of several main technical indexes of honeycomb paperboard described above is also tentative and immature. In addition, technical indicators such as moisture content, thickness, dynamic and static cushioning performance are also relatively heavy, which should also be considered in practical application

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