The quality of the product is the life of an enterprise, the quality of the product determines the fate of the development of the enterprise. No quality there is no market, no quality there is no benefit, no quality there is no development. Especially since the coronavirus epidemic, the global economy is in a downturn, we must pay more attention to product quality, and ensure enterprises achieve healthy development.
For the pulp molded tableware industry, strict quality control of products is more important. Because the tableware is in direct contact with the food, pulp molded tableware hygiene and cleanliness and other quality elements, directly affect the health of consumers, pulp molded tableware environmental protection and degradability, but also directly affect the health of the planet. We not only need to understand the quality requirements of pulp molded tableware but also need to know the quality inspection methods of pulp molded tableware, so what are the inspection methods of pulp molded tableware? Let’s explore together the following aspects.
The general performance inspection of pulp molded tableware
The appearance inspection of pulp molded tableware
In natural light or fluorescent light, according to the appearance quality requirements of pulp molded tableware, the appearance of samples was observed. Each sample of 10 for a group of samples. If more than 2 (including 2) samples do not meet the requirements, it is determined that they are unqualified.
The size deviation of pulp molded tableware
In order to avoid the large deviation between the product size and the nominal value of the pulp molded tableware, the size deviation requirement is stipulated.
- (1) Pulp molded lunch boxes
A vernier caliper with a dividing value of 0.02 mm was used to measure the bottom long edge, bottom short edge, and height (the whole height after covering the lid of the molded pulp lunch box).
- (2) Pulp molded dinner plates, dishes, trays
With the index value of 0.02mm vernier calipers to determine the long side, the short side of the pulp molded plates, dishes, trays. Round pulp molded plates, dishes, trays to determine the diameter of the products.
Volume Capacity deviation of pulp molded tableware
Applicable to pulp molded cups (bowls) and other products with capacity requirements.
pulp molded tableware capacity determination
Weight method
(1) Detection principle： By weighing the mass of water in the container of pulp molded tableware, the mass is divided by the density to calculate the capacity of the container.
(2) Testing equipment：Balance: 0.1g inductance.
(3) Testing steps
- Each sample to take five specimens for testing.
- Weigh the empty molded paper cups (bowls) with the balance and record the mass as m1;
- The temperature of (23 +/-1) ℃ water into the empty molded paper cup (bowl) to the cup (bowl) at the volume mark, for no volume mark of the cup or bowl, water should be added to the upper edge (overflow surface) at 5 mm.
- Weighing paper cups (bowls) and the total mass of water recorded as m2.
(4) Results processing: Pulp molded paper cups (bowls) capacity V calculation formula: V = (m2 – m1) / ρ.
In the formula:
- V——– capacity of the molded paper cup (bowl), mL;
- m1—— mass of the empty molded paper cup (bowl), g;
- m2—— molded paper cup (bowl) filled with water mass, g;
- ρ——– density of water, g/mL.
Volume method
The volumetric method directly uses a measuring cylinder or measuring cup to measure the volume of water contained in a paper cup (bowl) by the following process.
According to the size of the pulp molded paper cups (bowls), take the corresponding capacity of the measuring cylinder. Add water at a temperature of (23 +/-1 ℃) to the cup (bowl) to the cup (bowl) at the inner volume marker, for no volume marker of the cup or bowl, water should be added to the upper edge (overflow surface) 5mm, and then carefully pour the water into the measuring cylinder, read and record. Each sample measurement of 5 molded paper cups (bowls), record the measurement results, take the arithmetic mean.
Pulp molded tableware capacity deviation calculation
Molding paper cups (bowls) capacity deviation D, the formula is: D = (V1-V2)/V2X100
In the formula:
- D——- molded paper cup (bowl) capacity deviation, %;
- V1—— molded paper cup (bowl) capacity of the average, mL;
- V2—— molded paper cup (bowl) capacity of the logo specified value, mL.
The quality deviation of pulp molded tableware
For some pulp molded tableware with quality deviation requirements, such as pulp molded dinner plates, trays, etc., according to the need to choose a suitable scale weighing the mass of the sample, compared with the standard value to calculate the quality deviation.
The mechanical properties inspection of pulp molded tableware
Cup stiffness test
Applicable to pulp molded cup products.
(1) testing principle: As shown in the figure below, along both sides of the wall of the paper cup cup body opposite, in the cup body height of about two-thirds of the position, along the diameter of the direction of the relative speed of 5mm / min uniform application of force, the total deformation of the paper cup side wall to 9.5mm when the maximum force as a paper cup body stiffness.
(2) Testing equipment: Cup stiffness measuring instrument, the main parameters:
- ①Testing speed: (50 +/-2.5) mm / min
- ② probe relative movement distance: (9.5 +/-0.5) mm
- ③ probe alignment: <=0.2mm
- ④ two probe spherical radius: 5mm
(3) testing steps: Each group of samples to take 5 specimens for testing. Put the paper cup to be tested on the movable table of the cup stiffness tester, make the probe close to the side wall of the cup, adjust the height of the movable table, the vertical distance between the probe and the bottom of the cup is about two-thirds of the cup height, and make the seam of the cup to be tested face the tester, then start the instrument for testing.
(4) Result expression: Each group of samples measured 5 paper cup specimens, the average value of the measurement results, accurate to 0.01N.
Weight-bearing performance
Applicable to pulp molded lunch boxes.
(1) Testing equipment: 220*150*3mm flat glass, 3kg weight, metal ruler with 1mm index.
(2) Testing procedure: The pulp molded lunch box lid is fastened on a smooth horizontal table, and then the flat glass is placed on the box lid. Use a steel ruler to measure the height of the lower surface of the flat glass to the horizontal table. Then place a 3kg weight in the center of the plate glass, and after 1min of negative weight, measure the above height again to calculate the weight bearing performance of the sample. Two pulp molded lunch boxes were measured for each sample, and the arithmetic mean was taken.
(3) Expression of results: Weight-bearing performance of the specimen W formula: W = (Ho – H)Ho
In the formula:
- W——- weight-bearing performance, %;
- Ho—— specimen height, mm;
- H——– height of the specimen after 1min weight-bearing, mm.
Compression resistance
Applicable to pulp molded bowls
(1) Testing principle: Under the specified conditions, with a certain speed to the pulp molded food bowl specimen pressure, until the maximum compression force can be withstood by the collapse, expressed in N.
(2) Testing equipment: Paper bowl compressive strength tester, the main parameters.
- A. Deformation error: <=+/-0.1mm
- B. Platen area: 200mm * 200mm
- C. Platen parallelism: <=0.1mm
- D. Testing speed: (12.5+/-2.5)mm/min
(3) Testing steps: Each group of samples is taken 5 specimens for testing. The pulp molded dinner bowl should be placed at least 4h under the conditions conforming to GB/T10739-2002 “Standard Atmospheric Conditions for Handling and Testing of Paper, Paperboard and Pulp Specimens”, and measured under the conditions. Place the specimen in the center of the lower platen of the instrument. If the specimen is crushed during the test, the value should be discarded and the instrument parameters should be adjusted if necessary and the specimen should be resampled. The measurement should be done with the bowls of 5 specimens upward and the bowls of the other 5 specimens downward.
(4) Expression of results: Compressive performance to 10 specimens to determine the arithmetic mean of the results expressed in Newton (N), the results taken about to the integer.
Physical properties inspection of pulp molded tableware
Box cover folding test
Applicable to pulp molded food containers/lockboxes.
For the lid and container conjoined with the cover of the pulp molded plastic tableware samples, the lid will be continuous 0 ° ~ 180 ° open and close 15 times (an open and close for a time), observe the lid and box body connection there are no cracks, breakage phenomenon. Each group of samples measured 5 specimens, if 5 specimens are not cracked, broken phenomenon, the sample is judged to be crack-free, with no breakage.
Temperature resistance
Applicable to pulp molded tableware (paper pulp molded cups, paper pulp molded bowls, paper pulp molded lunch boxes, paper pulp molded plates, dishes, trays).
Heat resistance to water
The specimen is placed on a dry glass plate or plate lined with filter paper, filled with (95 +/-5) ℃ water, after 30 min of standing, observe whether the specimen has deformation, the bottom of the phenomenon of negative seepage, leakage. Each group of samples measured 5 specimens, if 5 specimens do not appear Yin seepage, leakage, deformation of the phenomenon, the sample is judged to have no Yin seepage, no leakage, no deformation.
Note: the test temperature difference between inside and outside the sample is caused by water vapor condensation at the bottom, this phenomenon is not considered as negative seepage, leakage.
Heat-resistant to oil
The specimen is placed on a dry glass plate or plate lined with filter paper, filled with (95 +/-5) ℃ edible oil, 30min after standing, observe whether the specimen has deformation, and observe whether the filter paper has oozing oil marks. Each group of samples measured 5 specimens, if 5 specimens are not deformed, and no oil marks on the filter paper, the sample is judged to have no negative seepage, no leakage, no deformation.
Water leakage
Applicable to pulp molded tableware (molded paper cups, paper bowls, paper lunch boxes, paper plates, dishes, trays).
Put the specimen on the plate or glass plate lined with filter paper, filled with (23+/-1)℃ water, and let it stand for 30min, then observe whether there is a watermark on the filter paper if there is the watermark, it is regarded as leakage, otherwise, it is regarded as no leakage. Each group of samples measured 5 specimens, if 5 specimens are no leakage, the sample is judged as no leakage.
Water content
In accordance with GB/T462-2008 “paper, paperboard and pulp analysis sample moisture determination” requirements for testing.
(1) Detection principle: Weigh the mass of the sample before drying, and then dry the sample to a constant weight and weigh the mass again, the difference between the mass of the sample before and after drying and the ratio of the mass before drying, that is, the moisture of the sample.
(2) Testing equipment:
- Balance: Sensitivity 0.0001g
- Specimen container: for the transfer and weighing of the specimen. The container should be able to prevent water vapor, and in the test conditions are not easy to change the light material made.
- Oven: can keep the temperature at (105 +/- 2) ℃.
(3) testing steps: Before taking samples should be clean and dry containers numbered and balanced in the atmosphere, and then each container will be weighed and covered. Take about 50g of sample into the container, weigh the container with the sample, and calculate the sample mass recorded as m1. will be equipped with the sample container, into the temperature can be maintained at (105 + / -2) ℃ oven drying. Drying, the lid of the container should be opened or the sample removed to spread, but the specimen and the container should be dried in the same oven at the same time.
Note: When drying the specimen, it should be ensured that no other specimen is put in the oven.
When the specimen has been completely dried, the specimen should be quickly put into the container covered the lid, and then put the container into the desiccator to cool down, the cooling time can be determined according to different containers. Open the lid of the container and cover it immediately to make the air pressure inside and outside the container equal, then weigh the container with the specimen and calculate the mass of the dried specimen. Repeat the above operation, the drying time should be at least half of the first drying time. When two consecutive times under the specified time interval, the difference in yield is not greater than 0.1% of the original specimen mass, the specimen can be considered to have reached constant weight, and the calculated specimen mass is recorded as m2.
(4) results expression: Moisture X (%) is calculated by the formula: X = (m1 – m2) / m1
In the formula:
- X——– moisture, %;
- m1—— the mass of the specimen before drying, g;
- m2—— the mass of the specimen after drying, g.
Drop test
Applicable to pulp molded tableware (pulp molded paper cups, pulp molded paper bowls, pulp molded paper lunch boxes, pulp molded paper plates, dishes, trays).
The specimen will be 0.8m high from the flat cement floor, the bottom of the free fall down once, observe whether the specimen is intact. Each group of samples measured 5 specimens, if 5 specimens are intact, the sample is judged to be undamaged.
Other non-standard performance measurement of pulp molded tableware
- Tensile performance testing
- Breakage strength test
- Folding resistance
- Tearing degree test
Some unconventional pulp molded tableware, there will be relevant non-standard performance measurement requirements, testing methods according to the design of tableware and customer requirements, there will be corresponding changes.
Pulp molded tableware testing, in China usually refer to QB/T 4763-2014 “pulp molded tableware” standard, in addition to the above test items, delivery moisture, lead, arsenic, formaldehyde, fluorescent whitening agent, potassium permanganate consumption, heavy metals (lead), microbial indicators, etc. also have relevant requirements, for more information, you can refer to the relevant standards and local industry requirements.
Inspection rules of pulp molded tableware
Master the pulp molded tableware inspection methods, at the same time, also need to follow the pulp molded tableware inspection rules. For example:
- Production plant should ensure that the production of pulp molded tableware in line with industry standards and customer requirements, the same specification of raw materials, the same process of continuous production of pulp molded tableware for a delivery quantity of one batch, each batch should not exceed 500,000.
- A failure of the safety requirements and raw materials for pulp molded tableware shall result in the batch being deemed unacceptable.
- The sampling inspection procedure shall be carried out according to GB / T2828.1, pulp molded tableware sample unit is carton mainly. Receiving quality limit (AQL): water leakage, temperature resistance, cup body stiffness,load bearing capacity, compression resistance AQL = 4.0; Cover fold test, drop test, delivery water, size deviation, capacity deviation, appearance AQL = 6.5. The sampling plan adopts normal inspection and secondary sampling plan.
- Pulp molded tableware packaging should be dust-proof and moisture-proof or mold-proof, direct contact with the tableware packaging materials should be non-toxic, harmless, clean. All packaging materials of pulp molded tableware should have sufficient sealing and solidity to ensure that pulp molded tableware in normal conditions of transport and storage without contamination.
- Pulp molded tableware in the transport process should be prevented from heavy pressure, fall, should try to avoid transport at high temperatures, should not be mixed with polluting substances.
- Pulp molded tableware products should be stored in a ventilated, dry, chemical-free and non-toxic warehouse, meanwhile ensure non-hazardous items in the warehouse.
For more details, please contact UV Tableware for an in-depth discussion, thank you.
