Tableware Inspection | Paper Cup Inspection Standards and Methods

Paper cups are disposable containers, usually used to hold drinks or food, and are widely used in parties, catering, take-out and other occasions. Its main raw material is paper, and there is often a thin coating on the outside, such as wax or plastic, to prevent liquid from penetrating and softening the paper. Paper cups are widely popular because of their lightness, cheapness and convenience. So how do you inspect paper cups? What are the methods for inspecting paper cups?

Terms and Definitions

Paper cup

The base paper for paper cup is processed by coating (wax) or laminating (filming) or laminating (filming) and then compounding with other materials, printing, die-cutting, forming and other processes to form a cup-shaped paper container.

Note: Printing is not a necessary process and can be omitted if printing is not required.

Paper cup for direct drinking liquid

A paper cup used to hold liquids, from which one can drink directly without any other auxiliary tools.

Paper cup for packaging container

As a packaging container for liquid and solid food, paper cups are required to be equipped with other auxiliary tools (such as spoons, straws, etc.) when holding liquid food before drinking (eating) the contents.

Grading and classification

• Paper cups are divided into superior products, first-class products and qualified products according to their quality.
• Paper cups are divided into direct drinking paper cups and packaging container paper cups according to their functions.
• Paper cups are divided into cold drink cups, hot drink cups, ice cream cups, yogurt (milk) cups, and cups for solid food according to their uses.

Sensory requirements for paper cup inspection

The appearance, printing, coating or laminating layer of the paper cup shall be inspected visually; the length of the unprinted part of the paper cup shall be measured with a ruler with a graduation value of 1mm.

The rim and bottom of the paper cup should not be concave or wrinkled; the laminating (coating) layer and coating (wax) layer should be uniform, and the cup body should be clean and free of foreign matter.

The printed pattern on the paper cup should have clear outline, uniform color, and no obvious color spots. No printing should be done within 15 mm (excluding 15 mm) from the cup mouth to the cup body. Capacity markings with a total length not exceeding 10 mm can be printed within the area of 15 mm (excluding 15 mm) from the cup mouth to the cup body.

Note: The requirement of “no printing within 15mm (not including 15mm) from the cup mouth to the cup body” only applies to paper cups for direct drinking, and does not apply to paper cups for packaging containers.

Paper cup inspection capacity deviation requirements

The capacity deviation of paper cups shall meet the requirements of Table 1.

Table 1 Capacity deviation

Nominal capacity V₂ mL	Deviation D %
	Superior products	First-class products	Qualified products
V₂≤300	±3.0	±4.0	±5.0
300	±2.5	±3.5	±4.5
V₂>500	±2.0	±3.0	±4.0

Physical performance requirements for paper cup inspection

Leakage performance of paper cups: There should be no water (liquid) leakage or seepage from the bottom and sides of the paper cups.

Note: Leakage performance of cups for solid food is not tested.

The stiffness of the paper cup should meet the requirements of Table 2.

Table 2 Cup body stiffness

Nominal capacity V₂ mL	Require N
	Superior products	First-class products	Qualified products
V₂ ≤250	≥3.00	≥2.60	≥2.10
250	≥3.20	≥2.80	≥2.30
300	≥3.40	≥3.00	≥2.50
400	≥3.60	≥3.20	≥2.70
500	≥3.80	≥3.40	≥2.90
Note 1: Paper cups with a nominal capacity greater than 1000 mL are not subject to the cup body stiffness test. Note 2: Paper cups with a diameter of less than 40mm at 2/3 are not subject to the cup body stiffness test. Note 3: Folding paper cups without curling edges are not subject to the test on cup body stiffness.

Paper cup inspection biodegradability requirements

The maximum biodegradability of paper cup finished products should be greater than or equal to 90% or reach more than 90% of the biodegradability of the reference material, and the maximum biodegradability of paper cup base paper should be greater than or equal to 90% or reach more than 90% of the biodegradability of the reference material. The maximum biodegradability of organic components greater than or equal to 1% in various materials used for coating, compounding, combination, printing, etc. other than paper cup base paper should be greater than or equal to 90% or reach more than 90% of the biodegradability of the reference material.

Note: Biodegradability is only assessed for paper cups that are explicitly stated to be biodegradable (biodegradable).

Paper cup capacity deviation inspection method

Paper cup capacity determination method

1. Weight method

Use a balance to weigh the mass m₁ of each empty cup, accurate to 0.1g, and record. Add water at a temperature of 23℃±1℃ into the empty cup until the highest point of the water surface in the cup is level with the plane of the cup mouth. If there is a capacity mark, add water to the capacity mark, weigh its mass m₂, and record.

Calculate the capacity V of the paper cup according to the formula. Measure 5 paper cups for each sample and record the measurement results. The average value is the capacity of the paper cup and the result is rounded to the integer.

2. Volumetric method

According to the size of the paper cup, take a measuring cylinder of corresponding capacity. Add water at a temperature of 23℃±1℃ into the cup until the highest point of the water surface in the cup is level with the plane of the cup mouth. If there is a capacity mark, add water to the capacity mark, then carefully pour the water into the measuring cylinder, read and record. For each sample, measure 5 paper cups and record the measurement results. The average value is the capacity of the paper cup, and the result is rounded to an integer.

Calculation of paper cup capacity deviation

Calculate the capacity deviation of the paper cup according to the formula.

Paper cup physical properties inspection method

Paper cup leakage performance test method

Select the appropriate test solution according to the requirements of Table 3, add the test solution to about 6mm from the cup mouth plane or the capacity mark, and then place the paper cup containing the test solution on a dry glass plate or flat plate. In order to avoid the water vapor generated in the contact area between the bottom of the cup and the dry glass plate or flat plate affecting the inspection results, it is advisable to place the paper cup above two parallel bars on the surface of the dry glass plate or flat plate, so that there is a certain distance between the bottom of the paper cup and the surface of the dry glass plate or flat plate. After standing for a specified time, observe whether there is a watermark on the glass plate or flat plate.

Example:

Bar material: 304 stainless steel

The size of the strip: length × width × height = 5 cm × 2 cm × 2 cm

Table 3 Test solutions and test conditions

Food category	Test solution	Test time
Hot drinks	Water at 90℃±5℃	30 min±1 min
Yogurt (milk)	23℃±1℃, 1% lactic acid solution (mass fraction)	60 min±2 min
other	Water at 23℃±1℃	30 min±1 min

Note: The test water is distilled water or deionized water.

Paper cup body stiffness inspection method

The cup body stiffness tester should comply with relevant requirements.

Place the paper cup to be tested on the movable sample stand of the cup body stiffness tester, adjust the height of the movable sample stand so that the probe is close to the side wall of the paper cup, the vertical distance between the probe and the bottom of the cup is about 2/3 of the cup height, and the cup body seam of the paper cup to be tested faces the tester. Start the instrument and measure the cup body stiffness.

For each sample, five paper cups were tested and the average value was taken to represent the test result, accurate to 0.01 N.

Technical requirements for cup body stiffness tester

A.1 Principle

Along the two opposite sides of the paper cup body, at a position about 2/3 of the cup body height, apply force uniformly along the diameter direction at a relative speed of 50.0mm/min±2.5mm/min. The maximum force applied when the total deformation of the side wall of the paper cup reaches 9.5mm±0.5mm is taken as the cup body stiffness of the paper cup.

A.2 Instruments

A.2.1 The cup body stiffness tester (hereinafter referred to as the instrument) should be able to accurately display the cup body stiffness value of the paper cup. Its display resolution should not be less than 0.01N, and its measurement accuracy should not be less than ±1%.

A.2.2 The instrument probe should be in spherical contact with the side wall of the paper cup, and the spherical radius is 5mm.

A.2.3 The instrument should have a device for centering the sample to ensure that the paper cup is stressed along its diameter. The offset of the common axis of the two measuring heads from the center line of the paper cup should not exceed 0.2 mm.

A.2.4 The instrument should be able to ensure that both sides of the paper cup are evenly stressed at the same time. Instruments that use a single probe movement to apply force should have a mechanism to drive the paper cup tray to move in the direction of force to prevent the paper cup from being stressed on one side and from slipping or flipping during the stress process.

Paper cup inspection mark, packaging, transportation and storage requirements

The sales packaging mark and transportation packaging mark of paper cups include the following:

a) The basic contents of product sales packaging mark include:

● Product name, implementation standard number, product type, nominal capacity (mL), quality grade, product quantity, main raw materials, production date and shelf life (when applicable), product qualification mark, usage instructions, usage precautions, purpose, name, address and contact information of the manufacturer and (or) distributor, and other matters that need to be marked;

●Degradable paper cups should also be labeled “biodegradable (degradable)” or “compostable”, or corresponding symbols.

b) The basic contents of the product transport packaging mark include:

- product name;

- product specifications;

——Graphical signs for packaging, storage and transportation;

——Other signs.

All packaging materials of paper cups should be sufficiently airtight and firm to ensure that the paper cups are not contaminated under normal transportation and storage conditions. Paper cup packaging should be dust-proof, moisture-proof or mildew-proof.

During transportation, heavy pressure and falling should be prevented, and transportation at high temperatures should be avoided as much as possible.

It should be stored in a ventilated, dry warehouse free of chemicals, non-toxic and harmless items.

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