A brief introduction to the common basic quality requirements for cosmetic tubes

Introduction: Tubes are commonly used packaging materials for cosmetics. They are divided into round tubes, oval tubes, flat tubes, and super flat tubes in terms of technology. According to the product structure, they are divided into single-layer, double-layer, and five-layer flexible tubes. They are different in terms of pressure resistance, penetration resistance, and hand feel. For example, the five-layer tube consists of an outer layer, an inner layer, two adhesive layers, and a barrier layer. This article introduces the common quality requirements for flexible tubes.The content is only for reference for friends who purchase packaging materials:

ONE

Basic appearance requirements

1. Appearance requirements: In principle, visual inspection should be conducted under natural light or 40W fluorescent light at a distance of about 30cm. There should be no surface bumps, embossing (no diagonal lines on the seal), abrasions, scratches, or burns.

2. The surface is smooth, clean inside and outside, evenly polished, and the glossiness is consistent with the standard sample. There are no obvious unevenness, extra stripes, scratches or indentations, deformation, wrinkles and other abnormalities, no foreign matter adhesion, and the number of small bumps on the whole tube shall not exceed 5. For tubes with a net content of ≥100ml, 2 spots are allowed; for tubes with a net content of <100ml, 1 spot is allowed.

3. The tube body and cover are flat, without burrs, damage, or missing threads. The tube body is tightly sealed, the sealing line is flush, the sealing width is consistent, the standard sealing height is 3.5-4.5mm, and the allowable deviation of the sealing line height of the same tube is ≤0.5mm.

4. Damage (there is damage or rot at any position of the tube or cap); closure; paint layer peeling off the hose surface > 5 square millimeters; cracked seal; broken head; serious thread deformation.

5. Hygiene: The tube is clean inside and outside, and there is no obvious dirt, dust or foreign matter on the inside of the tube and cap. There is no foreign matter such as dust, oil, etc., no odor, and it meets the hygiene requirements of cosmetic-grade packaging materials: that is, the total colony count is ≤ 10 cfu, and Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus must not be detected.

TWO

Surface treatment and graphic printing requirements

1. Printing:

· The overprint position deviation is between the upper and lower limit positions confirmed by both parties (≤±0.1mm), without ghosting.

· The graphics are clear and complete and match the sample color. The color difference of the tube body and its printed graphics does not exceed the color difference range of the standard sample.

· The size and thickness of the text are similar to the standard sample, without broken characters, smudged characters, or missing spaces, which does not affect recognition.

· The printed fonts should be correct without obvious rough edges or ink edges, without typos, missing characters, missing punctuation marks, missing strokes, blurriness, etc.

2. Graphics: Accurate overprinting, overprinting error of main parts ≤1mm, overprinting error of secondary parts ≤2mm. No obvious heterochromatic spots or spots.

· For tubes with a net content of ≥100ml, 2 spots on the front side with a size no larger than 0.5mm and a total area of no more than 0.2mm are allowed, and 3 spots on the back side with a size no larger than 0.5mm and a total area of no more than 0.2mm are allowed;

· For tubes with a net content of ≥100ml, 2 spots on the front side with a size no larger than 0.5mm and a total area of no more than 0.2mm are allowed, and 3 spots on the back side with a size no larger than 0.5mm and a total area of no more than 0.2mm are allowed;

    3. Position deviation:

· For tubes with a net content of ≥100ml, the vertical deviation of the printing plate shall not exceed ±1.5mm, and the horizontal deviation shall not exceed ±1.5mm;

· For tubes with a net content of less than 100ml, the vertical deviation of the printing plate shall not exceed ±1mm, and the horizontal deviation shall not exceed ±1mm.

     4. Content requirements:   

consistent with the film and sample confirmed by both the supplier and the buyer.

    5. Color difference:

The printing and hot stamping colors are consistent with the samples confirmed by both the supply and demand parties, and the color deviation is between the upper and lower limit colors confirmed by both parties.

THREE

Tube size and structural requirements

1. Specifications and dimensions: Measure with a vernier caliper according to the design drawings. The tolerance is within the specified range of the drawings: the maximum allowable deviation of the diameter is 0.5mm; the maximum allowable deviation of the length is 1.5mm; the maximum allowable deviation of the thickness is 0.05mm;

2. Weight requirements: Measured with a balance with an accuracy of 0.1g, the standard value and allowable error are within the agreed range by both parties: the maximum allowable deviation is 10% of the standard weight;

3. Full mouth capacity: After the container is filled with 20℃ water to the level of the container mouth, the full mouth capacity of the container is expressed by the mass of the water filled. The standard value and error range are within the agreed range of both parties: the maximum allowable deviation is 5% of the full mouth capacity of the standard sample;

4. Thickness uniformity (suitable for tubes with contents above 50ML): cut open the container and use a thickness gauge to measure 5 places at the top, middle and bottom respectively. The maximum allowable deviation shall not exceed 0.05mm. 5. Material requirements: according to the materials specified in the contract signed by the supply and demand parties, refer to the corresponding national industry standards for inspection, and be consistent with the sealed sample;

5. Material requirements: The materials specified in the contract signed by the supply and demand parties shall be inspected in accordance with the corresponding national industry standards and shall be consistent with the sealed sample.

FOUR

Closing requirements

1. The sealing method and shape shall comply with the contract requirements of both parties.

2. The height of the sealing part meets the contract requirements of both parties.

3. The seal tail is centered and straight, with left and right deviation ≤1mm.

4. Sealing firmness: Fill the specified volume of water, place between the upper and lower plates, the cover should be moved out of the plate, pressurize to 10kg in the middle of the upper pressure plate, and maintain for 5 minutes. There is no bursting or leakage at the tail. Use an air gun to apply 0.15Mpa air pressure to the hose for 3 seconds. No bursting tail.

FIVE

Tube functional requirements

1. Compression resistance: refer to the following two methods

· After filling the tube with about 9/10 of the maximum capacity of water, cover it with the matching cap (if it has an inner plug, it must be equipped with an inner plug) and place it flat in the vacuum dryer to evacuate to -0.08MPa and maintain it for 3 minutes without bursting or leakage.

· Randomly select 10 samples from each batch of materials; add water of the same weight or volume as the net content of each product into the sample tube and place it horizontally; use the specified pressure to vertically press the tube for 1 minute, and the pressure head area must be ≥1/2 of the container's force-bearing area.

2. Drop test: Fill the container with the specified volume of contents, cover the lid, and drop it freely from a height of 120cm onto the cement floor. There should be no cracks, bursts, or leaks. There should be no loose hoses or lids.

3. Cold resistance and heat resistance (compatibility test):

· Pour the contents into the hose or immerse the test piece in the contents, place it at 48℃, -15℃ for 4 weeks, if there is no change in the hose, test piece and contents, it is qualified.

· Test one batch out of every 10 batches of materials; extract 3 covers from each cavity in one batch of materials, with a total of no less than 20 sets of covers and tubes; add water of the same weight or volume as the net content into the tubes; heat 1/2 of the samples to 48±2℃ in a constant temperature box and leave for 48 hours; cool 1/2 of the samples to -5℃ to -15℃ in a refrigerator and leave for 48 hours; take out the samples and return them to room temperature for appearance inspection. Qualification standard: There shall be no cracks, deformation (appearance changes that cannot be restored to their original state) or discoloration in any part of the tube or cover; there shall be no cracks or breakages in the end seal of the tube.

4. Yellowing test: Place the hose under UV light for 24 hours or in sunlight for 1 week. If there is no obvious color change compared with the standard sample, it is qualified.

5. Compatibility test: Pour the contents into the tube or immerse the test piece in the contents, place it at 48℃, -15℃ for 4 weeks, if there is no change in the tube, test piece and contents, it is qualified.

6. Adhesion requirements:

· Pressure-sensitive tape peeling test: Use 3M 810 tape to adhere to the test area, and tear it off quickly and forcefully after it is flat (no bubbles are allowed). The tape is qualified if there is no obvious adhesion of ink, hot stamping (the area of ink and hot stamping falling off is required to be less than 5% of the total surface area of the printed font) and a large area of varnish (less than 10% of the total surface area).

· Impact of contents: Rub the contents back and forth 20 times with a finger dipped in the contents. The test is acceptable if the contents do not change color and the ink does not fall off.

· The hot stamping shall not have a diameter of more than 0.2mm falling off, no broken lines or broken characters, and the hot stamping position deviation shall not exceed 0.5mm.

· Silk screen printing, hose surface, hot stamping: one batch is tested for every 10 batches, 10 samples are randomly selected from each batch of materials, and soaked in 70% alcohol for 30 minutes. The hose surface does not fall off, and the unqualified rate is ≤1/10.

SIX

Fit requirements

1. The degree of tightness

· Torque test (applicable to thread fit): When the threaded cap is tightened at the hose mouth with a torque of 10kgf/cm, the hose and the cap are not damaged and the threads do not slip.

· Opening force (suitable for combination with flip cap and tube): moderate opening force.

2. After matching, the tube and cap are not skewed.

3. After the tube and cap is matched, the gap is uniform and consistent, and there is no obstruction when touching the gap with your hand. The maximum gap is within the range confirmed by both parties (≤0.2mm).

4. Sealing test:

· After filling the tube with about 9/10 of the maximum capacity of water, cover it with the matching cap (if there is an inner plug, it must be equipped with an inner plug) and place it flat in the vacuum dryer to evacuate to -0.06MPa and keep it for 5 minutes without leakage;

· Fill the container with water according to the net content specified, tighten the cap and place it flat at 40°C for 24 hours without leakage;