GB/T 7705-2008The offset lithographic prints for decorating (English PDF)

4.1 Fine products

It is a high-end decorative printed matter produced by high-quality printed materials and fine plate-making printing technology, and the quality meets the requirements of fine products.

4.2 General products

Decorative prints other than fine products.

5.1 Size deviation of finished product specifications

5.1.1

The dimensional deviation of the cut product should meet the requirements in Table 1.

5.1.2

Die-cut product size deviation should meet the requirements in Table 2.

5.1.3

The positional deviation of the finished pattern with symmetrical requirements shall comply with the provisions in Table 3.

5.2

Overprint error should meet the requirements in Table 4.

5.3

Field printing requirements should meet the requirements in Table 5.

5.4 Dot Printing Requirements

5.4.1 Bright tone dot reproduction percentage

fine products <= 3%; general products <= 5%.

5.4.2

The dot gain value of 50% of the normal ink volume should meet the requirements in Table 6.

5.5 Print appearance

5.5.1 Fine products

5.5.1.1

The finished product should be neat and tidy. The main parts of each finished product must not have ink skin, paper hair, etc. with a diameter greater than 0.3mm.

<=0.3mm of ink skin, paper hair, etc., shall not exceed 2 points; secondary parts shall not have ink skin, paper hair, etc.

No more than 3 points of ink skin, paper wool, etc. with a diameter of <=1 mm.

5.5.1.2

The printing of characters should be clear and complete, and characters smaller than 5.5P (size 7) should not affect recognition and reading.

5.5.1.3

There should be no scratches and streaks on the printed surface.

5.5.1.4

The image should be clear, the layers should be clear, and the dots should be clear and even without deformation and incompleteness.

5.5.1.5

The printing color should conform to the requirements of the printing sample.

5.5.2 General products

5.5.2.1

The finished product should be clean. The main parts of each finished product must not have ink skin, paper hair, etc. with a diameter greater than 1.5mm.

<=1.5mm of ink skin, paper hair, etc., shall not exceed 2 points; secondary parts shall not have ink skin, paper hair, etc.

No more than 5 points of dirt such as ink skin and paper wool with a diameter of <=2mm.

5.5.2.2

Character printing should be basically clear and complete, and characters smaller than 5.5P (size 7) should not affect recognition and reading.

Note. P-Point, 1P is approximately equal to 0.35mm.

5.5.2.3

There should be no obvious streaks on the printed surface.

5.5.2.4

The outlets should be relatively clear and even, and there should be no obvious defects or pasted patterns.

5.5.2.5

The corresponding printing color basically meets the requirements of the printing sample.

5.6 Appearance of stamping foil on printed surface

5.6.1 Fine products

5.6.1.1

Graphic and text hot foil should be complete, clear, firm and flat, free from false hot stamping, pasted version, dirty version and trachoma.

5.6.1.2

The handwriting on foil should be clear, free from fluff and broken strokes.

5.6.1.3

The surface of graphic and text stamping foil should be bright.

5.6.2 General products

5.6.2.1

Graphic and text stamping foil should be complete, clear, firm and flat, and there should be no obvious false stamping, paste or dirty plates.

5.6.2.2

The handwriting on the hot foil should be clear and there should be no obvious incompleteness.

5.6.2.3

There should be no significant difference in the brightness of the surface of the graphic foil foil.

5.7 Embossed appearance of printed surface

5.7.1 Fine products

5.7.1.1

The outline of the embossed graphic should be clear.

5.7.1.2

The unevenness of the graphic and text should be uniform, and the paper fibers should not be broken.

5.7.2 General products

5.7.2.1

The contours of graphic and text embossing should be basically clear.

5.7.2.2

The unevenness of the graphic and text should be basically uniform, and the paper fibers should not be broken.

5.8 Appearance of printed surface coating

5.8.1 Fine products

5.8.1.1

The film bonding should be complete and firm.

5.8.1.2

The coated surface should be clean and smooth, with good finish, no discoloration, and no wrinkles or blisters.

5.8.2 General products

5.8.2.1

The film bonding should be complete and firm.

5.8.2.2

The coated surface should be basically clean and smooth without obvious wrinkles or blisters.

5.9 Appearance of printing surface and calendering

5.9.1 Fine products

5.9.1.1

The glazing coating should be applied evenly, and there should be no air bubbles, streaks, wrinkles, etc. on the surface.

5.9.1.2

Both sides of the glazing film surface should have the same brightness and good gloss.

5.9.1.3

The brightness of the calendered surface should be consistent and high gloss.

5.9.2 General products

5.9.2.1

The coating of the glazing coating should be basically uniform, and a small amount of acceptable fine air bubbles are allowed on the surface, but there should be no streaks, wrinkles, etc.

5.9.2.2

The brightness of both sides of the glazing film surface should be basically the same and the gloss should be good.

5.9.2.3

The brightness of the calendered surface should be basically the same, and should have a relatively high gloss.

6.1 Inspection conditions

6.1.1 Temperature and humidity of the inspection room

the temperature is 23°C±5°C, and the relative humidity is 60%+15%-10%.

6.1.2 Sample pretreatment

under the conditions of 6.1.1, and placed in an environment without ultraviolet light irradiation, the time should be >= 8h.

6.1.3 Light source for viewing samples

meet the requirements of CY/T 3.

6.2 Appearance, hot foiling, embossing, lamination, coating/calendering

Place the sample under the light source in 6.1.3 for visual identification. Dirty spots are measured with a 20 times reading magnifying glass with an accuracy of 0.01mm.

6.3 Size deviation of finished product specifications

6.3.1 Size deviation of cut and die-cut products

Measure its length (accurate to 0.1mm) at the cut or die-cut finished product sample with specified size, and the difference from the specified size shall be taken as the

Finished product specification size deviation.

6.3.2 Position deviation of finished product pattern with symmetrical requirements

Measure the width of the blank space (accurate to 0.1mm) at any symmetrical part of the left and right (or up and down) of the sample, and then calculate the finished product drawing according to formula (1).

case position deviation.

6.4 Overprint error

Place the sample under the light source in 6.1.3, and use a 20 times reading magnifying glass with an accuracy of 0.01mm to measure the main parts and minor parts of the sample respectively.

The overprint error between any two colors of the part is 3 points each, and the maximum value is taken respectively as the overprint error of the main part and the secondary part of the sample.

6.5 Same color density deviation

6.5.1 Instruments

A reflection densitometer conforming to ISO 14981 is used.

6.5.2 Instrument Calibration and Use

According to the provisions of GB/T 18722.

6.5.3 Inspection steps

6.5.3.1

During the test, the printed matter should be placed flat on a surface that complies with GB/T 17934.1-1999 Appendix B "Backing material for measuring reflection density".

on the required backing material.

6.5.3.2 Calibration and use of the instrument

According to the requirements of 6.5.2.

6.5.3.3

For finished products with a format size of 135mm×195mm or less, use a reflective color densitometer to measure the

Measure 1 point in the middle and 1 point in the middle; for finished products with a format of 135mm×195mm or more, measure 5 points evenly on the same sample.

6.5.4 Test results

6.5.4.1

The same-color density deviation of each sample is calculated according to formula (2).

6.5.4.2

Compare the average value of the same-color density deviation of each color, and take the maximum value as the same-color density deviation of the sample.

6.6 Color difference of the same color in the same batch

6.6.1 Instruments

A spectrophotometer (color difference meter) conforming to ISO 13655 is used.

6.6.2 Instrument Calibration and Usage

According to the provisions of GB/T 18722.

6.6.3 Inspection steps

Choose one of the samples as a reference sample, first measure the Lab value of its CIELAb uniform color space with a spectrophotometer,

Then measure the color difference between the rest of the samples and the same color and part of the reference sample.

6.6.4 Test results

Compare the color difference of the same batch of different colors of the sample, and take the maximum value as the color difference of the same batch of the sample.

6.7 Glossiness of the ink layer

6.7.1 Instruments

Use a gloss meter conforming to ISO 15994.

6.7.2 Calibration and usage of the instrument

According to the provisions of ISO 15994.

6.7.3 Inspection steps

6.7.3.1

Take a flat, wrinkle-free sample.

6.7.3.2

Use a gloss meter to measure the surface of different color layers of the sample, measure 3 points on the color layer with an area <= 100cm2, the area

Measure 5 points on the color plane >100cm2.

6.7.3.3

When the difference of the glossiness measurement results of each color of each sample is more than 5 gloss units, the measurement points should be doubled.

6.7.4 Test results

Calculate the average value of the glossiness of the same color at each point of the sample as the glossiness of the ink layer of the color of the sample.

6.8

Abrasion resistance of the ink layer, abrasion resistance of the printing surface after the ink layer is varnished

6.8.1 Instruments

6.8.1.1 Friction testing machine

The friction table adopts a hard plastic body with a surface roughness not less than 1.60 µm, and has a device for fixing the sample; the friction body adopts two thick

8mm, the hardness is 50Hs ~ 53Hs, the size is 25mm × 50mm rubber, the distance between the inner sides of the two friction bodies is 45mm; the friction test

The friction times are up to 43 times/min±2 times/min, and the stroke is about 60mm. The friction testing machine is shown in Figure 1.

6.8.1.2 Reflection densitometer

The reflection densitometer is the same as 6.5.1 and 6.5.2.

6.8.2 Inspection conditions

6.8.2.1

The friction paper shall be 80g/m2 clean offset paper with a width of 50mm.

6.8.2.2

The load is 20N±0.2N.

6.8.2.3

The friction frequency is 43 times/min±2 times/min, and the stroke is about 60mm.

6.8.3 Inspection steps

6.8.3.1

The sample cut into a certain size is fixed on the friction table, and the area of the sample layer to be measured should be larger than the area rubbed by the friction body.

6.8.3.2

Measure the color density of the ink layer on the sample to be ground according to 6.5.3, measure 3 points and take the average value.

6.8.3.3

Fix the sample on the friction table, and fix the friction paper on the friction body.

6.8.3.4

Turn on the friction testing machine and rub back and forth 43 times/min±2 times/min, stop the machine and take down the sample.

6.8.3.5

Measure the color density of the most severely rubbed ink layer according to 6.5.3, and take the average value of 3 points.

6.9 Bright tone dot reproduction percentage

Take the sample (natural sample) printed with the printed measurement and control strips. The measurement and control strips should meet the requirements of GB/T 18720, and use a magnifying glass of 20 to 50 times to

Visually inspect the bright tone dots of each color on the sample printing control strip, and take the percentage of bright tone dots that can be seen as the bright tone dots of the sample

Reproducibility percentage.

6.10.1 Instruments

The reflection densitometer is the same as 6.5.1 and 6.5.2.

6.10.2 Inspection steps

6.10.2.1

Take the sample (natural sample) printed with the printed measurement and control strips, and the measurement and control strips shall comply with the provisions of GB/T 18720.

6.10.2.2

Use a reflective color densitometer that meets the requirements of 6.5.1 and 6.5.2 to measure any solid block of color on the sample printing control strip.

Density value, and then measure the dot density value of the same color nominal coverage.

6.10.2.3

Calculate the actual area coverage FD (%) value of 50% dots of any color on the sample according to formula (4).

6.10.3 Test results

6.10.3.1

Calculate the 50% dot gain value deltaF of any color according to formula (5).

6.10.3.2

Among the dot gain values of each color of the sample, take the maximum value as the 50% dot gain value of the color of the sample.

7.1

A group of unit products of the same variety, the same specification, and the same production cycle with basically the same production conditions is a batch.

7.2

Carry out sampling inspection according to GB/T 2828.1 inspection sampling plan. The sample unit is piece. The minimum number of samples taken per batch is generally

5 pieces.

7.3 Judgment of unqualified products

each product shall be inspected according to the provisions of this standard, if one or more technical indicators do not meet the requirements,

Then the product is a non-conforming product.

7.4 Judgment of unqualified batches

each batch of products shall be inspected according to the provisions of this standard, and if one or more of them are unqualified products, they shall be added

Double sampling re-inspection. If there are still 1 or more products that are unqualified, the batch is unqualified.

8.1 Signs

The conspicuous part of each package shall be labeled with a qualified label, indicating the user unit, product name, variety specification, quantity, manufacturer name, production date and

Inspector code, etc.

8.2 Packaging

According to the requirements of the contract or according to the volume, quality and quantity of the products, they should be bundled in cartons or with strong wrapping paper and strapping tapes.

8.3 Transportation

During transportation, it is not allowed to throw, smash, or step on it, and it should be protected from moisture, sun exposure, rain, heat, heavy pressure, corrosive gas, and liquid.

8.4 Storage

The storage environment requires ventilation, moisture-proof, dust-proof, sun-proof, oil-proof, mildew-proof, anti-corrosion gas, anti-liquid, and no heavy pressure. The storage period is generally self-produced

Not more than 6 months from the date.