GB/T 33248-2026Graphic technology - Blankets for offset printing (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document replaces GB/T 33248-2016 "Printing Technology - Offset Printing Rubber Blanket". Compared with GB/T 33248-2016, the only differences are in the structural design.

Aside from integration and editorial changes, the main technical changes are as follows.

a) The phrase "This standard does not apply to offset printing blankets without foam cushioning" in the "Scope" section has been removed (see Chapter 1 of the 2016 edition).

b) The terms "adhesive strength" (see 3.2 in the 2016 edition) and "compression" (see 3.6 in the 2016 edition) have been removed from the "Terms and Definitions" section.

c) The definitions of "rubber cloth" (see 3.1, 3.5 of the 2016 edition) and "lining" (see 3.5, 2016 edition) in "Terms and Definitions" have been changed.

3.8), "thickness difference" (see 3.6, 3.14 in the 2016 edition), "average thickness" (see 3.7, 3.4 in the 2016 edition), "shrinkage" (see...

3.12 (3.10 in the 2016 version)

d) Added "Surface Properties" (see 3.2), "Load at a Specific Compression" (see 3.10), and "Compression Performance" to the "Terms and Definitions" section.

"Compression capacity" (see 3.14), "Compression performance - indentation" (see 3.15);

e) Added "Information" (see 4.1) and "Average Thickness" (see 4.2.2) to the "Requirements" section;

f) The requirements for "adhesive strength" (see 4.5 in the 2016 edition) and "hardness" (see 4.8 in the 2016 edition) have been removed from the "Requirements" section.

g) The "Thickness" specification in the "Requirements" section has been changed (see 4.2.1, 4.1.1 in the 2016 version), and the "Note" in "Thickness" has been removed (see 2016 version).

Version 4.1.1);

h) The "Squareness" indicator in the "Requirements" section (see 4.2.4, 4.1.3 in the 2016 version) and the "Elongation" indicator in the "Requirements" section (see 4.3) have been changed.

The.2016 edition's 4.3), "Requirements" section on "Tensile Strength" (see 4.4, 2016 edition's 4.4), and "Compressive Properties" (see 4.5, 2016 edition) are also relevant.

Version 4.6), "Requirements" regarding "swelling and/or shrinkage caused by printing ink components" (see 4.6.1, 2016 version 4.7.1), revised.

The requirement addresses "swelling and/or shrinkage caused by rubber blanket cleaning agents" (see 4.6.2, 4.7.2 in the 2016 version).

i) Added "Test Environment" (see 5.1), "Load under Specific Compression" (see 5.5), and "Compression Performance" to the "Test Method" section.

"Trace amounts" (see 5.7), "Surface characteristics" (see 5.8), "Contact conditions of printing ink components" (see 5.9.3), "Contact conditions of cleaning agents" "Item" (see 5.9.4);

j) The "Adhesive Strength" option in "Test Methods" has been removed (see 5.5 in the 2016 edition);

k) Change "Compression Amount" in "Detection Method" to "Compression Performance---Compression Amount" (see 5.6, 2016 version of 5.6).

This document is equivalent to ISO 12636:2018 "Printing technology - Offset printing blankets".

The following minimal editorial changes have been made to this document.

---Added introductory text for sections 5.5, 5.6, and 5.7.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the State Press and Publication Administration.

This document is under the jurisdiction of the National Technical Committee on Printing Standardization (SAC/TC170).

Introduction

The printing blanket is an essential component of all offset printing presses. Its performance is crucial to the mechanical condition of the printing press and the visual quality of the printed products.

The results are greatly affected. Therefore, providing testing methods, standardized values, and tolerances for some basic properties of rubber blankets is very useful.

This will enable suppliers to describe the performance of different types of blankets using standardized, well-known methods. This can also help...

Printing companies select the appropriate blanket type for specific printing press types or printing press conditions. Furthermore, printing presses can also be configured according to the standard...

The design is based on the rubber blanket data obtained from a detection method.

Printing technology offset printing blanket

1 Scope

This document specifies the requirements for offset printing blankets, defines the terms and definitions, and describes the test methods.

This document applies to commonly used offset printing blankets, but not to offset printing blankets that are not tensioned or clamped, nor to seamless sleeve-type blankets.

Offset printing blanket.

2 Normative references

This document has no normative references.

3 Terms and Definitions

The following terms and definitions apply to this document.

Blanket

Composed of a rubber layer and a substrate (such as fabric), it is a composite material used in indirect lithography to transfer ink from the printing plate to the substrate.

Products.

[Source. GB/T 9851.4-2008, 4.2, with modifications] 3.2 Surface properties the average roughness (Ra) of the rubber blanket surface.

Note. The unit is µm.

Specifications sizes Cut the rubber sheet (3.1) to size (thickness, width, and length).

Around-the-cylinder direction the rubber blanket to be used (3.1) is along the direction of the side of the rotation direction.

Packing

Padding material placed under the rubber sheet (3.1).

thickness variation

The difference between the maximum and minimum thickness values.

Note. The unit is mm.

average thickness

The average value of the thickness measurement.