GB/T 24797.2-2022Film for wrapping rubber bales - Part 2: Natural rubber (English PDF)

Foreword

This document is drafted in accordance with GB/T 1.1-2020 "Directives for

standardization - Part 1: Rules for the structure and drafting of standardizing

documents".

This document is Part 2 of GB/T 24797 "Film for wrapping rubber bales". GB/T 24797

has issued the following parts:

- Part 1: Butadiene rubber (BR) and styrene-butadiene rubber (SBR);

- Part 2: Natural rubber;

- Part 3: Ethylene-propylene-diene rubber (EPDM), acrylonitrile butadiene rubber

(NBR), hydrogenated nitrile-butadiene rubber (HNBR), acrylic-ethylene rubber

(AEM) and acrylic rubber (ACM).

This document replaces GB/T 24797.2-2014 "Film for wrapping rubber bales - Part 2:

Natural rubber". Compared with GB/T 24797.2-2014, in addition to structural

adjustments and editorial changes, the main technical changes are as follows:

a) Change the description of the scope; clarify the applicable wrapping specifications

(see Clause 1; Clause 1 of the 2014 edition);

b) Change the normative references (see 5.3.2 and 5.3.3; 4.2.2 and 4.2.3 of the 2014

edition);

c) Add the Clause "Terms and definitions" (see Clause 3);

d) Change the thickness representation unit; add the thickness gauge (see 5.1; 4.1 of

the 2014 edition);

e) Add density requirements (see 5.2);

f) Change the requirements for peak melting temperature (see 5.3.3; 4.2.3 of the 2014

edition).

This document modifies and adopts ISO 20299-2:2017 "Film for wrapping rubber bales

- Natural rubber".

Compared with ISO 20299-2:2017, this document has made the following structural

adjustments:

- 5.1 and 5.2 correspond to 5.1 of ISO 20299-2:2017;

- Clause 6 corresponds to Clause 7 of ISO 20299-2:2017.

The technical differences between this document and ISO 20299-2:2017 and their

reasons are as follows:

- Change the expression of the scope; change the mass of the bale from 33.33 kg to

1 Scope

This document specifies the material and physical property requirements for non-

strippable low density polyethylene film for wrapping natural rubber bales. The

function of the film is to keep the bales separated from each other during transportation

and storage.

This document applies to each bale of block natural rubber of 33.3 kg or 35 kg; as well

as to each bale of rubber ribbed smoked sheets of 33.3 kg, 35 kg, 50 kg, and 111.11 kg;

or any other bale weights as mutually agreed between the relevant parties.

2 Normative references

The contents of the following documents, through normative references in this text,

constitute indispensable provisions of this document. Among them, for dated references,

only the edition corresponding to that date applies to this document. For undated

references, the latest edition (including all amendments) applies to this document.

GB/T 1033.1-2008 Plastics - Methods for determining the density of non-cellular

plastics - Part 1: Immersion method, liquid pycnometer method and titration method

(ISO 1183-1:2004, IDT)

GB/T 19466.3 Plastics - Differential scanning calorimetry (DSC) - Part 3:

Determination of temperature and enthalpy of melting and crystallization (GB/T

19466.3-2004, ISO 11357-3:1999, IDT)

ISO 306:2013 Plastics - Thermoplastic materials - Determination of Vicat softening

temperature (VST)

Note: GB/T 1633-2000 Plastics - Thermoplastic materials - Determination of vicat softening

temperature (VST) (ISO 306:1994, IDT)

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