Mould surfaces for rubber mixtures processing

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F19%3A63523903" target="_blank" >RIV/70883521:28110/19:63523903 - isvavai.cz</a>

Alternative codes found

RIV/70883521:28150/19:63523903

Result on the web

—

DOI - Digital Object Identifier

—

Result language

angličtina

Original language name

Mould surfaces for rubber mixtures processing

Original language description

The paper deals with the study of contamination of mould cavities. The solution to this problem is highly required in practice because especially the processors of rubber mixtures face the contamination of mould cavities very often. [1] The subject of the study were aluminium alloy plates imitating a mould cavity. The rubber composition is based on a combination of NR and SBR rubbers. Experimental plates simulating the mould cavity surface were previously used to mould 150 moulding cycles of tread or sidewall compound. Processing conditions: vulcanization temperature 170°C, time 7 minutes or vulcanization temperature 170°C, time 4.5 minutes. The plates were cleaned after the previous experiment with technical gasoline and acetone only. In the following experiment, the plates were subjected to 200 pressing cycles of the rubber mixture and then their surfaces were examined for the presence of adhering contaminants. A visual comparison of the surface of the mould cavities was performed by optical microscopy before and after the 200 pressing cycles. The images were supplemented with surface roughness measurement before and after 200 pressing cycles. The surface roughness of the plates was measured non-contact to avoid the surface being affected by the measuring tip. The same surface roughness was found for all boards. It was assumed that the surface roughness would decrease due to clogging of the surface texture depressions. [2, 3] The experiment did not prove this assumption, it cannot be unambiguously specified that the surface roughness was reduced or increased. Fourier transform infrared spectroscopy (FTIR) was used to determine the composition of the contaminants, indicating the presence of contaminants from plasticizers. [4] X-ray fluorescence spectrometry (XRF) was used to determine the elemental composition. Sulphur (probably from the vulcanization system - vulcanizing agent) and zinc (ZnO - vulcanization activator) were detected on the surface of the plates. FTIR analysis did not identify these elements by any band of spectra. To complete the experiment, a thermogravimetric analysis (TGA) of the rubber compound used was performed. Its results show that decomposition processes occur during the vulcanization process which releases volatile substances that are likely to adhere to the mould cavity surface.

Czech name

—

Czech description

—

Type

O - Miscellaneous

CEP classification

—

OECD FORD branch

20301 - Mechanical engineering

Project

—

Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů