In the field of Unsaturated Polyester Resins (UPR) we supply our clients with know-how, technology and equipment / machines for process lines as well as turnkey plant, including engineering, procurement, construction, training, commissioning and initial assistance in marketing.
UPR are most commonly used as composite materials which basically bridge the gap between conventional plastics, commodity plastics and specialist engineering plastics. Such plastics are widely used in applications where advantage may be taken of their good range of mechanical properties, corrosion resistance and low weight.
MAIN ADVANTAGES OF TECHNOBELL’S UNSATURATED POLYESTER RESINS PRODUCTION PROCESS
- STABILE QUALITY
Highly accurate control of both the time / temperature diagram of the reactor and of the difference in temperature between the reactor and the heating fluid obtains the best possible results from the resin and avoids the formation of by-products.
- LOW RAW MATERIAL COSTS
Based on raw material price changes, Technobell can vary the raw material composition for each type of UPRs to reach highest product performance parallel with lowest available raw material cost.
- LOW ALCOHOLS (GLYCOLS) EXCESS
The specially designed column enables us to operate with low glycol excess. This excess is in range of 2-3 wt% in the reaction water (depending on resin recipe) while older processes involves glycols excess of 5-6%. The benefit of reducing the amount of glycols in circulation is the reduction of resin production costs, and waste water pollution. Overall UPR production yield reaches 99,9 wt% (excluding reaction water formation).
UPR composites are made up of at least two separate components: reinforced fibre (glass, kevlar, carbon, etc.) and embedding matrix (UP Resin). Production takes place by introducing reinforcement while the resin is in an uncured, liquid state.
PROCESS DIAGRAM OF TECHNOBELL’S UNSATURATED POLYESTER RESINS TECHNOLOGY
UNSATURATED POLYESTER RESINS PRODUCTION PROCESS DESCRIPTION
Unsaturated polyester is formed by chemical reaction between glycol with di-basic unsaturated acid. This reaction, together with the addition of compounds such as saturated di-basic acids and cross-linking monomers, forms the basic process of unsaturated polyester manufacture. As a result there is a whole range of polyesters made from different acids, glycols and monomers – with combination of different ratios between them, all having varying properties.
Process of cross-linking
The molecular chains of uncured polyester can be represented as follows, where »B« indicates the reactive sites in the molecule.
With addition of styrene »S« and in the presence of a catalyst, the styrene cross-links the polymer chains at each of the reactive sites to form highly complex three-dimensional network cured polyester as presented.
Cured polyester is now chemically resistant (and usually) hard solid. The cross-linking or curing process is called »polymerization«. It is a non-reversible chemical reaction.
PROCESS VALUES
Process values
| PROPERTIES: | Guaranteed | Expected |
| Yield (wt%): | min 99,5 % | 99,7 – 99,8 % |
*Yield → ton of product UPR / tons of sum raw materials in percentage (excluding reaction water formation)
