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What are the applications of unsaturated polyester?

Jan 25, 2019

Application of unsaturated polyester

The main modified varieties of UP are:

Low shrinkage UP: by introducing styrene/butadiene copolymer as thermoplastic resin, the curing shrinkage of UP can be alleviated and the crack problem during sheet forming can be solved, especially for automobile parts.

High strength UP: increase the content of glass fiber, such as the use of 7.6 cm long fiber, the content of 50-70%, suitable for sheet forming, as car parts.

Impact resistance UP: introduction of long-chain acid or alcohol into the molecular chain, adjustment of double-chain density, blending of rubber particles or polyurethane and other methods, but the disadvantages are reduced mechanical strength, weather resistance, water resistance, luster.

Corrosion resistance UP: corrosion resistance UP can be synthesized from phthalic acid, terephthalic acid, neopentyl glycol, hydrobisphenol A and other raw materials.

Photoimmobilized UP: the disadvantage is that the added photosensitizer can reduce the weatherability, and the high-pressure mercury lamp is harmful to the operator's body.

Modification UP: dicyclopentadiene can be used to modify UP. The modification methods include initial method, semi-esterification method, ester anhydride method and end sealing method, etc., which can reduce the curing shrinkage of the resin, reduce its internal stress and improve the mechanical properties of the casting.

Blending methyl methacrylate, polystyrene and ancient Malone resin can increase bending and impact strength by 10%.

The curing shrinkage of UP can be reduced by blending polyvinyl acetate with high molecular weight.

And with waste polyester as the raw material, in normal pressure drop, and then condensed UP, useful also polyester industrial production, spinning and weaving process of waste UP, its formula is:

polyester waste, 46, propylene glycol, 78, 100, styrene glycerol 5, 45, maleic anhydride, phthalic anhydride, 65, catalyst, hydroquinone, 0.5 to 0.95.

In addition, there are flame retardant UP, fast - drying UP, heat - resistant UP and other new varieties.

Example 1: glass fiber reinforced unsaturated polyester sheet molding compound

The production process of glass fiber reinforced unsaturated polyester sheet molding plastics (SMC) is as follows:


The basic formula is as follows:

Unsaturated polyester 100

Filler: calcium carbonate 100

Reinforcement: chopped glass fiber 30

Mold release agent: zinc stearate 3

Thickener: magnesium oxide 1.5

Initiator: diisopropyl peroxide 1

SMC molding process conditions is: the molding temperature 140-150 ℃, touch plastic pressure 10-20 million mpa, 4-60 seconds per millimeter thick cure time.

Example 2: unsaturated polyester buttons

The technological process of producing UP buttons by plate method is as follows:

Ingredients plate making blanking curing milling button polishing inspection packaging

The basic formula of UP button is as follows:

UP resin: 103 # 100

Dilute crosslinker: styrene 1

Initiator: cyclohexanone 2-4 peroxide

Promoter: cobalt naphthenate 0.4-2

Colorant: inorganic or organic pigment 0.4-1

Pearling agent: basic lead carbonate 0.4-2

Lubricant: paraffin 0.1

Sometimes to set aside enough time: prevent too fast curing, add inhibitors to eliminate internal stress, reduce the collapse block.The inhibitor is hydroquinone.After processing to increase the gloss of the button, also in water polishing, and then wax polishing.

Example 3: polyester type scagliola

The process flow of UP type scagliola is as follows:

Ingredients mix materials in the mold to make flowers shock molding products

Raw materials: UP resin available 196#, 195#, 306#, 307#;Fillers: glass powder, porcelain powder, slag powder, hollow glass beads, mica powder, vermiculite powder, sea sand, fine metal chips, etc.Pigments can be selected iron oxide red, iron oxide yellow, chrome oxide green, carbon black, etc.

The mould is made of glass template, the frame is made of wood strip and the hard plastic strip is processed into fixed or detachable type.Mold release agent with polyvinyl alcohol/water/alcohol mixture, or with wax brush.

Basic formula: UP resin 100 initiator 4 promoter 1-2 filler 30


QuanZhou Neweco High Polymer Material Co.,Ltd.

Neweco is one of the leading unsaturated polyester resin manufacturers and  suppliers,widely used in automobiles, ships, rail transit, wind power  generation, pipe cans, heat and corrosion protection, building  materials, stone repair, sanitary ware, artificial stone and other  industries. Suitable for hand lay-up, spray, pultrusion, winding,  molding, vacuum introduction / RTM, casting and other molding processes. Neweco Resin is committed to excellence and focuses on the application  of composite materials to provide customers with comprehensive  solutions.

TEL:   86-18960460100