Application guide

Polyester Button Manufacturing

Buttons are cut from cast polyester sheet or rod, not moulded one at a time. What that means for the resin, and why clarity and a controlled cure matter more than strength.

Cast the blank first; the button is machined from it.

Polyester buttons are not moulded individually. The normal industry route is to cast a sheet or a rod first, let it cure, and then produce buttons from that blank by cutting, turning, drilling and polishing. Everything the resin is asked to do happens at the casting stage, before a single button exists, which is why a button producer buys on clarity, colour behaviour and a controlled cure rather than on the mechanical properties that matter in a laminate.

What manufacturers build

Producers in this category make buttons for garments and uniforms, fashion accessories and trims, and small decorative cast items. The Button Grade Resin Technical Data Sheet issued by Samrat Poly Resins, India lists buttons, fashion accessories and small casting work for the grade. In a garment supply chain the same producer usually runs many colours and finishes from one process, so repeatability across batches is the commercial constraint rather than any single property.

Why this material suits the work

Button Grade Resin is published by Samrat Poly Resins, India as a polyester (unsaturated) resin with a viscosity of 1,100 cPs, a gel time of 9.5 minutes, a curing time of 2 hours and a styrene content of 33%. The thicker body separates it from a laminating grade: a casting resin is not being asked to wet out fibre, it is being asked to hold pigment and effect evenly in a body that will be cut and polished afterwards. The published cure time matters for the same reason, since a blank that is machined before it is properly cured does not finish cleanly. Those are the manufacturer’s figures for the supplied resin, not a property of a finished button.

Required resin characteristics

A body that holds pigment and decorative effect in suspension rather than letting it settle out of a thin liquid
A controlled, documented cure, because blanks are machined afterwards and an under-cured blank does not finish cleanly
Consistency between batches, since a garment order is usually matched across many buttons and several runs
Clarity behaviour appropriate to the finish being produced, confirmed against the supplier document
Room-temperature cure, so casting does not require heated equipment

Process context

The general sequence used across the trade is to catalyse the resin, add pigment or effect, and cast a sheet or rod, allowing it to cure fully before anything is cut from it. Buttons are then produced from the blank by cutting or turning to shape, drilling the holes or fitting the shank, and finishing the edges. Polishing, often in a tumbling operation, produces the final surface. Catalyst dosage, pigment quantity, casting thickness, cure schedule and polishing media are workshop decisions governed by the current supplier documentation and your own approved procedure. This page publishes none of them, and the resin data sheet describes the liquid rather than the finished button.

Advantages

A published thicker body suited to holding pigment and effect in a cast blank
A documented cure time, which is the figure that governs when a blank can be machined
The supplier Technical Data Sheet and Safety Data Sheet are both on file and linked from the product page
One documented grade across a colour run keeps successive batches behaving the same way

Common products

Buttons for garments, shirting and uniforms
Fashion accessories and trims
Small decorative cast items
Cast sheet and rod blanks for downstream machining

Common questions

Can I use a general-purpose resin for buttons instead?

General-purpose grades are formulated to wet out glass reinforcement, which is not what this job asks for. There is a comparison guide covering the button grade against a general-purpose resin, and it is worth reading before substituting on price alone.

How is this different from a clear casting resin?

Both are casting rather than laminating resins, but they are positioned for different work and cure differently. We carry Clear Casting Resin separately for art and deep-pour casting, and there is a comparison guide covering the two.

What causes cracking or crazing in a cast sheet?

Casting faults are generally attributed to cure conditions: thickness, exotherm, catalyst level and ambient temperature. That is process territory rather than a resin fault, and the supplier documentation for the grade is the controlling reference. A batch behaving differently from the previous one is worth raising with us.

Do you supply pigments and effects for buttons?

We supply FRP Polyester Pigment in the range. Whether a particular pigment suits a button finish is a question for the supplier documentation, since a colour that works in a laminate does not automatically behave the same way in a cast and polished blank.

Producing polyester buttons or cast accessories?

Tell us the finished item, the casting format you work in, the colours and finishes you run and the quantity you expect to take, and we will review the grade and the current supplier documentation with you.

Contact Samrat FRP Traders