How Plastic Buttons are Made?

Plastic buttons, also known as molded plastic button are very common items in apparel trims. We as garment makers often use buttons for making garments like shirts, blouse, trouser, uniforms, suits and many other apparel products. But many of us don’t know how buttons are made in a plant. 

This article covers an introduction about plastic button manufacturing process. Read this to learn about button making process.

Raw materials used for buttons making

The main materials of plastic button making are liquid polyester (plastic material), waxes, dyes, and chemical catalyst.

Plastic buttons for apparels
Buttons | Image source: google search screenshot

Plastic button making process

Here plastic button making procedure is shown step by step. You may come across some new terms in this article.

Step-1: Mixing dyes and Liquid polyester
Dyes are mixed with liquid polyester to get buttons for desired color. Chemical catalyst is also added to harden the polyester. 1% wax is added to shining and easily removal purpose.

Step-2: Pouring material into the cylinder
After the dye is mixed, the liquid polyester (prepared mixture) is then placed into a large rotating metal cylinder made of steel and lined with chrome poured into a metal beaker from having capacity of approximately 3-gallons or 11 liters.

The cylinder is typically 2 feet long and 4 feet in diameter. The cylinder lies on its sides on rollers which rotate the drums at about 250 rotations per minute. The polyester mixture is slowly poured into the rotating interior of the cylinder. The centrifugal force of the rotation causes the polyester solution to spread, lining the drum with an even sheet. When thicker buttons are needed, greater amount of polyester is used while less polyester is used for making thinner buttons. A 2-inch lip around the ends of the cylinder prevents the polyester solution from leaking out.

Step-3: Hardening the plastic sheet
As a result of reaction with the chemical catalyst, polyester, rotating in the cylinder, begins to harden. As the wax rises to the top of the sheet, and also sinks to the bottom, the hardening polyester is held between two layers of wax. After about 20 minutes of rotation, the polyester sheet changes from its liquid state to a powdery solid sheet having consistency of stale cheese

Step-4: Cutting the plastic sheet from drum
When the sheet has reaches the proper hardness, the drum stop and sheet need to cut vertically. The wax makes it easy to remove from the drum. The sheet is still not so hard. The top layer of the plastic is rolled and placed to a Blanking Machine.

Step-5: Punching the blanks 
The blanking machine moves the polyester sheet on a conveyor belt. As the sheet passes along the belt, circular shaped cutting dies (made of steel) descend over it and punch out button-sized circles, known as blanks.

Standard size of buttons is specified and the dies are prepared accordingly, dies with different diameters according to the requirements can also be made and loaded into the blanking machine. After the blanks are cut, they fall into a channel, and the punched out polyester sheet rolls under the conveyor belt in a place. This whole process of cutting the sheets take about 2-4 minutes, depending upon the size of the buttons being made.

Step-6: Curing the blanks
As the blanks are still hot, so need a cooling process, having hot and cold baths. If we directly cool it on air, the blanks may brittle. So need hot and cold treatment. The blanks are placed into a tank of hot water, which is heated at 110°C. As the water slowly cools, the polyester blanks get hardened. Curing time is 10 to 24 hour depending of kinds of buttons. Then Use hydro machine for drying buttons

Step-7: Turning (hole making and designing of buttons)
The final stage of button making involves designing the buttons according to the buttons supplier’s specification. Different cutting tools are used for making different shaped buttons such as beveled edge, or a slightly concave button. 

The cutting tool is placed in the cutting machine and the buttons are poured into a hopper at the top of the machine. The blanks fall into a holder where they are clamped tightly and moved toward the cutting tool. The spinning blade comes out and cuts the button and then retracts. Then the buttons moves beneath a set of drills, which make the holes in them.

The design specification allows two or four holes, and also the diameter of the holes and the distance between them. After the holes are made, the buttons are sucked by vacuum out of the holder and into a box beneath the machine. Hundreds of buttons are made in a minute, though the number varies according to the size of buttons and complexity of the design.

Step-8: Polishing of buttons
Polish of buttons is done to make buttons shiny. Buttons are kept into tumbling drums that contain water, abrasive material, and a foaming agent. The drums spin for about 24 hours. The buttons bounce around in the drum until they are smooth and shiny. Lastly, the buttons are washed and dried by hydro machine. Button qty per drum is 30kg.

Step-9: Quality check and Packaging the Buttons
After the buttons are polished, they are put on a conveyor belt and visually inspected for faults. Quality control inspector checks each button for defects and removes any cracked or miscut buttons. The perfectly made and finished buttons are then packaged for sale and send to ware house for delivery to buyer.

About the author
K.M. Emran Hossain is a Mechanical Engineer and he is based in Bangladesh. He has working experience in garment manufacturing and garment accessory manufacturing field. He has worked in Epic group as industrial engineer, at Dekko group as asst. production manager, and at Pran-RFL group as operation manager of plastic products. Currently he is working as factory head at NZ group. He can be reached at emran.htlfl[at]

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