Are you curious to know How EVA sheet manufacturers work to design EVA foam sheets? EVA foam sheets is a very popular product which has been used and marketed in the areas of applications like toys, footwear, cushions, sports, leisure and many others. Ethylene Vinyl Acetate (EVA) is integrated using copolymers and is pressured by co-polymerization of ethylene and vinyl with free radical catalysts. EVA can be designed in several different shapes and molds. EVA copolymer is divided into three different types; each one differs in vinyl acetate content and the method of material usage. Learn about them from below
Benefits of EVA foam
- It is highly versatile and a good replacement of wood, fiberglass, and PVC foam.
- It resists harmful UV rays and harsh weather conditions.
- It endures compression and stress without breaking or even causing cracks.
- It is highly-durable, sturdy, and resists even the lowest temperatures.
- It has a color subsuming properties
Below is the process of how the EVA foam sheets are manufactured.
Step 1- Formula preparation of plastic raw materials
These formulas are prepared by blending the proper proportion of plastic raw materials and catalysts. The primary materials are Copolymer and polyethylene, filler of calcium carbonate and talcum powder, foaming promoter of zinc oxide AC, DCP crosslinking agent, lubricating agent of stearic acid.
In order to combine EVA foam materials, many additives are included in its making. To add colors, masterbatch is used widely. To enhance insulation and heat of EVA foam sheets the fire retardant additives are added into the chemical formula. Once the raw materials are ready to process then, you can proceed to the next step.
Step 2-Banbury Mixer processing
Once the right quantity of plastic and raw materials have been accumulated, it is put inside a Banbury mixer machine. This machine has sufficient capacity to accommodate large amounts of raw material and produces in mass-quantities. The mixture prepared earlier is blended inside the mixer by adding a little more pressure. The temperature in the internal mixture is adjusted before the materials are put into it.
Step 3- Processed using extruder and conveyor
Before using the extruder it is essential to set the speed of the machine otherwise it can cause trouble. The manufacturers will make sure the extruded foam sheets remain thick for the foaming process. Once the sheets are put inside the extruder, the plastic blend inside will be squashed with the high pressure. The blend will be divided into flat sheets by going through metal rollers present inside. After Eva sheets come out, only the foaming of sheets will be left.
Step 4- Vulcanizing machine
The foaming machine is adjusted to the right temperature and pressure, as lower or higher temperature can affect the density and quality of the EVA foam sheets. The technician places all the sheets into the foaming mold. This mold is made up of high-quality stainless steel and resists high-temperature and pressure. The EVA foam sheets are formed in mold and its size determines the size of EVA foam sheets. The machine brings out the thick EVA foam sheets and is fabricated later to make it longer and broader. The EVA sheets blended with catalysts inside the foaming mold undergo the vulcanization process and after certain hours of heating the sheets will have a proper density and will be colored. These sheets come out thick but are light in weight and can be adjusted in any shape.
For several years, Eva sheets have been used in industries like marine, healthcare, automotive, recreation, electronic and footwear industries. This sheet is versatile enough because of its characteristics like Weather-resistance, UV resistance, softness, lightweight and also resistance towards harmful chemicals. It is expected that these sheets will be adopted by other industries in the near future.