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Foam Injection Molding: The best material for water products

11/22/19

If you are a manufacturer or a distributor of marine or aquatic products, you may be on the lookout for a material well-suited for your application. Did you know that XL EXTRALIGHT® foam injection molding is a widely used material for a variety of water products, including boat and spa cushions and mats, swim kickboards, parts of life jackets, rescue tubes, and more? Discerning manufacturers worldwide prefer our foam to traditional EVA foams. But why is XL EXTRALIGHT® foam injection molding the best for water products and why does it beat out standard EVA foams? Let’s take a look at some of its properties.

What is EVA Foam Injection Molding?

EVA Foam injection molding is a manufacturing process that involves injecting molten Ethylene Vinyl Acetate (EVA) foam material into a mold cavity, where it solidifies and takes the desired shape. EVA is a versatile and durable foam commonly used in various industries for its cushioning and impact resistance properties. 

The injection molding method allows for the production of intricate and precise shapes, making it ideal for applications such as footwear, sports equipment, and protective padding. The process involves heating the EVA material until it reaches a molten state, injecting it into a mold under high pressure, and then cooling it to form the final product. This technique provides a cost-effective and efficient way to create foam components with consistent quality and performance.

The Manufacturing Process of EVA and Polyolefin Foam

EVA foam injection molding involves a meticulous process that transforms raw materials into the final foam product. The basic steps include:

  • Material Preparation: EVA, a copolymer of ethylene and vinyl acetate, serves as the primary material. To enhance its properties such as flexural strength, additives like foaming agents, stabilizers, and colorants are often introduced. The material is then pelletized for ease of handling.
  • Injection Molding Machine Setup: The prepared material is fed into a foam injection molding machine. The machine comprises a hopper for material feeding, a heating system to melt the EVA pellets, and an injection unit responsible for injecting the melted compound  material into  heated molds.
  • Injection : The molten EVA is injected into closed molds at a controlled injection pressure and speed. The molds are designed to create the desired product shape.
  • Ejection and Foaming: the foam product is ejected from the mold and the foaming happens instantaneously. The molds can then be reused for subsequent cycles
  • Cooling and Solidification: After injection, the  products cool down and slightly shrink. The cooling time is crucial in determining the product's mechanical properties and final shape. .

What is EVA foam and what are its common applications?

Benefits of Using Injection Molding for Water Products

There are multiple components that make injection molding with EVA foam the ultimate choice for water products. From the closed cellular structure affording its unparalleled strength resistance to its unbeatable surface quality providing comfort, here are some of the key benefits of utilizing EVA foam injection molding when manufacturing water merchandise. 

Excellent water resistance

One of the key components of injection molding with EVA foam is the water-resistant surfaces it creates. Our material is a closed-cell Polyolefin cross-linked foam, meaning that its surface finishes have low water and salt absorption: it is 100 % waterproof. Contrary to other types of open-cell foams, such as polyurethane foam injection molding, as well as other EVA foams, our foam structure also offers unmatched buoyancy, which is ideal for water products.

Great durability

When manufacturing water merchandise, it is essential that it has adequate tensile strength as well as abrasion resistance in order to be able to handle the wear and tear it will be subjected to. That is why all manufacturers require that the material that they use for their water products be very durable — as a symbol of quality. XL EXTRALIGHT® foam is specially designed to remain sturdy and withstand vibrations, impact, and long-term use without ever cracking or breaking. These material properties differ greatly from other EVA foams which struggle to handle the impact strength they are under. 

Lightweight and portable

Despite the need for durability, strength, and impact resistance, any finished products that are being used in water need to also be lightweight in order to float. Depending on customer needs, XL EXTRALIGHT® foam is perfect if weight (or lack thereof!) and portability are primary concerns. For example, rescue tubes should be lightweight and very portable so that lifeguards can easily grab and swim with them as they save lives. XL EXTRALIGHT® foam mitigates the issues surrounding other cumbersome, heavy materials and cheap EVA foams.

Amazing softness and comfort

High-end boat and spa manufacturers as well as end users looking to enhance their investments often turn to cushions and mats made with XL EXTRALIGHT® foam. The reason? Contrary to cheap EVA foams, our innovative alternative material is soft, yet firm enough to withstand compression and recuperate quickly over time. For maximum ergonomic comfort with water products, you can’t get better than our foam.

High UV-resistance

When designing marine or aquatic products, it is important to keep in mind sun exposure. Other raw materials, such as polyethylene terephthalate, can deteriorate and fade in the sun. However, XL EXTRALIGHT® foam will maintain its quality, finish, texture, and color for a long time.

Suitable for extremely hot and cold temperatures

When thinking about water products, the first thing manufacturers think about is how well the material will cope with heat. XL EXTRALIGHT® foam can definitely keep its sturdiness under extreme heat. But did you also know that our foam maintains its properties even at very low temperatures? As a result, any application in water—regardless of temperature can benefit from XL EXTRALIGHT® foam. Unfortunately, many low-cost foams cannot hold up when exposed to extreme temperatures.

Safe for humans

The number one feature you should be looking for when choosing versatile materials for your manufacturing process is whether or not it is safe for humans to use. As a closed-cell foam cell structure, XL EXTRALIGHT® foam keeps water and humidity out, which prevents the proliferation of bacteria. Considered to be a safe alternative to PU, our injection molded foam does not contain any harmful plasticizers like phthalates and is BPA-free.

Hardness vs Density: Key Factors in Foam Injection Molding

Common Water Products That Require EVA Foam Injection Molding 

EVA foam injection molding is commonly employed in the manufacturing of various water-related products due to its water-resistant properties, lightweight nature, and ability to provide cushioning and buoyancy. Some common water products that utilize EVA foam injection molding include:

  • Water Sports Equipment: EVA foam is widely used in the production of water sports equipment such as floating mats, kickboards, water noodles, and flotation devices. Its buoyant and shock-absorbing characteristics make it ideal for enhancing safety and comfort during water activities.
  • Footwear: Water shoes, aqua socks, and flip-flops often incorporate EVA foam in their soles for cushioning and comfort. The foam's water-resistant nature makes it suitable for footwear designed for wet environments, such as beaches and pools.
  • Swim Floats and Pool Accessories: EVA foam injection molding is employed to create swim floats, pool noodles, and other recreational accessories used in swimming pools. These products benefit from EVA's buoyancy and resistance to water damage.
  • Marine and Boating Products: EVA foam is used in the production of boat decking, marine flooring, and boat accessories due to its non-slip properties, resistance to water absorption, and ability to withstand harsh marine environments.
  • Water Toys: Various water toys, including floating toys and games designed for pools and beaches, often incorporate EVA foam for safety and playability. The foam's soft and lightweight characteristics contribute to the overall enjoyment and safety of water play.
  • Diving and Snorkeling Gear: Some diving and snorkeling equipment, such as fins and masks, utilize EVA foam for added comfort and buoyancy. The foam's resistance to water damage ensures the durability of these products in underwater environments.
  • Medical Devices: Certain medical devices designed for water-related environments, such as rehabilitation equipment used in aquatic therapy, make use of EVA foam for its biocompatibility and comfort.
  • Packaging Material: EVA foam's impact resistance, excellent strength, and ability to conform to product shapes make it an excellent choice for protective packaging, especially for fragile water-related goods.

Innovative EVA Foam Injection Molding Technology

If you are looking for the ultimate material and manufacturing process to create your water products, look no further than Foam Creations. Our state-of-the-art EVA foam technology is unlike anything on the market and is designed with lightweight flexibility in mind. Moreover, our material is free of phthalates, heavy metals, and latex, making it an environmentally friendly option that is assured to be safe for human use. Our XL EXTRALIGHT® foam surpasses all other types of EVA foams.

Contact our specialists today