Hongrui foams are all made from polyolefins, which is a collection of synthetic plastic materials that includes low density polyethylene, co-polymers of ethylene such as Ethylene-Vinyl Acetate (EVA) and high density polyethylene.
The feeling and performance of the foam are subjected to these raw materials, for example, our high density grade foams are rigid, absorb high levels of energy and have good temperature stability, while an EV grade foam (EVA) is soft, resilient but lacks the high temperature stability.
The lifespan of the foam is limitless. In most applications the foams have withstood many decades of use without failure.
In harsh chemical environments or under intense and continuous exposure to solar radiation the lifetime may be reduced to years but if predicted beforehand there are means to enhance performance. Please contact our online salessupport team if you wish to further discuss your application.
Polyethylene has a melting point below 110°C (230°F). The thermal stability is increased as we cross-link our product, but as you reaching this temperature the foam will tend to shrink at an increasing rate.
Hongrui foam product information sheets are based on a specific 24 hour test for 5% shrinkage of a foam piece. Many variables can make a difference to shrinkage such as time, temperature, dimensions, humidity, cell size, density, application of a load and even colour. To select the correct material, we advise testing and measurement first.
In the Download page you can find general information on our products as well as product information sheets, materials safety datasheets, technical bulletins, technical datasheets, statements regarding general regulations and test certificates.
There are up to 20 existing colour options for the most common grades of foam. For unusual colours we would suggest you to contact our online sales support to discuss your requirements in detail.
The product range covers:
High density products between 75° down to 85°.
Medium density products between 45° down to 38°.
Low density products between 35° down to 18°.
Sure! The foams are easy to convert into other dimensions for final use.
Thickness - thinner sheets (down to around 2mm) can be obtained by splitting (skiving) the sheet. Thicker sheets can be fabricated by either heat laminating sheets together (up to around 300mm) or by adhesive bonding.
Length and width - can be cut using simple equipment such as bandsaws, etc. Some will adopt die stamping or water jet cutting.
Hongrui foaming technology is very flexible. We provide a wide range of sheet sizes for you to choose, subject to your order quantity. We'd be glad to consider new developments to meet customer demand.
It's possible to bond foam to foam without the use of adhesives. Techniques such as heat laminating can achieve this purpose.
Regarding bonding foam to another material, aluminium, for an instance, we would always suggest you contact the adhesive manufacturers and further discuss the materials and requirements.
Moulded is achievable by existing techniques, for example, hot press forming (compression moulding) or sheet thermoforming (vacuum forming), as well as other techniques including embossing, etc. Usually a good mouldings can be achieved with very simple facilities.
It takes little forces to mould foam, you can try to use a wooden or plaster moulds for short term runs unless very long runs are likely.
What's more, by adopting techniques developed in the medical industry, the hot foams can be shaped directly onto the body by hand.
It's hard to say: our high density foams show the highest energy absorption in static compression and perform adequately in higher speed impacts. However, they are relatively rigid materials, thus they may be uncomfortable if you want a protection directly against the skin.
Low density grades offer a compromise in stiffness (comfort) and energy management. VA and EV grades are much more bouncy, both are tend to deflect an impact rather than intake the energy of impact.
Also, you can combine the above with or without other materials to a new development.
Sensitive objectives like electronics or munitions, it requires great attention. There are a number of factors which must be taking into consideration, including the size, weight and shape of the article, the fragility, likely drop height of any impact.
Hongrui team are proud to offer performance foam in packaging industry.
No, they can't. Our foams are all ‘closed-cell’ - sponge materials may be known as ‘open-cell’:
In closed cell foams the plastic is the only continuous phase (this is like having millions and billions of small bubbles of plastic all bonded together), thus the gas in the foam is trapped inside the bubbles.
In open cell foams, gas and the plastic are continuous phases. Under this circumstance, the gas will all be expeled when you squeeze the foam, but it will soon sucks air back when you release it (like a sponge).
In other words, our closed cell foams will not absorb a large amounts of water or other liquids, which is great for buoyancy and for seals and gaskets.
