Friday July 20th, 2018

Small step for the rubber industry, big step for usability

We are constantly developing our products to create better solutions for you. This is the only way, our technology can stay cutting edge. Our experts have come up with 4 innovations that might seem small, but they cause a significant improvement in usability. Learn about our latest innovations and stay on top of the industry trends.

Shiny finish for Viton ® / FKM hoses

We used to offer Viton ® / FKM hoses, especially the larger diameters, with a textured finish. These high-end turbo and spiral hoses are generally used in industries that require high performance. Lining with Viton ® or FKM creates a resistance to oil, diesel, petrol, chemicals and other fluids that are not compatible with silicone and fluorosilicone. The automotive industry uses turbo hoses for transferring high-pressure air. Responding to the increasing demand, we can now supply these hoses with a shiny / smooth finish. The novelty of the technology lies in the fact that we can achieve the shiny finish without compromising on the adhesion between the silicone and the Viton ® / FKM layers, keeping the bond cohesion much higher than the industry requirements of 1200 and 1400 N/m. Learn more about our turbo and spiral hoses here.


Figure 1 Viton (R) / FKM hoses with shiny finish

Primed fabrics for better bond strength

Why is the adhesion between the rubber and the fabric so important? When the bond is not cohesive, the fabric tears away freely from the rubber during testing even at low pressures. However, if the adhesion is good, the rubber tears along with the fabric. This is critical in some high demanding industries. When you are buying meta-aramid reinforced hose, you want it to perform well under extreme circumstances. Priming the fabric can improve the performance of the adhesion three to four times. Whereas an unprimed fabric hardly reaches the industry standard of 1400 N/m with its 800-1200 N/m adhesion, a primed fabric exceeds it significantly with a 4000 N/m cohesive ply-adhesion.

Priming is performed after washing and heat-setting, when the fabric is dipped into a water-based adhesive solution and then dried. Watch out because many manufacturers avoid priming to cut costs. We, at SIC Hungary, supply only primed fabrics, guaranteeing that our hoses are well-suited for demanding industries.


Overlapping fabric in wrapped hoses

The lack of overlapping in hand-wrapped hoses can cause weak-points in the hose. Just picture a 3-ply hose where the third layer ends slightly before the first layer begins. At that point the hose will only have two layers instead of three, which makes it the weakest and most vulnerable part of the hose. This is why, overlapping the fabric is so important. It’s better to safe than sorry. You may see that our 3-ply hoses have 4 plies in some areas to make the hose stronger. The overlap varies between 3 and 10 mm, depending on the operator’s hand dexterity.


Figure 2 Overlap in a 3-ply hose

Extruded and hand-wrapped organic rubber hoses

Under high positive and negative pressures, extruded reinforced hoses don’t do the job. For these applications, we supply a range of hand-wrapped hoses that are made of various materials such as EPDM, peroxide-cured EPDM, CR, NBR, PVC-NBR and AEM. Dual materials are possible, as well, for example NBR on the inside combined with CR on the outside. Both reinforced and non-reinforced versions are available. We recommend reinforced hoses for industries operation with extremely high pressures. Reinforced hoses can be made of knitted/woven polyester or knitted/woven 100% meta-aramid. We also offer strip-woven construction that strengthens the fabric without making it robust. For heavy negative pressure resistance, our hoses are equipped with an extra ply of SS or plastic wire. We offer organic rubber hoses in various sizes and shapes and we are happy to develop custom compounds for special acid resistance, as well. Learn more about our organic rubber hoses here.


Figure 3Extruded hoses

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