Rubber washers are ring seals with a square or rectangular cross-section, defined by the outer diameter, inner diameter and thickness, and they represent Zanini Rubber’s flagship product.

Washers are ideal for a wide range of applications and are especially popular for the following features:

• large sealing surface;
• resistance to even high pressure and crushing.

Depending on the different needs, rubber washers can be made with different compounds and in particular the most suitable are:

• natural rubber;
• nitrile rubber;
• neoprene (also flame retardant);
• silicone rubber.

Zanini Rubber is able to make this particular type of gasket in 5 different ways:

1. lathe cut washers from drawn rubber;
2. lathe cut washers from moulded rubber sleeve;
3. washers die-cut from sheets of rubber;
4. washers made with a cutting plotter;
5. moulded washers.

1. Lathe cut washers from drawn rubber: the cheapest option

The washers are obtained from a continuous piece of drawn rubber, even a few hundred metres long.

This system is certainly the cheapest, but it has some limitations such as:

• very wide tolerances;
• inconsistency of allowances, which can easily shift several times between the minimum and the maximum;

• acting quality of the compound poor;
• possible presence of foreign materials in the drawn rubber.

Drawn washers are generally suitable only in uses where quality is not the determining factor, but are ideal if you want to reduce costs and if you need to obtain washers of different thicknesses from the same drawn rubber, without having to proceed with the production of numerous moulds.

2. Washers cut from moulded rubber sleeve: perfect flatness and variety of thicknesses

The moulded sleeve process involves moulding a rubber sleeve with the inner and outer diameters exactly to the size of the washer to be made, but with a much greater height. Once the sleeve has been moulded, it is cut to obtain washers of the required thickness or thicknesses. The whole work process, including sleeve cutting, is carried out entirely in-house at Zanini Rubber, meaning precise control over the entire production process.

The main advantages of moulded sleeve washers are:

• guaranteed diameter tolerance, tolerance on thicknesses with low variability;
• perfect flatness of the pieces;
• possibility of obtaining washers in several thicknesses from the same sleeve;
• excellent value for money for large orders of washers with medium-large diameters;

3. Die-cut washers

Die-cut washers are obtained by die-cutting sheets of rubber. With die-cutting, flat rubber gaskets of different thicknesses can be made, from really thin ones to truly large. Thicknesses over 10 centimetres are even possible.

• The main features of these washers are:
• possibility of very small production runs.
• low prices

4.Washers made with a cutting plotter

The washers can also be cut continuously with bench-mounted blade cutting systems

The main features of these washers are

• reduced costs for small/medium batches, because there are no die-cutting costs
• large sizes are also possible
• not suitable for large-scale production runs

5. Moulded washers:
tight tolerances and excellent surface finishes

Il processo di produzione da stampo consente di

The mould production process makes it possible to produce washers with extremely reduced tolerance. The main features of these washers are:

• guaranteed required tolerances;
• excellent aesthetic and functional appearance;
• reduced cost of the moulds, especially for large quantities.