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Frequently Asked Questions (FAQs)

How many types of silicone exist?

There are basically three types of silicone, silicone oils, silicone rubbers and silicone resins, which in turn comprise more than a thousand other silicone semi-finished products.

At Merefsa We work with silicone rubbers for compression molding, transfer molding, horizontal extrusion (HTV silicones) and casting (LSR silicones).

What durability do silicone products have?

The durability of a silicone product will always depend on the working conditions to which it is subjected (temperature, mechanical stress, chemical resistance, etc.).

Silicones, once vulcanized and converted In final product, they have no expiration date. In its original packaging, we can ensure its perfect state of preservation for a period exceeding 10 years.

How is the price of an extruded silicone product calculated?

To be able to quote the cost of a product, we need to know:

  • Number of meters or quantity needed.
  • Plan, sketch or sample of the product to be manufactured .
  • Working temperature range that the material will have to withstand.
  • Food specifications if applicable.
  • Mechanical and chemical working conditions for its application.


Does the silicone yellow? Should it be thrown away?

Some yes and others no.

To the base of the silicone (a kind of paste) we add a catalyst to vulcanize and become a finished product. Basically we use three types of catalysts:

  • Platinum salt catalysts: they make the silicone enjoy a high transparency and do not yellow over time or sun exposure. They are suitable for food contact.
  • Peroxides catalysts of the DIACYL family: they are the least transparent and yellow over time, but are suitable for food contact.
  • Peroxides catalysts of the DIALKYL family: they transparent and yellow little over time, basically for industrial use.

Does the silicone yellow? Should it be thrown away?

No, silicone, although yellowing, still retains all its physical and chemical properties. We can continue to use it until it breaks or stops making the use we expect.

What colors are manufactured? What colors does Merefsa manufacture?

Those that are necessary. In Merefsa we can manufacture any RAL color from 25Kg of product. Our standard is translucent silicone in compact silicones and white in spongy silicones.

In addition, we can manufacture luminescent, fluorescent and metallic colors.

What temperature does silicone resist?

Our standard is a silicone base that supports from -50 ºC to + 200 ºC, although we have other bases that can support -90 ºC (PVMQ) and even + 315 ºC (THT). Our silicone bases are guaranteed by the manufacturer of raw material for continuous use for a minimum of 1,000 hours.


What hardnesses are manufactured? What hardnesses does Merefsa manufacture?

Our standard in compact silicone is 60° Shore A (± 5), and in sponge 0.25 gr / cm³.

In addition, our range of hardnesses in production of compact silicones ranges from 25° to 85° Shore A and in spongy silicones from 0.25 to 0.8 gr / cm³.


Does Merefsa sell raw material to third parties?

Yes. Although the main activity is the manufacture of finished products, we also market additive bases, ready for use.

Can urgent orders be made for deliveries in 24-48h?

Yes, for our standard compact extrusion silicones, assuming the customer a surcharge of 300€ per production stop, both in translucent and colored silicones, with hardnesses of 40 to 80Sh.


Alianza Empresarial para la Vacunación Infantil
ED Empleo
Consorcio del Caucho
Control Energético


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In accordance with the provisions of the General Data Protection Regulation, 679/2016 of May 2016, (hereinafter, RGPD), we inform you that your personal data will be included in a file owned by Manufacturados Españoles de Resinas Fluoradas, S.L.U., with NIF B08207284, and located in Castelló 9, ( 08830) Sant boi de Llobregat, Barcelona. We treat the information you provide us with in order to provide you with the requested service as well as to maintain the commercial relationship in accordance with current legislation. The data provided will be kept as long as the commercial relationship is maintained or for the years necessary to comply with legal obligations. The data will not be passed on to third parties except in cases where a legal obligation exists. You have the right to obtain confirmation as to whether Manufacturados Españoles de Resinas Fluoradas, S.L.U. is processing your personal data. You are therefore entitled to access your personal data, rectify inaccurate data or request their deletion when they are no longer necessary. To do so, you must request it by e-mail to rgpd@merefsa.com, or by sending a registered letter to the indicated address.


Castello, 9 08830 Sant Boi de Llobregat

Barcelona (Spain)

Tel (+34) 933 372 081

Fax (+34) 933 374 373

Office Schedule

Monday to Thursday from 8:00 to 13:00

Monday to Thursday from 14:00 to 17:15

Friday from 7:00 to 14:15

Warehouse Schedule

Monday to Friday from 9:00 to 14:00

Summer Intensive Schedule

From June 20th to September 13th from 07:00 to 14:15

Summer Vacation

Closed from 05/08/2024 al 23/08/2024

Download Merefsa's annual calendar

Page Code: DT560e1161


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