Simson STR 350



Simson STR 350 is an elastic multipurpose adhesive based on Silyl Modified Polymer (SMP). It is a good compromise of an adhesive and sealant, suitable for elastic constructions in industrial applications. Simson STR 350 is free of any solvent, isocyanate and silicone. It has good resistance to UV, weather and temperature. Simson STR 350 exhibits good adhesion performance on a wide variety of substrates (minimal or no pre-treatment necessary).


- Elastic bonding and sealing in e.g. caravan and trailer construction
- Bonding of metals, glass and plastics
- Multipurpose adhesive/sealant
- Easy to use
- Safe for workers and environments
- Solvent-, isocyanate- and PVC free
- Good UV-resistance and ageing properties
- Elastic within temperatures from -40°C till +90°C
In general, Simson STR 350 adheres well without primer on clean, dry, dust- and grease free substrates of aluminium, stainless steel, galvanised steel, zinc, copper, brass, powder coated metal, most lacquered metal surfaces, glass, PVC, polyester (GRP), painted and lacquered wood, etc. No adhesion on untreated polyethylene, polypropylene and teflon. In case of high adhesion demands, the use of Simson Prep M is recommended. Prep M degreases and prepares the surface of the substrate in one step. On plain, untreated wooden surfaces and other porous substrates Simson Prep P is recommended. For more details concerning Prep M and Prep P consult the Technical Data Sheets.
For not mentioned substrates and additional information consult Bostik.
Simson STR 350 can easily be extruded with a hand- or air pressure gun at temperatures between +5°C and +35°C. In sealing applications, Simson STR 350 should be tooled or smoothened within 10 minutes (at 20°C/50%R.H.) with a spatula or putty knife, occasionally moistened with a soap solution. Avoid soap solution penetrating between joint sides and sealant, because this will create loss of adhesion. In bonding applications the substrates have to be assembled within 20 minutes (at 20°C/50%R.H.) after applying Simson STR 350. In general an adhesive thickness of 2 mm is recommended. Cleaning tools or removing uncured residue of SIMSON STR 350 can be done with a clean colourless cloth, wetted with Simson Liquid 1. It is recommended to make a trial first to check possible attack of the substrate by Liquid 1.
Simson STR 350 can be stored for 18 months in cartridges and 12 months in sausages, in an original, unopened container in a dry place at temperatures between +5°C and +30°C.
The following publication is available on request: Material Safety Data Sheets (MSDS).
The information given and recommendations made herein are based on Bostik’s research only and are not guaranteed to be accurate. The performance of the product, its shelf life, and application characteristics will depend on many variables, including the kind of materials to which the product will be applied, the environment in which the product is stored or applied, and the equipment used for application. Any change in any of these variables can affect the product’s performance. It is the buyer’s obligation, prior to using the product, to test the suitability of the product for an intended use under the conditions that will exist at the time of the intended use. Bostik does not warrant the product’s suitability for any particular application. The product is sold pursuant to Bostik’s Terms and Conditions of Sale that accompanies the product at the time of sale. Nothing contained herein shall be construed to imply the nonexistence of any relevant patents or to constitute permission, inducement, or recommendation to practice any invention covered by any patent, without authority from the owner of the patent.



Basic material

Silyl Modified Polymer (SMP)

Curing method


Specific gravity

ca. 1.5

Skin forming time 20°C/50% R.H.

ca. 15

Open time 20°C/50% R.H.

< 15

Curing speed after 24 hrs 20°C/50% R.H.

ca. 3

Shore A hardness DIN 53505

ca. 57

Volume change DIN 52451


Tensile stress (100%) DIN 53504/ISO 37

ca. 2.3

Tensile stress at break DIN 53504/ISO 37

ca. 2.7

Elongation at break DIN 53504/ISO 37

ca. 180

Shear stress * DIN 53283/ASTM D1002

ca. 2.1

Tear propagation ** DIN 53515/ISO 34

ca. 15

Solvent percentage


Isocyanate percentage


Temperature resistance

- 40 till + 90

Application temperature

+ 5 till + 35

UV- and weather resistance


Colours (standard)

Black and white


290 ml cartridges 600 ml sausages

* Alu-Alu; adh. thickness 2 mm, test speed 50 mm/min.
** Type C, test speed 500 mm/min.