Rubatex Closing – Alternatives and Existing Inventory from Stockwell

RUBATEX ??? In June of 2010 Rubatex International abruptly closed their doors. No notice was provided – it was learned that the gate was padlocked. Rumors that the company was financially stressed had been buzzing but nobody expected the doors would close so suddenly.

While the shut down was abrupt, Stockwell has been able to service the majority of their customers with existing inventory levels of Rubatex closed cell sponge products. As with many materials offered by Stockwell, these inventoried materials allow for fast turn production. The primary Rubatex products offered by Stockwell are premium grade closed cell Neoprene, Epichlorohydrin and EPDM sponge materials. Stockwell will continue to sell its remaining inventory of Rubatex materials while transitioning customers to quality alternates manufactured by American National Rubber (ANR). View the alternatives to Rubatex now offered by Stockwell on our Closed Cell Rubber / Neoprene data sheets page.

American National Rubber manufactures a variety of closed cell sponge products to ASTM and UL specifications. In addition to the ANR products, Stockwell offers a variety of pressure sensitive adhesives (PSA) that can be laminated to the ANR closed cell sponges. These laminated materials can be readily die cut, slit or water jet cut by Stockwell.

For further information or to inquire about Rubatex materials and their replacements, please contact Stockwell at 215-335-3005, service@stockwell.com or visit http://www.stockwell.com/.

Silicone Rubber Gasket

Silicone rubber is more often being specified for gasket material, especially environmental seals. Silicone is made in wide variety forms such as solid silicone sheets, closed cell silicone sponge sheets and open cell silicone foam. All of these are available in a range of durometers and firmnesses. Solid silicone is readily available in 10 to 70 durometer (shore A scale). Closed cell silicone sponges are available in a firmness range; soft, medium, firm and extra firm. Open cell silicone foam are available in similar firmness as the closed cell sponge but also offered in extra soft and ultra soft grades. The wide range of durometer and firmnesses allow engineers and designers to choose the best match for their application. For example, electrical enclosure gasket, door gaskets or NEMA enclosure gaskets often require soft sponge or foam to compensate for the limited compressing fasteners (most often latches). Firmer solid silicone or other rubber gaskets do not give enough to make a proper seal. Conversely, solid gaskets often are better for rigid enclosures with fastener schemes offering good even compression.

Other attributes that make silicone rubber attractive to designer its resistance to UV & ozone, a wide operating temperatures, typically -100°F to 500°F (see data sheet for specific operating temperature) and its excellent rebound properties. Many of these properties lend themselves to UL, NEMA and Mil requirements such as MIL-STD-810.

For more information regarding silicone rubber gaskets, silicone sheet products and custom molded silicone parts, please visit our website at http://www.stockwell.com/ or call 215-335-3005.

New DP-1001 Silicone Pressure Sensitive Adhesive product now available

Stockwell Elastomerics has just launched a new product - Stockwell DP-1001. This silicone pressure sensitive adhesive (PSA) with easy to remove release liner can be used with die cut silicone gaskets and cushioning pads, greatly reducing the time required to remove the release liner. It also performs well in high temperature applications.

As part of this new product launch, Stockwell Elastomerics is new offering a DP-1001 product sample pack so that customers can see and touch the product to experience firsthand its benefits.

A product demo video be viewed on DP-1001 page or on the Stockwell Elastomerics' YouTube channel.

The DP-1001 press release provides additional details too.

Silicone Rubber and Pressure Sensitive Adhesives - Silicone Adhesive, Acrylic Adhesive or Combination Adhesive (3M 9731)… which is best???

With so many pressure sensitive adhesive (PSA) offerings on the market today, it can be tough to figure out which adhesive is best for a particular application. Since it is not feasible to stock every adhesive, Stockwell has hand picked 20+ adhesive offerings with a well represented cross section of products available from major tape manufacturers. Most pressure sensitive adhesives offered by Stockwell can be applied to any silicone sponge, solid silicone and silicone foam as well as other gasketing products such as Poron urethane foam, Neoprene, etc…

Silicone adhesives are most often specified when working with silicone rubber products or high temperature applications. Contrary to some ingrained industry thinking, acrylic adhesive can be applied to silicone products. Stockwell has several proprietary systems for preparing silicone sheet materials so they will readily accept acrylic adhesives. These systems have been used by Stockwell for over 20 years.

Silicone Adhesive on Silicone Rubber
An advantage of silicone pressure sensitive adhesive is they can be bonded directly onto smooth silicone rubber foam and solid without any surface preparation. Also, silicone PSA’s have a broad operating temperature -73°C to 260°F (-100°F to +500°F). The typical bond strength (to stainless steel) is 30 to 60 oz/in, which is relatively low when compared to acrylics with typical values of 70 – 150+ oz/in. The cost for silicone PSA’s can be 3 to 5 times the cost of acrylics.

Pros:
• Broad operating temperature range
• No material preparation (on smooth silicone rubber)

Cons:
• Moderate to low ultimate strength
• Higher cost
• The shelf life is limited – some manufacturers have 90 to 180 days


Example Products:
• 3M 9122 (transfer)
• DP1001 (double coated)

Combination Adhesive on Silicone Rubber
Combination adhesives are always double coated (or film supported). This means there is a support layer, typically PET, that is adhesive coated on both sides. The support layer is nearly invisible but unlike transfer adhesives they have X Y dimensional stability. With the combination adhesives the support layer is coated on one side with silicone and the opposite side with acrylic. These adhesives were designed for laminating to silicone rubber. The silicone PSA side bonds to silicone rubber, the end user exposes the acrylic side when the release liner is removed. The combination adhesives do not have the same operating temperature as silicone PSA’s due to the PET layer and acrylic adhesive side which reduce the overall temperature range.

Pros:
• No material preparation (smooth silicone rubber)

Cons:
• Moderate to low ultimate bond strength
• Higher cost

Example Products:
• 3M 9731 (double coated)
• NT1060 (double coated)

Acrylic Adhesive on Silicone Rubber
Stockwell has proprietary technologies that open the door to the vast options of acrylic pressure sensitive adhesive. Acrylic adhesives are available in a wide range of thicknesses and adhesion properties (greater than 200oz/in on stainless steel). Also, a new family of acrylic adhesives have been designed to address adhesion challenges such as bonding to powder coats and low surface energy plastics (3M 300LSE family). Acrylic adhesives have a reduced operating temperature range than silicone PSA’s, with typical operating temperatures of -40°C (-40°F) to 149°C (300°F). There are some grades that can withstand short term exposure of 204°C (400°F).

Pros:
• Wide range of options (thickness, strength, etc…)
• Lower cost
• High ultimate bond strength
• Longer shelf life

Cons:
• Material preparation required (silicone rubber)
• Not recommended for <-40° or >+300°F continuous

Example Products:
• 3M 9485
• Adchem 256M
• 3M 467


When working with silicone rubber and pressure sensitive adhesives it is important to understand the adhesive requirements. If the application requires very low or high temperature performance, silicone adhesive should be specified. If the temperature range of a silicone PSA is not required, significant cost savings as well as bonding performance can be gained by specifying an acrylic PSA.

For more information on Silicone, Combination, and Acrylic adhesive offerings on silicone rubber material and sample swatches, please contact Stockwell at 215-335-3005 or visit our website at www.stockwell.com .

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Wind Turbine Blade - Transportation Cushioning Pad

Cast liquid silicone rubber sheet materials have the tendency to grip smooth surfaces - especially table tops and similar work surfaces.

Stockwell Elastomerics has been working with a major Wind Turbine Blade manufacturer on a design and logistics challenge - how to hold and transport fragile wind turbine blades that are 110 feet long and greater - without squeezing the blade too firmly. Wind Turbine Blade damage can be an expensive problem, not just from the cost to repair the blade, but also from downtime and installment delays in bringing the units on-line.

After several iterations, we developed a combination of closed cell silicone sponge cushioning with a 'grippy' liquid silicone rubber coated fiberglass cloth surface lamination.
The result has been a soft holding pad with enough tensile strength to cradle the blade as it is transported to the installation site. We have been told the blade damage has been reduced by 40% when our transportation cushion pads are used.

Closed cell silicone sponge was selected for the cushioning layer due to its low compression set and age, sunlight and weather resistance in prolonged outdoor conditions. The closed cell silicone sponge can be laminated to virtually any thickness using silicone based bonding adhesives. Closed cell silicone sponge is available in 3 grades of firmness - soft, medium and firm. The grippy LSR coated fiberglass has the same inherent age resistance - making this laminated construction a great example of how Stockwell Elastomerics can develop a combination of properties to solve an engineering challenge.

UL94 V0 Flame Retardant Silicone Sponge Rubber

St. Gobain’s R-10400-M flame retardant silicone sponge is a unique expanded silicone sheet product. It has similar mechanical properties as standard silicone sponge rubber but with flame resistance, R-10400 holds an aggressive UL94 V0 flame rating. Silicone is a naturally heat resistant rubber, however without enhanced chemistry it is capable of burning in the presence of a flame. R-10400 may be used similarly to standard silicone sponge products such as enclosure gaskets, soft gasket, vibration dampening, environmental gaskets, and water sealing but also for application such as military and electronics that require a UL94 V0 flame rating or flame resistance.



Description: Flame Resistant Closed Cell Silicone Sponge Rubber
Put up: Silicone Roll or Silicone Sheet
Temperature Range: 100 – 500°F (-73 – 260°C)
Force Deflection: 10psi (@ room temp)
Compression Set: 10% (22hrs @ 212°F)
Thermal: Thermal Insulator, .02 W/m-K
Electrical: Electrical Insulator, Volume Resistivity 8E15 Ohm-cm
Flame Rating: Flame Retardant Rubber, UL94 V0
FDA Rated: 21 CFR 177.2600

Other properties such as UV resistant and a wide functional temperature range, makes R-10400 an ideal product for outdoor gasket and electronic enclosure gasket applications, where performance is paramount. Stockwell offers a wide range of adhesive backings (peel and stick) for ease of installation.

For more information on R-10400 flame resistant silicone sponge or other UL94 flame rated products, please call (215) 335-3005 or email service@stockwell.com.