- Category: Case Histories
- Published on Monday, 03 August 2009 18:38
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New Housings are Lightweight and Corrosion Resistant with Push-Button Controls
Today’s video cameras are more sophisticated yet smaller and easier to use than ever before. However, successful underwater shooting can be directly related to the quality of the camera housing. Ocean Images and Co. Inc., Cape Coral, Florida, has perfected the process for precision molding economical, watertight housings using high performance polyurethanes to reduce weight, optimize functionality and improve durability.
The polyurethanes, supplied by Innovative Polymers, Saint Johns, Michigan, produce robust housing components that can withstand exposure to corrosive marine environments and underwater pressures at depths of up to 200 feet.
According to Keith Loson, president of Ocean Images, “We have found that polyurethanes support our ability to quickly produce high quality housings for the ever growing variety of new camera models that are being introduced to the market. The polyurethane materials that we use also offer a variety of benefits for photographers.”
Loson explains that, in addition to requiring a significantly longer lead time to machine, aluminum housings are sometimes heavier and more cumbersome to handle than polyurethane housings. The polyurethane parts are also superior to clear ABS plastic housings.
“Clear housings can produce “ghost” images on shots because ambient light is able to penetrate the housing. By contrast, Ocean Images products are molded using black polyurethane. The solid-colored housings promote improved viewing of the video screen and reduce ghosting with light penetration limited to the clear front shooting port and the rear viewing/access plate,” he says.
Ocean Images designs and builds its underwater housings for a full range of camera model and styles from Sony (including the new XR series), Canon, Sharp and Panasonic. The polyurethane housings feature positive touch, push-button controls for fast, easy camera function adjustments. The housings also offer outstanding visibility of both the viewing screen and the housing interior.
Building the Housings
Ocean Images custom designs its housings for each specific camera model. The process begins by machining an aluminum core block that is used as a pattern to cast RTV silicone rubber tools and also in the molding process. When tooling is complete, threaded metal inserts that will be cast in place as an integral part of the housing are installed and all core and mold surfaces are released. Then IE-70D black polyurethane resin and hardener are mixed in a 2:1 resin:hardener ratio and vacuum degassed to remove air bubbles that might cause voids in the final housing. The low-viscosity polyurethane is poured into the silicone mold and the filled mold is placed into a pressure tank where the housing cures at 60 psi room temperature for about three hours. When the housing is fully cured, the mold is opened and a hydraulic press is used to remove the core. The cured Innovative Polymers polyurethane has a Shore 70D hardness, flexural modulus of 250,000 psi, notched Izod impact strength of 0.5 ft-lb/in and tensile strength of 5,350 psi.
To complete each housing, front port and rear access plate openings are machined along with grooves for O-rings and seals that will ensure that the parts are watertight.
Housing handles are installed using the threaded inserts that were cast in place. Housings are then coated with a high visibility chrome yellow urethane and pressure tested to 200 feet.
About Ocean Images
Ocean Images is a family-owned business that has manufactured quality and affordable underwater video camera housings for sports and professional scuba divers for many years. The company specializes in Sony digital video camera housings and carries a large inventory for the most popular models. Ocean Images is also equipped to create custom camera housings.
Our InnoTuf® TP-4014 now has a UL 94 V-O flammability rating with a yellow card. The Shore D hardness material, that simulates TPO, ABS and PC thermoplastics, is ideal for casting equipment housings as well as automotive interior and under-hood components. In addition to being flame retardant, the polyurethane has a high Notched Izod Impact Strength of 2.0 ft-lb/in, flexural modulus of 150,000 psi and heat deflection temperature of 192°F (89°C). Call today for samples!
The November issue of DESIGN NEWS featured an informative article prepared by Innovative Polymers that describes the latest developments in thermoset polyurethane chemistries and their performance capabilities.
» Click here to read the full story
Innovative Polymers specializes in providing technologically advanced polyurethanes for the toughest applications. Our technical support team welcomes the opportunity to partner with our customers in solving processing and performance challenges. If an existing product doesn’t meet project requirements our... » Read More