Release coatings have become an indispensable part of molded plastic production to resolve resin sticking and build-up on mold surfaces. However, the selection of the correct release coating always presents a difficult challenge and must be carefully determined from a variety of factors including the resin chemistry, surface material and morphology, and operating conditions of the mold. This paper will discuss the chemistry behind what causes build up problems in the first place, followed by the history, benefits and limitations of various Teflon and Silicon based release coatings to solve mold build up problems. We will also different application techniques and best practices, as well as how to measure coating performance and detect quality defects.
New polymeric materials have played an important role in accessing previously challenging oilfield environments. Polydicyclopentadiene (pDCPD) is the prototypical example of a thermoset polymer made by ring-opening metathesis polymerization (ROMP), and is characterized by high toughness, low water absorption, and excellent resistance to corrosive fluids. Despite a promising price/performance profile, applications of pDCPD have been limited in part by the sensitivity of the curative catalysts which restricted their use to unreinforced systems processed by reactive injection molding (RIM). Recent advances in catalyst technology have led to a series of curatives that are more robust and dramatically broadened the applicability of pDCPD beyond what was previously possible. The new catalysts are compatible with:
•Composite fillers, including fibers (glass and carbon) and particles (glass bubbles and mineralfillers)
•Alternative processing techniques, including casting, infusion (RTM, VARTM), rotomolding, andpultrusion
•Property modulators, to provide enhanced elongation, Tg, toughness, and chemical resistance
This paper will outline recent advances in ring-opening metathesis polymer development, with a particular emphasis on high temperature materials (up to 450 °F) and composites for downhole applications.
Hot melt epoxy resin based Bulk Molding Compounds offer significant advantages to the molder due to their ambient temperature shelf life, lack of VOCs, high mechanical properties and ease of molding. However, despite the high modulus exhibited by these materials, they are limited by the strain to failure owing to shorter fiber lengths that typify BMC type materials. We examine the effect of fiber length as well as that of resin toughening mechanisms on the ultimate strain and thus stress at failure for Epoxy resin based BMCs.
The objective of the work was to demonstrate the feasibility of a novel bio-based epoxy resin system derived from hemp seed oil for use in fiber reinforced composites (in this case a full-scale snowboard). Hemp is a renewable resource that is being grown in multiple locations in the United States and Canada. The hemp crop is beneficial to farmers and is carbon sequestering, thus providing a positive environmental impact. The work focused on developing the synthetic pathway to make a bio-based epoxy from commercially available hemp seed oil. A novel bio-based epoxy was synthesized from hemp seed oil. A bio-based epoxy formulation was developed to meet the technical requirements for the ski and snowboard industry. The final epoxy formulation that had greater than 50% bio-epoxy content and was used to build actual snowboards in a full- scale manufacturing production facility. The bio-based epoxy snowboards passed industry accepted testing protocols. The paper will highlight the key aspects of the product development work, scale-up and the snowboard build.
As automobile engines become smaller and lighter, and passenger car interiors grow quieter, mitigation of engine NVH (noise, vibration and harshness) is a key concern for OEMs. “Rubberized” engine sprockets (crank, cam and timing sprockets) are a solution that OEMs are implementing in order to dampen chain noise and reduce the chain drive’s contribution to engine NVH. Minnesota Rubber & Plastics provides an over-molded sprocket (rubber-on-metal) solution that can survive the substantial durability and compatibility requirements of automotive engine components.
Pre-pregs are a well-known, high performance, composite material used in demanding applications. Traditionally converted via tape placement or hand layup and then cured in an oven or autoclave, pre-pregs have only found use in applications where mass production or part economics were not the overriding concern. This presentation will address the historical context of these materials and processes, advancements in pre-pregs that make them suitable for compression molding, case studies of how hybrid molding (or co-molding) can provide designers with even greater design flexibility, and conclude with a look at the state of current development work.