Sealant Systems Research Articles

Red Coast Industries acquires UK sealant company

Private equity firm Red Coast Industries – which was spun off in 2022 by Banvest, a family run investment group based in Dubai, United Arab Emirates – has acquired the UK's Premier Sealant Systems Ltd in a deal backed by specialist financial services company Shawbrook.

Technology Focus: Cementing and Zonal Isolation (May 2023)

In 2022, the topics of the cementing and zonal isolation papers published were generally similar to those presented in previous years. A noticeable departure from previous years, however, was that many of the authors emphasized that their work would result in a reduction of greenhouse-gas emissions. The approaches taken to reduce emissions can be broadly split into three categories: improving operational efficiency, increasing the reliability of zonal isolation (primary cementing, annulus leak repair, and plug sealing), and reducing the CO2 footprint of sealing materials. Work to improve operational efficiency and increase the reliability of zonal isolation has been ongoing since the start of well construction as general good practice to improve safety and hydrocarbon recovery and reduce costs. The efficiency and reliability improvements, however, have not regularly been promoted as reducing the environmental impact, except for cases of leak repair. Reduction of the CO2 footprint of sealing materials is a growing source of research and development activity and subsequent publication. During the past year, 13% of the cementing and zonal isolation papers published covered work on the development of geopolymer systems. Although work to develop geopolymer systems for zonal isolation has been ongoing for more than 15 years, no case histories have been published to date. The long development time is not surprising because any new system will have to be at least as reliable as the current Portland-cement-based systems; otherwise, the overall environmental impact may be worse, with more repairs or less-efficient processes offsetting the reduced CO2 footprint of the sealant. Geopolymers are not the only option to replace Portland-cement-based systems for primary cementing, and the evaluation of alternate sealant systems is certainly not new (see paper SPE-508-G from 1956). Is it time to revisit previous work in light of new environmental constraints? Recommended additional reading at OnePetro: www.onepetro.org. IPTC 22019 Enhancing Slurry Pumping Efficiency, Improving Cement Coverage, and Ensuring Zonal Isolation With Temperature-Triggered Antisettling Technology by Xiangyu Liu, ChampionX, et al. SPE 210639 Thermodynamic Modeling on Wellbore Cement Integrity During Underground Hydrogen Storage in Depleted Gas Reservoirs by Lingping Zeng, Curtin University, et al. OTC 31562 Cementing the First Australian Offshore Carbon Capture and Storage Appraisal Well by Ariel Lyons, SLB, et al.

An injectable hemostatic PEG-based hydrogel with on-demand dissolution features for emergency care

Uncontrolled bleeding from internal noncompressible wounds is a major cause of prehospital death in military personnel and civilian populations. An ideal hemostatic sealant for emergency care should quickly control blood loss and be removed without debridement for the follow-up treatment in the operating room, yet the lack of suitable materials to meet both requirements is the bottleneck. Herein, we suggest an injectable and dissolvable hydrogel sealant for hemorrhage management of noncompressible wounds. To this end, a 4-arm poly(ethylene glycol) (PEG) crosslinker modified with thioester linkages and terminated with aldehyde groups is designed and synthesized, and to modulate the gel properties and make it suitable as a hemostatic sealant, a mixed amino component composed of poly(ethylene imine) and adipic dihydrazide is employed to react with the PEG crosslinker to form the adhesive and elastic sealant for the first time. The aldehyde groups provide the adhesion to the tissues, and the amino component affords the procoagulant ability. More importantly, the thioester moieties allow the on-demand dissolution of sealant via a thiol-thioester exchange reaction upon exposure to an exogenous thiolate solution. In the rat femoral artery puncture and liver injury models, the administration of the hydrogel sealant dramatically reduces blood loss, and its subsequent removal does not induce rebleeding. Consequently, this hydrogel sealant with the unique feature of on-demand dissolution can not only efficiently control bleeding in emergent scenarios, but also allow non-traumatic re-exposure of wounds during subsequent surgical care. Statement of significanceSealants, adhesives or hemostatic dressings currently used in emergency situations not only require manual pressure to control bleeding, but also face removal by cutting and mechanical debridement to enable eventual surgical treatment. In this study, we design and develop an injectable and adhesive hydrogel sealant with good procoagulant capacity and on-demand dissolution feature. The application of the hydrogel sealant substantially reduces bleeding from internal noncompressible wounds without the need for direct pressure, and demonstrates for the first time that its controlled removal without debridement does not cause rebleeding. Considering that there are currently no commercial wound sealant systems with the feature of on-demand dissolution, the hydrogel sealant developed by us is expected to address an unmet clinical need.

Sealing ability of different obturating techniques in apically separated rotary files: An In Vitro study

Aim:Testing whether two sealant systems (cold laterally compacted gutta-percha and Obtura II) can be used with extraction across two apically separated rotational nickel-titanium files was the primary objective of this study (RACE and K3).Materials and Methods:Both the positive and negative control teeth were randomly distributed among 62 mandibular premolars to create two groups of 30 each. Following the RACE and K3 approaches, four subgroups were created from the roots. Subgroups A1, B1, and A2, B2 (n = 10 each) were formed in the apical thirds of the canal at 3 mm from the tip. There was no division of instruments between groups A3, B3, B4, and A4. When it came to obturation, the Obtura II method was used for A2, A4, B2, B4, and A1, A3. A dye extraction process was employed to determine whether the specimens had been obliterated. Analysis of variance (ANOVA), Student t test (two-tailed, independent), and Leven's test were used to ascertain the values for each of the study groups.Results:Group A1 had a substantially lower leakage rate than group B1. Groups A2, B2 and A3, B3 had no statistically significant differences. Group A4 had a substantially lower leakage rate than group B4.Conclusion:Even when the cracked NiTi rotary system was not present, Obtura II-obturated groups had less leakage than the lateral condensation approach.

Quantifying Performance of Permeation Barrier—Encapsulation Systems for Flexible and Glass‐Based Electronics and Their Application to Perovskite Solar Cells

AbstractEffective transparent barrier/encapsulation systems represent a key enabling technology for large‐area electronics. Securing stability to the environment is vital. Here, the effects of architectures, application processes, and water vapor transmission rates (WVTR) of transparent flexible ultra‐high permeation barrier films (UHPBF) applied to substrates with adhesive resins are unraveled for attaining long lifetime, and compared with polyethylene terephthalate and glass barriers. How strongly performance of barrier/adhesive systems depends on barrier orientation, adhesion, manipulation, defects, and storage procedures is quantified via calcium tests. Furthermore, it is found that introducing an additional adhesion‐promoting layer on the standard UHPBF stack reduces WVTRs by a factor of 5 compared to barriers without it. Finally, barriers are used for sealing and encapsulation of perovskite solar cells (PSCs) enabling the extraction of a relationship between WVTRs of barrier/adhesive systems and degradation rates (DR) of PSCs. DR fall exponentially when WVTRs decrease from 101 to 10−3 g m−2 d−1. Outside that range any gains or losses are mitigated by tailing of the sigmoid curve relating the two parameters. Results highlight important factors which will help those developing strategies relating to encapsulation, barrier, adhesive and sealant systems and stable optoelectronic devices on glass and flexible substrates.

Comparative Evaluation of the Effect of Surface Polishing of a Glaze/composite Sealant and Different Polishing Systems on Surface Roughness of Three Composite Resin Type

The aim of the study was to evaluate the influence of different techniques of finishing and polishing as well as the use of sealants on the surface condition of some composite resins used in the dental office. 80 specimens of composite materials (Nanoceramic, Nanocomposit and Nanohybrid) were made and divided into 3 groups G1-coated composite with sealant lacquer, G2 - finished in 2 stages, and G3 - finished in 3 stages. Roughness (Ra) was determined with the Taylor Hobson Form Talysurf Profiometer. The data was analyzed using one-way ANOVA followed by a multiple comparison t test. Significant differences were found between the groups in terms roughness (p [ 0.001). The results showed that Seal - and - Shine (PULPDENT) was capable of reducing surface roughness and provided polished surfaces for all materials.

Adhesive and self-healing soft gel based on metal-coordinated imidazole-containing polyaspartamide

A supramolecular gel formed by coordination of Ni(II) with poly(2-hydroxyethyl-co-1-(3-imidazolyl)propyl aspartamide) (PHEA-API) is reported. Novel polyaspartamide copolymers, PHEA-API, were prepared from polysuccinimide, which is the thermal polycondensation product of aspartic acid, via a successive ring-opening reaction using 1-(3-aminopropyl imidazole) (API) and ethanolamine (EA). Ni(II)-mediated gels, cross-linked by metal–ligand coordination, showed self-healing viscoelastic behavior in rheological analysis, which was also well reflected in high bulk adhesion strength on various different substrates. The approach described here results in a promising self-healing adhesive hydrogel with potential for a variety of industrial and biomedical applications including tissue adhesive, sealant, and smart drug delivery systems.

Strength Development and Carbonation Characteristics of Slag Cement/Class C Fly Ash blended CO2Injection Well Sealant

CO2 injection well sealant is vulnerable to supercritical CO2 (scCO2) exposure. To develop an alternative to the conventional sealant system (class G cement/class F fly ash), the performance of slag cement (SPC) systems containing class F fly ash (FFA) or class C fly ash (CFA) was evaluated and compared with the conventional sealant under scCO2 conditions. All sealant systems showed an immediate increase in compressive strength upon scCO2 exposure and, at 37.6 MPa, SPC/CFA showed the highest compressive strength after 14 days, which was much higher than the 29.8 MPa of the conventional sealant system. Substantial decreases in porosity were observed in all sealant systems, which were partly responsible for the increase in strength. Carbonation reactions led to pH decreases in the tested sealants from 12.5 to 10~11.6. In particular, the greatest decrease in pH in slag cement/class C fly ash probably supported relatively sustainable alkali activation reactions and the integrity of cement hydrates in this system. XRD revealed the presence of CaCO3 and a decrease in the content of cement hydrates in the tested sealants upon scCO2 exposure. TGA demonstrated a greater increase of CaCO3 and calcium-silicate-hydrate phases in SPC/CFA than in the conventional sealant upon scCO2 exposure.

Sealing dispensing requirements to meet MEMS packaging and throughput impact

The MEMS industry has gained big momentum recently with significant unit growth, especially in the consumer market. While traditional MEMS devices like automotive accelerators have established high-volume manufacturing processes and packages with high reliability, most MEMS devices have been fragmented in packaging because of their unique requirements and small volumes, resulting in high packaging costs. In the cost-sensitive consumer market, devices such as MEMS microphones, accelerometers, and gyroscopes in mobile devices have rapidly increased their production volume and chased lower packaging cost while accepting relatively less reliability than traditional devices. Sealing dispensing can be applied to device or cap wafer for wafer capping process. Wafer capping protects active MEMS from dicing process after release because the additional cavity wafer with sealing covers the MEMS structure. There are manufacturing challenges because wafer capping requires precise alignment and a variety of bonding methods have technical drawbacks. Printing is one way to deposit sealing lines to cap wafers, but consumes a relatively wide area and may not work if the sealing line must go onto the MEMS die wafer. Sealing line can also be applied to organic substrate that contains MEMS device and ASIC and then lid is attached for bonding in cavity packages. Previous paper covered technical requirements for dispensing sealant, volumetric accuracy, and motion systems to meet packaging trends and addressed manufacturing cost reductions. This paper will include investigating the impact on the throughput model due to size reduction efforts in packaging. More dies can be produced per given wafer size, which means there is more dispensing area per wafer. In addition, sealing line requirements will be more challenging, and so this paper will address these demands.

Estimating the Stresses in Linear Viscoelastic Sealants Subjected to Thermally-Driven Deformations

A framework for linear viscoelastic analysis of sealants is presented for analyzing stresses resulting from thermally driven deformations. Assuming that the strains induced within the sealant are proportional to the change in temperature from the strain-free state, the nominal stress state within the sealant can be estimated. The analysis method is used to estimate the stress states resulting from assumed diurnal temperature profiles for two representative Dow Corning silicone glazing sealants: a conventional elastomer and a crosslinked hot melt adhesive containing a high volume fraction of a silicate-based nanoparticle filler. The latter exhibits considerably more rate- and temperature-dependence than conventional silicones. The viscoelastic analysis allows for comparisons of stresses resulting in these two sealant systems, which are presented for several sinusoidal thermal profiles. However, the pronounced yielding behavior exhibited by the hot melt appears to limit the stress buildup, resulting in stress states that are significantly below those predicted using the linear viscoelastic model. Estimates of the yielding envelope for a representative thermal cycle profile are provided, based on experimental results reported elsewhere for the time and rate dependent yielding of the hot melt.

Thermal Sealants Improve Cementing in SAGD Areas

Abstract With the high demand for oil and gas, operators are becoming increasingly interested in unconventional sources of hydrocarbon. One of the major sources in the world is heavy oil, which has been defined by the API as oil that has API gravity of less than 22.3 °API at 15.6 °C (60 °F) (extra heavy oil, or bitumen, has 10 °API or less). Because heavy oil does not flow on its own in the wellbore, a mechanism must be used to recover the oil by making it mobile. Among the different experimental and operational methods, steam-assisted gravity drainage (SAGD) has been the method of choice for the past few decades. This process uses steam to heat the immobile oil and reduce its viscosity so it can be extracted, usually by using pump jacks. These heavy oil wellbores need to be zonally isolated to help ensure that the reserves are produced properly without environmental or production optimization challenges. In Alberta and Saskatchewan, many wells are drilled and cemented in designated heavy oil fields where SAGD is applied to stimulate production. Most of these wells are successfully cemented, however, some wells experience zonal isolation failures that result in steam breakout or steam loss into non-targeted zones. While the problem may be related to the primary cement job, it may also have been created by post-cementing operations and/or conditions. Sometimes the problem may be temporarily solved by conventional methods, however, the ultimate remedy may have to be applied eventually. The long-term integrity of the cement sheath behind the casing should be planned with drilling, completion, production/injection and abandonment stages considered. A properly designed and engineered cement slurry system can help save a wellbore/field from additional unplanned expenses. The process is shown below:Cement slurries are designed under defined wellbore conditions and exposed to field conditions in the laboratory.The mechanical behaviour of the cement sheath under downhole conditions is studied using three-dimensional, finite element analysis software.The endurance of the cement sheath under applied conditions is predicted and optimized.Operation and placement of the selected slurry is studied to help ensure optimum execution. Stresses exerted on the cement sheath from wellbore operations during construction, injection or production that could damage the cement sheath are integral to the study. These conditions are analyzed to help engineers understand the post-cementing operational effects on the sealant system. This paper presents the design criteria for finding the fit-for-purpose sealant systems that can successfully protect wellbores under harsh environmental conditions of SAGD and cyclic steam stimulation (CSS) operations. Introduction The long-term integrity of a cement sheath throughout a well's life is the ultimate factor for determining whether the sealant will withstand the planned operations, production and injection that are planned for the well. In the case of heavy oil operations, the primary design considerations for a long-lasting sealant are the temperature and pressure regimes. The stresses caused by the extreme changes are exerted on casing, cement and the rock.

Evaluation of Shear Bond Strength and SEM Observation of All-in-one Self-etching Primer Used for Bonding of Fissure Sealants

To evaluate and compare enamel shear bond strength of an all-in-one self-etching primer (Prompt L-Pop) to regular acid etch material when bonded to two-fissure sealant systems (Concise and Dyract Seal). Forty newly extracted non-carious first permanent molars were embedded in a Teflon mold. The teeth were divided into four groups and each consisted of ten specimens. The bonding surfaces were treated with either Prompt L-Pop as recommended by the manufacturer or etched with phosphoric acid. After 24 hours of water storage, the specimens were evaluated for shear bond strength using an Instron testing machine. Scanning electron microscope (SEM) examinations were carried out to evaluate the failure sites of the sealants. The mean shear bond strengths using Prompt L-Pop were Concise: 23.46 MPa and Dyract Seal: 20.34 MPa. These values were higher than and statistically different from those of Dyract Seal (9.99 MPa) and Concise (8.85 MPa) when phosphoric acid was used. The failure was predominantly of the adhesive type. The SEM examination showed the failure of debonding was predominantly related to the type of etching systems used rather than the type of fissure sealants. The use of the all-in-one self-etching adhesive Prompt L-Pop improves the mean enamel shear bond strength of fissure sealants.

Adhesive and Cohesive Strength in Polyisoprene/Polychloroprene Blends

Abstract This study concerns the use of polymer blends to produce advanced high performance adhesive systems based on material economics as well as to gain knowledge about the thermodynamics of multi-component adhesive systems. In the adhesive industry, blends of natural rubber (polyisoprene) and polychloroprene are used not only to lower cost, but also to provide certain properties, which are not obtainable with either elastomer alone. This paper investigates the contribution of each elastomer in the blend to the cohesive and adhesive strength and durability of the system. Composites of synthetic cis-1,4-polyisoprene with different types of polychloroprene with modified structures have been prepared by mill compounding. Infrared spectra obtained for these composites when coated on metallic surface have been extremely useful in the elucidation of the molecular orientation and conformational changes associated with these polymers. Each sample has been laminated between metallic substrates and for each lamination; the lap shear has been measured. The measured lap shears have been correlated with the structural changes associated with polymer—polymer interactions, detected by reflection infrared spectroscopy. These results could have a significant bearing on the mechanism of the strength development in rubber blends for use in adhesive and sealant systems.

Experimental results obtained with proposed RILEM durability test method for curtain wall sealants

Over the past six year, RILEM TC 139-DBS has been developing a RILEM Technical Recommendation (RTR) for a durability test method for curtain wall joint sealants. As the committee started to converge towards the final test method, the importance of evaluating the behaviour of a set of sealants under comparative conditions became apparent in order to validate the proposed durability test method. This paper provides a summary of the results obtained with the procedure described in the April 1999 draft. The study shows that the test method is able to differentiate between products with regard to their resistance to accelerated ageing and mechanical cycling. The type of failure and the changes in surface appearance obseved during the test regime are similar to those observed in actual service conditions. Sealant degradation resulting from the durability cycles was slower than had been anticipated for most sealant systems. The dynamic conditioning procedure (movement during cure) reduced joint durability for some of the tested products, but increased it for others. The fatigue cycling clearly accelerated sealant degradation.

Lendrum (-MSB) Staining for Fibrin Identification in Sealed Skin Grafts

The significance and effect of fibrin sealant systems for woundhealing are still unknown, because of the use of insufficient, conventional staining methods for the demonstration of the fibrin components used by sealant systems. From 21 patients with extensive burns of 2nd and 3rd degree biopsies of the skin were obtained during consecutive operations to cover the defect of the skin with split-thickness skin grafting. In the present paper morphological results concerning the demonstration of fibrin components and morphological differences in woundhealing of sealed and unsealed skin grafts are presented using Lendrum (-MSB) staining. With this staining method it is possible to identify exogenous fibrin components of the sealant system and to differentiate between fresh and older fibrin components, due to colour changes depending on time.

Occlusal sealants: an overview of clinical studies.

Sealant application is a technic in which a rapid transfer of technology occurred from the research community, abetted by industry, to individual practitioners and public health personnel. Less than five years after publication of the results of the first clinical trial, sealant systems were commercially available. Since the first published report of the effectiveness of sealants in inhibiting occlusal caries, many other investigators have substantiated the dramatic caries-inhibiting potential and degree of retention that can be obtained with sealants. Despite the high degree of success and the universality of positive reports, there is a significant lag in the utilization of sealants both by dental practitioners and public health programs. One reason appears to be the perception that sealants are not cost-effective. This is a concept that the dental research community may have unwittingly fostered by conducting cost analyses on a technic that was still in its initial stages of development. It behooves the dental profession, both the public and private sectors, to accord sealants recognition for their proven effectiveness and retentive characteristics. At the same time, the dental profession should suspend judgment on their costs until reports of studies conducted specifically for this purpose appear.

Segmental Concrete Liner for Soft Ground Tunnels

Concrete is presented as a low-cost material for use as a sole tunnel liner material in future mass transit tunnel projects. Existing mass transit tunnels throughout the world which have used concrete liners are presented. A systems summary is given which outlines numerous factors that must be considered for implementation of concrete as a sole tunnel liner material. Various concretes and liner sealant systems are presented as well as past and current research efforts directed toward greater use of concrete in future transit tunnel projects. Many aspects for consideration in a sealant system test verification program are also presented.

The performance of ultraviolet lights used to polymerize fissure sealants

The performances of ultraviolet (uv) lights used to initiate polymerization in fissure sealant systems were studied with a view to establishing recommendations for improving clinical results. The relationship between the setting time of an uv polymerized sealant (Nuva-seal) and the intensity of radiation applied was first established. This was compared with the intensity and distribution of radiation from seven Nuva-lites and one Quartzlite. It was found that some of the Nuva-lites did not produce an average intensity of uv radiation sufficient to completely polymerize Nuva-seal within the manufacturer's recommended exposure times. It is suggested that this may be a factor contributing to the large variation in sealant retention found in the different clinical trials with Nuva-seal. Finally, a number of recommendations are made to ensure that sufficient uv radiation is applied to all sealant surfaces when the Nuva-seal system is used.