The choice of adhesive for the production of yarn glue method

It is proposed to use sericin, a component of silkworm cocoons, as an adhesive compound for the production of yarn by the adhesive method. An experiment was conducted to study the dependence of the adhesion forces of the binder to cellulose on the concentration of the adhesive substance on the example of solutions of PVA, PVA and sericin. A comparative analysis of this dependence is carried out. Mathematical models are constructed to predict the strength of the adhesive joint depending on the concentration of the adhesive composition. The calculation of the adhesion forces per one elementary fiber is carried out.

SIFAT FISIS DAN MEKANIS PAPAN KOMPOSIT DARI SERAT BATANG KELAPA SAWIT (Elaeis guineensis Jacq) DENGAN BERBAGAI KOMPOSISI PEREKAT PVAC

The purpose of this study was to determine the effect of PVAc adhesive composition on the physical and mechanical properties of the composite boards of palm oil stems and determine the best test example from a technical and economic point of view. This research will be carried out at the Banjarbaru Forestry Faculty Workshop. Research time ± 3. There are 3 levels (levels) of the PVAc adhesive composition tested, namely 40%, 45%, and 50%. The parameters of the composite board properties studied were physical properties, including: Moisture content and density, as well as the mechanical properties that fracture strength (MoR) and modulus of elasticity (MOE). The results showed that the physical and mechanical properties of composite boards were strongly influenced by the adhesive composition, the more the adhesive composition is used, the better the composite board properties, especially in terms of water content and MoR, where the results show that the water content is decreasing and the MoR is increasing. Nevertheless the use of a 40% adhesive composition has been able to produce a composite board that can meet SNI standards No. 03-2105 2006. Properties of palm oil stem waste composite boards made with PVAc adhesive (Crosslink X-PVAc) moisture content ranged from 9.49% - 13.07%, density 0.494 - 0.559 gr / cm³, and MoR 20.613 - 22.483 kg / cm².Tujuan penelitian untuk mengetahui pengaruh komposisi perekat PVAc terhadap sifat fisis dan mekanis papan komposit dari batang kelapa sawit dan menentukan contoh uji yang terbaik dari segi teknis. Penelitian ini dilaksanakan di Workshop Fakultas Kehutanan Banjarbaru. Waktu penelitian ±3. Ada 3 taraf (level) dari perlakuan komposisi perekat PVAc yang diuji cobakan, yaitu 40%, 45%, dan 50%. Adapun parameter sifat papan komposit yang diteliti adalah sifat fisis, meliputi: Kadar air dan kerapatan, serta sifat mekanisya itu keteguhan patah (MoR) dan keteguhan lentur (MOE). Hasil penelitian menunjukkan bahwa sifat fisis dan mekanis papan komposit sangat dipengaruhi oleh komposisi perekat, semakin bertambah komposisi perekat yang digunakan maka sifat papan komposit semakin baik, terutama ditinjau dari kadar air dan MoR, dimana hasil menunjukkan bahwa kadar air semakin berkurang dan MoR makin meningkat. Meskipun demikian penggunaan komposisi perekat 40% sudah dapat menghasilkan papan komposit yang dapat memenihi standar SNI no 03-2105 2006. Sifat papan komposit limbah batang kelapa sawit yang dibuat dengan perekat PVAc (Crosslink X-PVAc) kadar air berkisar 9,49% – 13,07%, Kerapatan 0,494 - 0.559 gr/cm³, dan MoR 20.613 – 22.483 kg/cm².

Histotopographic and morphometric characteristics of the oral mucosa postoperative wounds healing, depending on the method of connecting the wound edges

Implementation of high-quality tissue connections and hemostasis in oral surgery is an urgent problem of modern dentistry, due to the lack of available universal methods that would help to facilitate the work of oral surgeon and reduce wound healing time. The aim of the research. To investigate and study the regeneration processes in the oral mucosa after high-frequency electric welding, suturing and medical adhesive composition. Materials and methods. This study compared the effect of three connection methods and hemostasis: high-frequency electric welding (EKVZ-300M1 “PATONMED®”, Ukraine), suture method (nylon 5/0 “PIRUS®”, China), adhesive composition (“Histoacryl®”, Germany). 72 rabbits were involved in experiment. An incision of the soft tissues of the vestibulum of the oral cavity of the maxilla with a length of 1.3–1.5 cm was made. On days 3, 7, 14 and 21, tissue samples were excised, histological and morphometric examination of the material were performed. Results. By statistical data processing of 72 rabbits was found that the reliability of differences in the levels of morphometric parameters between groups on each day is very high, as evidenced by the calculated values ​​of the U-test. In 38 cases (90.5 %), the significance level was p≤0.01, in the other 4 cases – p≤0.05. The lowest value level of neutrophilic granulocytes was in rabbits of group No.1 (electric welding). In rabbits of group No. 1 GFBC were not observed in the 8 fields of view throughout the experiment. Conclusions. High-frequency electric welding of soft tissues can be used for effective intraoperative hemostasis and connection of the intraoral wound edges. Due to the absence of a foreign body (adhesive masses, filaments) and moderate alterative effect, histological examination indicates accelerated activation of regenerative processes in the early stages of observation in rabbits of group No. 1.

The Influence of Mixing Methods of Epoxy Composition Ingredients on Selected Mechanical Properties of Modified Epoxy Construction Materials

The proper process of preparing an adhesive composition has a significant impact on the degree of dispersion of the composition ingredients in the matrix, as well as on the degree of aeration of the resulting composition, which in turn directly affects the strength and functional properties of the obtained adhesive compositions. The paper presents the results of tensile strength tests and SEM microphotographs of the adhesive composition of Epidian 57 epoxy resin with Z-1 curing agent, which was modified using three fillers NanoBent ZR2 montmorillonite, CaCO3 calcium carbonate and CWZ-22 active carbon. For comparison purposes, samples made of unmodified composition were also tested. The compositions were prepared with the use of six mixing methods, with variable parameters such as type of mixer arm, deaeration and epoxy resin temperature. Then, three mixing speeds were applied: 460, 1170 and 2500 rpm. The analyses of the obtained results showed that the most effective tensile results were obtained in the case of mixing with the use of a dispersing disc mixer with preliminary heating of the epoxy resin to 50 °C and deaeration of the composition during mixing. The highest tensile strength of adhesive compositions was obtained at the highest mixing speed; however, the best repeatability of the results was observed at 1170 rpm mixing speed. Based on a comparison test of average values, it was observed that, in case of modified compositions, the values of average tensile strength obtained at mixing speeds at 1170 and 2500 rpm do not differ significantly with the assumed level of significance α = 0.05.

Evaluation of early healing of postoperative wounds oral mucosa depending on the method of hemostasis and connection of wound edges

Actuality. The final and obligatory stage of each surgical intervention in the oral cavity is the tight connection of the wound edges and ensuring quality hemostasis, in order to prevent postoperative complications and the fastest recovery of tissues. The literature describes various techniques for joining soft tissues, using suture material, staples, fabric adhesive compositions, but due to the emergence of new methods, it is important to compare them. Goal. Compare and evaluate the early stage of healing of postoperative wounds in the oral cavity after open alveolectomy and the use of three methods for hemostasis and connection of wound edges (high-frequency electric welding, suturing nylon 5/0 and N-butyl-2-cyanoacrylate medical adhesive composition). Materials and methods. The study involved 42 patients aged 56 to 83 years, who were in the stage of surgical preparation for prosthetics with removable dentures and required open alveolectomy. Patients with cognitive impairment, cancer, systemic disease, recent acute or long-term chronic cardiovascular and musculoskeletal disorders did not participate in the study. All patients who participated in the study were randomly divided into 3 groups according to the methods of hemostasis and connection of the wound edges. After performing an open alveolectomy, hemostasis and joining of the wound edges were performed. In group 1 (electric welding) consisting of 14 patients, hemostasis and connection of wound edges were performed by welding soft tissues with the device «EKVZ-300M1». In group 2 (suturing) consisting of 14 patients, hemostasis of the wound was performed by connecting its edges with suture material nylon 5/0. In group 3 (adhesive composition) consisting of 14 patients, hemostasis of the wound was performed by joining its edges with a synthetic N-butyl-2-cyanoacrylate medical adhesive composition. Assessment of pain in patients of each group was performed according to the visual-analog scale (VAS). Determination of postoperative wound healing was performed on the basis of the wound healing index according to Landry, Turnbull and Howley. The average time to achieve intra-wound hemostasis and connection of wound edges in each of the groups were determined. The average values of the length of the trapezoidal section in each of the groups were also determined. Results. The analysis of the obtained results showed statistically significant differences (p ≤ 0.05) on the first day in terms of pain sensitivity between groups 2 (sutures) and 3 (glue). On the third day on both indicators (pain and wound healing) between groups 2 and 3 there were no statistically significant differences (p > 0.05). Group 1 (electric welding) has no statistically significant differences in pain sensitivity for the first day with other groups (p > 0.05). Statistically significant differences (p ≤ 0.01) appear on the third day both in terms of pain sensitivity and in terms of wound healing. Conclusions. The method of high-frequency electric welding can be used for intra-wound hemostasis with almost simultaneous connection of the wound edges after open alveolectomy. We found that electric welding has better hemostatic properties, faster connection of wound edges, reduced surgical time, postoperative pain and better results of wound healing compared to suture and adhesive methods. The method of high-frequency electric welding can be an alternative to suture and adhesive methods of hemostasis and joining the edges of the wound oral mucosa after open surgery on the jaws. Key words: oral cavity, mucous membrane, high-frequency electric welding, nylon sutures, adhesive composition, hemostasis, connection, index assessment, oral surgery.

KARAKTERISTIK BALOK LAMINASI KAYU AKASIA (Acacia Mangium) DAN MERANTI MERAH (Shorea leprosula) BERDASARKAN SUSUNAN LAMINA DAN BERAT LABUR PEREKAT STYROFOAM

The potential for wood raw materials in Indonesia is very abundant, but the increasing need for processed wood as a building material makes it difficult to obtain sawn timber in large sizes and with quality, due to the increasingly limiting logging in natural forests. High quality wood is hard to find in the market, so it is necessary to combine low quality and high quality wood by engineering the product with an adhesive, one of which is glued laminated timber. This study aims to see the characteristics of the glued laminated timber of Acacia mangium and Shorea leprosula based on the arrangement of lamina and the weight of adhesive Styrofoam. The blocks used in this study were 120 cm x 5 cm x 3 cm in size with the adhesive composition used was 60% Styrofoam and 40% gasoline with an glue spread of 200, 220 and 240 gr / m2. Observations made to produce data that is, the moisture content obtained layer ranged from 4.14 to 8.86%, a density of 0.38 to 0.51 g / cm3, MOE and MOR ranged from 24.78 to 86.71 kg / cm2.

Sealing critical connections of the cylinder head with adhesives

The classification of adhesive compositions is considered. The requirements for adhesive compositions that provide a given joint strength are given. The design of the cylinder head and its components is described and the use of adhesive composition as a means of sealing is justified. The criteria for selecting the optimal adhesive connection are presented. A comparative analysis of adhesive compositions of different brands is presented.