& nbsp; & nbsp; Process guide for the application of silicone structural sealant
  & nbsp; & nbsp; 1、 Preparation for homework in the early stage
  & nbsp; & nbsp; 1. Compatibility and adhesion tests
  & nbsp; & nbsp; 2. The company will conduct compatibility tests in accordance with Appendix A of GB16776-1997 standard to recognize the compatibility of silicone structural adhesive with substrate and double-sided tape, and issue inspection statements and application claims.
  & nbsp; & nbsp; 6. Bonding width of silicone structural adhesive
  & nbsp; & nbsp; Wind load effect
  & nbsp; & nbsp; CS1=Wk· a/2f1
  & nbsp; & nbsp; Self weight effect
  & nbsp; & nbsp; CS2=Gk· a· b/(a+b) /f2
  & nbsp; & nbsp; Cs1—& mdash; Bonding width of silicone structural sealant required for wind load (mm)
  & nbsp; & nbsp; Cs2—& mdash; Adhesive width of silicone structural sealant required for self weight (mm)
  & nbsp; & nbsp; Wk—& mdash; Wind load standard (Kpa)
  & nbsp; & nbsp; Gk—& mdash; Unit area weight of glass (KN/m2)
  & nbsp; & nbsp; a—& mdash; Short edge length of glass (mm)
  & nbsp; & nbsp; b—& mdash; The length of the long side of the glass (mm)
  & nbsp; & nbsp; f1—& mdash; The allowable short-term strength of the adhesive is 140 Kpa
  & nbsp; & nbsp; f2—& mdash; The allowable value for the self weight strength of the adhesive is 7 Kpa.
  & nbsp; & nbsp; 2.2.2 Depth and bonding width of silicone structural adhesive
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; The minimum width of structural adhesive is 6 mm
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; The minimum depth of structural adhesive is 6 mm
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; The proportion of glue width and glue depth needs to be between 1:1 and 3:1
  & nbsp; & nbsp; 2.2.3 In addition to the above considerations, the planning of structural adhesive interfaces should also summarize and consider seismic effects, temperature differences, joint failures caused by irrigation or component equipment, and the displacement capacity of sealant based on specific circumstances.
  & nbsp; & nbsp; 2、 Basic Construction Requirements
  & nbsp; & nbsp; 1. Requirements for construction personnel
  & nbsp; & nbsp; The bonding of single components in glass curtain walls requires certain requirements for construction operators, who should meet the following conditions:
  & nbsp; & nbsp; 1. Have a high sense of responsibility and understand that the safety and reliability of glass curtain walls are closely related to construction quality.
  & nbsp; & nbsp; 2. Understand the construction process of structural sealant, proficiently grasp the construction operation technology and construction materials of structural sealant; Can understand the bonding and sealing parts and supporting materials in accordance with the rules of engineering drawings.
  & nbsp; & nbsp; 3. Master the basic knowledge of handling methods and technical safety after the failure of structural sealant bonding.
  & nbsp; & nbsp; 4. Requirements for construction technology environment and other conditions
  & nbsp; & nbsp; 5. It is necessary to use specialized materials (such as burnt cotton cloth and scraper, etc.) for the construction of silicone structural sealant. For two-component structural sealant, a dedicated mixing machine should be used for gluing.
  & nbsp; & nbsp; 6. The construction environment should be well lit, clean, and equipped with methods such as fire prevention, riot control, and dust prevention.
  & nbsp; & nbsp; 7. The construction environment temperature for single component structural sealant should be controlled between 10-40 ℃, and the relative humidity should be between 40% and 60%. The construction environment temperature for two-component silicone structural sealant should be controlled between 10-40 ℃.
  & nbsp; & nbsp; 8. Verify the production date, certificate of conformity, inspection statement, joint verification statement, and compatibility test statement of the structural adhesive one by one. The product should comply with the standards and curtain wall planning requirements& nbsp;& nbsp;
  & nbsp; & nbsp; 3、 Construction process procedure
  & nbsp; & nbsp; 1. Surface cleaning of substrate
  & nbsp; & nbsp; The cleaning of the surface of the adhesive material plays a decisive role in the quality of the project, therefore, strict surface cleaning is the key to ensuring project quality.
  & nbsp; & nbsp; 1.1 Cleaning materials:
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; For non oily dust, dirt, and frost, typically a 50% aqueous solution of isopropanol, isopropanol, and alcohol can be used
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; Regarding oily dirt and films, degreasing solvents such as toluene, xylene, or butanone are required
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; The compatibility statement issued by our company indicates the type of cleaning agent
  & nbsp; & nbsp; l & nbsp;& nbsp;& nbsp;& nbsp;& nbsp;& nbsp; The cleaning cloth should be a white, clean, soft, and burnt cotton cloth
  & nbsp; & nbsp; one.2 “ Double cloth wiping method& nbsp;
  & nbsp; & nbsp; 1）  Moisturize a clean cloth with the cleaning agent required in the compatibility statement to scrub the surface of the substrate. Scrubbing the adhered surface can only be done from one direction.
  & nbsp; & nbsp; 2）  Before the cleaning agent evaporates, immediately use a second monotonous and clean cloth to wipe off the cleaning agent on the surface of the adhered material, and do not allow the cleaning agent to dry on the substrate surface. The cloth block should be replaced on time to ensure that it does not cause a second pollution.
  & nbsp; & nbsp; 3）  The cleaning width should always be greater than the bonding and sealing construction width, generally about 1cm wide at each end.
  & nbsp; & nbsp; 4）  When cleaning deep and narrow areas, wrap a clean cloth around a suitable object and scrub according to the above procedure.
  & nbsp; & nbsp; 5）  The inspection of cleaning quality involves using a cloth moistened with a cleaning agent to scrub the adhered surface, ensuring that there is no contamination on the cloth.
  & nbsp; & nbsp; 6）  The cleaned surface should not be contaminated again by hand or any other method. The surface that is not coated with glue within one hour after cleaning should be cleaned from the beginning before applying glue before construction.
  & nbsp; & nbsp; 7）  After the white cloth is contaminated, it should be replaced in a timely manner, and when dipping the cleaning agent, the cleaning agent should be poured from the container onto the clean cloth instead of dipping the cloth into the container to prevent contamination of the cleaning agent. It is also not allowed to spray or brush the cleaning agent on the adhered surface, which may cause the cleaning agent to overflow on the adhered surface and cause the oil to dissolve and loosen into a larger plan.
  & nbsp; & nbsp; 8）  It is necessary to have excellent ventilation, fire prevention, and explosion prevention methods at the operation site, and to follow the technical safety regulations for the use of organic solvents.
  & nbsp; & nbsp; 1.3 Cleaning of porous material surfaces
  & nbsp; & nbsp; Porous stones such as granite or marble may not be effectively cleaned with solvents. Depending on the surface characteristics of porous materials, some require polishing and cleaning, some require solvent cleaning, and some have both. High pressure water flushing (or wire brushing with water flushing) is also a useful cleaning method. Porous materials will absorb solvents, primers, etc. during the cleaning process. Before applying glue, it is necessary to wait for them to completely evaporate.
  & nbsp; & nbsp; 2. Application of primer
  & nbsp; & nbsp; 2.1 Select the primer to be used based on compatibility and adhesion tests, and apply the primer after cleaning with the cleaning agent
  & nbsp; & nbsp; 2.2 Pour a satisfactory primer into a small container for immediate use (do not exceed 10 minutes of use), and tightly cover the container containing the remaining primer to prevent solvent evaporation or water absorption from degrading.
  & nbsp; & nbsp; 2.3 Use a hard bristled brush or a clean, lint free white cloth to apply a thin and uniform layer of primer on the surface to be adhered. Do not pour or apply too much primer. Excessive primer will form a powdery, chalky dust film on the substrate surface, causing the loss of adhesion between the adhesive and the primer (excessive primer can be removed with a clean, monotonous, and lint free cloth or non-metallic wire brush).
  & nbsp; & nbsp; 2.4 Apply primer only to surfaces that have been bonded, sealed, and glued within one hour. If there is a lot of dust, apply structural adhesive immediately after the primer dries (usually within 10-15 minutes).
  & nbsp; & nbsp; 2.5 The primer contains flammable solvents with transpiration properties, so it should be applied in a well ventilated environment with fire and explosion prevention methods.
  & nbsp; & nbsp; 2.6 If necessary, cover the edges of the adhered surface to prevent the primer from being applied to areas outside the adhered surface.
  & nbsp; & nbsp; 3. The injection procedure and product protection of structural adhesive.
  & nbsp; & nbsp; 3.1 Before gluing, cover the horizontal surface extending from the adhesive area with protective tape to prevent contamination of these areas during scraping.
  & nbsp; & nbsp; 3.2 Single component structural adhesive can be directly applied by manual or pneumatic glue gun, while two-component silicone structural sealant needs to be mixed using specialized gluing equipment according to the prescribed proportion, and the uniformity is checked using the butterfly test method (see butterfly test diagram), and recorded.
  & nbsp; & nbsp; 3.3 When using a pneumatic glue gun, the operating pressure should be adjusted to ensure satisfactory positive pressure to fill the entire sealant seam.
  & nbsp; & nbsp; 3.4 The caliber of the glue gun should be smaller than the thickness of the interface, so that the muzzle can be deepened by half the depth of the interface. The nozzle should move continuously, uniformly, and moderately to ensure that the interface is filled with structural adhesive. When injecting adhesive, it should be prevented from moving too quickly or reciprocating, which may cause bubbles or voids.
  & nbsp; & nbsp; After the 3.5 glue injection is completed, the excess structural glue outside the interface should be compressed into the interface with a scraper before forming a crust on the surface of the glue joint (usually 10-20 minutes), so that the structural glue contacts the side of the interface to reduce internal bubbles and voids, and ensure the contact between the structural glue and the adhered surface. After all, the interface surface should be scraped flat in the same direction.
  & nbsp; & nbsp; Do not use liquid auxiliary materials such as water, soapy water, alcohol, and other organic solvents to help scrape the sealant, as these materials will prevent the curing and bonding of the sealant and cause apparent problems.
  & nbsp; & nbsp; 3.7 After finishing the repair, remove the protective tape before the sealant forms a crust (approximately 15 minutes after scraping). And immediately mark the date and number on the unit panel glass or aluminum frame, and place it horizontally for protection.
  & nbsp; & nbsp; 3.8 Moving time again: Under standard conditions, single component protection is 7 days, and two-component protection is 12 hours.
  & nbsp; & nbsp; three9. Complete curing time: Under standard conditions, single component protection is 14 days, and two-component protection is 7 days.
  & nbsp; & nbsp; 4. Construction of updating and repairing projects
  & nbsp; & nbsp; During and after the construction process, there may be situations where repairs or equipment needs to be started from scratch, such as repairing single components in adhesive cutting tests, damage to glass surfaces caused by various situations, and failure of curtain wall systems such as adhesive failure or water leakage. The following procedures are generally implemented:
  & nbsp; & nbsp; 1）  Carefully record the date and specific situation and direction of the failure. For larger planning issues, it is necessary to contact our company and the planning and construction unit as soon as possible. Based on the specific situation, the entire system or part should be reviewed from scratch. Before receiving notification from relevant departments to continue construction, the next step of operation should be stopped.
  & nbsp; & nbsp; 2）  Perform adhesive cutting to leave a thin layer (approximately 0.5-1mm) on the surface of the material.
  & nbsp; & nbsp; 3）  Clean according to the two cloth cleaning method (for construction immediately after cutting off the glue, surface cleaning can be omitted).
  & nbsp; & nbsp; 4）  No need to use a primer, the new adhesive can achieve excellent bonding with the old adhesive.
  & nbsp; & nbsp; 5）  During the cleaning process, silicone may absorb some solvents, so it is necessary to allow the solvents to completely evaporate before applying new glue.
  & nbsp; & nbsp; 6）  Place the clean substrate in the correct position, temporarily fix the fixture of the equipment, and apply hidden tape around the interface.
  & nbsp; & nbsp; 7）  Inject fresh structural adhesive according to the prescribed construction steps, wait for the adhesive to fully solidify, check the bonding strength, and remove temporary fixtures& nbsp;
  & nbsp; & nbsp; 4、 Quality Management
  & nbsp; & nbsp; To ensure the quality of the project, the entire application process of silicone structural sealant should be excellently controlled
  & nbsp; & nbsp; 1. Pre construction inspection
  & nbsp; & nbsp; Firstly, check whether the product's manufacturing date, shelf life, outer packaging, product certificate of conformity, and user manual are complete. Check whether the quantity, specifications, and models of the products on the purchase invoice are correct to ensure the quality and quantity of production.
  & nbsp; & nbsp; 1.2 Single component silicone structural sealant; Crushing time/elasticity test
  & nbsp; & nbsp; Each batch of single component silicone structural sealant should undergo surface drying time and elasticity testing. The purpose of inspection is to check the leveling time of the sealant and ensure that the sealant can fully cure. The method is as follows:
  & nbsp; & nbsp; 1. & nbsp;& nbsp;& nbsp; Apply approximately 1mm of sealant onto the PE film, and lightly touch the surface of the sealant with a glass rod every 10 minutes.
  & nbsp; & nbsp; 2. & nbsp;& nbsp;& nbsp; The time when there is no adhesive on the glass rod is called the surface skinning time, which records the time required to reach that point& nbsp; & nbsp; & nbsp;
  & nbsp; & nbsp; 1.3 Two component silicone structural sealant; Butterfly test/tensile test
  & nbsp; & nbsp; Butterfly test and tensile test should be conducted on each batch of products and before each start-up, with the purpose of checking whether the main agent and catalyst are mixed evenly, the shelf life of the sealant, and ensuring that the sealant can be completely cured. The experimental method is as follows:
  & nbsp; & nbsp; one point three1 Butterfly Test
  & nbsp; & nbsp; 1）  Apply at least 5cm of JH-399 sealant to the center of a blank sheet of paper.
  & nbsp; & nbsp; 2）  Fold the white paper and knead the glue on it into a thin film.
  & nbsp; & nbsp; 3）  Open the white paper and visually inspect the adhesive surface. If mixed correctly, there will be no white gray stripes. If not mixed evenly, there will be white gray zebra stripes. If white gray zebra stripes appear, the adhesive should be applied& nbsp; & nbsp; The machine continues to operate and dispense glue until no white zebra stripes appear and stops.
  & nbsp; & nbsp; 4）  If white or gray stripes continue to appear, the glue machine should be checked by cleaning or replacing the mixing system or hose of the glue machine, the glue gun, or adjusting the proportioning valve to handle it. Please contact the glue machine manufacturer.
  & nbsp; & nbsp; Introduction to silicone structural sealant
  & nbsp; & nbsp; Silicone structural sealant is a single component, neutral curing adhesive specifically designed for bonding glass structures in building curtain walls. It can be easily extruded and used under a wide range of temperature conditions. Based on the moisture in the air, it solidifies into excellent, durable silicone rubber with high modulus and elasticity. The product does not require a primer for glass and can achieve excellent adhesion.
  & nbsp; & nbsp; Structural adhesive refers to high strength (compressive strength>65MPa, steel steel tensile bonding strength>30MPa, shear strength>18MPa), able to withstand large loads, and resistant to aging, fatigue, and corrosion. It is stable in use within the expected lifespan and is suitable for bonding strong structural components. Non structural adhesives have low strength and poor durability, and can only be used for general and temporary bonding, sealing, and fixation. They cannot be used for bonding structural components.
  & nbsp; & nbsp; The service life of construction projects is generally over 50 years, and the components are subjected to significant stress, which directly affects the lives of personnel and industrial safety. Therefore, structural adhesives should be selected as the adhesive type. Structural adhesive is widely used in engineering, primarily for the reinforcement, anchoring, bonding, and repair of components; Such as bonding steel, bonding carbon fiber, planting reinforcement, crack reinforcement, sealing, hole repair, road nail bonding, surface protection, concrete bonding, etc.