Application Description
A supporting role - Special adhesives for load-bearing glulam
Manufacturers of wood elements for load-bearing construction purposes face great challenges. On the one hand, the production process is subject to special standards, and on the other hand the used adhesives have to be approved for building purposes and certified. In addition, each individual application, whether fingerjointing or laminating, has a unique set of requirements. Jowat supplies a product portfolio with one-component, moisture-curing polyurethane prepolymer adhesives which are adapted specifically to the different applications and products – from glued laminated timber (GLT) to cross laminated timber (CLT), and from solid structural timber to I-Joist formwork beams. The performance of these adhesives from the Jowapur® series has been extensively verified in complex procedures before release. Due to their specific composition, characteristics and processing parameters, these adhesives meet the demands of the different applications in the manufacture of load-bearing glulam. For instance, several special adhesives from the Jowapur® series are particularly suitable for fast and flexible production processes due to their short processing time. Other products provide a long assembly time and therefore facilitate the manufacture of big parts and large batches.
Polyurethane adhesives provide several advantages for the manufacture of load-bearing wood parts and a superior product quality compared to other systems such as condensation resins. They are completely free of formaldehyde and can be applied in a much lower grammage due to a solids content of 100 %. In addition, prepolymers cure within a few minutes at room temperature and provide an invisible bondline due to their colorless appearance.
Jowapur® adhesives are processed as a single component. Mixing, pot life and adhesive remnants from too much prepared adhesive become obsolete. The minimal foaming prevents the lamellas from sticking together when they are stacked on top of or next to each other and significantly reduces the cleaning effort. PUR prepolymers are reinforced with fibers which prevent fingerjoints from sliding apart after pressing during production and curing time. Due to their low tendency to run off, they are ideal for contactless application systems. Jowat provides special adhesives for every application in the manufacture of load-bearing glulam and for all established application technologies.
Product Information
Get more information one our new certified portfolio for fingerjointing and laminating
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| Base | Viscosity [mPas] / Temperature [°C] | Max. Assembly Time [min] / Temperature [°C] | Application | Certificate |
Download technical data sheet (PDF) | |
|---|---|---|---|---|---|---|
| Jowapur® 686.20 | 1-Component PUR Prepolymer | 10500 / 20 | 10 / 20 | Manufacturing bonded load-bearing timber structures (Fingerjointing) | Adhesive Type: EN 15425–I–70–FJ–0.1–w | de en fr |
| Jowapur® 686.30 | 1-Component PUR Prepolymer | 10500 / 20 | 15 / 20 | Manufacturing bonded load-bearing timber structures | Adhesive Type: EN 15425–I–70–GP–0.3–w | de en fr |
| Jowapur® 686.60 | 1-Component PUR Prepolymer | 10500 / 20 | 45 / 20 | Manufacturing bonded load-bearing timber structures | Adhesive Type: EN 15425–I–70–GP–0.3–w | de en fr |
| Jowapur® 681.10 | 1-Component PUR Prepolymer | 15500 ± 2500 / 20 | 10 / 20 | Manufacturing bonded load-bearing timber structures | Adhesive type: EN 15425–I–70–GP–0.3–w | de en fr |
| Jowapur® 681.60 | 1-Component PUR Prepolymer | 15500 ± 2500 / 20 | 60 / 20 | Manufacturing bonded load-bearing timber structures | Adhesive type: EN 15425–I–70–GP–0.3–w | de en fr |
| Jowapur® 681.40 | 1-Component PUR Prepolymer | 15500 ± 2500 / 20 | 40 / 20 | Manufacturing bonded load-bearing timber structures | Adhesive Type: EN 15425–I–70–GP–0.3–w | de en fr |
The products listed only represent a limited selection of the available product portfolio. Product availability might differ by region. The technical data, characteristics and field of application provided in the table outline the differences between the individual adhesives of the product portfolio. Our Application Technology Department and our Sales Representatives are on hand to provide advice and support you finding the best adhesive for your particular application.
Note: The information on this page is based on test results from our laboratories as well as on experience gained in the field, and does in no way constitute any guarantee of properties. Due to the wide range of different applications, substrates, and processing methods beyond our control, no liability may be derived from these indications nor from the information provided by our free technical advisory service. Customer trials under everyday conditions, testing for suitability at normal processing conditions, and appropriate fit-for-purpose testing are necessary. For the specifications as well as further information, please refer to the latest technical data sheets.
News & Articles
High-performance gluing - Certified PUR adhesives for load-bearing glulam
The importance of load-bearing glulam in construction has been growing constantly over the years. Its use in new buildings is increasing and structures based on load-bearing glulam have become bigger and more sophisticated. At the same time, it provides possibilities for architectural creativity and aesthetics that are often unmatched. The adhesives specialist Jowat from Detmold is supporting this sustainable trend with an expertise based on many years of experience, with optimum service and with certified high-performance adhesives.
One family for all cases
The one-component PUR prepolymer adhesives of the Jowapur® 681.xx product family are certified according to EN 15425:2017 and are tailor-made to optimally meet the requirements for load-bearing glulam. They can be used in fingerjointing as well as in CLT/laminating applications, provide a choice of assembly times between 10 and 60 minutes, and facilitate an assembly time-pressing time ratio of up to 1:1. Industrial processors can therefore choose the adhesive that best fits their parameters to optimise their specific process and to either increase capacity or improve process reliability by only changing the adhesive and without the need for major investments.
PUR – Full of benefits
Compared to other technologies, PUR prepolymer adhesives for the manufacture of load-bearing timber parts provide several advantages in the manufacturing process as well as for the end product. They do not contain any formaldehyde or solvents, are free of emissions and completely odourless when fully cured, and require considerably lower application amounts due to a solids content of 100 %. Depending on the formulation, these adhesives can cure in a short period of time at room temperature already and facilitate almost invisible gluelines due to their colourless appearance. In addition, Jowapur® adhesives are processed as single components. Therefore, no mixing is necessary, pot lives become obsolete, and remnants from production are prevented.
A major secret behind the superior performance of the Jowapur® 681.xx product family are specially developed reinforcement fibres which are added to the adhesive in a specific procedure. Those fibres increase the strength of the glueline and help prevent the joined parts from sliding apart during production and curing. In addition, they lower the amount og foaming during the curing process and thereby considerably reduce the soiling of machines and equipment and help prevent the sticking together of parts that have been stacked or stored next to each other. The improved spread characteristics of these adhesives makes them an optimal choice for contactless applicator systems in fingerjointing units.
Sustainable construction
Jowat is confident that the importance of load-bearing glulam in construction will only continue to increase in coming years – partly due to global sustainability strategies. That development is to be supported with optimised high-performance adhesives. “Building with wood brings only benefits,” underscores Ralph Kirst from Business Development Load-bearing Glulam at Jowat SE. “And adhesive bonding is a future-oriented joining method that minimises construction costs and time in timber construction. Entire buildings can be prefabricated industrially and assembled on site.” Wood as a building material is therefore expected to continue on its upward trajectory. Apart from the economic benefits it provides, the material is also an ideal choice from an environmental point of view. Wood is a sustainable CO2 sink and thus actively supports the fight against global warming.
The article is published in the magazine ''Holzkurier 35/2020" in German language. You can download the original article down below.
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