glued laminated timber production, for outdoor use, UPR, ecoinvent 3.6, Allocation, cut-off
Reference product: glued laminated timber, for outdoor use [m3]
Location: RER - Europe
This dataset represents the production of one m3 glued laminated timber for outdoor use. The input of wood is assumed to be naturally dried sawn softwood, more specifically spruce.
The production takes place at a wooden board factory for organic bonded board; the dataset reflects a German production site, which is assumed representative for Europe. The figures origin from mainly calculations and literature values.
Data for glued laminated timber are estimated based on data for production of three layered laminated board. The overall quality of the data for glued laminated timber (represented by three layered laminated board) is good for such a wide class of products. Data quality, however, is not sufficient to allow for comparing with other wood boards.
[Dataset to be replaced by 'glued laminated timber production, for outdoor use, CH, 1986 - 2002' (3b0153b9-d177-588a-a119-ea9c989d1c45)]
[Dataset to be replaced by 'glued laminated timber production, for outdoor use, Europe without Switzerland, 1986 - 2002' (c60fdd36-c0fa-5831-ac02-658dee97bfe4)]
[This dataset has been generated using the system model "Allocation, cut-off by classification". A system model describes how activity datasets are linked to form product systems. The allocation cut-off system model subdivides multi-product activities by allocation, based on a physical properties, economic, mass or other properties. By-products of waste treatment processes are cut-off, as are all by-products classified as recyclable. Markets in this model include all activities in proportion to their current production volume.
Version 3 of the ecoinvent database offers three system models to choose from. For more information, please visit: https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system-models-in-ecoinvent-3.html)]
Estimate for glued laminated timber is based on data for three layered laminated board.
In the 1990s a special glue type for bonding laminates was developed based on using melamine-resorcinol-formaldehyde resins. These bondings are highly resistant to boiling water and give a pale glue line.
Laminated wood is made mostly from spruce, which is the easiest wood to process and fulfils the specific requirements of strength and durability. The three-layered laminated board made of spruce is produced in a large wood processing company in the Canton of Fribourg, Switzerland: out of rough sawn timber (u=70%) 22 mm lamellas are sawn, which are technically dried, planed, finger-jointed, glued with PVAc-adhesive at their ends to “never-ending” lamellas and finally glued to a bloc. This block is sawn to boards, which are planed. The spruce is mainly coming from the area around Fribourg. The thermal energy for the drying of the lamellas is mainly produced by industrial residual wood (8% of wood input). Lamellar boards are sawed from round wood trunks. The boards are pre-dried to ca. 10% residual moisture, graded, and then bonded in automatic plants to form continuous boards with dovetail joints. The moisture in the boards to be glued should be 2 3% below the expected equilibrium moisture level. Variations in the moisture content of the different boards should be not greater than 2%. The broad sides of these joined boards are planed until smooth and uniformly coated with adhesive. Constructing the beams, particular attention is paid to the positions of the annual rings in the cross section of the boards. The rifts (vertical) and the flats (horizontal) should be distributed regularly (Werner et al., 1997).
Werner F., Richter K., Bosshart S. and Frischknecht R. (1997) Ökologischer Vergleich von Innenbauteilen am Bsp. von Zargen aus Massivholz, Holzwerkstoff und Stahl. EMPA/ETH-Forschungsbericht, Dübendorf, Zürich.