LVL Handbook EUROPE

1. LVL AS A CONSTRUCTIONMATERIAL

Figure1.41.

Pre-pressing: the billet is cold pressed to spread the

glue evenly between the veneers.

Hot pressing is typically continuous to allow for variation

in product lengths. The maximum LVL length (18-25 m) is

limited either by the mill building or by delivery by road to the

customer. Hot pressing must ensure that all glue lines reach

the proper curing temperature. Once cured, the glue becomes

resistant to melting and water insoluble, i.e. highly weather

Figure1.42.

Hot press.

Figure1.43.

Feeding LVL billets into

3-level hot press.

resistant. With phenolic resins the pressing time ranges from

15 to 90 minutes depending on the thickness of the product.

Long pressing times and high pressures cause the wood fibres

to compress, resulting in higher product density.

1.6.5 Finishing

The LVL panels are normally cut to size according to the width

and length specifications of the customer. Additionally, the

LVL can be sanded or otherwise treated. Some manufacturers

use portal-type sawing units that enable inclined, diagonal or

chamfered cuts.

Finally, appropriate packaging protects the finished panels

against soiling, moisture and handling damage, keeping them

straight and easy to store and handle throughout the delivery

chain from mill to customer.

1.6.6 Production summary

The homogenous structure of LVL together with production

process optimization enable a wide range of structures and

products to be cut to size with virtually no raw material loss-

es. The veneer peeling system ensures that the best properties

of the veneer log are used with maximum efficiency. Produc-

tion volumes have increased globally and availability is im-

proving as new manufacturers emerge in the market. Demand

for LVL is continuing to rise as residential construction and

awareness of the environmental friendliness of wood products

are increasing. More detailed production descriptions can be

found in the Wood-based Panel Industry publication released

by Finnish Woodworking Engineers' Association 2018

LVL Handbook Europe