The presence of huge proportion of juvenile wood in a log will cause excessive shrinking and swelling, problems of warping, fuzzy grain and general instability in the manufacture and the use of the wood. This higher proportion of juvenile wood can have a significant effect on the log quality and the veneer quality.

Owing to younger age and shorter planting cycle, the juvenile wood is proportionally higher than the mature wood.

The most common factors are owing to the log's characteristics (species, log diameter, log quality, specific gravity, wood pores, grain structure, juvenile and mature wood). Numerous factors contribute to the veneer quality. The mechanical properties of LVL generally depend on a variety of factors particularly veneer quality (moisture content, density, lathe checks, surface roughness and thickness variation), adhesive quality (type of adhesive, mixture of resin and viscosity) and bonding quality (wettability, glue spread rate, pressure, time and temperature). The invention of a spindleless lathe in recent years had encouraged the use of fast-growing plantation species with small-diameter logs in the production of structural composite lumber such as laminated veneer lumber (LVL). Instead of the conventional planting rotation of 25–30 years, nowadays, rubber plantations in Malaysia are managed under a short planting cycle and the trees will be probably felled when they are around 15 years owing to the high demand for latex and rubberwood, which resulted in harvesting small-diameter logs. However, there has been a short supply of rubberwood logs for veneer production owing to the inadequate diameter of the logs for veneer peeling. Rubberwood is a well-known species and highly requested by the wood industry particularly for biocomposite production. These findings stress the importance of measuring and considering the lathe check depth and frequency during the lamination process to get a better understanding of bonding quality in veneer-based products. The presence of higher lathe check frequency on 2 mm veneer increased the wettability, thus facilitating optimum penetration of adhesive for stronger bonding. In addition, lathe check frequency was also shown to influence the bond strength. Owing to deeper lathe check on 3 mm rubberwood veneer, higher pressing temperature significantly increased the gluebond shear strength of the PF-bonded LVL. During the peeling of veneer, lathe checks as deep as 30–60% of the veneer thickness are formed.

Three-layer LVLs were prepared using phenol formaldehyde (PF) adhesive and hot pressed at different temperatures. Different thicknesses of rubberwood veneers was peeled from rubberwood logs with diameter less than 20 cm using a spindleless lathe. Hence, this raises the question of the properties of the produced laminated veneer lumber (LVL) from veneers peeled from small-diameter rubberwood logs using the spindleless lathe technology. Mold designs we offer are our product and they cannot be bought anywhere else.The peeling of small-diameter rubberwood logs from the current short-rotation practices undoubtedly will produce lower grade veneers compared to the veneers from conventional planting rotation. These models remain the property of the customer and have no further use. Molds are made to customer specification. As we keep mold designs, even after several years when needed the same model is available. It is important to notice that our rubber molds concerning the quality have a very acceptable price and eventually are less expensive than any other molds. Watching our video you can see the simplicity of decorative stone production. Preparation time and testing the quality of the rubber lasted two years. We have started with this production process six years ago and throughout this period we have perfected the way of producing molds and got the perfect one with outstanding characteristics. Molds made of silicone latex polyurethane have no better characteristics. The rubber mold quality is equal to the quality of the tires because it is made of the same material. This production is very effective and the mold produced this way has better characteristics than the mold produced by a casting system. They are produced at the temperature of 160 degrees Celsius and the pressure of 200 bars. The way we produce our molds is unique and innovative. Our company produces rubber molds for the production of decorative artificial stone and molds for the production of concrete products of various use.

Rubber veeer