In response to the growing awareness of end
consumers to make more eco-sensitive choices and the resultant shifting demand
by treaters for an alternative to metal-based solvent treatment products, Lonza
Wood Protection introduced Vacsol® Azure® to the South Africa market as the
first metal-free wood preservative in the light organic solvent sector. Eight
years later, this new generation preservative still holds full market share as
the only alternative with environmental advantages over its predecessor solvent-based
wood preservative products – namely TBTN, TBTO-L and PCP.
“The key attribute of promoting the use of more
wood in construction is that it is a truly renewable resource which plays a
vital role in reducing the carbon footprint of a building, as wood products
store carbon for the duration of the product’s lifetime. But equally important
to choosing wood in construction is the decision to use a metal-free,
organic-based wood preservative,” says JJ du Plessis, Business Manager at Lonza
Wood Protection South Africa.
Since the launch of Vacsol® Azure® in South Africa,
the demand for the product has grown exponentially and du Plessis provides
insight into the reasons behind its success.
“The facts speak for themselves. Vacsol® Azure® has
achieved a solid track record of performance excellence in the organic solvent
treatment segment for H2 and selected H3 hazard classes. We attribute this
success to its innovative design that ticks all the boxes for treating re-manufactured,
appearance, and engineered wood products where both moisture content during
processing and water repellence in the end-use product are critical. As a result,
the last eight years has seen Vacsol® Azure® become an essential component of wood
preservation in the South African market,” says du Plessis.
One of the popular features is the clear liquid
preservation solution, which on application maintains the wood’s natural colour
with a beautiful light honey shade. This makes it the logical choice for
treating architectural features such as stairways, laminated beams, roof trusses, ceiling
boards, flooring, panelling, doors, cupboards, skirting and window frames
The solvent based solution is another practical
feature that is very appealing to treaters of engineered products and
structural wood. Because the solution does not affect the wood’s moisture
content, strength, dimensions or glue bonds during the treatment process, wood
products can be treated in their final shape and form.
Du Plessis adds, “The Ecospecifier Global
endorsement, and the fact that Vacsol®
Azure® is rated among the contributing products to the achievement of the Green
Building rating tool credits, have been instrumental in building product
confidence – not only for our customers, but also for our customers’ customer”.
Initially, Lonza launched Vacsol® Azure® at four
treatment plants, one of which was Lamtim Products (Pty) Ltd situated in the
KwaZulu-Natal Midlands. Lamtim is the country’s largest specialist producer of
laminated timber materials, so being one of the first treaters to use Vacsol®
Azure® meant ensuring that the product met the company’s commitment to
providing quality products to its customers.
Lance Chapman, Director at Lamtim Products, elaborates,
“Vacsol® Azure® gives us the assurance that our beams will remain stable
without any dimensional distortion through the treatment process and into
service. What really stands out for us is that our beams retain their natural
colour. This is not only attractive, but also highly sought after. The
protection against wood decay and insect attack is of the highest quality and it
has environmental benefits – which is an important consideration in our company.
I can honestly say that the investment made into our treatment plant with Vacsol®
Azure® has added value to our business”.
The advanced protection against fungal decay,
woodborers and insect attack is a result of preservative constituents made up
of a synthetic pyrethroid insecticide – permethrin – and organic azole
fungicides – Tebuconazole and Propiconazole. In addition, the low pressure,
double vacuum treatment process drives the preservative deep into the cellular
structure of the wood to provide this enhanced protection.
However, du Plessis stresses that without an
effective on-site quality control management system to ensure that the correct penetration
requirements are met, the quality and service life of wood treated with Vacsol®
Azure® is compromised.
“Inadequate and non-uniform penetration for
pressure processes is always a concern as it leads to failure of the product in
the end-user stage. Regular and effective penetration tests are essential to
ensure that the chemical has penetrated deep enough for the wood to comply to
the SANS 1288 and SANS 10005 national specifications. Although the treatability of wood is related
to its porous structure, it is also influenced by other parameters such as wood
moisture content, drying technique, preservative formulation and the treatment
process. For this reason, our technical support team is always on hand to
assist our customers in achieving the correct degree of preservation and
thereby ensure the end-use performance of Vacsol® Azure® in the consumer market,”
says du Plessis.
“Penetration testing is most important at Lamtim
Products. Without testing and the support of Lonza’s technical backup, we
cannot maintain our SABS certification,” comments Chapman.
The penetration test for Vacsol® Azure® differs
from CCA and is carried out by placing
samples into the charge at various points among the bundle, which can be either
block stacked or strip stacked. The wood must be below a 17% moisture content
and should be in its final shape and form with all machining and rip sawing
It must also be free of any signs of fungal decay
and insect attack and should not be treated if it has been affected by sapstain,
as this results in excessive absorption of the treating solution.
Denise Conradie, Quality Assurance and Technical
Manager at Lonza, expounds: “Once the double-vacuum process is completed, the
samples must be removed, cut open halfway and sprayed with a PAN indicator. The
preferred method of applying the indicator is by spraying to get an even
wetting across the surface. It is inefficient to apply so much indicator that
it runs off the surface as this will result in it smearing and the
dis-colouration will not present the correct penetration levels. The colour of
the PAN indicator is yellow and when applied will change to red to indicate the
presence of Vacsol® Azure®”.
A penetration test is required to determine the degree
of preservation, which is expressed in two ways – namely retention and
penetration. The penetration is determined by measuring the depth of the red
discolouration from the wood surface. The retention
is calculated from the weight of preservative per cubic metre and expressed in
kg/m3. Importantly, the retention level will dictate the hazard
class of the treated wood.
When Vacsol® Azure® has been
correctly applied at the stipulated concentration, the retention level should
meet the required retention as per SANS specification for both H2 and H3 hazard
class applications. For the treatment of
selected H3 exterior above-ground applications, an additional suitable water
repellent and UV resistant coating is required.
In South Africa, all wood treatment plants are
monitored through a compulsory third-party product certification scheme. Sawn
treated wood must display the treater permit name, the stress grade marking, the
hazard class the wood has been treated to and a product certification mark of
one of the approved certification bodies – either the South African Bureau of
Standards (SABS), the South African Technical Auditing Services (SATAS) or
African Certification and Testing (Pty) Ltd (ACT). In addition to these
legislative requirements, wood treated with a preservative supplied by Lonza
Wood Protection must bear the TAN™ trademark.
Du Plessis concludes, “Introducing Vacsol® Azure® to
the South African market has proved to be yet another example of how listening
to our customers’ needs gives Lonza the opportunity to provide wood treatment
products that add value to our customers’ business and above all help to ensure
that the wood preservation industry will grow well into the future”.