- Written by Dr Peter Edwards, Global Gypsum Magazine
The 29th Eurogypsum Congress of Eurogypsum, the European Gypsum Association, took place at the Radisson Blu Hotel in Kraków, Poland on 10 – 11 May 2012. The event, held under the title, 'Gypsum is at the core of a sustainable and resource-efficient built environment,' was attended by around 85 delegates from Europe and further afield. The Congress heard a variety of presentations from the European Commission, architects, academics and other businesses in the gypsum industry and related areas.
- Written by David Hayes, Special Correspondent
Gypsum board factories with clients in north east Japan have faced unprecedented operational circumstances during the past year following the 11 March 2011 earthquake and tsunami. The disaster badly affected the Tohoku region and part of the neighbouring Kanto region, which includes Tokyo. Earthquake damage occurred in an area stretching about 500km north to south from Iwate to Tokyo along the east Japanese coastline and up 10km inland in some areas north of Tokyo. One year on, Special Correspondent David Hayes spoke to Yoshino Gypsum about the 12 months since the disaster.
According to the National Police Agency 15,782 people died and 4086 people were missing (as of 11 September 2011) following the Tohoku earthquake and tsunami in March 2011. The disaster severely damaged or destroyed over 270,000 buildings and caused flooding up to 10km inland, affecting a large number of communities, some of which were completely destroyed. Industrial, commercial and other enterprises in the Tohoku region and adjacent areas have been widely affected, although many have now recovered.
To fund rebuilding of homes, businesses, schools, hospitals and other public facilities, the government has approved two emergency budgets. However, work to rebuild the Tohoku region is likely to take some years to complete and the final cost remains unknown.
For Japan's gypsum wallboard industry the earthquake caused immediate disruption to the production and supply of plaster and plasterboard in the Tohoku region where the country's largest gypsum board manufacturer, Yoshino Gypsum Co Ltd, owns four plants. Fortunately for the company, none of the plants was damaged. However, power cuts, damage to roads and disruption to raw material supplies caused production to be halted at two of Yoshino's plants for a month after the earthquake.
- Written by Bob Bruce PhD, Innogyps Inc. & The NuGyp Corp.
At the Global Gypsum Conference & Exhibition in Paris, France, in 2010, Bob Bruce presented a paper about how the global gypsum industry was likely to be affected by the underlying trends shaping the world today. One year ago business in Western Europe and North America was suffering and everyone was hoping that conditions would improve soon. Meanwhile, much of the rest of the world was enjoying a growing market. So what has changed in a year?
On the face of it, not much has changed since the Global Gypsum Conference & Exhibition in Paris in October 2010. The USA was recovering, but now is facing a potential 'double-dip' recession and is pulling into its shell. Western Europe has been rocked by the debt issues in Greece and elsewhere. Japan has suffered a devastating earthquake/tsunami/radiation disaster.
But while these major economic centres were struggling, the developing countries continue to grow, especially in gypsum. At Innogyps we receive calls almost every week from someone wanting to get into the gypsum business somewhere in the world. So perhaps the gypsum business is not so bad after all.
- Written by Dipl. Ing. Bernd Lübbert, Claudius Peters Projects
A number of different factors have to be taken into consideration in the selection of bag filling systems for mortar and gypsum products. The filling process and filling time are essentially determined by the product and material characteristics, as well as by the chosen filling system. By means of measured bulk density characteristics such as flowability, aeration behaviour, bulk density, grain size distribution, fineness and wear behaviour, mortar and gypsum products can be evaluated regarding their filling behaviour. This measured data can be used for the selection of a suitable filling system.
Selection procedure
In order to be able to make a reasonable pre-selection of a powder filling system, the characteristics of the bulk material have to be determined. For this purpose, a standard dust test report is used. By means of the determined features in the dust test reports a classification regarding the filling system can be made with a modified Geldart diagram.
After the pre-selection of the filling principle either by turbine or by air filling principle the bulk material is examined at a test filling station regarding the filling times, weighing accuracy and the mass flow in coarse and fine flow. The evaluation of the results either confirms the assumed pre-selection or other filling systems have to be tested. For the filling tests the characteristics such as bag volume and air permeability of the valve bags to be used must be available (bag test certificate). Figure 1 shows the selection procedure in each steps.
- Written by Dustin Neumann, Neumann Process Control, Inc.
When building products manufacturing volumes are low, there is more competitive pressure to produce high-quality wallboard and the importance of maintaining customer loyalty by minimising claims becomes increasingly important. This article describes operational strategies for adjusting the dryer from volume-centric production methods to quality-centric methods during times of lower demand. Emphasis is placed on solutions requiring little or no capital.
Introduction
In this time of reduced economic activity, there is limited demand for building construction and therefore builders and contractors are adjusting their competitive emphasis from capacity and speed of construction to managing costs and offering superior quality. It follows that building materials such as gypsum wallboard are scrutinised closely for quality and conformance to specification.
The consequences of quality complaints or claims are compounded in an environment of strong competition for a limited market. This article is a discussion of controlling the factors that result in quality claims. The general subject is dryer performance and although there are a number of aspects of product quality that are interdependent, such as mechanical handling, formulation and other factors, it is dehydration and finished moisture variability specifically that is the main focus.
Among the greatest risks for defective product entering inventory are variations that cannot be easily detected with the senses. Easy-to-detect deficiencies that result in complete paper separation, mechanical damage to edges and gross moisture variations that can be detected audibly or through handling are not emphasised. Finally, the definition of industry terms such as 'dryer balance' are further refined through the introduction of a model that facilitates discussion of the complexities of managing moisture variability.
