Industrial Machinery News

Archive for August, 2009

Steel roofing comes in a wide range of styles and shapes.  The manufacturing of these shapes in a high speed production environment requires the use of some very specialized machinery.  Roll forming equipment is used to transform sheet steel in to shapes or profiles by bending the sheet through a number of rolls.  These rolls squeeze and form the sheet in to the various profiles used in metal roofing.  Common profiles include the Trapezoidal (or box) profile typically available painted in a range of colors.  This is one of the most common profiles used today. 

The tile sheet is also a very common profile that gives the appearance of traditional clay tiles.  This too is painted and formed using a roll forming machine.  Not ever roll former can produce quality products repeatability.  The number of stands or sets of rolls used to bend and shape the steel sheet is critical to the end quality of the tile sheet.  Many lower cost rollforming companies reduce the number of passes in order to reduce the overall cost of the equipment.  This short sighted method introduces a range of quality and operational inefficiencies that add to increased costs and poor customer satisfaction.

So how can you improve steel roofing manufacturing?

Steel roofing, tile sheet, composite panels and corrugated roofing are all manufactured using roll forming equipment.  It’s easy to see how choosing the right rollformer impacts the overall quality of any operation.  A well built roll former will reduce scrap metal, re-work and most importantly improve customer satisfaction.  Well known roll forming companies such as Samco Machinery understand this and design there systems to produce quality panels day in and day out.  If you are manufacturing various sizes or profiles of steel roofing products ensure that your equipment is capable of supplying your needs year over year. 

Steel Purlins are an excellent choice for floor structures, large ridge beams and tall walls.  Made from hot-dip galvanized steel and manufactured by utilizing roll forming machines.  Purlins are mold resistant, damp proof, energy efficient and are recyclable.  They provide for high load-bearing capacity are easy to assemble, lightweight and hold true to there shape.  Roll forming machines such as the Samco PurlinMaster provide a range of options when manufacturing these common construction items.  Structural and engineered buildings utilize steel purlins horizontally and vertically.  Cee and Zee purlins hold the loads for the roof deck, sheathing, and are supported by the rafters and building walls. 

In metal construction for building roof systems purlins are frequently used and are manufactured by forming (or bending) cold-formed steel in to Cee and Zee (or Zed) sections.  Another name used for Cee and Zed (or Zee) sections in a wall construction is ‘girts’.

Top quality roll forming machines utilize a quick change over process for forming both profiles (Cee and Zee) on the same machine.  Because of this ability to switch between profile shapes it is very important to select a roll forming manufacture that has a history of providing Purlin Machines.  Switching back and fourth from shape to shape can lead to poor part quality if the equipment is poorly designed.  Top roll forming manufactures such as the Samco Machinery (Purlin Master) have proven their ability to produce both types of purlins on one machine. 

Mounting options for the common and not so common Purlin

Purlins are used to bridge a gap in the construction process and require a varity of mounting configurations.  Holes are punched in to the Purlin to provide standard mounting options for the installer.  The placement of these holes is critical and requires a well engineered rollforming machines that provides high accuracy.  Imagine the holes punched in to a Purlin with a large tolerance.  During installation on the job site they would have to modify and create new mounting assemblies.  This inefficient process would cause havoc at the construction site holding up delivery and increasing costs.  To overcome this some roll forming manufactures (http://www.samco-machinery.com) have developed specialized hole punching to solve this problem.  Samco Machinery offers a range of hole punching options to accommodate any pattern requirement.  From simple standard punching to flexible Punch Anywhere systems accurate hole punching is as critical as the trueness of any Purlin.

Dónde comprar Goring Kerr manuales? 

The property of being absorbed by matter is very important for the application of x-rays in contaminant detection. Because higher density objects have smaller subatomic distances, they absorb more x-rays than lower density ones do. In reality, it is impossible to quantitatively examine the ability of materials absorbing x-rays without going into complex considerations on their subatomic structure. The following chart, as an example, shows how water in liquid phase absorbs x-rays as a function of x-ray energy. It should be noted that the graph is non linear.

Absorption in water.

In the graphs, :/D is the mass attenuation coefficient, and :en/D is the mass energyabsorption coefficient (defined in ICRU report 33, 1980). The graphs have been taken from NIST Physics Laboratory, Physical Reference Data (See http://Physics.nist.gov/PhysRefData).

If we consider a solid material, like glass lead, we can observe that there are points of

discontinuity because, at certain energies, x-rays match the energy of the orbital of the

atoms.

Absorption in glass lead.

To a first approximation, the mass attenuation coefficient varies as the third power of the atomic number of the absorber. (See X-Ray Fluorescence Spectrometry Second Edition, Ron Jenkins, edited by JohnWiley & Sons, Inc, section 1.1).

It is not our intention to go any further into this subject. We only wanted to show that considerations about the nature of the materials are essential in the design of an x-ray inspection machine. This is true for every part of the machine that can be exposed to x-rays, either in an active or in a passive mode.

Food safety and quality process are now utilizing the advanced features of inline X-ray systems.   Like traditional metal detection equipment X-Ray systems can detect, reject and report on metal contamination.  X-Ray systems also offer a more tangible value added feature that food producers and other manufactures such as pharmaceutical, and plastic companies can take advantage of.  X-Ray systems unlike metal detectors can ‘look inside’ packaged products and analyze their content.  They can count items, see the position of items and even recognize missing items.  These features now give valuable feedback instantaneously to the processing of goods.  Production lines can adjust accordingly and failed product can be automatically rejected, all adding value to the customer.

Principles of X-Rays

X-Ray definition, history.

Wilhelm Conrad Röntgen discovered x-rays at the end of the 19th century in Germany. X-rays are electromagnetic radiations produced by the deceleration of charged particles (normally electrons) or by the transition of electrons in atoms from one orbital level to another. The first method (deceleration of electrons) is the one used in the applications that are subject of this document.

The wavelengths of x-rays range from 10-8 m to 10-12 m, with corresponding frequencies of 1016 to 1021 Hz.

The energy of electromagnetic waves (such as gamma rays, ultraviolet, visible light, infrared, radio waves, etc.) is related to their frequency by the following formula:

E = h < [01]

Where E is the energy associated with the wave, h is Plank’s constant, and < is the frequency of the wave. This formula simply shows that the energy of an electromagnetic wave increases proportionally to the frequency. 

Wavelength and frequency of electromagnetic waves are related each other by the formula:

c = 8 < [02]

Where c is the speed of light in vacuum (equal to 3 108 m/s) 8 is the wavelength in m, and < is the frequency in Hz. This formula shows that an electromagnetic wave with a certain energy E can only have one wavelength 8 equal to: 

8 = c / < = h c / E [03]

Where h and c are constants. In particular, the wavelength of an x-ray decreases as the energy increases. This explains why higher energy x-rays penetrate better into matter. The matter is made of atoms with their electrons and nucleus, and of a lot of empty space. Denser matter has less empty space. To penetrate the matter without being absorbed, an x-ray has to find its way through the empty space without interacting with subatomic particles. In very simple terms, a wave with a smaller wavelength has a higher probability of passing through subatomic spaces without interaction. 

 Roll forming is a metal forming process in which metal strips and coils are fed into rolls of different configurations successively until parts of the required shape, thickness and uniform cross section are produced. Roll forming is used to produce various types of shapes and forms such as: angles, channel shapes like Cee, U, T, Zee, special forms like hat sections, round, square, and rectangular tubes, and hexagonal, pipes, etc. Roll forming is commonly used in metal for roofing and siding, home appliances, heating, ventilation, and air conditioning (HVAC) systems, and in the automotive and rail industries. Rolling may be either hot rolling or cold rolling methods. In hot rolling, the material is heated and passed through the rolls.

 Belt conveyor systems are used through all modern manufacturing processes.  Belting materials range from thin single or double layer flat belts, urethane rope belting, band belting to plastic chain belting.  Each belt type provides specific advantages for many applications.

Plastic chain belting allows for quick and easy repair or replacement and simpler system design.  Typically you do not need to track plastic chain belting.  The belt locks in to geared drive on the conveyor belt roller at both the tail and head pulley that align the belt automatically.  This design inherently removes complex belt tracking systems.  The disadvantage to plastic chain belting is smooth transfer; all sections are square and ‘bump’ as he round the pulleys and belt clogging or buildup of material.

Flat belting is used in many applications fro the snack food industry, packaging machinery, paper manufacturing and electronics.  The range is seemingly endless and option as far as you can see.  Flat belts come in layers and are built up to improve strength and wear characteristics.  The top surface can be made to grip or grab (rubber belt) materials and move them easily up hill.  The downside is that replacing a conveyor belt you typically need an exact replacement, or a belting repair kit to splice a new section in.  Some belting and applications allow for using a zipper for quicker repairs.

When choosing a conveyor design look carefully at how the belting system works and ask yourself - What will I do when the belt fails?