Layfield is a leading manufacturer of blast-hole liners, with over 25 years experience producing liners. Our experienced team of product engineers employed their technical and manufacturing expertise to develop a unique product for the mining industry which has improved on-site blasting performance. Our SAFETY-BLAST® liners are designed to exceed the toughest site blasting demands.

Our philosophy and approach to developing and producing Blast-Hole Liners (BHL’s) is based on the concept of Quality, Safety, Survivability and Advancement (QSSA). The concept of QSSA is derived from our background in the field, manufacturing Geo-membranes (Synthetic Lining/Containment Systems). It was developed to ensure installation and long-term survivability of these critical systems. The QSSA initiative has been applied to our SAFETY-BLAST® product line as follows:

Quality
Layfield Poly Films quality assurance program has been certified and accredited to the ISO 9001:2000 standard. ISO (International Organization for Standardization) is an organization that is recognized as a worldwide authority in setting quality standards. Layfield only ships product that meets or exceeds the published specifications for our liners. We test at every step of along the manufacturing process for conformance, from raw materials to finished product. In addition to the stringent ISO standards, Layfield sets even higher quality standards for SAFETY-BLAST® products. Every liner manufactured by Layfield is individually inspected for quality and performance factors, and a complete quality control checklist can be found in the pocket of every SAFETY-BLAST® blast-hole liner. In order to ensure that all SAFETY-BLAST® products are manufactured to exacting specifications, every quality identification tag identifies 5 separate quality checks, as well as the shift, date and operators initials. The audit trail initiative allows us to back-track production and test data specific to any liner produced at our plant.

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Survivability
As product survivability is a key component to performance, Layfield has over the years studied, produced, and tested many adaptations of what has evolved to be our current product line. The basic platform is built on Single (SW) and Double Wall (DW) blast-hole liner technology.

Layfield only uses first quality grade virgin raw materials and additives in producing our liners. Our BHL product blend has been specifically engineered for optimum strength, tear and puncture resistance. Because polyethylene derives strength through orientation, we extrude our film to optimum blow-up ratios, meaning we choose the best die path to optimize ratios. Our DW Liners are similar in concept to the Double Hull construction used in Oil Tankers – a tank within a tank – a tube within a tube. The outside liner protects the inner liner throughout the rigors of the down-hole installation process ensuring integrity of the inner liner. The concept of independent layers versus homogeneous structures has been proven far superior. Because of its effectiveness the concept is adapted to many different design applications. In the 1970’s ICI’s Canadian Division, then named CIL, developed a double wall polyethylene shipping sack for export shipments. Testing showed a 35% + increase in puncture strength versus a single layered film of the same resin blend & equal combined gauge. More importantly it confirmed film propagation (when scored PE film is prone to propagate in the machine direction) was greatly reduced.

DW liners come complete with 2 bottom seals plus a fold over and a 3rd seal on the inside liner (staggered for shock absorption) to optimize loading survivability. Our SW liners come with 2 seals staggered again to optimize load survivability SAFETY-BLAST® Double Wall liners are designed for high performance in demanding environments (deep holes, long sleep times, and wet conditions) and our Single Wall for moderate sleep times in dryer - wet conditions. Back to Index

Product Development

1. To enhance our liner performance we have recently developed a pocket that will ensure the liner is not left hanging above hole-bottom, when anchored, therefore subjecting the bottom of the liner to supporting loads in excess of 10,000 lbs. (for a 200’ + deep hole). This pocket configuration allows for liner & pocket bottoms to concurrently reach bottom. In studying installation methods, we have identified this as a key issue for potential liner failure. We have in the past tried to overcome this issue through on site awareness and education. Because our liners are exact in length we have printed increments on the liners (for some of our clients), therefore, allowing for quick calculation to determine required slack in hole prior to anchorage. Again, in this case, we have drawn on our geo-membrane know-how to assess the issue and to build a better system.
   
   
2. We are in the process of developing a Double Wall BHL with leak detection capabilities by applying conductive material to the inside liner. This innovation will create a better tool for managing blast performance.
   
   
3. We have developed a liner for coal blasting operations c/w tear away, allowing for removal of material in the area being stemmed, hence preventing potential for contamination.

Manufacturing

1. Layfield has just completed a $5 million capital project that entails the turn-key installation of a new multi-layered co-extrusion line for our Vancouver plant. This new line gives us the capability to produce ultra high strength film structures. As an example, we are targeting to produce lighter weight liners with equivalent or greater strength characteristics to that of our current Double Wall product. The economic and performance opportunities of this undertaking are very exciting.
   
   
2. Layfield has developed and perfected proprietary inline automated manufacturing processes to produce both single wall & double wall SAFETY-BLAST® blast-hole liners. We have also recently increased our capacity to produce single wall & double wall liners to service our USA initiative.

Please feel free to download Layfield’s SAFETY-BLAST® brochure, in Adobe PDF format, by clicking on the following links: [Low Resolution273 KB]   [High Resolution16.8 MB]

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On top of Layfield’s extensive research into the area of blasting through use of blast-hole liners, there have been independent studies that have also confirmed that the use of liners and ANFO increase blasting efficiencies. The National Science Foundation (NSF Award Number DMI-0216042) preformed three experimental cast blast tests as part of a five year research project. The experimental cast blasts were extensively studied using all the procedures that have been developed as a result of this research. It became obvious from these tests were liners were employed that the blasting agent efficiency was quite different as compared to another mine site that the NSF team had previously experimented at which were using blends. The ANFO blasting agent did not smoke orange, whereas the half emulsion / half ANFO blasting agent typically smoked if not detonated very quickly. These three experimental blasts culminated the NSF’s efforts to utilize innovative blasting to eliminate nitrogen dioxide formations while maximizing energy efficiency in surface mining.

Perhaps the most interesting piece of data to be discovered by the NSF was the change in Velocity of Detonation (VOD). VOD is the analytical procedure that measures blasting agent efficiency, by looking at five separate parameters. These five parameters are borehole diameter, power of initiation, particle size, blasting agent density and the oxidizer to fuel ratio. It was determined that every powder column that was subjected to blast pressure from an adjacent borehole detonation increased its detonation velocity by 3,000 feet per second. No previously published literature has stated that ANFO in a lined borehole becomes a more efficient blasting agent when compressed by the pressure of the blast. This is part of the reason that ANFO does not deflagrate to form nitrogen dioxide.

The NSF team was also able to successfully measure the pressure form the first powder column detonations. The borehole adjacent to the Point of Initiation (POI), immediately behind and diagonal to the POI were all fitted with 50,000 psi pressure gauges. The pressure measurements indicated that nearly every pressure pulse passing through the surrounding unexploded powder columns was in excess of 50,000 psi. These 50,000 psi hits either increase the density of the ANFO to make it burn more contiguous or actually breaks the ammonium nitrate into smaller particles so it burns quicker. Both suggested mechanisms explain the increase in the VOD when compressed.

For more information regarding the NSF study, please feel free to view or print the following paper, in Adobe PDF format, by clicking on the following link: [Download PDF] or by viewing the PowerPoint presentation on the topic, also available by clicking on the following link: [Download PowerPoint]

If you are interested in getting everything—document, brochure, presentation as well as our exclusive video footages—in one package, we have a ZIP archive available: [Presentation Package94.7 MB]

Please also feel free to download our SAFETY-BLAST® brochure, in Adobe PDF format, by clicking on the following links: [Low Resolution273 KB]   [High Resolution16.8 MB]

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Liner integrity is a key requirement for consistent site blasting performance. Tests have shown that a film rupture, or pinholes in a liner below water level, may saturate the blasting solution enough to cause only a partial blast, or no blast at all. Layfield’s SAFETY-BLAST® blast-hole liners are manufactured from specific blends of engineered resins to provide a tough membrane for containment of blasting solutions, and are designed to resist abrasion and water penetration.

Some of the benefits of using Layfield SAFETY-BLAST® blast-hole liners include:

Durability and strength where they’re needed. Our highly specialized manufacturing process utilizes Layfield’s unique resin blends in both our single and double wall liners. Reliability you can count on. Our tough single wall liners, and our ultra-strong double wall liners are designed for extremely demanding applications where un-compromised performance is essential Peace of mind regarding safety. Use of our readily available anti-static liners, for areas where the presence of methane gas may occur. Layfield’s specially engineered liners reduce static electricity by as much as 85%. Anti-static liners are easily identifiable on-site with a unique pink tint. Proven track record. To illustrate the quality/effectiveness of our product, we service large surface, deep hole/angled hole mining customers that shifted from using emulsion and blend products to 100% (Ammonium Nitrate/Fuel Oil) ANFO in combination with our single and double-wall liners.

Environmentally friendly. ANFO lined blast-hole liners provide a more “Environmental Friendly Solution” versus emulsions/blends, through the elimination of Oxides of Nitrogen (NOx) smoke.

For more information about Layfield’s SAFETY-BLAST® line of single and double-wall liners, or advice as the suitability for your application, please feel free to contact our National Customer Service Center toll free at 1-866-375-9740 or via email at info@safety-blast.com.

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The SAFETY-BLAST® line of products is produced by Layfield Poly Films, which is part of the Layfield Group of Companies. In addition to manufacturing SAFETY-BLAST® liners, Layfield produces a diverse range of products, including: plastic packaging and films, geosynthetics, and industrial fabrics. The company also installs highly advanced environmental containment systems used in site remediation. For more information about any one of these products, please feel free to click on the following link www.layfieldgroup.com to be taken to our main corporate website.