SILAWRAP,
ITW CROP PACKAGING SYSTEMS
IDA Industrial Estate,
Courtown Road,
Gorey,
Co Wexford, Ireland.
Phone: IRL 053 9422990
UK: 0800 7317586.
Europe: 00353 53 9422990.
Email: sinfo@itwstretch.com
Silawrap - Technical Information
Manufacturing Silawrap
Silawrap is produced from polyethylene resins which are made from oil and gas. Polyethylene or PE resins are broken into different groups depending on their properties. High density polyethylene or HDPE is used to make soft drink bottles and milk containers. ITW Crop Packaging use Linear Low Density Poly Ethylene or LLDPE resins in the production of Silawrap. LLDPE resins are split into C4, C6 and C8 resins. This details the number of bonds between the molecules. A C8 resin has 8 bonds and is therefore stronger. ITW selects its resins for elasticity or ability to stretch and strength or resistance to puncture and tearing. The resins come in granules similar in size to prilled urea. We use 100% C8 resins. These are dearer than other materials but produce a stronger better quality film.
Other raw materials include colour called master batch, UV light inhibiter and tack or glue. Sun light causes film to break down. UV light inhibiter prevents this from happening. UV light levels vary around the world. For example UV levels are higher in Australia than Ireland. Therefore more UV light inhibiter is added to Silawrap destined for this market.
Tack is used to seal the film, in other words it is the glue. There are many types. ITW uses a viscous or thick formulation. This has to be heated in order to flow properly in the manufacturing process. Some of our competitors use a more liquid form of tack. This evaporates from between the layers of film during storage, allowing in air and reducing silage quality.
ITW guarantee that no recycled resins are used in the manufacture of Silawrap. This is to ensure farmers receive top quality film every time. Recycled resins when used lead to impurities in the film, reduced strength and variations in the tack level or seal.
160 Million Bales Wrapped Worldwide.
Extruding Silawrap.
Silawrap extrusion is a continuous process, operating 24 hours per day, 7 days a week. Lines shut down for annual maintenance and at regular intervals for service. It costs over £1,800 or €2000 to start a line. Extruders are built for a specific purpose, for example manufacturing silage wrap or pallet wrapping film. It is very difficult to make quality bale wrapping film on an extruder built to make pallet wrapping film.
Silawrap is a triple layered film which means 3 layers of molten resins are fused together. This makes Silawrap tougher. It also allows ITW to vary the resin mixture from layer to layer to maintain high quality and durability.
Quality Silage from Quality Grass
With Irish and UK farming undergoing constant change and challenges the importance of maintaining and improving profitability has never been higher. The introduction of the extended grazing season in Spring and Autumn means farmers have to adapt and manage their grazing systems. With this comes the importance of having good quality baled silage on farm to supplement when the need arises over the winter period. Baled silage has proven itself over the last few years to be the product of choice when you want quality and flexibility.
Performance levels from different DMD Silage. |
|||||
DMD % |
Protein % |
ME [energy] |
Milk yield Lit /Day |
|
|
70 |
11.6 |
10.6 |
11 |
|
|
67 |
11.7 |
10.3 |
8.8 |
|
|
68 |
11.7 |
10.4 |
10.3 |
|
|
Figures from Teagasc Silage averages 1 July 09 to 31 Jan 10.
Performance from Silage only No concentrate fed.
The difference from 67DMD V 70 DMD Silage is 2.2 lit milk per day at present prices ,
At .25c/lit or 24p/lit = 55c or 52.8p per day extra.
You can see from these results how important it is to be flexible in your cutting date. And when wrapping how important it is to use a quality product like Silawrap that you can depend on.
Silage of a High Feed value {DMD} and energy value {ME} is far easier achieved with the flexibility of baled silage. Cutting when the crop has reached the proper maturity is the key to quality silage. When heading of the grass starts to takes place and with 40% of the ears emerged this is the optimum time for cutting. Each week delayed after this will drop feed value by approximately 4% points of DMD. With the performance level of silage dropping week by week this is where Baled Silage proves its flexibility. Being able to cut fields as they mature is the key to quality feed.
Good quality silage comes from good quality grasses and with regular reseeding, proper grass variety selection with good grassland management is essential.
Grass varieties in new mixtures are now determined by not only yield but heading date, sugar % and ground cover. When you are reseeding it is important to look at your main purpose for reseeding. This will determine the mix type of grassed that you use.
Example of some Varieties and there heading dates,
Variety |
Heading Date |
Total Annual yield |
Spring Growth |
Autumn Growth |
Ground Cover [1-9] |
Intermediate |
|
|
|
|
|
Shandon [D] |
24-May |
97 |
103 |
98 |
7.1 |
Cashel [D] |
26-May |
98 |
91 |
97 |
7.2 |
Premium [D] |
01-Jun |
97 |
96 |
98 |
7.4 |
Lismore [T} |
28-May |
101 |
94 |
100 |
6.7 |
Dunluce [T] |
31-May |
102 |
99 |
108 |
6.1 |
Late |
|
|
|
|
|
Tyrone [D] |
07-Jun |
96 |
75 |
100 |
7.1 |
Portstewart [D] |
09-Jun |
98 |
96 |
100 |
7 |
Denver [D] |
13-Jun |
98 |
102 |
97 |
7.5 |
Navan [T] |
09-Jun |
102 |
86 |
108 |
6.6 |
Twymax [T] |
13-Jun |
102 |
91 |
98 |
6.8 |
Abercraigs [T] |
06-Jun |
102 |
106 |
99 |
6.5 |
[D] = Diploid. [T] = Tetraploid.
Reseeding of pasture is a process that takes place every 7/10 years but continuous Silage ground will be reseeded a lot more often. So when reseeding select a good mix of both heading dates and growth patterns that when baled with Silawrap will return quality feed.
