Most people interested in shrink wrapping know you must have a shrink wrap machine to shrink wrap products. What is a shrink wrap machine? Some people are unsure, some people think of the sealer and others think of the shrink tunnel as the shrink wrap machine. Both machines, the tunnel and the sealer should be considered a shrink wrap machine. They both work together to produce professional looking packaging that will protect products from dust, moisture, and tampering. As well as provide a see-through packaging to display the product.
Most shrink wrap operations require two shrink wrap machines to function. Below is a brief description of each element needed to properly shrink products for retail packaging.
Heat Sealer- Most all shrink wrap operations use a heat sealer to seal the open ends of the shrink wrap material. There are some exceptions when a sealer is not required or used, but most applications use a heat sealer. Shrink wrap sealers can come in a variety of sizes and forms depending on production needs. The two most common heat sealers are I-Bar sealers and L-Bar sealers. Below are pictures and descriptions of each sealer type.
I-Bar Sealers- These sealers are named I-Bar because of the single sealing bar they have. I-Bar sealers are found in many low output operations. There are high speed shrink wrap applications that use I-Bar sealers with shrink tubing and shrink bags. The single sealing bar works great for shrink bags and shrink tubing in high speed operations.
As you can see with the pictures, the single sealing bar works great with the tubing and the bags because they require a seal or two running in the same direction. The L-Bar sealer works great with the more common centerfold shrink wrap. See the description and pictures below for a better explanation.
L-Bar Sealers- These sealers cost more, but are often more efficient for higher speed production. The L-Bar sealer has two sealing bars in the shape of a backward L. They are designed to seal centerfold shrink film rolls. The centerfold shrink film rolls are folded in half lengthways. The product is placed in the crease of the fold and the other three sides need to be sealed. After the first seal, only two sides need to be sealed. The ending seal on the first product is the beginning seal for the next product.
Heating Element- Once the shrink film is sealed, heat needs to be applied to the film to shrink it down to conform to the product. Different shrink wrap materials require different heat temperatures. Most lower output operations use a heat gun to apply heat to their products. They are inexpensive, but not efficient when producing a high to a moderate number of shrink wrapped products. For medium to higher output products, a shrink tunnel is recommended. The box on the left side of the picture above is the shrink tunnel. Shrink tunnels have a conveyor belt running through them to feed the products through. Adjusting the speed of the conveyor belt and the temperature of the tunnel is important to finding the proper shrink settings.
This post is only a bare-bones article to explain and demonstrate what most shrink wrap operations need. As mentioned above, some products do not require a sealer. An example would be a candle maker using a shrink tubing. The candle is slid into the tubing, the tubing is heated and the ends are left open and not sealed. There are a large number of variables when preparing a shrink wrap operation. Call us (1-800-441-5090) we would be happy to help you set up an efficient and cost-effective shrink wrap operation.