Saturday, May 4, 2013

Ways to process 3D laminates, brands of membrane presses for thermofoil

There are various ways to process 3D Laminates. In this article I will mention all the ways you can process 3D Laminates and also mention some common machine names used in membrane pressing and vacuum pressing.

MEMBRANE PRESSES:
At the time of me writing this article, the most common brands of membrane presses in North America are Wemhoner which is sold by Stiles Machinery, Shaw Almex which is sold by Black Brothers, Italpress which has their own office, Orma, and Burkle.

Advantages of membrane presses: Membrane presses typically use rubber or silicone membranes to firstly transfer heat to the components more rapidly and secondly they apply positive pressure on top of the components to press the material while the vacuum on the bottom of the press can also have suction. The pros are that the cycle times are fast and its easier to get more detail in the component under most conditions. The cons are that they membranes need to be replaced periodically depending upon the cycles ran and also based upon the parts produced. The other con would be the cost of a membrane press. They typically cost $200K to over $500K however you may find one for less or a used one. Please do keep in mind that some membrane presses are capable of removing the membrane  from the machine and still operating but not all.

VACUUM PRESSES:
The most common brands of vacuum presses sold in North America are Shaw Almex, Italpress and Greco. If you are a maker of vacuum presses and do not see your company's info here please contact me. I apologize if I overlooked it.

Advantages of vacuum presses: Vacuum presses are more affordable however they do not have positive pressure on top. Vacuum presses rely solely on the vacuum power below and they use light bulbs or heat plates on top in some machines. Most vacuum presses have longer press cycle times and do not get as much detail into the components. There are some tricks such as drilling holes in the backs of the components to enable vacuum to pull through the MDF and also some companies will score the glue line on the side of the component with a knife which breaks the seal a bit and enables more vacuum. In general, companies who produce mass components for others prefer a positive pressure membrane press with or without the membrane in lieu of a vacuum press. Vacuum presses are an inexpensive way to get in the business however they are more suited for companies who use the components internally for their own cabinets or fixtures and less suitable for companies who mass produce components for others and whose livelihood is attached to selling components due to the longer press cycle times.

FLAT LAMINATION:
3D Laminates or vinyls can also be flat laminated either by a flat lamination machine utilizing PUR adhesive typically. These machines are designed for fast flat lamination. The other way to flat laminate is by a nip roller using a 2 part epoxy glue.

PROFILE WRAPPING
3D Laminates can also be processed by profile wrapping moldings

MITER FOLDING
Miter folding is where material is flat laminated or membrane pressed to a component with a v groove in the back of the part. A line of glue can be ran in the groove and then the part is simply folded to create a seamless fold. The vinyl acts as a hinge. Please note that white lines can appear on the fold with vinyls which is caused by various reasons. Companies use wooden blocks to rub or heat guns to remove the white lines. Some laminate manufacturers can produce vinyl so that they will not whiten when folded.

HAND LAMINATION:
3D Laminates can be processed by contact cement, peel stick or laminate backed for hand applications. The laminates are not specifically made for this type application so this is the exception rather than the rule.

CONCLUSION:
This post is just a teaser and does not get deep into the topics. If your company is a processor in North America and has technical questions you can contact me for more detailed information, tips and tricks.