Seaming polycarbonate faces

[SJvL]

I am looking for ideas on seaming polycarbonate (Lexan) faces with clean, invisible results. I would appreciate any ideas.

Thanks,

Sean

[dave C.]

I am looking for ideas on seaming polycarbonate (Lexan) faces with clean, invisible results. I would appreciate any ideas.

Thanks,

Sean

What is your final overall size going to be? You can buy poly in rolls up to 100" tall and 400 feet long? Is it going to be illuminated? If it is I think there will always be, upon close scrutiny, a visible seam. Dave

[fishing nut]

The way I used to do it is drill some small holes along the seam and use alluminum tie wire to secure them together. This way when you have to service the lamps you can cut the wire and slide the faces enough to re-lamp. Whe it is done properly you dont see the seam or the wire.

[SJvL]

I am looking for ideas on seaming polycarbonate (Lexan) faces with clean, invisible results. I would appreciate any ideas.

Thanks,

Sean

What is your final overall size going to be? You can buy poly in rolls up to 100" tall and 400 feet long? Is it going to be illuminated? If it is I think there will always be, upon close scrutiny, a visible seam. Dave

Thanks for you quick response... These are 10' tall, internally LED illuminated channel letters with many of them over 100" wide, so seams are required in some places. The white poly has 1st surface vinyl. We would like the seams to be as imperceptible as possible. We are gluing the seams now with a clear backup and getting a 'smudged' result when illuminated. Would appreciate any better ideas.

Thanks,

Sean

[fishing nut]

Ultrasonic welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a solid-state weld. It is commonly used for plastics, and especially for joining dissimilar materials. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together.

Took this from Wilki. If the customer is that anal about the seem this may be your only option.

[dave C.]

I am looking for ideas on seaming polycarbonate (Lexan) faces with clean, invisible results. I would appreciate any ideas.

Thanks,

Sean

What is your final overall size going to be? You can buy poly in rolls up to 100" tall and 400 feet long? Is it going to be illuminated? If it is I think there will always be, upon close scrutiny, a visible seam. Dave

Thanks for you quick response... These are 10' tall, internally LED illuminated channel letters with many of them over 100" wide, so seams are required in some places. The white poly has 1st surface vinyl. We would like the seams to be as imperceptible as possible. We are gluing the seams now with a clear backup and getting a 'smudged' result when illuminated. Would appreciate any better ideas.

Thanks,

Sean

Press your pieces tightly together that you want to glue, making a "butt seam". then use clear tape on both sides. Once they are taped together take a razor blade and cut the tape on the seam, seperate the pieces enough to use some of the resin based glues made for lexan. push tightly together. Once dry you can peel the clear pieces of tape off both surfaces giving you as clean of a seam as you can get. The tape should prevent any bleeding of the glue onto the face side. vinyl on top of that should help even more. If it is located close to an edge or maybe a serif that should help minimize the strain on the seam as it still will be the weak spot.

Good Luck with it, Dave

[SJvL]

Thanks Dave, we'll give that a try.

Sean

[YYZ]

Ultrasonic would be extremely tough, as the materials need to be shaped to mate in a certain way, and then the energy is applied to very focused locations at a time. There are companies that have portable equipment to do remote plastic welding, so it might not hurt to make a couple of calls, but IIRC, PC is one of the tougher materials to work with.

Most of the time, sign companies would just install 2 pieces with a small lap joined to the backside of one of the piece's edges, which fills any potential gaps and stops light leaks - but you still get a line of some kind as less light comes through the lapped layer. In this case, the white laps would still show a white line in between where the colored vinyl joins up.

Most of the time it becomes a height/distance thing, where you have to be up close on your bucket to see it enough to care. From the ground or driving by, most solutions will probably look just fine.

[geraldi]

You're going to have to seam the vinyl anyway if its that big. I would plan the seams to work with my vinyl seams. We cut the two pieces to fit tightly together and then use a piece of clear on the backside and glue it with Weld on #14. It dries clear whereas the the instant set glues dry a milky white. You can see it up close but, 30 ft in the air, you can't.

[nsw systems]

I am looking for ideas on seaming polycarbonate (Lexan) faces with clean, invisible results. I would appreciate any ideas.

Thanks,

Sean

Hello

I maybe to late but have you talked to Spartec they produce 125" wide sheet sizes we get that size for our 10'x20' vacuum former..

another trick is if you have or can rent a hot air welder LESTER brand you bevel or V grove the edge of two sheets and butt together then using the polycarb rod shaped like a triangle join the sheets together much better than a glued joint the weld is on the inside of the face and with practice you can get a flat weld.

we would cnc out or vacuum form the 10' faces in one piece but we have 10'x30' cnc tables and formers. Go look at IKEA and see how they are produced formed sections just think about the service guy and how they are going to service the sign later in life..

Good luck

Mike

NSW