Ultrasonic Welding Line Design and Debugging of Ultrasonic Welding Machines

1 strength can not achieve appetitive standard.

Of course, we must understand the ultrasonic welding operation strength can never reach integrated strength, can only say that close to the integrated intensity, and the welding strength requirements must depend on the number of complexes, these complexes are what?

The plastic material: ABS and ABS mutually fused result is definitely better than the ABS and PC weld strength to strong, because two different material whose melting point is also not the same, of course, welding strength can not be the same, although we discuss ABS and PC the two materials can mutual welding?Our answer is absolutely can weld, but whether or not after welding strength is what we want?It is not certain!On the other hand, thinking if ABS and nylon PP, PE phase melting and what is the situation?If ultrasonic instantaneous HORN issued 150 degree heat, although the ABS material is melted, but the nylon, PVC, PP, PE is softening.We continue to heating to 270 degrees above, the nylon, PVC, PP, PE has been up to in the ultrasonic welding temperature, but the ABS material has parsed into another molecular structure!From the above discussion can be summarized three conclusions:

1 identical to the melting point of the plastic material welding intensity is strong.

The 2 plastic material melting point difference is bigger, the smaller the weld strength.

The 3 plastic material density is higher than the density of (hard) lower (toughness) weld of high strength.

2 products surface bruise or cracks.

Ultrasonic welding in operation, product surface scars, with breaks or cracks are common.Because the ultrasonic operation will produce two kinds of situations: 1 hyperthermia can directly contact the surface of the transmission of vibration plastic products 2.So ultrasonic vibration effects in the plastic products, the product surface is prone to burn, and less than 1m/m thickness of thin plastic column or a hole, it is easy to crack phenomenon, this is the first ultrasound operation phenomenon is inevitable.On the other hand, because the ultrasound output energy deficiency (extension station and the HORN mode), vibration friction energy is converted to heat energy needs long time to weld, to accumulate heat to make up for the lack of output power.The welding mode, not in an instant to vibration friction and heat, and the need to rely on weld time to accumulate energy, make plastic products point to become the welding effect, thus causing heat stay on the product surface is too long, and the accumulated temperature and pressure will cause the product burnt, broken or rupture.Is at this time must consider the power output (number), welding time, dynamic pressure and coordination factors, to overcome the work deletion.

Solution method:

1 pressure reducing.

2 reduction in delay time (early vibration)).

3 reduced weld time.

4 reference medium coverage (such as PE bag).

The 5 fixture surface treatment (hardening or chrome plated).

6 machine sections reduce mold Expanding ratio.

7 easily cracked or broken products, fixture should be made of soft resin or buffer, such as cork and cover (this means does not affect the weld strength).

8 broken products at right angles with the R angle.

3 products distortion.

The transfiguration of our rules, there are three reasons:

1 body and desire frit or in degrees or radians cannot agree with each other..

2 thin product thickness (less than 2m/m) and excess length of more than 60m/m.

3 products for injection molding pressure conditions lead to distortion.

So when our products by ultrasonic operation and deformation occurred, from the surface appears to be ultrasonic welding causes, however, this is only a result, plastic products without any factors before welding, welding after the formation of the results.If there is no reason to explore for, it will waste a lot of time in processing is an antidote against the disease problems, but also in the ultrasonic indirect conduction welding operations (non melting straight), 6kg following pressure cannot change plastics bremsstrahlung and inertia.So don't try to use strong pressure, to change before welding deformation (splicer maximum pressure of 6kg), including the fixture forced extrusion.Maybe we will be in a blind spot, that is from the surface of deformation, i.e. not before welding the naked eye can not see, but completed by ultrasonic welding, it is clear that deformation.Its reason is in before welding, due to fusion guide lines exist, and more difficult to find the product itself, various angle radian and the remaining material accumulated error, and at the completion of ultrasonic welding, it appears in the form of the naked eye can see deformation.

Solution method:

1 lower pressure (preferably at a pressure below 2kg).

2 reduction in ultrasonic welding time (reduced intensity standard).

3 increase of hardening time (at least 0.8 seconds).

Analysis of 4 ultrasonic upper and lower mold can local adjustment (when necessary).

Analysis of 5 deformation reason, to improve.

4 products internal parts damage

The ultrasonic welding occurring after product failure causes are as follows:

1 ultrasonic welding machine output power is too strong.

2 ultrasonic energy to expand energy output is too strong.

3 the bottom die fixture force of suspension, by ultrasonic conduction vibration and damage.

4 plastic products high, fine into the bottom right, without buffer ease energy R angle.

5 incorrect ultrasonic machining conditions.

6 plastic products or more vulnerable parts of the column, open in the plastic mold parting line.

So when our products by ultrasonic operation and deformation occurred, from the surface appears to be ultrasonic welding causes, however, this is only a result, plastic products without any factors before welding, welding after the formation of the results.If there is no reason to explore for, it will waste a lot of time in processing is an antidote against the disease problems, but also in the ultrasonic indirect conduction welding operations (non melting straight), 6kg following pressure cannot change plastics bremsstrahlung and inertia.So don't try to use strong pressure, to change before welding deformation (splicer maximum pressure of 6kg), including the fixture forced extrusion.Maybe we will be in a blind spot, that is from the surface of deformation, i.e. not before welding the naked eye can not see, but completed by ultrasonic welding, it is clear that deformation.Its reason is in before welding, due to fusion guide lines exist, and more difficult to find the product itself, various angle radian and the remaining material accumulated error, and at the completion of ultrasonic welding, it appears in the form of the naked eye can see deformation.

Solution method:

Early 1 ultrasonic vibration time (to avoid exposure to vibration).

2 lower pressure, reduce ultrasonic welding time (reduced intensity standard).

3 reduction of machine power number or small power machine.

The 4 lower die ultrasound expansion ratio.

5 the bottom die stress buffering rubber pad.

6 the bottom die and products to avoid the impending or gap.

7.HORN (die) cut holes after heavy frequency measurement.

8 die cut holes after the paste on the flexible material.

5 products produced flash or Flash

The ultrasonic welding products after the spill material or burrs, the reasons are as follows:

1 ultrasonic power is too strong.

2 ultrasonic welding time is too long.

The 3 air pressure (dynamic) is too large.

The 4 upper and lower pressure (static) is too large.

5 upper die (HORN) energy expansion ratio is too large.

6 plastic products fusion guide line outside or too high or too coarse.

The above six as a cause of ultrasonic welding work product flash burr reasons, but one of the most critical is the sixth ultrasonic fusion guide line opened, generally in the ultrasonic welding operation, the air pressure in the range of about 2~4kg, according to experience the best ultrasonic waveguide weld line, is at the bottom of the 0.4~0.6m/m x height 0.3~0.4m/m such as: this type of Δ, angle was about 60 °, beyond this value will lead to the ultrasonic welding time, pressure, machine or mold power increases, so will the 1~6 caused flash and burr causes.

Solution method:

1 lower pressure, reduce ultrasonic welding time (reduced intensity standard).

2 reduction of machine power number or small power machine.

The 3 lower die ultrasound expansion ratio.

4 the use of ultrasound machine positioning fixed.

5 modified ultrasound-guided fuse.

6 welding products cannot be controlled in tolerance dimension

※ in ultrasonic welding operations, products cannot be controlled in tolerance range of the following reasons:

1 (without additional energy conversion machine stability safety factor).

2 plastic deformation beyond natural fusion ultrasonic range.

3 positioning or bear force is unstable.

4 on the ultrasound mode energy to expand output do not match.

5 welding processing conditions without additional safety factor.

Solution method:

1 increase in welding safety coefficient (in order by the welding time, pressure, power).

2 enable tuning screws (can be controlled to 0.02m/m).

3 check on the ultrasound mode output energy is enough (less increase in number).

4 check the positioning and product capacity is steady.

5 modified ultrasound-guided fuse.

Ultrasonic plastic welding water, airtight fusion guide line (wire) design

We need to water, air products function, localization and ultrasonic waveguide fuse is the success or failure of the important key, so in the product design are considered, such as: position, material, thickness, and the ultrasonic waveguide fuse corresponding proportion have absolute relationship.In the general water, air tightness requirement, fusion guide line height should be in the 0.5~0.8m/m range (as the product thickness.), such as lower than 0.5m/m, to achieve water airtight function, unless the positioning set to be very standard, and has 5 more than m/m, otherwise poorly.General requirements for water tightness product positioning and ultrasound-guided weld lines in the following manner:

Oblique cutting type: suitable for water tightness and large product welding, surface contact angle =45 °, x=w/2, d=0.3~0.8mm.

Stepped tip: for water tightness and prevent the outer convex or cracking method, surface contact angle = 45 °, x=w/2, d=0.3~0.8mm.

Peak and valley tip: for water tightness and high strength welding, d=0.3~0.6mm medial contact surface height h in shape and size and change, but about h around 1~2mm.

Products to implement ultrasonic operation cannot reach water, airtight, except the ultrasound waveguide fuse, positioning, product positioning itself and other factors, ultrasonic conditions is a main cause of.We are here to probe more deeply into the Xiangshui air another reason (welding conditions), in our implementation of ultrasonic welding operation, efficiency and fast is the most basic goal, but often ignored the efficiency method, normal two phenomenon:

One, drop speed, buffer too soon: the formation rate, so that the dynamic pressure plus the acceleration of gravity will put the ultrasound waveguide molten flattening, the fuse can not play the role of guide melting, forming image fusion.

Two, welding time: plastic products for receiving prolonged heat, not only makes the plastic melting, and causing the plastic tissue coking phenomenon, cause sand hole, water or gas which penetrate out of sand hole.This is the most general production technology is not easy to find a place.