PVC Windows & Doors Manufacturing Technique
1.1.0 PVC Windows & Doors Manufacturing Technique
The PVC windows & doors manufacture is divided into a few major working areas:
- Workpiece area;
- PVC windows welding area;
- PVC windows corner cleaning area;
- Mullion and rubber seal installation area;
- Hardware installation area;
- Finished double-glazed windows installation area and the final adjustment of windows;
Let's separately consider each area.
1.1.1 Workpiece Area
On this area the following operations are performed:
Reinforcing profile cutting. The reinforcing profile is cut for the pieces according to the order form, which are marked and installed into the specific trolley to provide free access to them.
PVC profile cutting is performed according to the order form considering the 5-6 mm margin for welding (welding margin is a parameter that depends on the welding machine setup, and it can be in the range of 2.5 to 3 mm per side).
Frame and sash profiles are cut at an angle 45°.
Mullion is cut at an angle 90° considering margin for projections from each side, 2.5 - 6 mm per side (depending on the end milling machine setup).
Milling of all necessary holes in the PVC profiles, namely drainage and ventilation holes, holes for the main lock installation and for the lock cylinder in the entrance door.
Mullion end milling.
Installation of the reinforcing profile of the needed length into the PVC profiles according to the labeling on the profile.
Fastening of the reinforcing profile by self-tapping screws with a drilling head of 3.9 х 16 (3.9 х 19) mm.
Blowing profiles using compressed air.
It should be noted that the quality of windows is already set at the workpiece area.
Profiles used for workpieces cutting should not be damaged.
The protective film should not be damaged.
Overall dimensions of the cross section of the profile must exactly match with the table of
profile permissible deviations. It is unacceptable to use the profiles with the cross section deviations in the PVC windows manufacture.
Incoming profile quality control should be
organized on each production site.
1.1.2 PVC Windows Welding Area
Profile welding is performed by means of the specific machines. Welding machines can have one, two or four welding heads. The most productive is the machine with four welding heads, because the welding process goes on for one cycle. By means of two-headed machine, the welding is performed for two cycles. And by means of one-headed machine, it is performed for four cycles respectively.
During the welding process it is necessary to comply with the welding requirements:
- Welding plate temperature is 230 - 250 °С.
- The plate surface must be clean. The teflon coating plate is wiped every hour with clean cotton or paper towel, in the "hot" state, without solvents.
- The melting time of profiles is 18-40 sec.
- The welding time of profiles is 25-40 sec. Before the placing of profiles onto the welding machine it is necessary to assure of the welding surface cleanliness, because the lubricator, dust, PVC or metal chips are distinctly deteriorate the quality of welding .
- Repair the welding surfaces with a sharp razor if necessary.
- In the end of the welding process, visual quality control of the weld seam is performed.
- The seam must be of white color (darkening is unacceptable, since it indicates that the heating temperature of the welding plate or the heat-up time was overstated).
- The seam must be uniform.
- The profiles must be welded over the whole welding surface.
- Conformity check of the overall dimensions of products according to the order form.
1.1.3 PVC Windows Corner Cleaning Area
The corner cleaning is performed manually or by means of the specific machine. In the manual cleaning a narrow width edge chisel and a specific crescent shaped knife are used. In case of the corner cleaning with the corner cleaning machine, it is necessary to pay attention to the front surfaces of the profile to avoid their damage with the milling tools.
The automatic machine cleans one angle at a time.
After the cleaning operations and the cleaning quality control, the products are placed onto the specific storage stands.
1.1.4 Mullion And Rubber Seal Installation Area
The mullion profile usually is connected by means of the metal connectors.
- Mullion profile has special cameras, in which the 4х40 mm screws are drilled for the mullion connector fixation. Sometimes when installing the 4 х 25 mm self-tapping screws are used, that weakens the fixation of connector to the mullion.
- The marking of places of the mullion installation. It should be noted that the marking is performed from the one frame side and then the distance is controlled on the other side of the frame.
- By means of the special jig the hole for self-tapping screw of 5 х 70 mm is drilled.
- The mullion along with the connector is taken into the frame and is installed just according to the marking.
- The mullion connector is fixed to the frame profile with 4 self-tapping screws of 4 х 25 mm.
- 5 х 70 mm self-tapping screw is twisted into the previously drilled hole.
It should be noted that when setting up the mullions into the reinforced frame profile, four fixing self-tapping screws will be drilled only into the plastic. For security of the fixation, the additional fixing of the mullion connector with the 5 х 70 mm self-tapping screw is applied.
In case of the mullion installation into the sash or onto the mullion, the four fixing self-tapping screws of 4 х 25 mm are drilled into the metal reinforcing profile. In this case the additional 5 х 70 mm fixation is not required.
If the mullion is installed correctly, you should proceed with the installation of the sealing rubber.
Sealing rubber installation
The sash construction seal is performed with single piece of the sealing rubber. The sealant driving into the slot mortise should be started in the middle of the upper head of construction. The sealing rubber is manually inputed into the accepting slot mortise in such a way as to avoid its extension. The sealant is abutted with a specific glue (А, С).
The sealant is additionally glued at the corners of the sashes (ID 227). In the window construction with the mullion in case of the frame sash, it is necessary to perform a selection (you can use a chisel or manual milling machine) in the mullion abutting place (В). The sealant ID 227 is placed without cracks, in one piece. In fixed windows the sealant ID 255 or
254 are used, which are allowed to join (А). Then it is not necessary to perform the selection in the places of mullion and frame joint.
The sealant is also glued to the joint with a specific glue.
Here the hole drilling for pressure balancing is performed. The holes are drilled by means of the jig in the upper horizontal part of the frame baffler end and on the inside rabbet ledge side.
1.1.5 Hardware Installation Area
On this area the necessary hardware installation according to the order form is performed.
In general, it will be just like this:
- The scissors (angular switchers), espagnolette (lock connectors and center locks), fixing with the self tapping screws of 4 х 25 mm, are mounted onto the sash.
- The main lock (espagnolette) is cut to the necessary size by means of the pneumatic guillotine.
Before cutting a worker must accurately measure the size of sash according to the rabbet. The error in the measurements leads to the faulty production!
- The main lock is mounted onto the sash and is fixed with 4 х 25 mm self-tapping screws. All hardware types initially have special clamping locks retaining the hardware in neutral position. It is necessary for the correct all hardware parts joint between each other when mounted. The clamping locks are broken on the first knob turning. However, the worker should check the correct position of hardware parts before the installation.
- Sash scissors are cut to the necessary size by means of the pneumatic guillotine, are mounted onto the sash and are fixed with 4 х 25 mm self-tapping screws.
- If hardware housing in the sash is higher than 800 mm, then it is required to install the additional clamp of the sash between the upper and lower hinges. For some hardware systems it is used a middle lock. Standard size of the middle lock is previously chosen depending on the sash height.
- For the correct sash positioning relative to the frame, the specific guides are used.
The guides are locked inside the frame (two guides in each angle) and then the sash is input into the frame. The guide usage allows to hardly estimate the sash and frame manufacture accuracy. If the sash is dangled, it was likely made undersized or the frame was made oversized. If it is impossible to put the sash into the frame, it evidences the opposite: the frame is smaller or the sash is bigger.
- Onto the sash of tilt and turn window by means of the template it is mounted the lower frame hinge and is fixed with long self-tapping screws of 4 х 40 mm. The longer self-tapping screws are used, because they are only applied into the plastic.
The self-tapping screws must as a minimum get through two baffles. The length of 3.9 х 25 mm of the self-tapping screw is not enough in this case.
- The upper and the lower hinges are mounted onto the frame and are fixed with the self-tapping screws of 4 х 25 mm.
- The sash and the frame are connected into the united construction.
- All necessary strikes are mounted onto the frame.
- Functional test. The hardware must work without jams and jerks.
- The checking of distance between face surface of the frame and the sash (it must be equal to 16-16.5 mm) must be performed. A piece of paper clamped between the frame and the sash must not be easily removable.
1.1.6 Double-Glazing Installation Area
The double-glazing installation into the PVC windows is performed according to the technical requirements. The final sash adjustment is performed at the specific stand. The stand allows simulating the real window installation into the window opening. At this stage, it is necessary to perform the general quality control of the products.
1.1.7 Function Of Double-Glazing Backing Strips
The double-glazing backing strips are designated for the following:
- To distribute the weight of the double-glazing, in such a way levelling the rabbet load, and additionally to exclude the adverse stress resulting from the temperature difference, operational conditions, etc.
- To prevent the possibility of squeezing in case of its breaking.
- To exclude the undesirable contact of the double-glazing with rabbet of the frame or the sash.
1.1.8 Sash Adjustment Technique During The Double-Glazing Installation
The rabbet levelling backing strips ID 171 are mounted into the sash into those places, where there will be installed the double-glazing backing strips, at a distance of 5 cm from the angles of the double-glazing. The double-glazing is mounted onto the window sash onto two backing strips, each with the thickness of 5 mm No.1 and No. 2. Then you have to level the double-glazing position in the window opening by means of the spudger, and install the backing strips No. 3 and No. 4 each with the thickness of 5 mm. The backing strip No. 2 is taken out, and thus the whole weight of the double-glazed window goes to the backing strip No. 1.In case of the sash whipping it is necessary to:
- Insert the spudger between the frame rabbet and top of the double-glazing.
- Pushing onto the double-glazing, to move up the frame top and install the backing strip No. 6 with the necessary thickness.
- Check the sash operation and change thickness of the backing strip No. 6 if necessary.
If the sash height is over than 1.3 m, it is necessary to install the additional distant backing strips No. 7 and No. 8. In the process of theirs installation you have to select the backing strips thickness as to avoid a curvature of the sash vertical parts.
All backing strips are fixed with a small quantity of the silicone joint sealant. It is necessary to avoid the backing strips distortion during the glazing bead installation and transportation.
After the glazing bead installation, it is obligatorily to set down the sash parts with the plastic hand hummer.
All sash adjustment operations are performed upright on the stand, and after the product installation into the window opening on-site. The backing strips are mounted at the distance of 50 – 70 mm from the inside angle according to the rabbet. If the sash width is more than one meter it is allowed to remove the backing strips for the distance till 250 mm from the inside angle according to the rabbet.
The rabbet levelling backing strips (ID 171) are installed into the locations of carrier strips and spacers.
The double-glazing is installed onto the carrier strips No. 1 and No. 2 with the thickness of 5 mm.
The double-glazing window position is levelled in the frame opening.
The spacers No. 3 and No. 4 with the needed thickness are selected.
In case of glazing of the constructions with a transom, it is necessary to pass the weight of upper double-glazing to the building frame through the strips and bottom double-glazing window. To do that it is necessary to put the additional strips No. 5 and No. 6 on the top of the bottom double-glazed window.
Sash clamp adjustment.
After the final sash adjustment and control by quality inspector, the product is sent to the finished product storage. In case of manufacturing the product made of colored or laminated plastic, it is to be packed in cardboard.