Purpose of Ironing / Pressing
Sweater ironing is not just for appearance—it has several technical objectives:
✔ Remove wrinkles and unevenness
Created during washing, drying or handling.
✔ Set the final measurements
After washing, sweaters relax and require shaping during ironing.
✔ Stabilize stitches and panel shape
Especially rib areas, necklines and edges.
✔ Smooth the garment surface
Enhances hand feel and premium look.
✔ Prepare garment for final QC and packing
Ensures garment is presentable and retail‑ready.
✔ Activate softeners or finishing chemicals
Heat helps finishing chemicals settle uniformly.
Types of Ironing / Pressing Used in Sweaters
Different fibres and constructions require specific ironing techniques.
Steam Ironing
Used for:
- ✓ Acrylic
- ✓ Cotton blends
- ✓ Wool blends
Steam relaxes knit loops and restores shape.
Hand Flat Ironing (Manual Pressing)
Using a steam iron on:
- ✓ Fine gauge sweaters
- ✓ Rib areas
- ✓ Delicate constructions
- ✓ Collars & cuffs
Requires very skilled operators.
Steam Table Pressing
A steam table is a flat work surface equipped with industrial steam irons connected through insulated hoses. In the images, sweaters are spread out on the table and pressed using a continuous supply of steam. The steam penetrates the knit fibers, relaxing them and allowing the operator to shape the garment precisely—especially at areas such as:
- Shoulder lines
- Armholes
- Side seams
- Neckline
- Cuffs and bottom rib
Using steam softens the yarn and helps set the garment to its required dimensions. The wide table surface allows large pieces such as full‑body sweaters to be laid flat without stretching.
Vacuum Table Pressing
A vacuum table works in combination with steam. After steam is applied, the table uses suction to:
- Remove excess moisture
- Lock the garment into shape
- Prevent distortion or stretching
- Provide a crisp and flat surface finish
The vacuum effect ensures that the sweater stays in position and cools quickly, which is crucial for dimensional accuracy.
In production settings, vacuum tables often have a wire‑frame structure supporting a padded pressing surface. This provides stability while keeping the structure lightweight. The table can handle multiple sweaters at once, making it suitable for high‑volume finishing operations.
Form Board (Ironing Board Pressing)
Typical applications:
- Setting shoulder slopes
- Ensuring straight side seams
- Smoothing sleeve caps
- Controlling hem and neckline shape
- Achieving consistent panel dimensions
Form boards are especially important for knitwear because knits are flexible and can change shape easily. The rigid board surface helps maintain accurate measurements during pressing.
3. Ironing Process Flow
A typical sweater ironing workflow includes the following stages:
Moisture Preparation
Sweaters iron best when slightly moist.
Methods:
- ✓ Light steaming
- ✓ Spray mist
- ✓ Humidity-controlled room
Proper moisture ensures:
- ✓ Loop relaxation
- ✓ Smooth surface
- ✓ Easy shape control
Ironing / Pressing Operation
Step 1: Lay garment flat
On a steam table or ironing board.
Step 2: Apply steam
Relax stitches and soften fibres.
Step 3: Shape garment manually
Adjust:
- ✓ Chest width
- ✓ Body length
- ✓ Armhole shape
- ✓ Sleeve length
- ✓ Collar alignment
- ✓ Bottom hem straightness
Step 4: Apply vacuum
Locks shape, removes excess heat.
Step 5: Press special areas
- ✓ Collar
- ✓ Placket
- ✓ Cuffs
- ✓ Ribs
Step 6: Final shaping
Ensures garment matches spec sheet.
Post-Ironing Cooling
Garment must cool completely before folding.
Why?
- ✓ Prevents shape distortion
- ✓ Prevents moisture re-absorption
- ✓ Locks the finish
Temperature & Pressure Guidelines (By Fibre Type)
Correct temperature prevents yellowing, melting or shrinkage.
| Fibre Type | Iron Temp | Steam Use | Notes |
|---|---|---|---|
| Acrylic | 120–140°C | Light steam | High heat can melt fibres |
| Cotton/Cotton Blends | 160–180°C | Medium steam | Holds shape well |
| Wool | 110–130°C | Heavy steam | Avoid direct pressure to prevent shine |
| Cashmere | 100–120°C | Light steam | Handle very gently |
| Viscose Blends | 120–150°C | Medium steam | Avoid stretching |
| Polyester Blends | 110–130°C | Medium steam | Overheating may cause glazing |
Key Areas Requiring Special Attention
Collar
- ✓ Must lie flat
- ✓ No buckling
- ✓ Correct shape
Ribs (hem, cuffs, neck rib)
- ✓ Should retain elasticity
- ✓ No overstretching
- ✓ Straight alignment
Shoulder & Armhole
- ✓ Smooth curve
- ✓ No iron marks
Plackets & Button Areas
- ✓ Sharp but not stiff
- ✓ No shine from heat
Jacquard / Fancy Knit
- ✓ Minimal pressure
- ✓ Avoid flattening texture
Ironing Defects & Their Causes
Shine Marks
Cause: excessive pressure on acrylic/wool.
Solution: use steam only or cloth overlay.
Over-stretching
Cause: pulling panels during ironing.
Solution: maintain flat, relaxed handling.
Distorted Measurements
Cause: uneven steam or manual mishandling.
Yellowing / Heat Damage
Cause: high temperature on synthetics.
Water Marks
Cause: dirty or hard water in steam system.
Rib Expansion
Cause: over-steaming or pulling ribs.
Quality Standards for Ironing
After ironing, sweaters must show:
- ✓ Clean, smooth appearance
- ✓ Correct measurements within tolerance
- ✓ No shine marks or damage
- ✓ Aligned seams & ribs
- ✓ Flat collars and cuffs
- ✓ Zero wrinkles or folding lines
- ✓ Good texture preservation (cables, pointelle, jacquard)
Garments that do not meet standards go back for re-pressing or mending.
Ironing is the bridge between washing and final quality control, making it a vital step in the entire sweater production cycle.
