Wonderful PVA-PS

Prosthetic and orthotic workshops use PVA-PS. Technicians laminate sockets, frames and orthotic shells over a positive plaster model, and every lamination starts with a PVA layer between the model and the resin. A pre-shaped bag turns that step into a single movement: the bag goes over the model, and the build moves on.

In a typical lamination, the technician prepares and dries the plaster model, pulls on the first PVA bag, and builds up the reinforcement layers of stockinette, fibreglass or carbon. A second PVA bag then encloses the lay-up, resin is poured in, and vacuum draws the bag down so the resin flows through every layer. The PVA-PS serves either role, depending on the size chosen.

Hospital prosthetic departments, private prosthetic clinics, and orthotic laboratories all use this process for new devices and replacement sockets. Patients whose residual limb has changed shape need a new socket, and each new socket is a new lamination. Six sizes, from slim 130 mm widths to broad 500 mm widths, cover slim models through to broad ones.

Orthotic laboratories follow the same sequence for laminated ankle-foot orthoses, knee orthoses, and spinal shells, where the longer one-metre bags match the model's full length. Training workshops for prosthetic and orthotic students use PVA bags in every lamination exercise. A ready-made bag lets students concentrate on the lay-up and the resin.

Day to day, prosthetic and orthotic technicians, prosthetists, and students handle the bags, and the patient wears the finished laminated device.

Ready to fit

The bag arrives pre-shaped. It goes over the model as it comes, with nothing to form first.

Six sizes for different models

Lengths of 600, 700 and 1000 mm and widths from 130 to 500 mm match a wide range of model shapes. The technician chooses the closest fit.

Fewer folds under vacuum

A bag close to the model's size leaves little excess material. The surface of the lay-up comes out smoother as a result.

Clean release

PVA separates cleanly from cured resin. The laminate comes away from the model with a clean inner surface.

Shapes over contours

Moistened PVA softens and eases over curves and edges. The bag follows the model closely.

Works for both layers

The same product serves as the inner separating layer and as the outer vacuum envelope. One stock item covers both stages.

Simple to stock

Bags store flat in a dry cupboard. Supply is the only upkeep, and each size is replaced as it is used.

Suits teaching and production alike

Ready-made bags keep exercises and production runs moving. Time at the bench goes into the lay-up itself.

Polyvinyl alcohol film

The bag is made from PVA, the film used for prosthetic lamination. It releases from cured resin and softens with moisture.

Pre-shaped form

Each bag is formed ahead of use. It slips over the positive model closed end first.

600 × 130 × 40 mm

The shortest and narrowest size. It suits small, slim models.

700 × 190 × 50 mm

A 700 mm bag of moderate width. It suits mid-length models of average girth.

700 × 270 × 50 mm

A wider bag at the same 700 mm length. It takes broader mid-length models.

1000 × 190 × 50 mm

A full metre in length at a moderate width. It suits long, slim models.

1000 × 260 × 50 mm

A metre-long bag of greater width. It takes longer models with more girth.

1000 × 500 × 50 mm

The largest size in the range. It suits the broadest models.

Item number PVA-PS

The product is catalogued as PVA-PS. Each size is ordered as its own item.

Vacuum lamination use

The bag forms the envelope that vacuum draws down over the lay-up. Resin then flows evenly through the reinforcement.

Flat supply

Bags are supplied flat. They store neatly in a cupboard or drawer.

Single-use per lamination

Each bag serves one lamination. Fresh bags come from stock for every new device.

The PVA-PS suits prosthetic and orthotic workshops, hospital departments and training centres that laminate over plaster models and want a PVA bag ready to use. Its strength is the pre-shaping: a bag that goes straight over the model, with six sizes from 600 × 130 × 40 mm to 1000 × 500 × 50 mm covering slim models through to broad ones. Matching the size to the model keeps folds down under vacuum, and the PVA releases cleanly from the cured laminate. For a workshop that wants one lamination bag product stocked across the model sizes it sees most, the PVA-PS keeps every lay-up moving, with supply as its only upkeep.